CN109898821B

CN109898821B - Construction method of high-altitude cantilever formwork support frame body

Info

Publication number: CN109898821B
Application number: CN201910217766.8A
Authority: CN
Inventors: 王彤; 高仓; 张毅; 司利军; 姬文虎; 庞光海; 高慧; 曹保明; 巨丹峰; 赵涛
Original assignee: SCEGC No 9 Construction Engineering Group Co Ltd
Current assignee: SCEGC No 9 Construction Engineering Group Co Ltd
Priority date: 2019-03-21
Filing date: 2019-03-21
Publication date: 2019-12-17
Anticipated expiration: 2039-03-21
Also published as: CN109898821A

Abstract

the invention discloses a construction method of a high-altitude overhanging formwork support frame, which comprises an overhanging steel support platform and a formwork support frame, wherein the overhanging steel support platform comprises a plurality of upper overhanging steel main beams, the upper parts of the upper overhanging steel main beams are provided with steel wire rope suspension devices, and the lower parts of the upper overhanging steel main beams are provided with inclined support devices; the method comprises the following steps: firstly, erecting an overhanging steel supporting platform; secondly, carrying out a loading test on the cantilever steel supporting platform; thirdly, sealing the lower frame body of the cantilever steel supporting platform; fourthly, erecting a template support frame; and fifthly, closing the formwork support frame. The cantilever steel supporting platform is convenient and fast to construct and good in safety, the stability of the cantilever steel supporting platform can be effectively improved, the cantilever steel supporting platform is prevented from deforming, the template supporting frame on the upper portion of the cantilever steel supporting platform is prevented from overturning, meanwhile, the cantilever steel supporting platform can be guaranteed to have enough bearing capacity through a loading test on the cantilever steel supporting platform, and the construction safety is guaranteed.

Description

Construction method of high-altitude cantilever formwork support frame body

Technical Field

the invention belongs to the technical field of high-altitude cantilever structure construction, and particularly relates to a construction method of a high-altitude cantilever formwork support frame body.

Background

At present, with the rapid development of economic construction and urbanization, high-rise or super high-rise buildings with different shapes are rapidly erected in large and medium cities, and in order to expand the building personality and display the variety of shapes, a high-altitude overhanging method is often adopted to overhang a certain floor or roof out of the plane of the building to form a high-altitude overhanging structure, so that the shape becomes a symbolic landscape line of the city building. The high-altitude overhanging structure, particularly a cast-in-place structure, needs to be constructed by building an overhanging template support frame body. The high-altitude overhanging structure has larger dead weight and wind load, the requirements on the stability and rigidity of the template supporting system are high during construction, and the construction process of the whole supporting system is required to have absolute reliable safety during high-altitude operation, so that the high-altitude overhanging structure is very important for selecting the supporting form and the material of the whole supporting system.

At present, a common cantilever formwork support frame adopts a lower-support and upper-pull formwork support form consisting of a steel wire rope and a support rod. If the calculation is completely carried out according to the cantilever structure, the steel wire rope does not participate in bearing load, for the overlong cantilever structure, the section size of the profile steel cantilever beam can be very large, so that the great material waste is caused, the requirement on the structural safety is not easy to achieve, the cantilever support frame in the air is required to bear great wind load, the risk of great overturning exists when the cantilever structure plate is poured, and the structure plate for anchoring the cantilever beam is likely to cause damage due to additional load bearing.

Disclosure of Invention

the technical problem to be solved by the invention is to provide a construction method of an overhead cantilever formwork support frame body, aiming at the defects in the prior art, a lower-support and upper-pull cantilever steel support platform is arranged on one side of a building structure, a formwork support frame is erected on the cantilever steel support platform for construction of a cantilever structure, the stability and the bearing capacity of the cantilever steel support platform can be effectively improved, the cantilever steel support platform is prevented from deforming, and further the formwork support frame on the upper part of the cantilever steel support platform is prevented from overturning, the method is convenient and fast in construction and good in safety, a vertical steel pipe is fixed at the outer end of the cantilever section of an upper cantilever steel girder, a leveling principle of a level gauge is utilized, a length measuring scale is arranged on the vertical steel pipe as a monitoring mark, the cantilever steel support platform is ensured to have the bearing capacity required by construction of the cantilever structure, and meanwhile, the deformation value of the cantilever steel support platform can be continuously monitored in the construction process of the cantilever structure, the construction is ensured to be carried out safely.

In order to solve the technical problems, the invention adopts the technical scheme that: a construction method of a high-altitude overhanging formwork support frame body comprises an overhanging steel support platform arranged on a building structure and a formwork support frame which is positioned at the upper part of the overhanging steel support platform and is used for constructing an overhanging structure, wherein the height of the overhanging structure is 2H, H is the height of one floor of the building structure, the formwork support frame comprises an external formwork support frame arranged at the outer side of the overhanging structure and an internal formwork support frame arranged at the inner side of the overhanging structure, the upper part of an upper overhanging steel girder is provided with a plurality of upright anti-sliding steel bar heads used for positioning upright rods of the external formwork support frame, and each upright anti-sliding steel bar head is sleeved with an upright rod; the cantilever steel supporting platform comprises a plurality of upper cantilever steel main beams anchored on the Nth floor of the building structure, wherein N is a positive integer and is more than or equal to 3, the length of a cantilever section of each upper cantilever steel main beam is greater than the width of the cantilever structure, the upper cantilever steel main beams are parallel to each other, a steel wire rope suspension device is arranged at the upper part of the cantilever section of each upper cantilever steel main beam, and an inclined supporting device is arranged at the lower part of the cantilever section of each upper cantilever steel main beam;

the structure comprises a building structure and is characterized in that a plurality of lower overhanging steel main beams for installing inclined supporting devices are anchored on an N-2 floor slab of the building structure, the lower overhanging steel main beams and an upper overhanging steel main beam are equal in number and correspond to each other one by one, each inclined supporting device comprises a plurality of groups of inclined supporting assemblies, each inclined supporting assembly is supported between an overhanging section of the upper overhanging steel main beam and an overhanging section of the lower overhanging steel main beam, each group of inclined supporting assemblies comprises two long inclined supporting rods symmetrically arranged on two sides of the upper overhanging steel main beam, one or more groups of short inclined supporting rod assemblies are arranged between the overhanging section of the upper overhanging steel main beam and the floor slab on the N-1 floor, each group of short inclined supporting rod assemblies comprises two short inclined supporting rods symmetrically arranged on two sides of the upper overhanging steel main beam, and the short inclined supporting rods are positioned on the inner sides of the long inclined supporting rods; the cantilever scaffold composed of the long diagonal rods, the transverse horizontal rods, the longitudinal horizontal rods and the short diagonal rods is an outer cantilever support frame body, the uppermost longitudinal horizontal rod in the outer cantilever support frame body is supported at the lower part of the upper cantilever steel main beam, a plurality of limiting channel steel secondary beams for limiting the long diagonal rods are fixedly mounted at the upper part of the cantilever section of the lower cantilever steel main beam, the limiting channel steel secondary beams are parallel to each other and are mutually vertical to the lower cantilever steel main beam, the number of the limiting channel steel secondary beams is equal to that of the oblique supporting assemblies, the limiting channel steel secondary beams correspond to the oblique supporting assemblies one by one, and the lower ends of the long oblique supporting rods are abutted to the grooves of the limiting channel steel secondary beams;

The construction method is characterized by comprising the following steps:

Step one, building an overhanging steel supporting platform:

Step 101, installing an upper cantilever steel girder: according to an overhanging construction scheme and drawing requirements, popping up a plurality of upper overhanging steel main beam positioning lines at equal intervals on the Nth floor, mounting the upper overhanging steel main beams on the corresponding positioning lines, wherein the length of the overhanging section of each upper overhanging steel main beam is greater than the width of an overhanging structure;

Step 102, pulling up the upper overhanging steel girder: a steel wire rope suspension device is arranged between the overhanging section of the upper overhanging steel main beam and a building structure, and the upper overhanging steel main beam reaches the designed arching height through the steel wire rope suspension device;

Step 103, mounting a lower cantilever steel girder: according to an overhanging construction scheme and drawing requirements, popping up a plurality of lower overhanging steel main beam positioning lines at equal intervals on an N-2 floor, installing the lower overhanging steel main beams on the corresponding positioning lines, wherein the length of an overhanging section of the lower overhanging steel main beam is smaller than that of an overhanging section of an upper overhanging steel main beam, the length of an overhanging section of the lower overhanging steel main beam is smaller than that of an anchoring section of the lower overhanging steel main beam, and arranging K limiting channel steel secondary beams which are parallel to each other and horizontally arranged in the direction perpendicular to the lower overhanging steel main beam, wherein K is the number of an oblique supporting assembly and is 1,2, …, K, wherein K is a positive integer and is more than or equal to 2, and the openings of the limiting channel steel secondary beams are upward and the bottoms of the limiting channel steel secondary beams are welded on the upper part of the lower overhanging steel main beam;

104, supporting the upper cantilever steel girder and the lower cantilever steel girder: the upper end of each first group of inclined supporting rods is connected with the upper end of a corresponding first group of inclined supporting rods, the lower end of each first group of inclined supporting rods is connected with the upper end of a corresponding first group of inclined supporting rods, the upper end of each first group of inclined supporting rods is connected with the upper end of a corresponding first group of inclined supporting rods, and the lower end of each first group of inclined supporting rods is connected with the upper end of each first group of inclined supporting rods;

And 105, supporting the upper cantilever steel girder and the floor of the (N-1) th floor: one or more groups of short inclined support rod assemblies are arranged between the upper cantilever steel girder and the (N-1) th floor slab, the upper ends of two short inclined support rods in each group of short inclined support rod assemblies are respectively clung to the two sides of the upper cantilever steel girder, the lower ends of two short inclined support rods in each group of short inclined support rod assemblies are fixed on the (N-1) th floor slab, the upper ends of two short inclined support rods in each group of short inclined support rod assemblies are connected together through a longitudinal horizontal rod, the longitudinal horizontal rod connected to the upper ends of the short inclined support rods is supported at the lower part of the upper cantilever steel girder, and a first double fastener is arranged on each short inclined support rod to limit the lower part of the longitudinal horizontal rod;

step 106, setting up an outward-picking support frame body: set up between the steel girder of encorbelmenting in upper portion and the steel girder of encorbelmenting in lower part and encorbelment the scaffold frame and form the support frame body of encorbelmenting outward, the support layer is encorbelmented outward in the connection of Nth floor that the support frame body was encorbelmented outward in upper portion, the support layer is encorbelmented outward in the connection of Nth floor, the N-1 floor that from top to bottom laid in proper order, the support layer is encorbelmented:

1061, arranging a plurality of circular through holes on a cross beam at the lower part of the Nth floor according to the erection position of the long inclined supporting rod, arranging a transverse horizontal rod in each circular through hole, connecting the transverse horizontal rod with the long inclined supporting rod and the short inclined supporting rod which are close to the transverse horizontal rod, and connecting longitudinal horizontal rods at the intersection of the long inclined supporting rod and the transverse horizontal rod and the intersection of the short inclined supporting rod and the transverse horizontal rod to form an Nth floor connecting outer cantilever supporting layer;

1062, connecting a plurality of transverse horizontal rods between the Nth floor connecting outer cantilever supporting layer and the (N-1) th floor along the length direction of each long inclined supporting rod, connecting the transverse horizontal rods with the corresponding short inclined supporting rods together, gradually reducing the lengths of the transverse horizontal rods from top to bottom and enabling the lengths of the transverse horizontal rods to be smaller than the lengths of the transverse horizontal rods in the Nth floor connecting outer cantilever supporting layer, and connecting longitudinal horizontal rods at the intersections of the long inclined supporting rods and the transverse horizontal rods and the intersections of the short inclined supporting rods and the transverse horizontal rods to form an upper outer cantilever supporting layer;

1063, arranging a plurality of circular through holes on a cross beam at the lower part of the (N-1) th floor according to the erection position of the long inclined supporting rod, arranging a transverse horizontal rod in each circular through hole, connecting the transverse horizontal rod with the long inclined supporting rod and the short inclined supporting rod which are close to the transverse horizontal rod, and connecting longitudinal horizontal rods at the intersection of the long inclined supporting rod and the transverse horizontal rod and the intersection of the short inclined supporting rod and the transverse horizontal rod to form an N-1 th floor connecting and outward-picking supporting layer;

1064, connecting a plurality of transverse horizontal rods between the N-1 th floor connecting outer cantilever supporting layer and the N-2 th floor along the length direction of each long inclined supporting rod, connecting the transverse horizontal rods with the corresponding short inclined supporting rods together, gradually reducing the lengths of the transverse horizontal rods from top to bottom and enabling the lengths of the transverse horizontal rods to be smaller than the lengths of the transverse horizontal rods in the lowest floor of the N-1 th floor connecting outer cantilever supporting layer, and connecting longitudinal horizontal rods at the intersections of the long inclined supporting rods and the transverse horizontal rods and the intersections of the short inclined supporting rods and the transverse horizontal rods to form a lower outer cantilever supporting layer;

step 107, pulling and reinforcing the cantilever support frame body: full framing scaffolds are erected between the (N-2) th floor and the (N-1) th floor and between the (N-1) th floor and the (N-1) th floor to form a first foundation frame body for carrying out tie reinforcement on the overhanging support frame body;

Step two, the loading test of the cantilever steel supporting platform comprises the following processes:

Step 201, erecting a bamboo scaffold board at a specified position of an upper overhanging steel girder to form a loading test platform, arranging a level gauge on an Nth floor, fixing a vertical steel pipe with the height of 1.2-1.5 m at the outer end of an overhanging section of the upper overhanging steel girder, setting a length measuring scale matched with the level gauge as a monitoring mark on the inner side of the vertical steel pipe by utilizing the leveling principle of the level gauge, and arranging a loader on the loading test platform to carry out loading test on an overhanging steel support platform;

Step 202, judging whether the reading variation of the level gauge exceeds a threshold value: the numerical value of the level is read at regular time in the loading process, and if the reading of the level is not changed obviously, the level is unloaded after the cantilever steel supporting platform is completely stabilized for two days; otherwise, go to step 203;

Step 203, unloading the loading test platform immediately, checking the joints of the parts of the cantilever rigid support platform, reinforcing the loose part, and circulating the step 201 until the cantilever rigid support platform after the loading test meets the requirements;

step three, sealing the lower frame body of the overhanging steel supporting platform: fully paving a bamboo scaffold board on the lower cantilever steel main beam, filling waste square wood in a gap between the bamboo scaffold board and the cantilever support frame body, nailing the waste square wood and the bamboo scaffold board firmly, paving a layer of waste mirror board on the upper part of the bamboo scaffold board, fully paving a layer of fireproof asbestos cloth on the waste mirror board, and hanging a dense mesh net and a safety net outside the cantilever support frame body to seal the cantilever support frame body;

Step four, erecting a template support frame: erecting a full-hall scaffold between the nth floor and the (N + 1) th floor to form a second foundation frame body, erecting a full-hall scaffold between the (N + 1) th floor and the top plate to form a third foundation frame body, erecting a scaffold connected with the second foundation frame body on the overhanging steel support platform to form an external formwork support frame, and erecting a scaffold outside the third foundation frame body to form an internal formwork support frame;

and step five, closing the template support frame.

the construction method of the high-altitude cantilever formwork support frame body is characterized by comprising the following steps of: the upper cantilever steel girder and the lower cantilever steel girder are I-shaped steel, the upper cantilever steel girder is anchored on the Nth floor slab through an I-shaped steel compression ring, and the lower cantilever steel girder is anchored on the N-2 th floor slab through an I-shaped steel compression ring.

the construction method of the high-altitude cantilever formwork support frame body is characterized by comprising the following steps of: each horizontal rod is provided with k second double fasteners for preventing the long inclined supporting rod from sliding, and the second double fasteners are supported on the outer side of the long inclined supporting rod.

the construction method of the high-altitude cantilever formwork support frame body is characterized by comprising the following steps of: when the exterior cantilever support frame body is subjected to pulling and reinforcing in the step 107, the inner end of each horizontal rod in the exterior cantilever support frame body erected in the step 106 is connected with a horizontal pull rod by adopting a rotary fastener, full framing scaffolds are erected between the (N-2) th floor and the (N-1) th floor and between the (N-1) th floor and the (N) th floor respectively on the basis of the horizontal pull rods to form a first base frame body, and the first base frame body is connected with a shear brace.

the construction method of the high-altitude cantilever formwork support frame body is characterized by comprising the following steps of: the steel wire rope suspension device comprises a first steel wire rope and a second steel wire rope, the lower end of the first steel wire rope is fixed at the end of the overhanging section of the upper overhanging steel main beam, the upper end of the first steel wire rope is fixed on the top plate, the lower end of the second steel wire rope is fixed at the middle of the overhanging section of the upper overhanging steel main beam, the upper end of the second steel wire rope is fixed on the (N + 1) th floor slab, and steel wire rope clamps are arranged on the first steel wire rope and the second steel wire rope.

The construction method of the high-altitude cantilever formwork support frame body is characterized by comprising the following steps of: and a third steel wire rope is connected between the overhanging section of the lower overhanging steel girder and the (N-1) th floor, the lower end of the third steel wire rope is fixed at the end part of the overhanging section of the lower overhanging steel girder before the step 104, the upper end of the third steel wire rope is fixed on the (N-1) th floor, a steel wire rope clamp is arranged on the third steel wire rope, and the lower overhanging steel girder reaches the designed arching height by adjusting the steel wire rope clamp.

the construction method of the high-altitude cantilever formwork support frame body is characterized by comprising the following steps of: the lower part of the upper cantilever steel girder is provided with a first steel wire rope positioning assembly and a second steel wire rope positioning assembly, the first steel wire rope positioning assembly is fixed at the end part of the upper cantilever steel girder, the second steel wire rope positioning assembly is fixed at the middle part of the upper cantilever steel girder, the lower part of the lower cantilever steel girder is provided with a third steel wire rope positioning assembly, and the first steel wire rope positioning assembly, the second steel wire rope positioning assembly and the third steel wire rope positioning assembly are identical in structure and comprise two steel wire rope anti-sliding steel bar heads.

The construction method of the high-altitude cantilever formwork support frame body is characterized by comprising the following steps of: the outside template support frame for set up on encorbelmenting steel supporting platform and with encorbelmenting structure outside shape assorted scaffold frame, horizontal horizon bar in the outside template support frame links together through rotating fastener with the horizontal horizon bar in the basic support body of second, the inside template support frame for set up in third basis support body one side and with the scaffold frame of encorbelmenting the inboard shape of structure and mutually supporting, horizontal horizon bar in the inside template support frame links together through rotating fastener with the horizontal horizon bar in the basic support body of third.

The construction method of the high-altitude cantilever formwork support frame body is characterized by comprising the following steps of: and the external template support frame, the internal template support frame, the second basic frame body and the third basic frame body are all connected with a cross brace.

Compared with the prior art, the invention has the following advantages:

1. According to the invention, the plurality of upper cantilever steel girders are anchored on the Nth floor slab of the building structure, the steel wire rope suspension device is arranged on the upper parts of the upper cantilever steel girders, and the inclined support device is arranged on the lower parts of the upper cantilever steel girders to form the downward-supporting and upward-pulling cantilever steel support platform, so that the stability and the bearing capacity of the cantilever steel support platform can be effectively improved, the cantilever steel support platform is prevented from deforming, and the template support frame on the upper part of the cantilever steel support platform is further prevented from overturning.

2. According to the invention, the lower overhanging steel main beams for installing the inclined supporting devices are anchored on the Nth-2 floor slab of the building structure, so that the inclined supporting devices are supported between the lower overhanging steel main beams and the upper overhanging steel main beams, the overhanging length of the overhanging steel supporting platform can be increased, the construction of a special-shaped overhanging structure is facilitated, meanwhile, the inclination angle of the inclined supporting devices can be reduced, and the integral supporting strength of the overhanging steel supporting platform is improved; the short inclined supporting rod is arranged between the (N-1) th floor slab and the overhanging section of the upper overhanging steel main beam, so that the upper overhanging steel main beam can be further supported to reduce the possibility of inclination.

3. according to the invention, the first foundation frame bodies for fixing the cantilever support frame bodies through the pulling connection are arranged between the N-2 th floor slab and the N-1 th floor slab and between the N-1 th floor slab and the N-1 th floor slab, so that the cantilever support frame bodies can be firmly fixed with a building structure through the first foundation frame bodies, the overall strength and stability of the high-altitude cantilever formwork support frame bodies are improved, and the high-altitude cantilever formwork support frame bodies are prevented from overturning.

4. According to the invention, the external formwork support frame is arranged for supporting the outer side of the overhanging structure to be constructed, and the internal formwork support frame is arranged for supporting the inner side of the overhanging structure to be constructed, so that the difficulty of poor concrete pouring compactness of the inclined plate can be effectively solved.

5. According to the invention, the leveling instrument is arranged in the floor of the building structure, the vertical steel pipe with the height of 1.2-1.5 m is fixed at the outer end of the overhanging section of the upper overhanging steel girder, and the length measuring scale is arranged on the vertical steel pipe as the monitoring mark by utilizing the leveling principle of the leveling instrument, so that the overhanging steel supporting platform is ensured to have the bearing capacity required by the construction of the overhanging structure, and meanwhile, the deformation value of the overhanging steel supporting platform can be continuously monitored in the construction process of the overhanging structure, and the safe construction is ensured.

6. According to the invention, the bamboo scaffold board is fully paved on the lower overhanging steel girder, and the layer of the waste mirror surface board is paved on the upper part of the bamboo scaffold board, so that the construction waste can be prevented from falling from the gap of the bamboo scaffold board in the construction process to influence the personal safety of constructors, and the fire hazard in the construction process can be prevented from causing certain property loss and casualties to further influence the construction progress by fully paving the layer of the fireproof asbestos cloth on the waste mirror surface board.

In conclusion, the invention arranges the lower-supporting and upper-pulling type overhanging steel supporting platform at one side of the building structure, and a template support frame is erected on the overhanging steel supporting platform for construction of an overhanging structure, so that the stability and the bearing capacity of the overhanging steel supporting platform can be effectively improved, the overhanging steel supporting platform is prevented from deforming, further avoiding the overturning of the formwork support frame at the upper part of the overhanging steel support platform, meanwhile, the method adopted by the invention has convenient construction and good safety, by fixing the vertical steel pipe at the outer end of the overhanging section of the upper overhanging steel girder and utilizing the leveling principle of the level gauge, the vertical steel pipe is provided with a length measuring scale as a monitoring mark, so that the cantilever steel supporting platform is ensured to have the bearing capacity required by the construction of a cantilever structure, and simultaneously, can continuously monitor the deformation value of encorbelmenting steel supporting platform in the structure work progress of encorbelmenting, guarantee that the safety of construction goes on.

the technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

drawings

fig. 1 is a schematic structural view of the high-altitude overhanging formwork support body of the invention.

fig. 2 is an enlarged view of fig. 1 at a.

fig. 3 is an enlarged view of fig. 1 at B.

fig. 4 is an enlarged view of fig. 1 at C.

fig. 5 is a schematic structural view of the cantilever steel support platform of the present invention.

fig. 6 is a schematic view of the positional relationship of the diagonal support assembly, the upper cantilever steel main beam and the lower cantilever steel main beam of the present invention.

Fig. 7 is a structural schematic diagram of a loading test of the cantilever steel support platform of the present invention.

FIG. 8 is a block flow diagram of a method of the present invention.

description of reference numerals:

1-upper overhanging steel girder; 2, overhanging a steel main beam at the lower part; 3-short diagonal bracing bars;

4-a first base frame body; 4-1-horizontal pull rod; 5-a first steel wire rope;

6-a second wire rope; 7-long inclined supporting rod; 8-an I-steel compression ring;

9-a top plate; 10-the (N + 1) th floor slab; 11-nth floor;

12-the (N-1) th floor slab; 13-the Nth-2 floor slab; 14-transverse horizontal bar;

15-longitudinal horizontal bar; 16-limiting channel steel secondary beams; 17-a third wire rope;

18-1 — a first wire rope positioning assembly;

18-2-a second wire rope positioning assembly;

18-3-a third wire rope positioning assembly; 19-a cross brace;

20-external formwork support; 20-1-vertical rod; 21-internal formwork support;

22-a second foundation frame body; 23-a third base frame body; 24-1-a first double fastener;

24-2-a second double fastener; 25-overhanging structure; 26-a cross beam;

27-upright rod anti-sliding steel bar head; 28-vertical steel pipes; 29-length measuring ruler;

30-a level gauge; 31 — loader.

Detailed Description

As shown in fig. 1,2, 4, 5 and 6, a method for constructing a high-altitude cantilever formwork support frame, the high-altitude overhanging formwork support frame body comprises an overhanging steel support platform arranged on a building structure and a formwork support frame which is positioned at the upper part of the overhanging steel support platform and is used for constructing an overhanging structure 25, the height of the overhanging structure 25 is 2H, wherein H is the height of one floor of the building structure, the formwork support frame comprises an external formwork support frame 20 arranged at the outer side of the overhanging structure 25 and an internal formwork support frame 21 arranged at the inner side of the overhanging structure 25, the upper part of the upper overhanging steel girder 1 is provided with a plurality of upright anti-sliding reinforcement heads 27 for positioning the upright 20-1 of the external formwork support frame 20, and each upright anti-sliding reinforcement head 27 is sleeved with an upright 20-1; the cantilever steel supporting platform comprises a plurality of upper cantilever steel main beams 1 anchored on the Nth floor 11 of the building structure, wherein N is a positive integer and is not less than 3, and the length L of the cantilever section of the upper cantilever steel main beam 1₁the width W of the cantilever structure 25 is larger than that of the upper cantilever steel main beam 1, the upper cantilever steel main beam 1 is parallel to each other, a steel wire rope suspension device is arranged at the upper part of the cantilever section of the upper cantilever steel main beam 1, and an inclined support device is arranged at the lower part of the cantilever section of the upper cantilever steel main beam 1;

A plurality of lower overhanging steel main beams 2 for installing the inclined supporting device are anchored on the N-2 floor 13 of the building structure, the lower overhanging steel main beam 2 and the upper overhanging steel main beam 1 are equal in number and correspond to each other one by one, the inclined supporting device comprises a plurality of groups of inclined supporting components, the inclined support components are supported between the overhanging section of the upper overhanging steel girder 1 and the overhanging section of the lower overhanging steel girder 2, each group of the inclined support components comprises two long inclined support rods 7 symmetrically arranged at two sides of the upper overhanging steel girder 1, one or more groups of short inclined support rod assemblies are arranged between the overhanging section of the upper overhanging steel girder 1 and the N-1 floor 12, each group of short inclined support rod assemblies comprises two short inclined support rods 3 symmetrically arranged at two sides of the upper overhanging steel girder 1, and the short inclined support rods 3 are positioned at the inner sides of the long inclined support rods 7; the oblique supporting device is characterized in that a plurality of long oblique supporting rods 7 and short oblique supporting rods 3 which are parallel to each other and are positioned on the same side of the upper cantilever steel main beam 1 are connected into a whole through a plurality of transverse horizontal rods 14, the intersection points of the long oblique supporting rods 7 and the transverse horizontal rods 14, the intersection points of the upper cantilever steel main beam 1 and the transverse horizontal rods 14 and the intersection points of the short oblique supporting rods 3 and the transverse horizontal rods 14 are respectively connected with a longitudinal horizontal rod 15, the cantilever scaffold consisting of the long oblique supporting rods 7, the transverse horizontal rods 14, the longitudinal horizontal rods 15 and the short oblique supporting rods 3 is an outer cantilever support body, the longitudinal horizontal rod 15 on the uppermost layer in the outer cantilever support body is supported on the lower part of the upper cantilever steel main beam 1, a plurality of limiting channel steel secondary beams 16 for limiting the long oblique supporting rods 7 are fixedly mounted on the upper part of the cantilever steel main beam 2 in the lower part, the plurality of limiting channel steel secondary beams 16 are parallel to each other and are perpendicular to the lower overhanging steel main beam 2, the number of the limiting channel steel secondary beams 16 is equal to that of the oblique supporting assemblies and corresponds to that of the oblique supporting assemblies one by one, and the lower ends of the long oblique supporting rods 7 are abutted against the grooves of the limiting channel steel secondary beams 16;

During the in-service use, through a plurality of upper portions steel girder 1 of encorbelmenting on Nth floor 11 of building structure, and set up wire rope suspension device and carry out the pull-up to upper portion steel girder 1 of encorbelmenting on the upper portion of steel girder 1 of encorbelmenting in upper portion, form the steel supporting platform of encorbelmenting of formula of pulling down behind the lower part of steel girder 1 of encorbelmenting in upper portion sets up the bearing device, can effectively improve the stability and the bearing capacity of steel supporting platform of encorbelmenting, prevent that the steel supporting platform of encorbelmenting from taking place to warp, and then avoid encorbelmenting the formwork support frame on steel supporting platform.

Particularly, a plurality of lower overhanging steel main beams 2 for installing the inclined supporting devices are anchored on the Nth-2 floor slab 13 of the building structure, so that the inclined supporting devices are supported between the lower overhanging steel main beams 2 and the upper overhanging steel main beams 1, the overhanging length of the overhanging steel supporting platform can be increased, the construction of a special-shaped overhanging structure is facilitated, the inclination angle of the inclined supporting devices can be reduced, and the integral supporting strength of the overhanging steel supporting platform is improved; by arranging the short inclined support rods 3 between the (N-1) th floor slab 12 and the overhanging section of the upper overhanging steel girder 1, the upper overhanging steel girder can be further supported to reduce the possibility of inclination.

It should be noted that, two long inclined supporting rods 7 in each group of inclined supporting assemblies are symmetrically arranged on two sides of the upper overhanging steel girder 1, and two short inclined supporting rods 3 in each group of short inclined supporting rod assembly are symmetrically arranged on two sides of the upper overhanging steel girder 1, so that the upper overhanging steel girder 1 can be tightened, the upper overhanging steel girder 1 is prevented from swinging in the horizontal direction in the construction process, and the construction safety is ensured.

In this embodiment, be used for carrying out the formwork to the structure 25 outside of encorbelmenting that needs the construction through setting up outside template support frame 20, be used for carrying out the formwork to the structure 25 inboard of encorbelmenting that needs the construction through setting up inside template support frame 21, can effectively solve the difficult point that swash plate concrete placement compactness is relatively poor.

When the long inclined supporting rod is actually used, the plurality of limiting channel steel secondary beams 16 are arranged on the overhanging section of the lower overhanging steel main beam 2, so that the lower end of the long inclined supporting rod 7 can be clamped in the groove of the limiting channel steel secondary beams 16, the long inclined supporting rod 7 is limited, and the lower end of the long inclined supporting rod 7 is prevented from sliding; the lower extreme of long bearing diagonal pole 7 is provided with the oblique angle, can make long bearing diagonal pole 7 be the slope form and support when encorbelmenting steel girder 1 in upper portion and the lower part and encorbelment between the steel girder 2, the oblique angle of long bearing diagonal pole 7 lower part just is parallel to each other with the tank bottom of spacing channel-section steel secondary beam 16, and then improves the support stability of long bearing diagonal pole 7.

In this embodiment, the support height of the support frame body of encorbelmenting outside of steel supporting platform lower part is the height of two stories, to carrying out the construction of the structure of encorbelmenting greatly in the high air, bearing capacity, stability etc. can both satisfy, simultaneously, because the support frame body of encorbelmenting outward has sufficient bearing capacity, consequently is convenient for increase the construction area of encorbelmenting steel supporting platform in order to be applicable to the construction of the structure of encorbelmenting greatly in the high air.

in actual use, the length of the overhanging section of the upper overhanging steel girder 1 is madeDegree L₁be greater than the width W of structure 25 of encorbelmenting, can guarantee to set up the security of the outside form support frame 20 on the upper portion of encorbelmenting steel girder 1 upper portion, guarantee setting up smoothly of outside form support frame 20, avoid outside form support frame 20 to stretch out to the upper portion and encorbelment the steel girder 1 outside, the security is relatively poor.

it should be noted that, a plurality of vertical rod anti-sliding reinforcing steel bar heads 27 are welded on the upper portion of the upper overhanging steel girder 1, the vertical rod anti-sliding reinforcing steel bar heads 27 are vertically arranged with the upper overhanging steel girder 1, when the external formwork support frame 20 is erected, the lower end of the vertical rod 20-1 is sleeved on the vertical rod anti-sliding reinforcing steel bar heads 27, so that not only can the arrangement position of the vertical rod 20-1 be accurately positioned, but also the vertical rod 20-1 can be prevented from sliding in the construction process, and the stability of the whole external formwork support frame 20 is ensured.

In this embodiment, the (N + 1) th floor 10 is a second floor from top to bottom in the building structure, that is, the (N + 1) th floor 10 is a floor next to the top plate 9.

as shown in fig. 8, the construction method of the present invention includes the steps of:

step one, building an overhanging steel supporting platform:

step 101, installing an upper cantilever steel girder: according to the overhanging construction scheme and the drawing requirements, ejecting a plurality of upper overhanging steel girder 1 positioning lines at equal intervals on the Nth floor 11, installing the upper overhanging steel girder 1 on the corresponding positioning lines, and enabling the length L of the overhanging section of the upper overhanging steel girder 1 to be equal to the length L of the upper overhanging steel girder₁Greater than the width W of the cantilevered structure 25;

In practical use, in order to facilitate construction, an anchoring section and an overhanging section of the upper overhanging steel girder 1 can be determined according to an overhanging construction scheme and drawing requirements, and then a plurality of upright anti-sliding reinforcing steel bar heads 27 are welded on the overhanging section of the upper overhanging steel girder 1 at equal intervals according to the upright setting standards of a scaffold so as to accurately position the upright 20-1; meanwhile, two steel wire rope anti-sliding reinforcement heads are respectively welded at the end part and the middle part of the overhanging section of the upper overhanging steel girder 1 and used for positioning the lower end of the first steel wire rope 5 and the lower end of the second steel wire rope 6. And the anchoring section of the upper overhanging steel girder 1 is fixed on the Nth floor slab 11 through an I-shaped steel pressure ring 8.

Step 102, pulling up the upper overhanging steel girder: a steel wire rope suspension device is arranged between the overhanging section of the upper overhanging steel main beam 1 and a building structure, and the upper overhanging steel main beam 1 reaches the designed arching height through the steel wire rope suspension device;

step 103, mounting a lower cantilever steel girder: according to the overhanging construction scheme and the drawing requirements, a plurality of lower overhanging steel main beam 2 positioning lines are popped up on the N-2 th floor 13 at equal intervals, the lower overhanging steel main beam 2 is installed on the corresponding positioning line, and the length L of the overhanging section of the lower overhanging steel main beam 2₂Is less than the length L of the overhanging section of the upper overhanging rigid girder 1₁Length L of overhanging section of lower overhanging steel girder 2₂less than the length L of its anchoring section₃K limiting channel steel secondary beams 16 which are parallel to each other and horizontally arranged are arranged in the direction perpendicular to the lower overhanging steel main beam 2 in a through-length mode, wherein K is the number of an oblique supporting component and is 1,2, … and K, K is a positive integer and is more than or equal to 2, the opening of each limiting channel steel secondary beam 16 faces upwards, and the bottom of each limiting channel steel secondary beam is welded to the upper portion of the lower overhanging steel main beam 2;

During the in-service use, according to the construction scheme of encorbelmenting and the drawing requirement, need determine its anchor section and the section of encorbelmenting on the steel girder 2 of encorbelmenting of lower part to the tip welding two wire rope antiskid reinforcing bar heads of the section of encorbelmenting of steel girder 2 of lower part are used for spacing the lower extreme of third wire rope 17.

the length L of the overhanging section of the lower overhanging steel main beam 2 is set to be equal to or less than the length L of the overhanging section of the lower overhanging steel main beam₂is less than the length L of the overhanging section of the upper overhanging steel girder 1₁The bending deformation of the lower cantilever steel girder 2 can be smaller than that of the upper cantilever steel girder 1, a long inclined supporting rod 7 is convenient to be arranged between the upper cantilever steel girder 1 and the lower cantilever steel girder 2, and then the cantilever section of the upper cantilever steel girder 1 is supported, so that the bending deformation of the upper cantilever steel girder 1 is prevented from being large, and further the construction quality is influenced.

In particular, the length L of the overhanging section of the lower overhanging steel girder 2₂Less than the length L of its anchoring section₃Can ensure the lower overhanging steelthe main beam 2 is firmly fixed, and the possibility of flexural deformation of the lower overhanging steel main beam 2 is reduced.

104, supporting the upper cantilever steel girder and the lower cantilever steel girder: k groups of oblique supporting components are arranged along the length direction of each upper cantilever steel main beam 1, the upper ends of two long oblique supporting rods 7 in a kth group of oblique supporting components arranged on each upper cantilever steel main beam 1 are respectively clung to the two sides of the upper cantilever steel main beam 1, the lower ends of two long oblique supporting rods 7 in the kth group of oblique supporting components arranged on each upper cantilever steel main beam 1 are respectively butted in a groove of a kth limiting channel steel secondary beam 16, the upper ends of two long oblique supporting rods 7 in the kth group of oblique supporting components arranged on each upper cantilever steel main beam 1 are connected together through a longitudinal horizontal rod 15, the longitudinal horizontal rod 15 connected with the upper end of each long oblique supporting rod 7 is supported at the lower part of the upper cantilever steel main beam 1, a first double fastener 24-1 is arranged on the long inclined supporting rod 7 to limit the lower part of the longitudinal horizontal rod 15;

during the in-service use, the lower extreme of two long bearing diagonal poles 7 in the kth group's diagonal bracing subassembly of installation all sets up on same spacing channel-section steel secondary beam 16 on each upper portion steel girder 1 that encorbelments.

And 105, supporting the upper cantilever steel girder and the floor of the (N-1) th floor: one or more groups of short inclined support rod assemblies are arranged between an upper cantilever steel main beam 1 and an N-1 floor slab 12, the upper ends of two short inclined support rods 3 in each group of short inclined support rod assemblies are respectively clung to two sides of the upper cantilever steel main beam 1, the lower ends of the two short inclined support rods 3 in each group of short inclined support rod assemblies are fixed on the N-1 floor slab 12, the upper ends of the two short inclined support rods 3 in each group of short inclined support rod assemblies are connected together through a longitudinal horizontal rod 15, the longitudinal horizontal rod 15 connected to the upper ends of the short inclined support rods 3 is supported on the lower part of the upper cantilever steel main beam 1, and a first double fastener 24-1 is arranged on each short inclined support rod 3 to limit the lower part of the longitudinal horizontal rod 15;

During the in-service use, the lower surface that the lower part of the steel girder 1 of encorbelmenting in upper portion hugs closely upper portion steel girder 1 of encorbelmenting is provided with a plurality of vertical horizon bars 15, is located two of same group diagonal bracing subassembly long diagonal bracing 7 all is fixed with vertical horizon bar 15, through all being provided with first pair fastener 24-1 in the upper end of long diagonal bracing 7 and short diagonal bracing 3 to make first pair fastener 24-1 support in the lower part of vertical horizon bar 15, can carry on spacingly to the junction of vertical horizon bar 15 and long diagonal bracing 7, and then avoid long diagonal bracing 7 to encorbelment steel girder 1 and slide relatively upper portion steel girder 1.

Step 106, setting up an outward-picking support frame body: set up between the steel girder 2 of encorbelmenting in upper portion 1 and the lower part of encorbelmenting the scaffold frame and form the support frame body of encorbelmenting outward, the support frame body of encorbelmenting outward is connected including the Nth floor slab that from top to bottom lays in proper order and is encorbelmented the support layer outside support layer, upper portion, the support layer is encorbelmented outward in the connection of Nth-1 floor slab and the support layer is encorbelmented outward in the lower part, and:

step 1061, according to the setting position of the long inclined supporting rod 7, forming a plurality of circular through holes on a cross beam 26 at the lower part of the nth floor 11, arranging a transverse horizontal rod 14 in each circular through hole, connecting the transverse horizontal rod 14 with the long inclined supporting rod 7 and the short inclined supporting rod 3 which are close to the transverse horizontal rod 14, and connecting longitudinal horizontal rods 15 at the crossing positions of the long inclined supporting rod 7 and the transverse horizontal rod 14 and the crossing positions of the short inclined supporting rod 3 and the transverse horizontal rod 14 to form an nth floor connecting outer cantilever supporting layer;

1062, connecting a plurality of transverse horizontal rods 14 between the Nth floor connecting outer cantilever supporting layer and the (N-1) th floor 12 along the length direction of each long inclined supporting rod 7, connecting the transverse horizontal rods 14 with the corresponding short inclined supporting rods 3 together, gradually reducing the lengths of the plurality of transverse horizontal rods 14 from top to bottom and being smaller than the lengths of the transverse horizontal rods 14 in the Nth floor connecting outer cantilever supporting layer, and connecting longitudinal horizontal rods 15 at the intersections of the long inclined supporting rods 7 and the transverse horizontal rods 14 and the intersections of the short inclined supporting rods 3 and the transverse horizontal rods 14 to form an upper outer cantilever supporting layer;

Step 1063, according to the setting position of the long inclined supporting rod 7, forming a plurality of circular through holes on the cross beam 26 at the lower part of the (N-1) th floor 12, arranging a transverse horizontal rod 14 in each circular through hole, connecting the transverse horizontal rod 14 with the long inclined supporting rod 7 and the short inclined supporting rod 3 which are close to the transverse horizontal rod 14, and connecting longitudinal horizontal rods 15 at the crossing part of the long inclined supporting rod 7 and the transverse horizontal rod 14 and the crossing part of the short inclined supporting rod 3 and the transverse horizontal rod 14 to form an N-1 th floor connecting outward-picking supporting layer;

1064, connecting a plurality of transverse horizontal rods 14 between the (N-1) th floor connecting outer cantilever supporting layer and the (N-2) th floor 13 along the length direction of each long inclined supporting rod 7, connecting the transverse horizontal rods 14 with the corresponding short inclined supporting rods 3 together, gradually reducing the lengths of the plurality of transverse horizontal rods 14 from top to bottom and being smaller than the length of the transverse horizontal rods 14 in the lowest floor of the (N-1) th floor connecting outer cantilever supporting layer, and connecting longitudinal horizontal rods 15 at the intersections of the long inclined supporting rods 7 and the transverse horizontal rods 14 and the intersections of the short inclined supporting rods 3 and the transverse horizontal rods 14 to form a lower outer cantilever supporting layer;

step 107, pulling and reinforcing the cantilever support frame body: full framing scaffolds are erected between the (N-2) th floor 13 and the (N-1) th floor 12 and between the (N-1) th floor 12 and the (N-1) th floor 11 to form a first foundation frame body 4 for carrying out tie reinforcement on the externally-cantilevered support frame body;

step 201, erecting a bamboo scaffold board at a designated position of an upper overhanging steel girder 1 to form a loading test platform, as shown in fig. 7, arranging a level gauge 30 on an Nth floor 11, fixing a vertical steel pipe 28 with the height of 1.2-1.5 m at the outer end of an overhanging section of the upper overhanging steel girder 1, setting a length measuring scale 29 matched with the level gauge 30 as a monitoring mark on the inner side of the vertical steel pipe 28 by utilizing the leveling principle of the level gauge, and arranging a loader 31 on the loading test platform to carry out loading test on an overhanging steel support platform;

step 202, judging whether the reading variation of the level gauge exceeds a threshold value: the numerical value of the leveling instrument 30 is read in a timing mode in the loading process, and if the reading of the leveling instrument 30 is not changed obviously, the leveling instrument is unloaded after the overhanging steel supporting platform is completely stabilized for two days; otherwise, go to step 203;

During the in-service use, through setting up spirit level 30 in the floor of building structure, the vertical steel pipe 28 of the fixed height 1.2m ~ 1.5m in the outer end of the section of encorbelmenting of steel girder 1 on upper portion simultaneously, utilize spirit level 30 to copy the flat principle, set up length measurement chi 29 as the monitoring sign on vertical steel pipe 28, the steel supporting platform of guaranteeing to encorbelment has the required bearing capacity of the structure construction of encorbelmenting, simultaneously, can continuously monitor the deformation value of the steel supporting platform of encorbelmenting in the structure work progress of encorbelmenting, the safety of guaranteeing the construction goes on.

In this embodiment, the length measuring ruler 29 is a waste steel measuring tape, the length of the waste steel measuring tape is 20 cm-40 cm, and a loading laboratory is performed, so that the graduated side of the waste steel measuring tape is arranged towards the building structure direction, and the waste steel measuring tape is attached to the inner side of the vertical steel pipe 28 and keeps vertical arrangement. The level 30 is movable within a floor of the building structure to facilitate observation of the value on the length measurement scale 29.

during actual use, at least three parts of the upper cantilever steel girder 1 are selected to be provided with bamboo scaffold boards as loading test platforms, when loading is carried out, the balance weight of the loader 31 is gradually increased, the cantilever steel supporting platform is gradually loaded, the reading change of the level 30 is observed once when the platform is loaded once in the loading process, if the reading does not change obviously, the loading is continued until the total loading weight is larger than the sum of combined load values calculated by the scheme, the loading is stopped, the reading of the level 30 is observed within 12 hours after the loading is finished, and the recording is carried out once every hour, and if the reading does not change obviously, the recording is carried out once every four hours; the loader 31 is a field spiral reinforcing steel bar, and the loading test is carried out step by increasing the number of the spiral reinforcing steel bars on a loading test platform manually.

step three, sealing the lower frame body of the overhanging steel supporting platform: the lower cantilever steel girder 2 is fully paved with a bamboo scaffold board, a gap between the bamboo scaffold board and an outer cantilever support frame body is filled with waste square timber, the waste square timber and the bamboo scaffold board are firmly nailed, a layer of waste mirror board is paved on the upper part of the bamboo scaffold board, a layer of fireproof asbestos cloth is fully paved on the waste mirror board, and the outer side of the outer cantilever support frame body is hung with a dense mesh net and a safety net to seal the outer cantilever support frame body;

during the in-service use, through encorbelmenting on the steel girder 2 in the lower part and having paved the bamboo scaffold board to lay the old and useless mirror surface board of one deck on the upper portion of bamboo scaffold board, can avoid building rubbish to drop from the gap of bamboo scaffold board in the work progress, influence constructor's personal safety, through the one deck fire prevention asbestos cloth of full pavement on old and useless mirror surface board, can prevent to take place the conflagration in the work progress, cause certain loss of property and casualties, and then influence the construction progress.

Step four, erecting a template support frame: erecting a full-hall scaffold between the nth floor 11 and the (N + 1) th floor 10 to form a second foundation frame body 22, erecting a full-hall scaffold between the (N + 1) th floor 10 and the top plate 9 to form a third foundation frame body 23, erecting a scaffold connected with the second foundation frame body 22 on the overhanging steel support platform to form an external formwork support frame 20, and erecting a scaffold outside the third foundation frame body 23 to form an internal formwork support frame 21;

And step five, closing the template support frame.

During the in-service use, when carrying out the closure of template support frame, fill bamboo scaffold board on the steel girder 1 of encorbelmenting in the upper portion, pack old and useless square timber at bamboo scaffold board and the space department of outside template support frame 20 to with old and useless square timber and bamboo scaffold board nailing, lay the old and useless mirror surface board of one deck on the upper portion of bamboo scaffold board, fully lay one deck fire prevention asbestos cloth on old and useless mirror surface board the outside of outside template support frame 20 and the outside of inside template support frame 21 are all hung and are established close mesh net and safety net and seal it.

in this embodiment, the upper cantilever steel girder 1 and the lower cantilever steel girder 2 are i-beams, the upper cantilever steel girder 1 is anchored on the nth floor 11 through an i-beam compression ring 8, and the lower cantilever steel girder 2 is anchored on the nth-2 floor 13 through an i-beam compression ring 8.

during the in-service use, through I-steel clamping ring 8 with the steel girder 1 anchor of encorbelmenting in upper portion on N floor 11, with the steel girder 2 anchor of encorbelmenting in lower part on N-2 floor 13 simultaneously, can make the steel girder 1 of encorbelmenting in upper portion and the steel girder 2 of encorbelmenting in lower part all with building structure fastening connection as an organic whole, improve the stability of the just supporting platform of whole encorbelmenting.

In this embodiment, each of the horizontal bars 14 is provided with k second double fasteners 24-2 for preventing the long diagonal support bar 7 from sliding, and the second double fasteners 24-2 are supported outside the long diagonal support bar 7.

during the in-service use, through all being provided with a plurality of second double fasteners 24-2 that prevent long diagonal bracing 7 from taking place to slide on each horizontal pole 14, can consolidate long diagonal bracing 7, prevent that long diagonal bracing 7 from taking place to slide relative horizontal pole 14, improve the stability of choosing the support frame body outward.

In this embodiment, when the overhanging support frame body is subjected to the pulling and strengthening in step 107, the inner end of each horizontal rod 14 in the overhanging support frame body erected in step 106 is connected with a horizontal rod 4-1 by using a rotary fastener, full framing scaffolds are erected between the nth-2 floor 13 and the nth-1 floor 12 and between the nth-1 floor 12 and the nth floor 11 based on the horizontal rods 4-1 to form a first base frame body 4, and the first base frame body 4 is connected with a shear brace 19.

during the in-service use, through with first basis support body 4 sets up to full hall scaffold frame, and is provided with bridging 19 on it, and the construction of being convenient for can guarantee that it has certain stability simultaneously, is difficult to take place crooked in the work progress.

It should be noted that the upper and lower ends of the vertical rod in the first foundation frame body 4 are respectively limited between two adjacent floor slabs, so that the vertical rod is integrally fixed with the structural building as much as possible, and a good tie effect can be achieved on the cantilever support frame body.

In this embodiment, the wire rope hanging device includes first wire rope 5 and second wire rope 6, the lower extreme of first wire rope 5 is fixed at the tip that the section was encorbelmented to upper portion steel girder 1, the upper end of first wire rope 5 is fixed on roof 9, the lower extreme of second wire rope 6 is fixed at the middle part that the section was encorbelmented to upper portion steel girder 1, the upper end of second wire rope 6 is fixed on the (N + 1) th floor 10, all be provided with the wire rope card on first wire rope 5 and the second wire rope 6.

during the in-service use, the ligature of first wire rope 5's upper end is on crossbeam 26 of roof 9 lower part, first wire rope 5's lower extreme is walked around upper portion and is encorbelmented steel girder 1 back through wire rope clamp rather than self chucking, second wire rope 6's upper end ligature is on crossbeam 26 of the (N + 1) th floor 10 lower part, second wire rope 6's lower extreme is walked around upper portion and is encorbelmented steel girder 1 back through wire rope clamp rather than self chucking.

It should be noted that, the lower end of the first steel wire rope 5 is fixed to the end of the overhanging section of the upper overhanging steel girder 1, and the upper end of the first steel wire rope is fixed to the top plate 9 of the building structure, the lower end of the second steel wire rope 6 is fixed to the middle of the overhanging section of the upper overhanging steel girder 1, and the upper end of the second steel wire rope is fixed to the N +1 th floor 10 of the building structure, so that different parts of the overhanging section of the upper overhanging steel girder 1 can be fixed at different angles, the first steel wire rope 5 and the second steel wire rope 6 are mutually matched to fix the upper overhanging steel girder 1 doubly, and the possibility of deformation of the upper overhanging steel girder 1 is reduced.

in this embodiment, a third steel wire rope 17 is connected between the overhanging section of the lower overhanging steel girder 2 and the N-1 st floor 12, before step 104, the lower end of the third steel wire rope 17 is fixed at the end of the overhanging section of the lower overhanging steel girder 2, the upper end of the third steel wire rope 17 is fixed on the N-1 st floor 12, a steel wire rope clamp is arranged on the third steel wire rope 17, and the lower overhanging steel girder 2 reaches the designed arching height by adjusting the steel wire rope clamp.

during actual use, the third steel wire rope suspension device is arranged on the upper portion of the lower cantilever steel girder 2, so that the third steel wire rope 17 connects the cantilever section of the lower cantilever steel girder 2 with the (N-1) th floor 12, upward pulling force can be provided for the lower cantilever steel girder 2, the lower cantilever steel girder 2 and a building structure are fixedly connected into a whole in a pulling mode, the lower cantilever steel girder 2 is prevented from being pressed and inclined downwards, and the stability of the lower supporting structure of the long inclined supporting rod 7 can be guaranteed.

as shown in fig. 2, 3 and 4, in this embodiment, a first steel wire rope positioning component 18-1 and a second steel wire rope positioning component 18-2 are arranged at the lower part of the upper cantilever steel main beam 1, the first steel wire rope positioning component 18-1 is fixed at the end part of the upper cantilever steel main beam 1, the second steel wire rope positioning component 18-2 is fixed at the middle part of the upper cantilever steel main beam 1, a third steel wire rope positioning component 18-3 is arranged at the lower part of the lower cantilever steel main beam 2, and the first steel wire rope positioning component 18-1, the second steel wire rope positioning component 18-2 and the third steel wire rope positioning component 18-3 are all the same in structure and each includes two steel wire rope anti-sliding reinforcing steel bar heads.

when the device is actually used, two pairs of steel wire rope anti-sliding steel bar heads are welded at the lower part of the upper cantilever steel main beam 1 to respectively form a first steel wire rope positioning component 18-1 and a second steel wire rope positioning component 18-2, so that the lower end of a first steel wire rope 5 can be hung at the end part of the upper cantilever steel main beam 1 and limited by the first steel wire rope positioning component 18-1, the lower end of the first steel wire rope 5 is clamped between the two steel wire rope anti-sliding steel bar heads in the first steel wire rope positioning component 18-1, the lower end of a second steel wire rope 6 is hung at the middle part of the upper cantilever steel main beam 1 and limited by the second steel wire rope positioning component 18-2, the lower end of the second steel wire rope 6 is clamped between the two steel wire rope anti-sliding steel bar heads in the second steel wire rope positioning component 18-2, and the first steel wire rope 5 and the second steel wire rope 6 are prevented from sliding on the upper cantilever steel main beam 1, and then the upper overhanging steel girder 1 is rocked.

it should be noted that a pair of steel wire rope anti-sliding steel bar heads are welded on the lower portion of the lower overhanging steel girder 2 to form a third steel wire rope positioning assembly 18-3, so that the lower end of the third steel wire rope 17 is hung on the end portion of the lower overhanging steel girder 2 and is limited by the third steel wire rope positioning assembly 18-3, and the third steel wire rope 17 is prevented from sliding relative to the lower overhanging steel girder 2, so that the lower overhanging steel girder 2 is prevented from shaking, and the stability of the whole overhanging steel support platform is further influenced.

in this embodiment, the upper end of the third steel wire rope 17 is bound to the cross beam 26 at the lower part of the N-1 st floor 12, and the lower end of the third steel wire rope 17 is clamped with the lower overhanging steel main beam 2 by a rope clamp after bypassing the main beam.

In this embodiment, outside formwork support frame 20 for set up on encorbelmenting steel supporting platform and with encorbelment structure 25 outside shape assorted scaffold frame, horizontal horizon bar in the outside formwork support frame 20 links together through rotating fastener with the horizontal horizon bar in the second basis support body 22, inside formwork support frame 21 for set up in third basis support body 23 one side and with encorbelment the scaffold frame of 25 inboard shapes of structure mutually supporting, horizontal horizon bar in the inside formwork support frame 21 links together through rotating fastener with the horizontal horizon bar in the third basis support body 23.

In practical use, the second foundation frame body 22 for reinforcing the external formwork support frame 20 is arranged between the nth floor 11 and the (N + 1) th floor 10, so that the external formwork support frame 20 can be fixed in a pulling mode, the stability of the external formwork support frame 20 is improved, and meanwhile, the load of the cantilever steel support platform is reduced; through be provided with third basis support body 23 between roof 9 and the (N + 1) th floor 10, can set up the platform for inside template support frame 21 provides a fine support body, help setting up of inside template support frame 21.

In this embodiment, the outer formwork support frame 20, the inner formwork support frame 21, the second foundation frame body 22 and the third foundation frame body 23 are all connected with a cross brace 19.

During the in-service use, all be provided with continuous bridging 19 on outside template support frame 20, inside template support frame 21, second basis support body 22 and the third basis support body 23, through setting up bridging 29, can improve the stability of support body, prevent that the support body from taking place to collapse or topple.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, changes and equivalent structural changes made to the above embodiment according to the technical spirit of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. a construction method of a high-altitude cantilever formwork support frame body comprises a cantilever steel support platform arranged on a building structure and a formwork support frame which is positioned at the upper part of the cantilever steel support platform and is used for constructing a cantilever structure (25), wherein the height of the cantilever structure (25) is 2H, the formwork support frame comprises an external formwork support frame (20) arranged on the outer side of an overhanging structure (25) and an internal formwork support frame (21) arranged on the inner side of the overhanging structure (25), a plurality of upright rod anti-sliding steel bar heads (27) used for positioning upright rods (20-1) of the external formwork support frame (20) are arranged on the upper portion of an upper overhanging steel main beam (1), and each upright rod anti-sliding steel bar head (27) is sleeved with an upright rod (20-1); the cantilever steel supporting platform comprises a plurality of upper cantilever steel main beams (1) anchored on the Nth floor (11) of the building structure, wherein N is a positive integer and is more than or equal to 3, the length of the cantilever section of each upper cantilever steel main beam (1) is greater than the width of a cantilever structure (25), the upper cantilever steel main beams (1) are parallel to each other, a steel wire rope suspension device is arranged on the upper part of the cantilever section of each upper cantilever steel main beam (1), and an inclined supporting device is arranged on the lower part of the cantilever section of each upper cantilever steel main beam (1);

A plurality of lower overhanging steel main beams (2) for installing an inclined supporting device are anchored on an N-2 floor (13) of a building structure, the lower overhanging steel main beams (2) and an upper overhanging steel main beam (1) are equal in number and correspond to each other one by one, the inclined supporting device comprises a plurality of groups of inclined supporting components, the inclined supporting components are supported between an overhanging section of the upper overhanging steel main beam (1) and an overhanging section of the lower overhanging steel main beam (2), each group of the inclined supporting components comprises two long inclined supporting rods (7) symmetrically arranged at two sides of the upper overhanging steel main beam (1), one group or a plurality of groups of short inclined supporting rod components are arranged between the overhanging section of the upper overhanging steel main beam (1) and the N-1 floor (12), each group of the short inclined supporting rod components comprises two short inclined supporting rods (3) symmetrically arranged at two sides of the upper overhanging steel main beam (1), the short inclined supporting rod (3) is positioned at the inner side of the long inclined supporting rod (7); lie in the bearing diagonal device that upper portion encorbelments steel girder (1) with a plurality of long bearing diagonal poles (7) of one side and short bearing diagonal pole (3) between connect as an organic wholely through a plurality of horizontal horizon bar (14) that parallel, the crossing point department of long bearing diagonal pole (7) and horizontal horizon bar (14), the steel girder (1) encorbelments on upper portion and the crossing point department of horizontal horizon bar (14) and the crossing point department of short bearing diagonal pole (3) and horizontal horizon bar (14) all is connected with a vertical horizon bar (15), the scaffold that encorbelments that long bearing diagonal pole (7), horizontal horizon bar (14), vertical horizon bar (15) and short bearing diagonal pole (3) constitute is the support body of encorbelmenting outward, vertical horizon bar (15) of the internal superiors in the support body support the lower part of upper portion encorbelmenting steel girder (1), the upper portion fixed mounting of lower part encorbelmenting steel girder (2) the overhang section has a plurality of being carried out spacing bearing diagonal pole (7) to long bearing diagonal The limiting channel steel secondary beams (16) are parallel to each other and are perpendicular to the lower overhanging steel main beam (2), the number of the limiting channel steel secondary beams (16) is equal to that of the oblique supporting assemblies and corresponds to that of the oblique supporting assemblies one by one, and the lower ends of the long oblique supporting rods (7) are abutted to the grooves of the limiting channel steel secondary beams (16);

the method is characterized by comprising the following steps:

step one, building an overhanging steel supporting platform:

step 101, installing an upper cantilever steel girder: according to the cantilever construction scheme and drawing requirements, popping up a plurality of upper cantilever steel main beam (1) positioning lines at equal intervals on the Nth floor (11), installing the upper cantilever steel main beams (1) on the corresponding positioning lines, wherein the length of the cantilever section of each upper cantilever steel main beam (1) is greater than the width of each cantilever structure (25);

Step 102, pulling up the upper overhanging steel girder: a steel wire rope suspension device is arranged between the overhanging section of the upper overhanging steel main beam (1) and a building structure, and the upper overhanging steel main beam (1) reaches the designed arching height through the steel wire rope suspension device;

Step 103, mounting a lower cantilever steel girder: according to an overhanging construction scheme and drawing requirements, popping up a plurality of lower overhanging steel main beams (2) at equal intervals on an N-2 floor (13), installing the lower overhanging steel main beams (2) on corresponding positioning lines, wherein the length of an overhanging section of the lower overhanging steel main beams (2) is smaller than that of an overhanging section of the upper overhanging steel main beams (1), the length of an overhanging section of the lower overhanging steel main beams (2) is smaller than that of an anchoring section of the lower overhanging steel main beams, and setting K limiting channel steel secondary beams (16) which are parallel to each other and horizontally arranged in the direction perpendicular to the lower overhanging steel main beams (2), wherein K is the number of an oblique supporting component and is 1,2, … and K is a positive integer and is larger than or equal to 2, the openings of the limiting channel steel secondary beams (16) face upwards, and the bottoms of the limiting channel steel secondary beams are welded on the upper part of the lower overhanging steel main beams (2);

104, supporting the upper cantilever steel girder and the lower cantilever steel girder: k groups of oblique supporting components are arranged along the length direction of each upper cantilever steel main beam (1), the upper ends of two long oblique supporting rods (7) in a kth group of oblique supporting components arranged on each upper cantilever steel main beam (1) are respectively clung to the two sides of the upper cantilever steel main beam (1), the lower ends of two long oblique supporting rods (7) in the kth group of oblique supporting components arranged on each upper cantilever steel main beam (1) are abutted to the groove of a kth limiting channel steel secondary beam (16), the upper ends of two long oblique supporting rods (7) in the kth group of oblique supporting components arranged on each upper cantilever steel main beam (1) are connected together through a longitudinal horizontal rod (15), the longitudinal horizontal rod (15) connected to the upper ends of the long oblique supporting rods (7) is supported at the lower part of the upper cantilever steel main beam (1), a first double fastener (24-1) is arranged on the long inclined supporting rod (7) to limit the lower part of the longitudinal horizontal rod (15);

And 105, supporting the upper cantilever steel girder and the floor of the (N-1) th floor: one or more groups of short inclined supporting rod assemblies are arranged between an upper cantilever steel main beam (1) and an N-1 floor (12), the upper ends of two short inclined supporting rods (3) in each group of short inclined supporting rod assemblies are respectively clung to two sides of the upper cantilever steel main beam (1), the lower ends of the two short inclined supporting rods (3) in each group of short inclined supporting rod assemblies are fixed on the N-1 floor (12), the upper ends of the two short inclined supporting rods (3) in each group of short inclined supporting rod assemblies are connected together through a longitudinal horizontal rod (15), the longitudinal horizontal rod (15) connected to the upper ends of the short inclined supporting rods (3) is supported on the lower part of the upper cantilever steel main beam (1), and a first double fastener (24-1) is arranged on each short inclined supporting rod (3) to limit the lower part of the longitudinal horizontal rod (15);

Step 106, setting up an outward-picking support frame body: encorbelmenting on upper portion steel girder (1) and the lower part encorbelment and set up between steel girder (2) and encorbelment the scaffold frame and form the support frame body of encorbelmenting outward, encorbelmenting the support frame body outward including the Nth floor connection that from top to bottom lays in proper order and encorbelmenting the support layer outward, the upper portion, the connection of Nth-1 floor is encorbelmented the support layer outward and is encorbelmented the support layer outward with the lower part, the process is:

Step 1061, according to the setting position of the long inclined supporting rod (7), a plurality of circular through holes are formed in a cross beam (26) at the lower part of an Nth floor (11), a transverse horizontal rod (14) is arranged in each circular through hole, the transverse horizontal rod (14) is connected with the long inclined supporting rod (7) and the short inclined supporting rod (3) which are close to the transverse horizontal rod, and longitudinal horizontal rods (15) are connected at the crossing part of the long inclined supporting rod (7) and the transverse horizontal rod (14) and the crossing part of the short inclined supporting rod (3) and the transverse horizontal rod (14) to form an Nth floor connecting outward-picking supporting layer;

1062, connecting a plurality of transverse horizontal rods (14) between the Nth floor connecting outer cantilever supporting layer and the (N-1) th floor (12) along the length direction of each long inclined supporting rod (7), connecting the transverse horizontal rods (14) with the corresponding short inclined supporting rods (3), wherein the lengths of the transverse horizontal rods (14) are gradually reduced from top to bottom and are smaller than the lengths of the transverse horizontal rods (14) in the Nth floor connecting outer cantilever supporting layer, and connecting longitudinal horizontal rods (15) at the intersections of the long inclined supporting rods (7) and the transverse horizontal rods (14) and the intersections of the short inclined supporting rods (3) and the transverse horizontal rods (14) to form an upper outer cantilever supporting layer;

1063, arranging a plurality of circular through holes on a cross beam (26) at the lower part of the (N-1) th floor slab (12) according to the erection position of the long inclined supporting rod (7), arranging a transverse horizontal rod (14) in each circular through hole, connecting the transverse horizontal rod (14) with the long inclined supporting rod (7) and the short inclined supporting rod (3) close to the transverse horizontal rod, and connecting the longitudinal horizontal rods (15) at the intersection of the long inclined supporting rod (7) and the transverse horizontal rod (14) and the intersection of the short inclined supporting rod (3) and the transverse horizontal rod (14) to form an N-1 th floor slab connection outward-picking supporting layer;

1064, connecting a plurality of transverse horizontal rods (14) between the (N-1) th floor connection outward-picking supporting layer and the (N-2) th floor (13) along the length direction of each long inclined supporting rod (7), connecting the transverse horizontal rods (14) with the corresponding short inclined supporting rods (3), gradually reducing the lengths of the transverse horizontal rods (14) from top to bottom and being smaller than the length of the transverse horizontal rod (14) in the lowest floor of the (N-1) th floor connection outward-picking supporting layer, and connecting longitudinal horizontal rods (15) at the intersections of the long inclined supporting rods (7) and the transverse horizontal rods (14) and the intersections of the short inclined supporting rods (3) and the transverse horizontal rods (14) to form a lower outward-picking supporting layer;

step 107, pulling and reinforcing the cantilever support frame body: full framing scaffolds are erected between the (N-2) th floor (13) and the (N-1) th floor (12) and between the (N-1) th floor (12) and the (N) th floor (11) to form a first foundation frame body (4) for carrying out tie reinforcement on the cantilever support frame body;

Step 201, erecting a bamboo scaffold board at a designated position of an upper cantilever steel girder (1) to form a loading test platform, arranging a level gauge (30) on an Nth floor (11), fixing a vertical steel pipe (28) with the height of 1.2-1.5 m at the outer end of an overhanging section of the upper cantilever steel girder (1), setting a length measuring scale (29) matched with the level gauge (30) as a monitoring mark on the inner side of the vertical steel pipe (28) by utilizing the leveling principle of the level gauge, and arranging a loader (31) on the loading test platform to carry out loading test on the cantilever steel support platform;

Step 202, judging whether the reading variation of the level gauge exceeds a threshold value: the numerical value of the leveling instrument (30) is read at regular time in the loading process, and if the reading of the leveling instrument (30) is not obviously changed, the leveling instrument is unloaded after the cantilever steel supporting platform is completely stabilized for two days; otherwise, go to step 203;

Step three, sealing the lower frame body of the overhanging steel supporting platform: the lower cantilever steel main beam (2) is fully paved with a bamboo scaffold board, a gap between the bamboo scaffold board and an outer cantilever support frame body is filled with waste square wood, the waste square wood and the bamboo scaffold board are firmly nailed, a layer of waste mirror board is paved on the upper portion of the bamboo scaffold board, a layer of fireproof asbestos cloth is fully paved on the waste mirror board, and the outer side of the outer cantilever support frame body is hung with a dense mesh net and a safety net to seal the outer cantilever support frame body;

Step four, erecting a template support frame: erecting a full-space scaffold between the Nth floor (11) and the (N + 1) th floor (10) to form a second foundation frame body (22), erecting a full-space scaffold between the (N + 1) th floor (10) and the top plate (9) to form a third foundation frame body (23), erecting a scaffold connected with the second foundation frame body (22) on the overhanging steel supporting platform to form an external formwork supporting frame (20), and erecting a scaffold on the outer side of the third foundation frame body (23) to form an internal formwork supporting frame (21);

And step five, closing the template support frame.

2. the construction method of the high-altitude cantilever formwork support frame body according to claim 1, characterized in that: the upper portion steel girder (1) of encorbelmenting and lower part steel girder (2) of encorbelmenting are the I-steel, upper portion steel girder (1) of encorbelmenting is through I-steel clamping ring (8) anchor on N floor (11), lower part steel girder (2) of encorbelmenting is through I-steel clamping ring (8) anchor on N-2 floor (13).

3. the construction method of the high-altitude cantilever formwork support frame body according to claim 1, characterized in that: each horizontal rod (14) is provided with k second double fasteners (24-2) for preventing the long inclined supporting rod (7) from sliding, and the second double fasteners (24-2) are supported on the outer side of the long inclined supporting rod (7).

4. the construction method of the high-altitude cantilever formwork support frame body according to claim 1, characterized in that: when the drawknot is performed and the cantilever support frame body is reinforced in the step 107, the inner end of each horizontal rod (14) in the cantilever support frame body erected in the step 106 is connected with a horizontal pull rod (4-1), based on the horizontal pull rods (4-1), full framing is erected between the N-2 th floor (13) and the N-1 st floor (12) and between the N-1 st floor (12) and the N-11) to form a first basic frame body (4), and the first basic frame body (4) is connected with a shear brace (19).

5. the construction method of the high-altitude cantilever formwork support frame body according to claim 1, characterized in that: the steel wire rope suspension device comprises a first steel wire rope (5) and a second steel wire rope (6), the lower end of the first steel wire rope (5) is fixed at the end part of the cantilever section of the steel main beam (1) on the upper part, the upper end of the first steel wire rope (5) is fixed on the top plate (9), the lower end of the second steel wire rope (6) is fixed at the middle part of the cantilever section of the steel main beam (1) on the upper part, the upper end of the second steel wire rope (6) is fixed on the (N + 1) th floor slab (10), and steel wire rope clamps are arranged on the first steel wire rope (5) and the second steel wire rope (6).

6. The construction method of the high-altitude cantilever formwork support frame body according to claim 5, characterized in that: the steel girder that encorbelments of lower part (2) is connected with third wire rope (17) between the section of encorbelmenting and N-1 floor (12), before carrying out step 104, fixes the lower extreme of third wire rope (17) at the tip of the section of encorbelmenting of steel girder (2) of encorbelmenting in the lower part, the upper end of third wire rope (17) is fixed on N-1 floor (12), be provided with the wire rope card on third wire rope (17), make the steel girder (2) of encorbelmenting in lower part reach the design and rise to encircle the height through adjustment wire rope card.

7. the construction method of the high-altitude cantilever formwork support frame body according to claim 6, characterized in that: the lower part of the upper cantilever steel girder (1) is provided with a first steel wire rope positioning component (18-1) and a second steel wire rope positioning component (18-2), the end part of the upper cantilever steel girder (1) is fixed by the first steel wire rope positioning component (18-1), the middle part of the upper cantilever steel girder (1) is fixed by the second steel wire rope positioning component (18-2), the lower part of the lower cantilever steel girder (2) is provided with a third steel wire rope positioning component (18-3), the structures of the first steel wire rope positioning component (18-1), the second steel wire rope positioning component (18-2) and the third steel wire rope positioning component (18-3) are all the same and comprise two steel wire rope anti-sliding steel bar heads.

8. the construction method of the high-altitude cantilever formwork support frame body according to claim 1, characterized in that: outside template support frame (20) for set up encorbelment on the steel supporting platform and with encorbelment structure (25) outside shape assorted scaffold frame, horizontal horizon bar in outside template support frame (20) and the horizontal horizon bar in second basis support body (22) link together through rotatory fastener, inside template support frame (21) for set up in third basis support body (23) one side and with encorbelment the scaffold frame of mutually supporting of structure (25) inboard shape, horizontal horizon bar in inside template support frame (21) and the horizontal horizon bar in third basis support body (23) link together through rotatory fastener.

9. the construction method of the high-altitude cantilever formwork support frame body according to claim 8, characterized in that: and the external template support frame (20), the internal template support frame (21), the second basic frame body (22) and the third basic frame body (23) are all connected with a cross brace (19).