CN116163217A - Construction method of assembled bridge - Google Patents

Abstract

The invention discloses a construction method of an assembled bridge, which comprises the following steps: installing arch leg supports, stiff framework supports and arch rib supports; the top ends of the arch support and the stiff framework support are provided with cross beams; mounting the stiffening skeleton on the cross beam; synchronously installing arch rib shells from two ends of an arch bridge to the middle; installing a tie bar bottom die on the stiff framework to form an initial bridge; hoisting and installing the initial bridge frame to a tie bar arch bridge bracket; pouring an arch springing on the stiff framework; removing the arch leg support, and pouring concrete in the arch rib shell to form an arch rib; pouring a tie bar in the tie bar bottom die to form a tie bar; performing bridge deck construction to form a bridge deck; and installing guardrails on the bridge deck, paving asphalt, and forming the tied arch bridge. According to the invention, the initial bridge is formed by pre-installing outside the river channel, and then the initial bridge is hoisted to the preset installation position to finish construction, so that the construction speed on land is high, the installation period is short, and the influence on the river reach where the preset installation position is located is reduced.

Description

Construction method of assembled bridge

Technical Field

The invention relates to the technical field of bridge construction, in particular to a construction method of an assembled bridge.

Background

The tied-arch bridge, which is a member of the family of arch bridges, has the general characteristics of an arch bridge and has unique characteristics of itself. The bridge combines the two basic structural forms of arch and beam together to bear load, and the structural performance and combination effect of the bent and pressed arch are fully exerted. The arch and the chord are connected by a vertical rod with two hinged ends.

In the bridge construction technology in the prior art, the whole bridge is constructed on the water surface, and because the construction of operators and the material transportation are inconvenient in the construction on the water surface, the construction speed of the bridge on the water is low, the installation period is long, and in the construction process, the water area of the construction section cannot navigate, so that the traffic of the waterway is influenced in the construction process.

Disclosure of Invention

The invention mainly aims to provide a construction method of an assembled bridge, and aims to solve the problems that the existing bridge construction technology is low in construction speed and long in installation period on water, and the traffic of the waterway is affected.

In order to achieve the above object, the present invention provides a construction method of an assembled bridge, comprising the steps of:

installing arch springing brackets, stiff skeleton brackets and arch rib brackets, installing cross beams at the top ends of the arch springing brackets and the stiff skeleton brackets, and installing the stiff skeleton on the cross beams;

synchronously installing arch rib shells from two ends of the arch bridge to the middle and enabling the arch rib shells to be installed at the top ends of the arch rib brackets, wherein the number of the arch rib shells is multiple, and the two corresponding arch rib shells are symmetrically arranged along the vertical central line of the arch rib;

installing slings on the rib shells;

dismantling the arch rib bracket, and installing a tie bar bottom die on the stiff framework to form an initial bridge;

installing a tied-arch bridge bracket at a preset installation position of the tied-arch bridge, and hoisting and installing the initial bridge frame to the tied-arch bridge bracket;

pouring an arch springing on the stiff framework;

removing the arch leg support, and pouring concrete in the arch rib shell to form an arch rib;

binding tie bar steel bars in the tie bar bottom die, and pouring to form tie bars in the tie bar bottom die;

performing bridge deck construction on the tie bars to form a bridge deck;

and installing guardrails on the bridge deck, paving asphalt, and forming the tied arch bridge.

Preferably, a limiting assembly is arranged at the top end of the arch rib bracket, and the limiting assembly encloses a limiting cavity;

the step of synchronously installing arch rib shells from two ends of the arch bridge to the middle and enabling the arch rib shells to be installed at the top ends of the arch rib brackets comprises the following steps of:

sequentially lifting a plurality of arch rib shells to the top ends of the corresponding arch rib brackets from the bottoms of the two ends of the arch bridge upwards;

hanging the arch rib shell into the limiting cavity;

and installing cable ropes on two sides of each arch rib shell, and fixing the other ends of the cable ropes on the bridge deck and tensioning.

Preferably, the arch rib shell comprises an arch bottom shell, a middle shell, an arch top shell and a folding shell, wherein the number of the arch bottom shell, the number of the middle shell and the number of the arch top shell are two, the arch bottom shell, the middle shell and the arch top shell are sequentially stacked from bottom to top, and two ends of the folding shell are respectively connected with the two arch top shells;

the cable rope arranged on the arch bottom shell is perpendicular to the horizontal plane, and the cable rope arranged on the middle shell and the arch bottom shell is inclined at 45 degrees with the horizontal plane.

Preferably, the step of mounting a sling on the rib shell comprises:

installing a top sling conduit at the top end of the arch rib shell and a bottom sling conduit on the stiff framework;

the top end of the sling is penetrated and arranged in the top sling guide pipe and fixed, and the bottom end of the sling is penetrated and arranged in the bottom sling guide pipe and fixed;

and tensioning the sling.

Preferably, the step of casting the footing on the stiff skeleton comprises:

setting up arch foot supports on the stiff framework;

a supporting frame is erected below the arch support, and a prestressed pipeline and an anchor are arranged in the supporting frame;

installing a template on the support frame;

and pouring concrete into the templates to form the arch springing.

Preferably, the two ends of the arch rib shell close to the arch springing are provided with pressure injection openings;

the step of removing the arch leg support and casting concrete in the arch rib shell to form an arch rib comprises the following steps:

removing said arch support from under said arch;

communicating the two pressure injection ports with a pumping pipe;

and simultaneously carrying out concrete pouring on the two pressure pouring openings until the concrete fills the arch rib shell to form the arch rib.

Preferably, the step of binding tie bar steel bars in the tie bar bottom die and pouring the tie bar steel bars in the tie bar bottom die to form the tie bars comprises the following steps:

binding tie bar steel bars, and installing an inner template in the tie bar steel bars;

a plurality of vibrating holes for inserting vibrating rods are formed in the inner template at intervals;

installing an outer template outside the tie bar steel bars;

and pouring concrete in the outer die plate and vibrating the inner die plate through the vibrating rod to form the tie bars.

Preferably, after the step of pouring concrete in the outer form and vibrating the inner form to form the tie bars, the method further comprises:

the tie bar is prestressed and tensioned.

Preferably, the step of performing bridge deck construction on the tie bars to form a bridge deck comprises:

a plurality of lane plates are arranged at intervals along the extending direction of the tie bars;

connecting any two adjacent roadway plates through binding steel bars;

and pouring concrete on the surface of the traffic lane plate to form the bridge deck.

Preferably, after the step of synchronously installing the rib shells from both ends of the arch bridge to the middle and installing the rib shells on the top ends of the rib brackets, the method further comprises:

performing sand blasting on the outer wall of the arch rib shell;

and coating the outer wall of the arch rib shell.

According to the technical scheme, firstly, an arch support, a stiff framework support and an arch rib support are arranged outside a river channel, then, a cross beam and the stiff framework are arranged at the top ends of the arch support and the stiff framework support, then, an arch rib shell, a sling and a tie rod bottom die are arranged at one time to form an initial bridge, at the moment, the bridge is hoisted to a corresponding preset installation position, and at the moment, concrete pouring and ending work of the arch, the arch rib and the tie rod are carried out, so that bridge construction can be completed. According to the invention, the initial bridge is formed by pre-installing outside the river course, and then the initial bridge is hoisted to the preset installation position to finish construction, so that the time period for installing the formed bridge can be shortened, the river reach where the preset installation position is located can still navigate, and the construction speed is high, the installation period is short, and the influence on the river reach where the preset installation position is located is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a block flow diagram of a method of constructing an assembled bridge in accordance with one embodiment of the present invention;

FIG. 2 is a schematic illustration of a tied-arch bridge according to an embodiment of the invention;

fig. 3 is a schematic cross-sectional view of a rib portion of a tied-arch bridge in accordance with an embodiment of the invention.

Reference numerals illustrate:

reference numerals	Name of the name	Reference numerals	Name of the name
				1	Tie bar arch bridge	20	Arch leg
10	Arch rib shell	30	Stiffness skeleton
				11	Arch bottom shell	40	Spacing subassembly
12	Intermediate shell	50	Arch leg support
				13	Vault shell	51	Stiff skeleton support
14	Folding shell	52	Arch rib support

The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The technical solutions of the present embodiment will be clearly and completely described below with reference to the drawings in the present embodiment, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that all the directional indications (such as up, down, left, right, front, and rear … …) in this embodiment are merely for explaining the relative positional relationship, movement conditions, and the like between the components in a certain specific posture (as shown in the drawings), and if the specific posture is changed, the directional indication is changed accordingly.

Furthermore, descriptions such as those referred to as "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying an order of magnitude of the indicated technical features in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless specifically stated and limited otherwise, the terms "connected," "affixed," and the like are to be construed broadly, and for example, "affixed" may be a fixed connection, a removable connection, or an integral body; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, the technical solutions of the embodiments of the present invention may be combined with each other, but it is necessary to be based on the fact that those skilled in the art can implement the technical solutions, and when the technical solutions are contradictory or cannot be implemented, the combination of the technical solutions should be considered as not existing, and not falling within the scope of protection claimed by the present invention. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

The invention provides a construction method of an assembled bridge.

Referring to fig. 1, the construction method of the assembled bridge of the present embodiment includes the following steps:

s100: installing arch springing brackets, stiff skeleton brackets and arch rib brackets, installing cross beams at the top ends of the arch springing brackets and the stiff skeleton brackets, and installing the stiff skeleton on the cross beams;

s200: synchronously installing arch rib shells from two ends of the arch bridge to the middle and enabling the arch rib shells to be installed at the top ends of the arch rib brackets, wherein the number of the arch rib shells is multiple, and the two corresponding arch rib shells are symmetrically arranged along the vertical central line of the arch rib;

s300: installing slings on the rib shells;

s400: dismantling the arch rib bracket, and installing a tie bar bottom die on the stiff framework to form an initial bridge;

s500: installing a tied-arch bridge bracket at a preset installation position of the tied-arch bridge, and hoisting and installing the initial bridge frame to the tied-arch bridge bracket;

s600: pouring an arch springing on the stiff framework;

s700: removing the arch leg support, and pouring concrete in the arch rib shell to form an arch rib;

s800: binding tie bar steel bars in the tie bar bottom die, and pouring to form tie bars in the tie bar bottom die;

s900: performing bridge deck construction on the tie bars to form a bridge deck;

s1000: and installing guardrails on the bridge deck, paving asphalt, and forming the tied arch bridge.

A pile leg bracket 50, a stiffening skeleton bracket 51 and a rib bracket 52 are inserted on the upstream dyke of the river course by adopting a drawing machine, wherein the rib bracket 52 comprises a soil-entering part and an exposed part, the soil-entering part is driven into a pipe pile by the drawing machine, and the exposed part is hung to the top of the soil-entering part by a crane and is installed; the top ends of the arch leg support 50 and the stiff framework support 51 are respectively provided with a top steel backing plate, a cross beam is arranged on the top steel backing plates, the components are transported to an assembly site according to the sectional sequence according to the sectional condition of the stiff framework 30, and are assembled in sequence, and the next stiff framework 30 can be continuously assembled after welding of two adjacent sections of joints is completed until the installation is completed; the method comprises the steps that an arch rib and an existing factory are processed into a plurality of segmented arch rib shells 10, the arch rib shells 10 are hoisted to preset positions through a crane, then the arch rib is installed and fixed, then an air brace is installed on the arch rib, during the processing of the arch rib in the factory, the side face is welded with a long air brace short joint, an air brace limiting plate is welded below the outer sides of the selected air brace and the short steel beam joint, after all the straight braces are hoisted in place, a worker welds an air brace butt joint weld on an air operation platform, and finally diagonal braces are installed and welded; installing a sling sleeve after the stiff framework 30, the arch ribs and the wind brace are installed, sequentially connecting the sling with a top sling sleeve and a bottom sling sleeve, tensioning the sling, controlling the stretching amount by using a double-control single-end tensioning method during tensioning, and checking the error of a theoretical calculated value of the actually measured stretching amount and the corrected value within a range of +/-6%; removing the arch rib bracket 52 after stretching the tie bars, installing a tie bar bottom die, wherein the tie bar bottom die consists of a bottom bracket I-shaped steel beam, longitudinal square lumber, a bamboo plywood, two side protection rails, a pavement template and other components, the tie bar bottom die is welded on the side surface of the stiff skeleton 30 by a hook rib and connected by a steel gasket, and then placing the I-shaped steel beam to lock a bottom die system on the stiff skeleton 30; and then carrying out integral hoisting of the initial bridge frame, wherein the drop points are symmetrically arranged on two sides of the arch rib shell 10, the hoisting weight and the position of the suspension point are required to be calculated and determined, then a proper crane is selected, the hoisting height of the initial bridge frame is required to be 500-1000 mm higher than the top surface of the installation position, the collision of the pier body is avoided, and the initial bridge frame slowly descends to the installation position after reaching the upper part of the installation position. In order to prevent the temporary support from being damaged by uneven stress, a temporary supporting point is arranged on the outer side of the support, a steel pipe with the diameter of 325 mm multiplied by 16mm is used as the temporary supporting point, the temporary supporting point is 20mm higher than the support, and the temporary supporting point is cut off after the tie bar arch is safely positioned; and constructing the arch feet 20 on two sides of the arch rib after hoisting, sequentially concreting to form the arch rib and the tie bars, and then completing bridge deck construction and subsequent guardrail and asphalt construction to complete the construction of the tie bar arch bridge 1.

In the technical scheme of the invention, firstly, an arch support 50, a stiff skeleton support 51 and an arch rib support 52 are arranged outside a river channel, then, a cross beam and the stiff skeleton 30 are arranged at the top ends of the arch support 50 and the stiff skeleton support 51, then, an arch rib shell 10, a sling and a tie rod bottom die are arranged at one time to form an initial bridge, at the moment, the bridge is hoisted to a corresponding preset installation position, and at the moment, the bridge construction can be completed by carrying out concrete pouring and ending work of the arch 20, the arch rib and the tie rod. According to the invention, the initial bridge is formed by pre-installing outside the river course, and then the initial bridge is hoisted to the preset installation position to finish construction, so that the time period for installing the formed bridge can be shortened, the river reach where the preset installation position is located can still navigate, the construction speed on land is high, the installation period is short, and the influence on the river reach where the preset installation position is located is reduced.

In an embodiment, a limiting component is installed at the top end of the arch rib bracket, and the limiting component encloses a limiting cavity; step S200 includes:

s210: sequentially lifting a plurality of arch rib shells to the top ends of the corresponding arch rib brackets from the bottoms of the two ends of the arch bridge upwards;

s220: hanging the arch rib shell into the limiting cavity;

s230: and installing cable ropes on two sides of each arch rib shell, and fixing the other ends of the cable ropes on the bridge deck and tensioning.

Specifically, the arch rib adopts a dumbbell-shaped section, and the arch rib is easy to rotate during installation, so that the segmented arch rib is not in the same plane, and the integral linearity and structural stress are influenced, therefore, the limiting assemblies 40 are arranged on the top of the cross beam of the arch rib bracket 52, the accurate positioning of the two ends of the arch rib is ensured, and the limiting assemblies 40 are arranged on the two sides of the arch rib and are used for abutting against the side walls of the arch rib so as to prevent the arch rib from shifting; in order to ensure the stability of the arch rib plane, the three-point positioning principle is utilized, besides saddle measures at two ends, wind-collecting ropes are arranged in the middle of each arch rib section to serve as fixing measures, phi 16mm steel wire ropes are adopted as the wind-collecting ropes, 1 wind-collecting rope is respectively arranged at the left side and the right side of each arch rib shell 10 when the arch rib shells 10 are installed, and the whole linearity of the arch ribs is smoother and the structure is more stable through the design of the limiting assemblies 40 and the cable wind ropes.

Further, the rib shell 10 includes a bottom shell 11, a middle shell 12, a top shell 13 and a folding shell 14, the number of the bottom shell 11, the middle shell 12 and the top shell 13 is two, the bottom shell 11, the middle shell 12 and the top shell 13 are sequentially stacked from bottom to top, and two ends of the folding shell 14 are respectively connected with the two top shells 13;

the cable rope mounted on the arch bottom shell 11 is arranged vertically to the horizontal plane, and the cable ropes mounted on the middle shell 12 and the arch bottom shell 13 are arranged obliquely to the horizontal plane at an angle of 45 degrees.

The arch bottom shell 11 is arranged close to the stiffness framework 30, the middle shell 12 is arranged above the arch bottom shell 11 and is connected with the arch bottom shell 11, the arch top shell 13 is arranged above the middle shell 12 and is connected with the middle shell 12, the folding shell 14 is positioned at the vertical center line of the arch rib and is respectively connected with the two arch top shells 13, the shells are arranged in a segmented mode, compared with the whole shell, the deformation is smaller, the hoisting installation is easier, and the construction efficiency is improved.

In one embodiment, step S300 includes:

s310: installing a top sling conduit at the top end of the arch rib shell and a bottom sling conduit on the stiff framework;

s320: the top end of the sling is penetrated and arranged in the top sling guide pipe and fixed, and the bottom end of the sling is penetrated and arranged in the bottom sling guide pipe and fixed;

s330: and tensioning the sling.

In one embodiment, the sling tube is installed after the stiff frame 30, ribs and struts are installed, the top sling tube is exposed 25cm from the bottom edge of the ribs, the bottom sling tube is exposed 15cm from the top edge of the tie rod, and the entire sling tube cannot be installed directly, so that the cable tube needs to be installed in steps.

The first step: cutting off the cable duct at a position 30cm away from the bottom opening, and welding the cut-off 30cm sleeve pipe on a steel plate on the top of the tie bar embedded cable duct.

And a second step of: the upper residual cable duct stretches into the arch rib cable upper adjusting steel pipe under the lifting of a crane and the manual traction, and the manual traction is slowly released until the lower opening is in butt joint with the truncated cable duct.

And a third step of: welding and polishing a welding seam on the sling sleeve at the cut-off position, welding an upper adjusting steel pipe and the sling sleeve, and polishing the welding seam;

the hanging rod cable installation comprises the following steps:

1) Anchor mounting

a. A long steel wire rope is hung on a lifting hook by an automobile crane right above a sling, the steel wire rope penetrates into a top sling pipe of the sling to be installed on an arch rib, a specially designed reducing sleeve is screwed on the anchor head of a suspender rope, and the steel wire rope is connected with the reducing sleeve by a clamp.

b. The sling anchor cup is screwed on to guide, and the traction steel wire rope is connected with the anchor cup, so that whether residues exist in the threads or not is checked, and if residues need to be removed in time.

c. And (3) stably hoisting, and when the upper anchor enters the top sling guide pipe, the special person is responsible for seeing the upper anchor, so that the smoothness of the anchor cup entering the top sling guide pipe is ensured.

d. In the process of lifting the inhaul cable, an operator needs to communicate with a person taking care of lifting the sling at any time, the lifting speed must be slowed down when the inhaul cable is lifted to the vicinity of the upper anchor top sling guide pipe, and the operator is arranged in the direction of the inhaul cable anchor head, so that the anchor head can smoothly enter the upper anchor top sling guide pipe.

e. When the upper anchor is out of the top sling catheter, the anchor ring is screwed, and the position of the anchor ring is flat with the end part of the anchor cup.

2) Anchor mounting

a. After the upper anchor is installed, a cotton yarn rope is hung on the lifting hook of the automobile crane, the cotton yarn rope is tied up below the lifting rod, the automobile crane is lifted, the lower anchor is aligned to the position in the top sling pipe, the automobile crane is lowered, the lower anchor enters the top sling pipe, and after a reserved hole is formed, an anchor ring is screwed.

b. The distance that the lower anchor exposes out of the top sling catheter is insufficient, the anchor ring of the upper anchor cannot be screwed on, the suspension rod can be loosened by adjusting the anchor ring of the upper anchor until the lower anchor is screwed on, and the anchor ring position of the lower anchor is positioned in the middle of the anchor cup as much as possible, so that the upper anchor can be adjusted during tensioning.

The hanging rod cable tensioning comprises the following steps:

1) Preparation before stretching

a. An operating platform must be arranged above the arch rib, and armrests must be arranged on both sides of the arch rib so as to facilitate the tensioning operation of operators, and the tensioning of the method is carried out on the steel pipe arch.

b. After the boom cable is installed, the guiding and connecting piece is removed, and a pull head matched with the external thread of the anchor head of the finished cable is selected and screwed on the anchor head. It should be noted at this point that the anchor head must be screwed to the bottom of the pull head thread.

c. The supporting feet of the jack are placed at proper positions so that the jack does not move when the pull rod and the jack are in place. The center of the supporting feet and the center of the anchor are kept concentric, and the phenomenon of eccentricity is avoided, so that external threads of the anchor are prevented from being damaged in the subsequent stretching.

d. And (5) loading the pull rod. Note that the tie rod must be in place when it is screwed into the slider, otherwise pull-off will be possible.

e. The jack is in place, the jack is light when placed on the foot, requires a flat contact surface with the foot, and requires centering.

f. And (3) assembling a nut, wherein the nut is not required to be screwed too tightly after being assembled, so that a free space for the jack to move is provided. The distance from the jack to the ground is 1-2 cm, which is beneficial to adjusting the center positions of the jack, the supporting feet and the anchor, and is also beneficial to oil supply of the jack.

2) Boom tensioning

The stretching of the suspender adopts double-control single-end stretching, stretching force is used for controlling during stretching, the stretching amount is checked, and the error of the theoretical calculated value of the actually measured stretching amount and the corrected value is required to be within +/-6 percent.

And tensioning the suspenders in a tensioning sequence, namely tensioning the suspenders in a long bundle and then tensioning the suspenders in a short bundle in a jumping mode, wherein the suspenders are tensioned symmetrically in pairs.

a. And (3) connecting the oil pipes of the oil pump and the jack, checking whether the precision pressure gauge is consistent with the jack, and moving two strokes under the condition of no load before tensioning to ensure that the jack has no problem during tensioning.

b. The tensioning jack and the oil pressure gauge must be calibrated before tensioning, and tensioning is carried out one by one according to the tensioning force of the inhaul cable.

c. And starting the oil pump, slowly lifting the finished rope in the tensioning process, and simultaneously downwards screwing an upper anchor ring of the finished rope to ensure that the finished rope is not too high from the position of the anchor backing plate.

d. When the design and monitoring requirements are met, the oil pressure is stabilized, and then the anchor ring is screwed tightly, so that the anchor ring and the anchor backing plate are fully combined.

e. And finally, oil pressure is removed, oil return, shutdown and power failure are performed, and tensioning work is completed.

In one embodiment, step S600 includes:

s610: setting up arch foot supports on the stiff framework;

s620: a supporting frame is erected below the arch support, and a prestressed pipeline and an anchor are arranged in the supporting frame;

s630: installing a template on the support frame;

s640: and pouring concrete into the templates to form the arch springing.

And after the initial bridge frame is hoisted, the arch foot support is firstly constructed, so that the construction efficiency is improved, and the stability of the arch rib in the subsequent arch rib construction process is ensured.

In a specific embodiment, a GPZ (2009) basin-shaped support is adopted as an arch foot support, a good foot bolt hole site is reserved in advance when a capping beam is poured, when the capping beam concrete is poured and the strength reaches the design requirement, the chiseling capping beam corresponds to the concrete of a support bolster portion, the support bolster top elevation is reversely pushed according to the support seat height, sundries in a foundation bolt hole are removed, the support seat is placed, meanwhile, a steel plate with the thickness of 2cm is needed to be supported under the support seat, the levelness of the support seat top surface and the later pouring of support seat mortar are regulated, the support seat elevation, the axis deviation and the four corner height difference are repeatedly measured until the standard is reached, and finally the support seat mortar is poured; the construction is carried out by adopting a full framing, backfilling is carried out on a bearing platform foundation pit before the supporting frame is erected, a small impact rammer is used for ramming, the construction can be carried out when the bearing capacity reaches more than 150Kpa, after the bearing platform foundation pit is dug downwards for 60cm outside the backfilling range, 5% of lime soil is doped for layered rolling, the layered thickness is controlled to be 20cm, the bearing capacity of the foundation after backfilling is controlled to be more than 150Kpa, and then a 10cm concrete hardening layer is poured on the foundation; after the foundation treatment is finished, a tray buckle bracket is erected, the longitudinal spacing of the bracket in the arch foot range is 60cm, the transverse spacing is 30cm, the spacing of other positions is 60cm multiplied by 60cm, the layer spacing is 120cm, 10 multiplied by 10cm square timber is transversely arranged on the top support of the bracket, 10 multiplied by 10cm longitudinal square timber and 1.5cm bamboo plywood are sequentially arranged upwards, a D70mm metal corrugated pipe is used as an end beam prestress pipeline, and an anchor is an OVM15-7 anchor; the tie bar prestressed pipeline is a D90mm metal corrugated pipe, the anchor is an OVM15-11 anchor, and after the plate manufacturing and the block processing are finished, the 16# common bolts are used for connection, and the bolt spacing is 20cm.

The side mould panel is made of a steel plate with the thickness of 5 mm; the horizontal stiffening is arranged by adopting 10# channel steel, and the interval is 30cm; the vertical stiffening is arranged by adopting double-spliced 16# channel steel, and the interval is 70cm; the stretch-die steel bar is arranged by adopting phi 25mm round steel, two ends of the vertical stiffening steel bar are respectively oppositely pulled, pre-assembling, rust removing and release agent coating are carried out on the ground before the arch springing template is installed, and template installation is carried out after the steel bar engineering inspection and acceptance are qualified. The template installation is carried out by adopting an automobile crane to cooperate with manual work, the template installation is carried out according to the manufacturing section in a blocking way, double-sided foam adhesive tapes are stuck between the template joints for filling, and slurry leakage between the joints is ensured; in order to ensure that concrete at the bottom of the arch springing can vibrate normally in the pouring process, the template at the top surface of the arch springing is manufactured in blocks and installed in blocks. Installing the top face templates block by block in the concrete pouring process, installing the upper layer of templates when the lowest position of the concrete pouring templates is 10cm, and then pouring concrete and installing the templates until the pouring of arch springing concrete is completed. The template is subjected to concrete pouring, and aiming at the characteristics of dense arch springing steel bars and difficult concrete vibration, the number and the types of vibrating bars are increased on one hand during concrete pouring, so that the vibrating bars can be ensured to cover each vibrating point to the greatest extent under complex conditions of large quantity, dense steel bars and the like; on the one hand, to the vibration position that the vibrting spear hardly reaches, adopt the vibrting spear pipe, stretch into appointed position by the pipe earlier, stretch into the vibration district with the vibrating plate along the pipe inner wall again, realize "zero leakage shake".

In one embodiment, the two ends of the arch rib shell close to the arch springing are provided with pressure injection openings;

step S700 includes:

s710: removing said arch support from under said arch;

s720: communicating the two pressure injection ports with a pumping pipe;

s730: and simultaneously carrying out concrete pouring on the two pressure pouring openings until the concrete fills the arch rib shell to form the arch rib. Concrete is injected through the two ends simultaneously, so that the concrete heights at the two ends of the arch rib are approximately consistent, the arch rib is uniformly stressed, no inclination is generated, and the stability of the arch rib is improved.

In a specific embodiment, two automobile pumps for arch rib concrete injection are symmetrically and uniformly injected from two arch feet at one time, and the concrete adopts retarder type cement, high-efficiency water reducing agent and expanding agent, and C40 self-compacting micro-expansion concrete is injected in upper and lower arch pipes of the arch rib and in the web plate. The construction adopts a pumping roof pressure-increasing injection method, and the injection is completed by symmetrically injecting pressure once from the arch springing to the arch crown. In order to reduce the shrinkage of the concrete, an external expanding agent is adopted, and the concrete strength is as follows: fc7 is greater than or equal to 49.2Mpa, and fc28 is greater than or equal to 52.1Mpa;

concrete setting time: initial setting time: the final setting time is not more than 12 hours and not more than 16 hours;

slump at the time of concrete injection: 18 cm-22 cm, slump loss: the length of the water is less than or equal to 6cm in 4 hours;

concrete limiting expansion rate: 28d,0.00% -0.02%;

the concrete has good workability and pumpability, and no bleeding phenomenon.

The concrete mixing ratio is optimally designed by adopting an orthogonal test method, and control parameters are designed:

1. and (3) cement: the cement grade P.042.5 produced by Jiangsu Jinfeng Cement group Co., ltd, the apparent specific gravity of which is 3.1g/cm3, and other projects were detected to be qualified.

2. Mixing water: well water is used.

3. Yellow sand: jiangxi Ganjiang, ganzhong, specification Chinese sand, fineness modulus 2.8, apparent specific gravity 2.604g/cm3.

4. Broken stone: 5-25mm continuous graded broken stone on Jiangsu Pei, the apparent specific gravity is 2.702g/cm3.

5. Additive: PCA-I type high-performance water reducer produced by Jiangsu Su Bote New Material Co., ltd, the mixing amount is 1.3% of the mass of the cementing material, and the water reducing rate is 25%.

6. And (3) an expanding agent: BRJ-F4 multifunctional composite expanding agent of Jiangsu Bai Ji New Material Co.

The concrete mix ratios are shown in the following table:

material name	Cement and its preparation method	Fine aggregate	Coarse aggregate	Water and its preparation method	Additive agent	Expanding agent
							The dosage per cubic meter (kg)	427	751	1037	169	5.55	36
Unit ratio	1	1.76	2.43	0.4	0.013	0.084

And the top of each steel pipe arch is provided with an air outlet hole. The air outlet hole is obliquely welded with a conveying pipe with the diameter of 125 mm and the length of 2m at an angle of 45 degrees to be used as a back pressure pipe of the concrete, so that the compactness of the concrete is ensured. The purpose of oblique welding is to prevent the concrete from polluting the surface of the arch rib after emerging. A plurality of air holes with the diameter of 2cm are formed in dead angles on two sides of the steel pipe according to design requirements, and air is discharged to prevent cavities;

and a grouting hole is respectively formed at a position 50cm away from the arch springing concrete line. A grouting port is welded with a conveying pipe which has the same inner diameter as a concrete conveying pipeline (the diameter is 125 mm), forms an included angle of 30 degrees with a tangent line at the intersection point of the upper edge line of the arch rib and the flank (a reinforcing steel hoop is required to be avoided), and has the length of 100cm, the injection pressing pipe is connected with the horizontal conveying pipe by adopting a pipe joint, the connecting part is required to be fastened, and a plugboard valve is connected;

all openings are carried out before hoisting, opening cover plates are reserved in number, after the concrete strength reaches 50% of the design strength, the upper steel pipe, the lower steel pipe and the conveying pump steel pipe on the lacing plate are cut off, and repair welding is carried out on the opening cover plates according to the design requirement; the air outlet holes of the arch ribs are obliquely arranged at the top at an angle of 45 degrees.

When the concrete is injected, a certain amount of cement paste (the thickness is about 30 em) is pumped, the pipe wall is lubricated, the friction force between the concrete and the pipe wall in the pumping process is reduced, and the free falling concrete coarse aggregate can be prevented from bouncing. The chord tube and the abdominal cavity of the single arch rib should be symmetrically injected with concrete by adopting two automobile pumps from two arch foot ends, the concrete injection speed should be basically the same, the height difference of the concrete jacking surface cannot exceed 3m, and when the concrete jacking surface approaches to the arch crown, the height difference of the concrete jacking surface cannot exceed 1m, so as to ensure the longitudinal stability of the arch rib. The concrete injection in the pipe should be continuously carried out, and the process is finished at one time. When the concrete is required to be intermittent, the intermittent time cannot exceed the initial setting time of the concrete. If the jacking is difficult in the concrete injection process, an attached vibrator can be properly arranged on the pipe wall of the steel pipe to assist the concrete to flow, if the jacking speed is accelerated by adopting a method of increasing the pumping pressure, care is taken, and the pumping pressure cannot exceed the pressure born by the pipe wall so as to prevent the pipe from explosion.

The concrete pouring rate should not be too fast. When the concrete jacking surface is close to the top end of the steel pipe, two automobile pumps are used for simultaneous pouring, two pumps are used for alternate pressure pouring, the pumping speed is slowed down, and each pump needs to be stopped; simultaneously, manually matching bamboo poles and the like to draw and insert in the slurry discharging holes so as to discharge redundant gas and slurry until qualified concrete overflows the slurry discharging holes; and then the conveying pump is stabilized for 2min, and a concrete backflow stop valve at the grouting hole is closed to prevent the concrete from flowing back.

The steel plates cut by the grouting holes and the slurry discharging holes are required to be welded back after the concrete strength reaches 50% of the design strength; in order to ensure that the deformation of the arch ribs after loading can be relatively symmetrical, two arch ribs in the same pouring stage ensure that pouring is completed in one day as much as possible. That is, if the left rib is poured, the right rib is poured immediately after the pouring.

Before filling, a scale mark is marked every 2 meters along the arc length of the arch rib by chalk. In the pouring process, 2 persons are respectively arranged at two sides of each arch to monitor the position of the concrete surface by adopting a method of recording pouring square quantity and knocking and listening, and the height difference of the concrete surfaces at two sides is controlled within 1 meter (arc length distance).

After the pumping of concrete is completed and the concrete reaches a certain strength, manual hammering or ultrasonic wave is adopted for detection. If the place is found to be not compact, cement paste with the same label can be pressed into the opening on the steel pipe and the lacing plate to compact the inside of the steel pipe and the lacing plate.

The ambient temperature requirement when pouring the arch pipe concrete is more than 5 ℃, and the pouring time from the arch springing to the arch crown of each arch rib is required to be less than the initial setting time of the first coil pipe concrete.

The driver operates the concrete conveying pump to press and pour concrete into the arch rib according to the principle of uniform speed, symmetry and low pressure. The speed of the pressure injection of the abdominal cavity concrete is controlled within 25m 3/h. The speed of pressing and pouring the upper pipe concrete and the lower pipe concrete is controlled within v less than or equal to 30m 3/h. And stopping pressing and injecting after the concrete is discharged from the pressurizing pipe cap arranged at the top of the arch rib.

When the concrete is pressed and injected, a measurer observes the arch foot displacement and the arch rib vertical displacement, and once the displacement reaches a critical value, a commander is informed to stop the concrete pressing and injecting work, and the concrete can be pressed and injected continuously after adopting corresponding technical measures.

If the first-stage pumping pressure injection is blocked, a second pressure injection pipe is immediately installed, and the pressure injection is continued until the vault pressurizing pipe emerges out of the concrete.

And controlling the horizontal displacement of the pier top. Arranging a measurer to observe the horizontal displacement of the pier top by using a total station, stopping grouting concrete when the measured horizontal displacement of the pier top exceeds 6mm, and continuing grouting concrete after partial prestress is applied to the tie rod. The magnitude of the prestress applied by the tie bars is determined by observing the horizontal displacement of the pier top restoration.

In one embodiment, step S800 includes:

s810: binding tie bar steel bars, and installing an inner template in the tie bar steel bars;

s820: a plurality of vibrating holes for inserting vibrating rods are formed in the inner template at intervals;

s830: installing an outer template outside the tie bar steel bars;

s840: and pouring concrete in the outer die plate and vibrating the inner die plate through the vibrating rod to form the tie bars.

Through the vibration of the inner template, the uniformity of the concrete in the outer template is guaranteed to be improved, and the strength and the stability of the concrete are improved.

In a specific embodiment, the inner mold is made of foam, the inner mold is 500cm long, 80cm wide and 200cm high, 10 x 10cm chamfers are arranged on 8 sides of the inner mold, the inner mold is made of solid foam by processing, through-length vibrating holes are formed in the upper and lower sides of the foam for guaranteeing the vibrating quality, the aperture is 100mm, 1 vibrating hole is formed in each 100cm, a bamboo plywood with the thickness of 1.5cm is used for the tie rod side mold, and the tie rod side mold is fixed by using a die stretching rib. The template seam is processed by adopting double faced adhesive tape, so that the template seam is neat and consistent, no slurry leakage is ensured, the outer mold is fixed by a drawing rib, the laminated bamboo plywood is provided with vertical square timber with the length of 10cm multiplied by 10cm, the center distance of the square timber is 25cm, the outer side of the square timber is selected to use a longitudinal steel pipe with the length of phi 48 multiplied by 3.5mm as a back support, the interlayer distance is 50cm, and the joint is locked by adopting a cross fastener.

Concrete is supplied by a mixing station, a concrete transport vehicle is transported to the site, and an automobile pump is pumped into the mould.

(1) And (5) pouring concrete once for casting and forming.

(2) In casting, the concrete is required to be cast in layers from one end of the beam Duan Gaocheng, which is lower, to the other end.

(3) In the pouring process, uninterrupted settlement tracking observation is carried out on the foundation and the support, a special person is dispatched to the measuring shift to watch for one time every 30 minutes according to the pouring speed, and a master engineer is informed of settlement abnormality in time so as to take corresponding treatment measures.

(4) The following embedded parts are placed in the construction process:

a. stretching end anchor backing plates by tie bars;

b. pulp discharging holes are distributed at 3-4 positions of the tie bar prestress beam pipeline at equal intervals along the axis;

c. the suspension rod is used for fixing the end anchor backing plate and the lower guide pipe, the suspension rod is welded on the tie bar reinforcing steel bars and anchored on the template, and the plane position and the verticality of the concrete are accurately measured before and after the concrete is poured.

d. When the binding of the steel bars is disturbed, the principle that the common steel bars let prestressed steel bars and the small steel bars let large steel bars is followed.

e. Before concrete pouring, a plastic hose is placed in the corrugated pipe in advance, and after concrete pouring is completed, the hose is drawn out at random, so that the corrugated pipe is prevented from being blocked.

In one embodiment, after step S840, the method further includes:

s850: the tie bar is prestressed and tensioned. Stretching the tie bar to improve the strength of the tie bar.

In one embodiment, step S900 includes:

s910: a plurality of lane plates are arranged at intervals along the extending direction of the tie bars;

s920: connecting any two adjacent roadway plates through binding steel bars;

s930: and pouring concrete on the surface of the traffic lane plate to form the bridge deck.

The bridge deck is paved through the prefabricated traffic lane plates, so that the construction efficiency is improved, the bridge deck construction is completed rapidly, and the construction time is reduced. The traffic lane plates are longitudinally folded in strips along the tie bars, symmetrically erected, cast in situ for 10cm bridge deck pavement and the guardrail is completed

In one embodiment, after step S200, the method further includes:

s201: performing sand blasting on the outer wall of the arch rib shell;

s202: and coating the outer wall of the arch rib shell.

After the arch rib shell is subjected to sand blasting coating treatment, the rust of the arch rib shell is prevented from affecting the performance, and the service life of the arch rib shell is prolonged.

The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the scope of the invention, but rather is intended to cover any equivalents of the structures or equivalent processes disclosed herein or in the alternative, which may be employed directly or indirectly in other related arts.

Claims (10)

1. The construction method of the assembled bridge is used for constructing the assembled tied arch bridge and is characterized by comprising the following steps of:

installing arch springing brackets, stiff skeleton brackets and arch rib brackets, installing cross beams at the top ends of the arch springing brackets and the stiff skeleton brackets, and installing the stiff skeleton on the cross beams;

synchronously installing arch rib shells from two ends of the arch bridge to the middle and enabling the arch rib shells to be installed at the top ends of the arch rib brackets, wherein the number of the arch rib shells is multiple, and the two corresponding arch rib shells are symmetrically arranged along the vertical central line of the arch rib;

installing slings on the rib shells;

dismantling the arch rib bracket, and installing a tie bar bottom die on the stiff framework to form an initial bridge;

installing a tied-arch bridge bracket at a preset installation position of the tied-arch bridge, and hoisting and installing the initial bridge frame to the tied-arch bridge bracket;

pouring an arch springing on the stiff framework;

removing the arch leg support, and pouring concrete in the arch rib shell to form an arch rib;

binding tie bar steel bars in the tie bar bottom die, and pouring to form tie bars in the tie bar bottom die;

performing bridge deck construction on the tie bars to form a bridge deck;

and installing guardrails on the bridge deck, paving asphalt, and forming the tied arch bridge.

2. The method of constructing an assembled bridge as defined in claim 1, wherein a spacing assembly is mounted on the top end of the arch rib bracket, the spacing assembly enclosing a spacing cavity;

the step of synchronously installing arch rib shells from two ends of the arch bridge to the middle and enabling the arch rib shells to be installed at the top ends of the arch rib brackets comprises the following steps of:

sequentially lifting a plurality of arch rib shells to the top ends of the corresponding arch rib brackets from the bottoms of the two ends of the arch bridge upwards;

hanging the arch rib shell into the limiting cavity;

and installing cable ropes on two sides of each arch rib shell, and fixing the other ends of the cable ropes on the bridge deck and tensioning.

3. The method for constructing an assembled bridge according to claim 2, wherein the arch rib shell comprises a bottom shell, a middle shell, a top shell and a folding shell, the number of the bottom shell, the middle shell and the top shell is two, the bottom shell, the middle shell and the top shell are sequentially stacked from bottom to top, and two ends of the folding shell are respectively connected with the two top shells;

the cable rope arranged on the arch bottom shell is perpendicular to the horizontal plane, and the cable rope arranged on the middle shell and the arch bottom shell is inclined at 45 degrees with the horizontal plane.

4. A method of constructing a fabricated bridge as claimed in claim 1 wherein said step of installing slings on said rib shells comprises:

installing a top sling conduit at the top end of the arch rib shell and a bottom sling conduit on the stiff framework;

the top end of the sling is penetrated and arranged in the top sling guide pipe and fixed, and the bottom end of the sling is penetrated and arranged in the bottom sling guide pipe and fixed;

and tensioning the sling.

5. The method of constructing a fabricated bridge as defined in claim 1, wherein said step of casting a footing onto said rigid skeleton comprises:

setting up arch foot supports on the stiff framework;

a supporting frame is erected below the arch support, and a prestressed pipeline and an anchor are arranged in the supporting frame;

installing a template on the support frame;

and pouring concrete into the templates to form the arch springing.

6. The method of constructing an assembled bridge as claimed in any one of claims 1 to 5, wherein said rib shells are provided with pressure injection openings at both ends thereof adjacent to said legs;

the step of removing the arch leg support and casting concrete in the arch rib shell to form an arch rib comprises the following steps:

removing said arch support from under said arch;

communicating the two pressure injection ports with a pumping pipe;

and simultaneously carrying out concrete pouring on the two pressure pouring openings until the concrete fills the arch rib shell to form the arch rib.

7. The method of constructing an assembled bridge as claimed in any one of claims 1 to 5, wherein the steps of binding tie bar reinforcement bars in the tie bar form and casting tie bars in the tie bar form include:

binding tie bar steel bars, and installing an inner template in the tie bar steel bars;

a plurality of vibrating holes for inserting vibrating rods are formed in the inner template at intervals;

installing an outer template outside the tie bar steel bars;

and pouring concrete in the outer die plate and vibrating the inner die plate through the vibrating rod to form the tie bars.

8. The method of constructing a fabricated bridge as defined in claim 7, wherein said step of pouring concrete in said outer form and vibrating said inner form to form said tie bars further comprises:

the tie bar is prestressed and tensioned.

9. A method of constructing a fabricated bridge as claimed in any one of claims 1 to 5, wherein said step of constructing a deck on said tie bars to form a deck comprises:

a plurality of lane plates are arranged at intervals along the extending direction of the tie bars;

connecting any two adjacent roadway plates through binding steel bars;

and pouring concrete on the surface of the traffic lane plate to form the bridge deck.

10. A method of constructing a fabricated bridge as claimed in any one of claims 1 to 5, wherein after said step of synchronously installing rib shells from both ends of said arch bridge to the middle and installing rib shells on top of said rib brackets, further comprising:

performing sand blasting on the outer wall of the arch rib shell;

and coating the outer wall of the arch rib shell.

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