CN112554206A

CN112554206A - PC plate beam shared by foundation pit support structure and basement outer wall and installation method thereof

Info

Publication number: CN112554206A
Application number: CN202011583630.8A
Authority: CN
Inventors: 张越
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-12-28
Filing date: 2020-12-28
Publication date: 2021-03-26

Abstract

The invention discloses a PC plate beam shared by a foundation pit support structure and a basement outer wall and an installation method thereof, wherein the PC plate beam is a prestressed hollow concrete plate beam; interlocking devices which are mutually connected are arranged between the adjacent PC plate beams; the cross section of the PC plate beam is divided into a single-hole rectangle and a double-hole rectangle; the interlocking device comprises split rings, shafts and the like which are distributed on two adjacent sides of the PC plate beam; the length dimension of the PC plate beam is designed into a modular standard component; the PC plate beam is lengthened along the length direction by adopting a strong mechanical connection joint; the construction method is that the PC plate beam is inserted into the fluid state solidified soil body premixed in the stratum or directly inserted into the soft soil stratum by a mechanical vibration method to form a continuous underground wall body; the PC plate beam, the supported waist beam and the underground structure are connected by adopting a method of screwing the embedded nuts into the anchoring steel bars. The foundation pit support structure assembled in the way has the social values of environmental protection, energy conservation and emission reduction, can reduce the manufacturing cost and shorten the construction period, and has great economic value.

Description

PC plate beam shared by foundation pit support structure and basement outer wall and installation method thereof

Technical Field

The invention relates to the technical field of civil engineering, in particular to a two-in-one structure of an assembled deep foundation pit enclosure wall and a basement outer wall.

Background

The underground continuous wall enclosure structure in foundation pit engineering is characterized by that in the currently-used cast-in-situ reinforced concrete structure, a grooving machine is used to cut rectangular groove, and the slurry is used to protect wall, then the reinforcing cage is inserted into the groove to reproduce cast concrete, and between every two walls the profile steel joints are used to make every two underground walls mutually connected so as to form continuous structure, so that it has the double action of stopping water and retaining soil. The conventional construction method of the underground continuous wall has the problems that a large amount of slurry is produced in the grooving process and wall protection slurry is discharged in the construction process, serious adverse effects are generated on the surrounding environment, the quality of an underwater cast-in-place concrete structure is difficult to guarantee all the time, and the wall body has the problems of mud inclusion, cracks, looseness, cavities and the like. In addition, the shape of the formed underground continuous wall is determined according to the stability of the wall of the groove, and when the groove is formed in a weak and unstable stratum, the exposed wall body after excavation has the defect of uneven shape, so that the formed underground continuous wall cannot be used as an outer wall of an underground structure.

The method for assembling the underground continuous wall structure by adopting the PC plate beams is always explored in the engineering industry, the PC plate beams used for compensation are mainly single-section concrete plate piles, the adjacent plate beams are not connected with each other, so that the size of gaps between the adjacent plate piles cannot be controlled, the gaps can only be filled with grouting bodies, and the potential safety hazards of water leakage and large deformation exist. The single-section sheet pile is long and heavy, so that a lot of difficulties are brought to transportation and hoisting.

Because the flatness and the mutual gaps of the existing underground continuous wall assembled by using sheet piles cannot be controlled, the hidden danger of water leakage and deformation exists, and the underground continuous wall cannot be used as the outer wall of a basement. In order to ensure the safety of the underground structure, the outer wall of the underground structure still needs to be reset, a fertilizer groove is reserved between the outer wall of the underground structure and the foundation pit enclosure wall, and a construction space is reserved for the construction of the outer wall of the underground structure, so that more land area is occupied.

With the large development area and deep excavation of underground space, the foundation pit enclosure structure assembled by the existing prefabricated sheet piles cannot meet the requirements of engineering.

Therefore, the engineering industry needs to find a prefabricated enclosure plate beam with a reasonable section, the dimension of the prefabricated enclosure plate beam is designed according to the standard, the defects of the traditional enclosure plate pile and the cast-in-place underground continuous wall can be overcome, the integration of the foundation pit enclosure structure and the basement outer wall is realized, the utilization rate of the land is improved, the engineering cost can be reduced, the construction speed is accelerated, the surrounding environment is protected, and the civilized construction is realized.

Disclosure of Invention

The invention aims to solve the technical problems that the existing prefabricated underground wall structure is unreasonable in stress, long in construction period, high in manufacturing cost, difficult to construct, transport and hoist and the like, and provides a novel PC plate beam enclosure structure and a construction method thereof.

In order to achieve the purpose, the technical scheme adopted by the patent is as follows:

the PC plate beam shared by the foundation pit enclosure structure and the basement outer wall is a prefabricated prestressed hollow concrete plate beam; the cross section of the PC plate beam is divided into a single-hole rectangle and a double-hole rectangle; the interlocking device comprises split rings, shafts and the like which are distributed on two adjacent sides of the PC plate beam; the length of the PC plate beam is designed into a modular standard component; the length dimension design modulus of the PC plate beam is 15m, 10m,5m,2m,1m and 0.5 m; the width design modulus is 4m,3.5m,3m,2.5m,2m, 1.5m, 1m, 0.5 m; the design modulus of thickness is 1m, 0.9m,0.85m,0.8m, 0.75m,0.7m,0.65m,0.6m,0.55m,0.5m, 0.45m,0.4 m.

The PC plate beam is a prestressed high-strength reinforced concrete member, the stressed main reinforcement is a high-strength reinforcement, and the strength grade of the concrete is greater than C40; the inner hole is a chamfer rectangle or a round; the upper end surface and the lower end surface of the PC plate beam are pre-embedded with a mechanical joint connecting part; and the PC plate beam is positioned on the inner side surface of the foundation pit and is pre-embedded with a connecting nut according to the elevation position of the horizontal support of the foundation pit and the connecting position with the underground structure.

The interlocking devices are distributed on the side edges of the adjacent PC plate beams and are arranged in pairs; the number is one pair or two pairs, so that adjacent PC board beams are meshed together to form a continuous structure. The interlocking device is arranged in the middle of two sides of the PC plate beam or in the front and back of two sides.

The fluid solidified soil body is formed by mixing foundation soil at the position of the foundation pit enclosure structure with a curing agent through rotary spraying, stirring or drilling replacement; the curing agent is a cement or soil hardening agent.

The horizontal connecting joints of the adjacent PC plate beams can be arranged at the same horizontal elevation; can also be arranged on different horizontal elevations, so that the horizontal connecting seams are staggered.

The PC plate beam is lengthened along the length direction by adopting an equal-strength mechanical connection joint of each stressed main rib, and the concrete contact surface is bonded by adopting a fluid resin adhesive;

the connection between the PC plate beam and the crown beam is realized by screwing in anchoring steel bars through nuts at the end parts of the components, binding the anchoring steel bars with steel bars in the crown beam and connecting the anchoring steel bars with cast-in-place concrete;

the side direction of the PC plate beam, the supported waist beam and the underground structure are connected by adopting a method of screwing the embedded nuts into the anchoring steel bars.

The horizontal connecting seam opening of the PC plate beam is covered by a steel plate, and the steel plate and the upper and lower sections of the PC plate beam are fixed together by anchor bolts so as to enhance the bending resistance and the shearing strength of the joint.

And grouting pipes are pre-embedded on the adjacent sides of the PC plate beams, and can be opened to carry out water sealing and grouting treatment after the construction of the underground structure is finished.

The method for installing the PC plate beam shared by the foundation pit support structure and the basement outer wall comprises the following specific steps:

firstly, constructing on a fender pile position by adopting a rotary spraying method, a stirring method, a double-wheel milling and stirring method, a TRD grooving stirring method or a drilling method to form a fluid state solidified soil body;

secondly, installing a guide frame for implanting the PC plate beam, and using the guide frame for construction guide and temporary fixation of the PC plate beam;

thirdly, implanting a PC plate beam before initial setting of the fluid solidified soil body, and lengthening the PC plate beam on site to reach the designed length; two adjacent PC plate beams are mutually meshed together by adopting an interlocking device to form a continuous wall type enclosure structure

And fourthly, constructing the cast-in-place concrete crown beam on the top of the PC plate beam, namely screwing anchoring reinforcing steel bars into embedded nuts at the end part of the PC plate beam, binding the anchoring reinforcing steel bars with reinforcing steel bars of the crown beam, installing a template, pouring concrete to form the crown beam, and connecting the PC plate beam into a whole.

And fifthly, connecting the side surface of the PC plate beam with the waist beam or the underground structure by screwing the anchoring reinforcing steel bars into the embedded nuts on the side surface of the PC plate beam, connecting and binding the anchoring reinforcing steel bars with the waist beam or the top and bottom plate reinforcing steel bars of the underground structure, and pouring concrete to form the waist beam or the underground structure after the upper template is installed, so that the PC plate beam becomes a part of the underground structure.

And sixthly, after the underground structure is completed, opening the grouting holes of the PC plate beams and injecting cement slurry, so that the gaps between the connecting walls are filled compactly, and the seepage-proofing grade is improved.

Has the advantages that: according to the invention, the standardized PC plate beams are directly implanted into the stratum, so that the assembly operation in the construction process is realized, the underground continuous wall structure is formed, the functions of soil retaining and water stopping are realized, the share of the foundation pit enclosure structure and the basement outer wall is realized, the utilization rate of town land and the occupation rate of underground space are increased, and the soil excavation amount of the foundation pit and the construction cost of the underground structure are reduced. The invention has strong field construction operability, high component assembly degree and efficiency, can ensure the integrity of the assembly structure and the construction quality of the underground structure, reduces the construction cost and has good construction implementation effect.

Drawings

The invention is further described with reference to the following figures and detailed description.

FIG. 1 is a plan view of a single hole PC board beam with a locking ring laterally;

FIG. 2 is a plan view of a single hole PC board beam with a lock shaft in the lateral direction;

FIG. 3 is a plan view of a single hole PC board beam with two locking rings laterally;

FIG. 4 is a plan view of a single hole PC plate beam with two lock shafts in the lateral direction;

FIG. 5 is a plan view of a dual hole PC board beam with locking rings laterally;

FIG. 6 is a plan view of a two-hole PC plate beam with a laterally located latch shaft;

FIG. 7 is a plan view of a dual hole PC board beam with two locking rings laterally;

FIG. 8 is a plan view of a two hole PC plate beam with two lock shafts in the lateral direction;

FIG. 9 is a schematic view of a PC board beam length joint connection.

FIG. 10 is a plan view of an underground diaphragm wall formed by laterally interlocking single-hole PC board beams;

FIG. 11 is a plan view of an underground diaphragm wall formed by two laterally interlocked single-hole PC plate beams;

FIG. 12 is a plan view of an underground diaphragm wall formed by laterally interlocking double-hole PC board beams;

FIG. 13 is a plan view of an underground diaphragm wall formed by two laterally interlocked double-hole PC plate beams;

FIG. 14 is a plan view of the assembled and connected underground diaphragm wall constructed by implanting PC board beams into rectangular grooves;

FIG. 15 is a plan view of the assembled and connected underground diaphragm wall constructed by the PC plate beams embedded in the mixing pile holes;

FIG. 16 is an inside elevation view of the assembled PC board beams as an underground diaphragm wall;

FIG. 17 is a schematic view of a PC slab beam shared by a lining wall and a foundation pit support structure on the outer side of a structural structure

FIG. 18 is a schematic view of a structural structure and a foundation pit support structure directly sharing a PC plate beam

FIG. 19 is a schematic diagram of the hoisting and assembly of a PC plate beam when the construction is implanted into the ground;

in the figure: 1-single-hole PC plate beam, 11-cavity, 12-stressed main rib, 13-stirrup, 14-grouting pipe, 15-upper PC plate beam, 16-lower PC plate beam, 17-high-strength adhesive, 2-porous PC plate beam, 3-lateral connection interlocking device, 31-annular lock hole, 32-annular lock bolt, 4-vertical mechanical connection joint of PC plate beam, 41-bolt of mechanical connection joint, 42-hole seat of mechanical connection joint, 5-embedded nut of support connection, 51-crown beam, 6-underground structure connection embedded connector, 61-underground structure, 62-underground structure waterproof layer, 63-underground structure lining wall, 71-lower plate beam clamping device, 72-upper plate beam clamping device, 73-telescopic jack, 74-suspension arm, 75-hanger, 76-hammer, 8-rectangular vibration groove, 82-solidified soil, 81-stratum, 83-stirring wall.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further explained below by combining the specific drawings.

The PC board beam is a modular component in cross-section as shown in fig. 1, 2, 3, 4, 5, 6, 7 and 8. A single-hole PC plate beam 1 or a double-hole PC plate beam 2 with an interlocking device 3 in the lateral direction is composed of a cavity 11, a stressed main rib 12, a stirrup 13, a grouting pipe 14, an annular lock hole 31 and an annular lock bolt 32.

A single annular lock hole 31 and an annular lock bolt 32 are distributed on the side surface of the PC board beam, as shown in fig. 1, 2, 3 and 4. Two annular lock holes 31 and annular lock bolts 32 are distributed on the side surface of the PC plate beam; as shown in fig. 5, 6, 7, 8. Fig. 9 is a schematic diagram showing the connection of the length joints of PC plate beams, and it can be seen from the diagram that the length of the standardized PC plate beam is designed according to a certain module, and the upper plate beam 15 and the lower plate beam 16 are connected and lengthened through the mechanical joint 4 according to the design requirement in practical use, this mechanical joint 4 is locked by inserting the bolt 41 of the mechanical joint into the hole seat 42 of the mechanical joint, and the concrete surfaces in contact with the mechanical joint are bonded together by the high strength adhesive 17.

Fig. 10 is a plan view of an underground diaphragm wall assembled by laterally interlocking single-hole PC plate beams 1, and it can be seen that a single-hole PC plate beam 1 is assembled and connected into an underground diaphragm wall by a lateral group of connecting and interlocking devices 3.

Fig. 11 is a plan view of an underground diaphragm wall assembled by two single-hole PC plate beams 1 laterally interlocked, and it can be seen that one single-hole PC plate beam 1 is assembled and connected into the underground diaphragm wall by two lateral sets of connecting and interlocking devices 3.

Fig. 12 is a plan view of an underground diaphragm wall assembled by laterally interlocking two-hole PC plate girders 2, and it can be seen that one two-hole PC plate girder 2 is assembled and connected into an underground diaphragm wall by a lateral set of connecting and interlocking means 3.

Fig. 13 is a plan view of an underground diaphragm wall assembled by two laterally interlocked double-hole PC plate beams 2, and it can be seen that one double-hole PC plate beam 2 is assembled and connected into the underground diaphragm wall by two laterally coupled interlocking devices 3.

Example I method for implanting assembly type underground continuous wall in multi-shaft stirring shaft

In order to implant the assembled PC board beam 1 into the ground 81 to form the underground continuous wall, a multi-shaft mixing pile machine is firstly used to construct the continuous mixing pile wall 83 at the position of the foundation pit enclosure structure, then the PC board beam 1 is implanted into the mixing pile wall 83, the front and back surfaces of the PC board beam 1 and the middle cavity 11 are filled with solidified soil 82, so that the PC board beam 1 and the ground 81 are tightly combined together, and the assembled underground continuous wall is shown in fig. 14.

The concrete hoisting and implanting method is shown in fig. 19, a hoisting tool 75 is pulled by a hoisting arm 74 of a hoisting device and provided with a vibration hammer 76, and the upper section beam 15 and the lower section beam 16 are assembled in a butt joint mode through hoisting. The device for clamping the plate girder is used in the butt joint, and the device consists of a lower section plate girder clamping device 71, an upper section plate girder clamping device 72 and a telescopic jack 73. The plate girder 1 is fixed and positioned.

Example two method for implanting fabricated underground continuous wall in rectangular cutting stirring tank

The stratum 81 is cut by adopting a TRD or CSM method and is mixed and stirred with a soil curing agent or cement to form a rectangular groove type stirring wall 83.

Before the solidified soil 82 in the mixing wall 83 is initially set, the

plate girder

1 or 2 is inserted, and the separated

plate girders

1 or 2 are tightly assembled together by the lateral interlocking means 3 to form the underground continuous wall as shown in fig. 16. The method for lifting, assembling and implanting each

plate girder

1 or 2 is shown in fig. 19.

Example III method for sharing prefabricated PC plate girder by assembled underground continuous wall and underground structure

In order to fully utilize the value of the fabricated underground diaphragm wall, the

PC slab beam

1 or 2 used as a foundation pit enclosure is used as a partially permanent underground structure 61.

In order to connect the PC board beam 1 with a foundation pit supporting structure (such as a horizontally supported purlin or an anchor-supported wale) and an underground structure 61, a connection nut 5 and a connection member 6 need to be embedded at different positions of the inner side of the

PC board beam

1 or 2, as shown in fig. 16.

Fig. 18 is a sectional view showing a PC plate girder shared by a fabricated underground diaphragm wall and an underground structure. As can be seen from the figure, the connection nut 5 pre-embedded on the plate girder 1 realizes the connection between the crown girder 51 and the waist girder of the foundation pit enclosure structure, and establishes the connection between the vertical enclosure structure and the inner support system.

When the underground structure 61 is built after the foundation pit is excavated to the bottom, the connecting piece 6 positioned at the bottom plate of the underground structure on the inner side of the plate girder 1 can be connected with the underground structure 61 through the connecting reinforcing steel bars.

For better waterproofing, an underground structure waterproof layer 62 can be arranged on the inner side of the PC board beam, and a thin underground structure lining wall 63 is poured at the same time. The assembled underground continuous wall and the underground structure share the PC plate beam, namely the traditional two-in-one wall is realized, as shown in figure 17.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are given by way of illustration of the principles of the present invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A PC plate beam shared by a foundation pit enclosure structure and a basement outer wall and an installation method thereof are characterized in that the PC plate beam is a prefabricated prestressed hollow concrete plate beam; the section shape of the device is divided into a single-hole rectangle and a double-hole rectangle; interlocking devices which are mutually connected are arranged between two adjacent sides of the PC plate beam; the interlocking device consists of a split ring and a shaft; the length dimension of the PC plate beam is designed into a modular standard component; lengthening the PC plate beam along the length direction by adopting an equal-strength mechanical connection joint of each stressed main rib, and bonding the concrete contact surface by adopting a fluid resin adhesive; the construction method is that the PC plate beam is inserted into the fluid state solidified soil body premixed in the stratum or directly inserted into the soft soil stratum by a mechanical vibration method to form a continuous underground wall body; the connection of the PC plate beam and the crown beam is realized by screwing in anchoring reinforcing steel bars through nuts at the end part of the PC plate beam and binding with reinforcing steel bars in the crown beam and connecting the anchoring reinforcing steel bars and the reinforcing steel bars in the crown beam through cast-in-place concrete; the connection between the lateral side of the PC plate beam and the supported waist beam and the underground structure adopts a method of screwing the embedded nuts into the anchoring steel bars.

2. The PC board beam shared by the foundation pit enclosure structure and the basement exterior wall and the installation method thereof as claimed in claim 1, wherein the stressed main reinforcement in the PC board beam is high-strength steel bar, and the strength grade of concrete is greater than C40; the inner hole is a chamfer rectangle or a round; the upper end surface and the lower end surface of the PC plate beam are pre-embedded with a mechanical joint connecting part; and the PC plate beam is positioned on the inner side surface of the foundation pit and is pre-embedded with a connecting nut according to the elevation position of the horizontal support of the foundation pit and the connecting position with the underground structure.

3. The PC board beam shared by the foundation pit enclosure structure and the basement exterior wall and the installation method thereof as claimed in claim 1, wherein the interlocking devices are distributed on the side edges of the adjacent PC board beams and are arranged in pairs; the number is one pair or two pairs, so that adjacent PC board beams are meshed together to form a continuous structure.

4. The PC plate beam shared by the foundation pit enclosure structure and the basement exterior wall and the installation method thereof as claimed in claim 1, wherein the fluid solidified soil is a solidified soil formed by mixing the foundation soil at the position of the foundation pit enclosure structure with a curing agent through rotary spraying, stirring or drilling replacement; the curing agent is a cement or soil hardening agent.

5. The PC board beam shared by the foundation pit enclosure structure and the basement exterior wall and the installation method thereof as claimed in claim 1, wherein the length design modulus of the PC board beam is 15m, 10m,5m,2m,1m, 0.5 m; the width design modulus is 4m,3.5m,3m,2.5m,2m, 1.5m, 1m, 0.5; the design modulus of thickness is 1m, 0.9m,0.85m,0.8m, 0.75m,0.7m,0.65m,0.6m,0.55m,0.5m, 0.45m,0.4 m.

6. The PC board beam shared by the foundation pit enclosure structure and the basement exterior wall and the installation method thereof as claimed in claim 1, wherein the horizontal connecting joints of the adjacent PC board beams can be arranged at the same horizontal elevation; or can be arranged on different horizontal elevations, so that the horizontal connecting seams are staggered.

7. The PC board beam shared by the foundation pit enclosure structure and the basement exterior wall and the installation method thereof as claimed in claim 1, wherein the horizontal connecting seam opening of the PC board beam is covered by a steel plate, and the steel plate and the upper and lower sections of the PC board beam are fixed together by an anchor bolt to enhance the bending strength and the shearing strength of the joint.

8. The PC board beam shared by the foundation pit enclosure structure and the basement exterior wall and the installation method thereof as claimed in claim 1, wherein the interlocking device is arranged in the middle of two sides of the PC board beam or in the front and back of the two sides.

9. The PC plate beam shared by the foundation pit enclosure structure and the basement exterior wall and the installation method thereof as claimed in claim 1, wherein grouting pipes are pre-buried in the end faces of the adjacent side edges of the PC plate beam, and the grouting pipes can be opened for grouting anti-seepage treatment after the construction of the underground structure is completed.

10. The method for installing the PC plate beam shared by the foundation pit support structure and the basement outer wall is characterized by comprising the following steps of:

And fifthly, connecting the side surface of the PC plate beam with a waist beam or an underground structure of the foundation pit supporting structure by screwing the anchoring reinforcing steel bars into the embedded nuts on the side surface of the PC plate beam, connecting and binding the anchoring reinforcing steel bars with the waist beam or the reinforcing steel bars of the top plate and the bottom plate of the underground structure, and pouring concrete to form the waist beam or the underground structure after the upper template is installed, so that the PC plate beam becomes a part of the underground structure.