CN118793069A

CN118793069A - Easy-to-dismantle assembled reinforced concrete foundation pit support system and construction method

Info

Publication number: CN118793069A
Application number: CN202411214351.2A
Authority: CN
Inventors: 刘斌; 夏刚; 王良超; 张天明; 张喜红; 叶建军; 吴天龙; 许开军; 许国辉
Original assignee: China University of Geosciences Wuhan; Hubei University of Technology; First Construction Co Ltd of China Construction Eighth Engineering Division Co Ltd
Current assignee: China University of Geosciences Wuhan; Hubei University of Technology; First Construction Co Ltd of China Construction Eighth Engineering Division Co Ltd
Priority date: 2024-08-31
Filing date: 2024-08-31
Publication date: 2024-10-18

Abstract

The invention relates to the field of construction engineering, and discloses an easily dismantled assembled reinforced concrete foundation pit support system and a construction method. The system adopts foundation pit support beam sections and foundation pit support cross-shaped beams as assembled components, and the support structure in the foundation pit is arranged in the form of orthogonal bracing. The beam sections are spliced with each other through inserted bars, and a plurality of supporting steel lattice columns are arranged in the middle of the support system. A jack is arranged between the support beam and the crown beam or the waist beam, and the crown beam or the waist beam is provided with a rope threading hole for subsequent dismantling. The construction method of the easily dismantled assembled reinforced concrete foundation pit support system provided by the invention is a detailed process of assembling and constructing from the top layer to the lower layers step by step. The method has a faster construction speed than a cast-in-place support beam, a lower construction cost, and is easy to dismantle. The foundation pit support beam sections, jacks and other components can be recycled and reused, and is a successful practice of the green building concept in the field of foundation pit support.

Description

Assembled reinforced concrete foundation pit supporting system convenient to disassemble and construction method

Technical Field

The invention belongs to the technical field of building construction, and particularly relates to an assembled reinforced concrete foundation pit supporting system convenient to disassemble and a construction method.

Background

In foundation pit engineering projects, foundation pit supports play a vital role. The foundation pit supporting device has the main functions of effectively supporting surrounding soil bodies and constructing a stable and reliable supporting system, so that the overall stability of the foundation pit is ensured.

In the occasion of larger ground stress, the cast-in-situ reinforced concrete internal support is a better choice. The device has the advantages of flexible design, good integrity, large bearable pressure and high reliability. But also has the defects of long construction period, difficult disassembly, short service life, difficult recovery and higher manufacturing cost.

In order to overcome the defects of cast-in-place concrete supports, the foundation pit with larger ground pressure and square shape is supported by adopting the reinforced concrete of the assembled foundation pit, so that the assembled supporting beam can be conveniently detached and installed, can be recycled and reused, and shortens the construction period.

Disclosure of Invention

The invention aims at providing an innovative assembly type foundation pit supporting system and a corresponding construction method thereof aiming at the remarkable problems existing in the current foundation pit supporting system. By implementing the system and the method, the purposes of realizing the safety, reliability, high efficiency, rapidness, cost optimization and material recoverability of the foundation pit supporting process are achieved, so that the comprehensive benefit of the foundation pit supporting engineering is comprehensively improved.

The technical scheme for solving the technical problems is as follows:

The assembly type reinforced concrete foundation pit supporting system is convenient to disassemble and is characterized by comprising a peripheral standard area and an internal standard area; the internal standard area is an orthogonal pair support system consisting of a plurality of foundation pit support beam sections with the same length and section size; the surface of the foundation pit supporting beam section is provided with a beam sleeve, the beam sleeve is provided with side steel plates, the pipe walls at two ends of a preset transverse embedded pipe are respectively welded on the hole wall of the side steel plates at two sides to form transverse dowel holes, the beam sleeve is provided with an end steel plate, and the pipe wall at one end of the preset longitudinal embedded pipe is welded on the hole inner wall of the end steel plate to form longitudinal dowel holes;

When the two foundation pit support beam sections are axially connected, end face steel plates of the two foundation pit support beam sections are in seamless fit, longitudinal dowel holes of the two foundation pit support beam sections are aligned one by one, and connecting steel bars are arranged in the longitudinal dowel holes; when the four foundation pit support beam sections are connected in a cross manner or the three foundation pit support beam sections are connected in a T-shaped manner, after the two foundation pit support beam sections are axially connected, the four foundation pit support beam sections are vertically connected with the other foundation pit support beam section or the other foundation pit support beam sections at the axial connection position, the longitudinal dowel holes of the one foundation pit support beam section or the two foundation pit support beam sections are aligned with the transverse dowel holes at the axial connection position of the two foundation pit support beam sections one by one at the vertical connection position, and connecting rebars are arranged in the transverse dowel holes;

the support system is provided with a peripheral standard area in a contact area with the crown beam or the waist beam, wherein the peripheral standard area comprises N foundation pit support beam sections perpendicular to the crown beam and the waist beam and foundation pit support splayed beams arranged on two sides of the foundation pit support beam sections;

The length and the section size of the splayed beam of the foundation pit support are the same; one end is a right-angle end, the other end is an oblique-angle end, the surface of the splayed beam of the foundation pit support is provided with a splayed Liang Liangtao, and the oblique-angle end is provided with a splayed Liang Chajin hole;

The foundation pit supporting beam section and the foundation pit supporting splayed beam are connected in an axial mode, and then are butted with the bevel end of the foundation pit supporting splayed beam at the axial connection part, and the connection mode is as follows: the splayed Liang Chajin holes are aligned with the transverse dowel holes at the axial connection part of the two foundation pit support beam sections one by one, and connecting steel bars are arranged in the transverse dowel holes;

the peripheral standard area and the internal standard area are connected by a plurality of foundation pit supporting beam sections with the same size, which are arranged in the peripheral standard area or the internal standard area; so as to achieve the purpose that the peripheral standard area and the internal standard area are matched with the corresponding foundation pit size.

On the basis of the technical scheme, the invention can be improved as follows.

Preferably, when the peripheral standard area and the internal standard area are connected by using a plurality of foundation pit supporting beam sections with the same length and cross section size and cannot be matched with the foundation pit size, the non-standard area connection is set, wherein the non-standard area comprises a non-standard area foundation pit supporting beam section with the length being less than 2 times that of the foundation pit supporting beam section, or comprises a non-standard area foundation pit supporting beam section with the length being less than 2 times that of the foundation pit supporting beam section and a foundation pit supporting beam section so as to be matched with the corresponding foundation pit size, and other settings of the non-standard area foundation pit supporting beam section are the same as those of the standard area foundation pit supporting beam section.

Preferably, the crown beam and the waist beam are provided with a bearing platform and a bracket, and the foundation pit supporting beam section in the peripheral standard area is placed on the bearing platform fixed on the crown beam or the waist beam; the splayed beams of the foundation pit support in the peripheral standard area are placed on a bearing platform fixed on the bracket; the bearing platform is provided with a jack for jacking and supporting the foundation pit supporting beam section or the foundation pit supporting splayed beam; and a tray is arranged below the joint of the foundation pit supporting beam sections and welded on the steel lattice columns.

Preferably, the longitudinal dowel holes are in two rows, and the transverse dowel holes are in one row; the distance between two rows of longitudinal dowel holes is equal to twice the distance between the transverse dowel holes and an end face steel plate, the vertical distance between the adjacent longitudinal dowel holes or the transverse dowel holes is the same, the distance between the uppermost longitudinal dowel hole and the upper edge of a beam sleeve is equal to the distance between the lowermost transverse dowel hole and the lower edge of the beam sleeve, the distance between two rows of splayed Liang Chajin holes is equal to twice the distance between the transverse dowel holes and the end face steel plate of a foundation pit supporting beam section, the distance between the uppermost splayed Liang Chajin hole and the upper edge of the foundation pit supporting splayed beam is equal to the distance between the uppermost transverse dowel hole and the upper edge of the foundation pit supporting beam section, and the distance between the vertically adjacent splayed Liang Chajin holes is the same as the distance between the vertically adjacent transverse dowel holes.

Preferably, the diameters of the transverse dowel holes, the longitudinal dowel holes and the splayed Liang Chajin holes are the same.

Preferably, a first rope penetrating hole for rope saw cutting is formed in the crown beam, the first rope penetrating hole is formed by embedding an L-shaped PVC pipe in the crown beam, two ends of the L-shaped PVC pipe are provided with openings, one end of the L-shaped PVC pipe is provided with an opening on the side face of the crown beam, and the other end of the L-shaped PVC pipe is provided with an opening on the top face of the crown beam; the waist beam on be provided with the second rope hole that is used for rope saw cutting, the second rope hole is that a straight PVC pipe is pre-buried perpendicularly in the waist beam forms, straight PVC pipe both ends opening, one end opening is located the waist beam top surface, the other end opening is located the waist beam bottom surface.

Preferably, the bearing platform is formed by welding a first steel plate, a second steel plate, a third steel plate and a fourth steel plate, the planar shape of the first steel plate and the second steel plate (503) is rectangular, the planar shape of the third steel plate and the fourth steel plate is trapezoid, and a concave pillow for fixing the jack is welded on the second steel plate.

Preferably, the steel plate I for welding the cushion cap is pre-buried in the hat beam or the waist beam, the steel bar is welded on the steel plate I, the steel bar is perpendicular to the face of the steel plate I, the pre-buried direction of the steel bar is perpendicular to the side face of the hat beam or the waist beam, and the steel bar is fixed on a steel bar cage of the hat beam or the waist beam through steel wires, the bracket is in the shape of a straight triangular prism, the bracket is arranged on the hat beam or the waist beam, and the steel plate I is pre-buried at the position of the bracket.

Preferably, the branch parts of the steel lattice column are angle steels, the decoration materials are steel plates, a tray is welded on the steel plates, the tray consists of a panel and eight triangular steel plates, the decoration materials are not welded in the same distance with the height of the foundation pit supporting beam section above the tray which is not supported by the first path, and 4 angle steels are used for reinforcing the 4 branch parts in the range; the first support is directly placed on the top tray of the steel lattice column, and the non-first support is placed on the tray after passing through the steel lattice column.

The construction method of the assembled reinforced concrete foundation pit supporting system convenient to dismantle comprises the following steps:

10. the method of constructing a ready-to-remove fabricated reinforced concrete pit support system according to any one of claims 1-9, comprising the steps of:

1) After the hole is formed by rotary digging, constructing to form a support pile, a stand column pile and a steel lattice column;

2) After roughening treatment is carried out on the pile head of the support pile, carrying out steel bar binding work of the crown beam; the method comprises the steps of carrying out pre-burying operation of a first rope penetrating hole of a crown beam while binding reinforcing steel bars, fixing the first rope penetrating hole through steel wires, setting the first rope penetrating hole from a foundation pit angle point of 2.5 m-5 m, setting a first rope penetrating hole every 2.5 m-5 m, and sealing by adopting gypsum; then, welding steel bars on the first steel plate, and fixing the welded steel bars on a steel bar cage of the crown beam, and simultaneously ensuring that the first steel plate is attached to the side face of the crown beam;

3) Carrying out formwork supporting work of brackets on the crowns Liang Jiguan beams, pouring concrete after formwork supporting is completed, and carrying out subsequent construction after concrete curing is completed;

4) Excavating earth to the elevation of the bottom of the first inner supporting beam; in order to facilitate welding of trays on the steel lattice columns, the steel lattice columns are excavated at least 1m more deep; the method is characterized in that a bearing platform on the crown beam is conveniently welded, and the bearing platform is excavated at least 1m deep;

5) Welding a tray on the steel lattice column;

6) The method comprises the steps that a crane is used for conveying a foundation pit supporting beam section and a foundation pit supporting splayed beam to a design position, the bearing pressure of a transverse foundation pit supporting beam section and a longitudinal foundation pit supporting beam section is analyzed, the foundation pit supporting beam section and the foundation pit supporting splayed beam which are opposite to each other at the middle position in the direction of larger bearing pressure are assembled firstly, and the opposite supports are assembled from the middle to two ends; firstly, mounting a pair of foundation pit support beam sections of the support, which are positioned in an internal standard area, then mounting a pair of foundation pit support beam sections of the support, which are positioned in a non-standard area, then mounting a pair of foundation pit support beam sections of the support, which are positioned in a peripheral standard area, then mounting a pair of foundation pit support splay beams of the support, which are positioned in the peripheral standard area, after the construction of the pair of supports is completed, mounting the foundation pit support beam sections of which the two sides bear the opposite support in the direction of smaller pressure, then mounting the adjacent two opposite support sides bear the opposite support in the direction of larger pressure, and then mounting the foundation pit support beam sections of which the two opposite support sides bear the opposite support in the direction of smaller pressure, and repeating the operation until all the foundation pit support beam sections and the foundation pit support splay beams of the first inner support are mounted on a tray;

7) Welding a bearing platform by utilizing a first steel plate pre-buried on a corbel of a crown beam or the crown beam, placing a foundation pit supporting beam section and a splayed Liang Junyi end of the foundation pit supporting beam at the edge on the bearing platform, placing a jack on a concave pillow of the bearing platform, and extending the jack to form a first inner support;

8) Excavating earth to the elevation of the bottom of the supporting beam in the second channel; in order to facilitate welding of trays on the steel lattice columns, the positions of the steel lattice columns are excavated at least 1m deep; the method is characterized in that a bearing platform on the crown beam is conveniently welded, and the bearing platform is excavated at least 1m deep;

9) Welding a tray on the steel lattice column;

10 Roughening the support pile, binding steel bars of the waist beam, embedding second rope holes, fixing the second rope holes through steel wires, setting the second rope holes from the foundation pit angle point of 2.5 m-5 m, setting one second rope hole every 2.5 m-5 m, and sealing by adopting gypsum; then, welding steel bars on the first steel plate, and fixing the welded steel bars on a steel bar cage of the waist beam;

11 Performing formwork supporting work of the waist beam and the corbels on the waist beam, pouring concrete after the formwork supporting is completed, and performing subsequent construction after the concrete curing is completed;

12 The method comprises the steps of) transporting foundation pit support beam sections and foundation pit support splay beams to a designed position by adopting a crane, analyzing the bearing pressure of the transverse foundation pit support beam sections and the longitudinal foundation pit support beam sections, firstly assembling the opposite foundation pit support beam sections and the foundation pit support splay beams of the middle position in the bearing pressure larger direction, assembling the opposite foundation pit support beam sections from the middle to two ends, firstly installing the foundation pit support beam sections of the opposite support in an internal standard area, then assembling the foundation pit support beam sections of the opposite support in a non-standard area, then assembling the foundation pit support beam sections of the opposite support in a peripheral standard area, then assembling the foundation pit support splay beams of the opposite support in the peripheral standard area, assembling the foundation pit support beam sections of the opposite support in the bearing pressure smaller direction, then assembling the opposite support beam sections of the opposite support in the bearing pressure smaller direction on the two sides, repeating the operation until all the foundation pit support beam sections and the foundation pit support splay beams of the opposite support in a second path are assembled, and then, and after the construction of the opposite support beam sections in the second path are assembled, the foundation pit support beam sections are arranged on a lattice steel support plate;

13 Welding a bearing platform by utilizing a first steel plate pre-buried on a corbel of a crown beam or the crown beam, placing a foundation pit supporting beam section and a splayed Liang Junyi end of the foundation pit supporting beam at the edge on the bearing platform, placing a jack on a concave pillow of the bearing platform, and extending the jack to form a second internal support;

14 Repeating the working procedures in 8), 9), 10), 11), 12) and 13) to finish the construction of the rest of internal supports below the second internal support;

15 After the lowest support installation is completed, pouring the foundation slab.

Compared with the prior art, the technical scheme of the application has the following beneficial technical effects:

(1) The invention provides an assembled reinforced concrete foundation pit supporting system convenient to dismantle, which adopts a foundation pit supporting beam section and a foundation pit supporting splayed beam as supporting members of an inner support, eliminates procedures of reinforcement cage binding, concrete curing and the like of the inner support of the foundation pit, shortens the construction period of the inner support of the foundation pit, greatly saves time cost and labor cost, and reduces the cost of foundation pit supporting.

(2) The foundation pit is divided into a peripheral standard area, a non-standard area and an internal standard area, wherein the non-standard area can not exist, so that the foundation pit can adapt to foundation pits with different shapes, and has wide application prospect and good economic and social benefits.

(3) The invention provides a construction method of an assembled reinforced concrete foundation pit supporting system convenient to dismantle, which is characterized in that a foundation pit supporting beam section is connected with a splayed beam of a foundation pit support in a dowel manner, and the foundation pit supporting beam section is connected with the splayed beam of the foundation pit support in a dowel manner, so that the construction speed of the internal support of the foundation pit is greatly increased, and the subsequent dismantling work of the internal support is facilitated.

(4) The foundation pit supporting beam section and the foundation pit supporting splayed beam are adopted as supporting members of the inner support, and the members of the inner support are connected by the dowel bars, so that the foundation pit supporting beam section and the foundation pit supporting splayed beam are very suitable for occasions where the support only bears axial force. After the foundation pit supporting beam section and the foundation pit supporting splayed beam can be completely recycled after the foundation pit supporting beam section and the foundation pit supporting splayed beam are used, the foundation pit supporting beam section and the foundation pit supporting splayed beam can be repeatedly used, the single cost of the support in the foundation pit is greatly reduced, and the foundation pit supporting beam section and the foundation pit supporting splayed beam are significant breakthroughs of circular economy in the aspect of foundation pit supporting.

(5) The cross section sizes of the foundation pit supporting beam section and the foundation pit supporting splayed beam are the same, the standardization of the foundation pit supporting beam section and the foundation pit supporting splayed beam is realized, and the foundation pit supporting beam section and the foundation pit supporting splayed beam are convenient to transport, assemble and disassemble and can be used repeatedly better. The standardization can be a foundation pit range, a region, a province or even a national range. The standardization is realized in a larger range, and the economic and social benefits are higher.

(6) According to the invention, the whole life design concept is adopted, the rope threading holes are pre-embedded in the crown beam and the waist beam of the foundation pit, and in the process of cutting and dismantling the crown beam and the waist beam of the foundation pit by the rope saw, the drilling-free is realized, the dismantling speed of the crown beam and the waist beam of the foundation pit is accelerated, the dismantling cost is saved, the labor cost is reduced, the carbon emission is reduced, and the green building concept is implemented.

(7) According to the invention, the jack is arranged between the inner support and the crown beam or the waist beam as a supporting medium, and the installation position of the jack provides enough gaps for beam segment assembly, so that the beam Duan Tongguo dowel bars are spliced and installed into a whole; after the jack is lifted, the installation clearance can be eliminated quickly, so that the supporting beam is stressed quickly; the jacks are adjusted together, so that the stress and deformation of the supporting beam are close, the occurrence of overlarge local stress deformation is avoided, the visualization of the stress of the supporting beam is realized, the pressure of the jacks can be adjusted at any time, and the foundation pit support is more reliable and controllable.

(8) The thought provided by the invention can promote the generation of a brand-new leasing service, namely, the service of leasing the foundation pit support beam segments and the foundation pit support splayed beams in a certain area or city; the invention also provides more method choices for foundation pit support design.

Drawings

FIG. 1 is a schematic illustration of a standard size support of an assembled reinforced concrete foundation pit support system for ease of removal;

FIG. 2 is a schematic illustration of a non-standard size support of an assembled reinforced concrete foundation pit support system for ease of removal;

FIG. 3 is a schematic view of a dowel bar structure of a foundation pit support beam segment;

FIG. 4 is a schematic diagram of a foundation pit support figure Liang Chajin;

FIG. 5 is a schematic view of the beam sleeve structure of the foundation pit support beam section;

FIG. 6 is a schematic diagram of a splayed Liang Liangtao structure of a splayed beam of a foundation pit support;

FIG. 7 is a schematic view of the overall structure of a non-standard section beam segment;

FIG. 8 is a schematic view of a first support node structure;

FIG. 9 is a schematic view of a first support edge structure;

FIG. 10 is a schematic illustration of a non-standard section beam application;

FIG. 11 is a schematic view of an underlying support node structure;

FIG. 12 is a schematic view of an underlying support edge structure;

FIG. 13 is a schematic view of a crown deck position;

Fig. 14 is a schematic view of a waist beam table position;

FIG. 15 is a schematic view of the layout of the support planes in the foundation pit of example 1;

FIG. 16 is a schematic view of the layout of the support planes in the foundation pit of example 2;

fig. 17 is a schematic view of the layout of the support planes in the foundation pit of example 3.

In the figure: 1. a foundation pit support beam section; 101. longitudinal dowel holes; 102. transverse dowel holes; 103. a beam sleeve; 103-1, side steel plates; 103-2, end face steel plates; 2. the foundation pit supports the splayed beam; 201. the splayed beam transversely penetrates through the rib holes; 202. splayed beam sleeve; 3-1, a first rope penetrating hole; 3-2, a second rope penetrating hole; 4. a jack; 5. bearing platform; 501. a first steel plate; 502. reinforcing steel bars; 503. a second steel plate; 504. a steel plate III; 505. a steel plate IV; 506. a concave pillow; 6. waist beam; 7. a bracket; 8. a crown beam; 9. steel lattice columns; 10. a tray; 10-1, a panel; 10-2, triangular steel plates; 11. a foundation pit supporting beam section in a non-standard area; 12. connecting steel bars; 13. supporting piles; A. a peripheral standard region; B. an internal standard region; C. non-standard regions. (in the figure, the thick solid line is a region dividing line, the foundation pit inner support is divided into a peripheral standard region A and an internal standard region B, or the foundation pit inner support is divided into a peripheral standard region A, an internal standard region B and a non-standard region C.)

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without making any inventive effort, are within the scope of the present invention based on the embodiments of the present invention (the uppermost support being the first support, and the second support, the third support, and so on, in that order, down to the lowermost support).

In an embodiment, as shown in fig. 1-17, the assembled reinforced concrete foundation pit supporting system is convenient to disassemble, and is characterized in that the supporting system comprises a peripheral standard area A and an inner standard area B; the internal standard area is an orthogonal pair support system consisting of a plurality of foundation pit support beam sections (1) with the same length and section size; the two ends of the foundation pit supporting beam section 1 are provided with beam sleeves 103, the beam sleeves 103 are provided with side steel plates 105, the side steel plates 105 are provided with transverse dowel holes 102, the two ends of the foundation pit supporting beam section 1 are provided with end steel plates 104, and the end steel plates 104 are provided with longitudinal dowel holes 101;

When the two foundation pit support beam sections 1 are axially connected, end face steel plates 104 of the two foundation pit support beam sections 1 are in seamless fit, longitudinal dowel holes 101 of the two foundation pit support beam sections 1 are aligned one by one, and connecting steel bars 12 are arranged in the longitudinal dowel holes 101; when the four foundation pit support beam sections 1 are connected in a cross shape or the three foundation pit support beam sections 1 are connected in a T shape, after the two foundation pit support beam sections 1 are axially connected, the foundation pit support beam sections are vertically connected with one or two other foundation pit support beam sections 1 at the axial connection position, the longitudinal dowel holes 101 of one or two foundation pit support beam sections 1 are aligned with the transverse dowel holes 102 at the axial connection position of the two foundation pit support beam sections 1 one by one at the vertical connection position, and connecting steel bars 12 are arranged in the transverse dowel holes 102;

a peripheral standard area is arranged in the contact area of the support system and the crown beam 8 or the waist beam 6, and the peripheral standard area comprises N foundation pit support beam sections 1 perpendicular to the crown beam 8 and the waist beam 6 and foundation pit support splayed beams 2 arranged on two sides of the foundation pit support beam sections;

The length and the section size of the splayed beam 2 of the foundation pit support are the same; one end is a right-angle end, the other end is an oblique-angle end, the right-angle end is provided with a splayed Liang Liangtao and 202, and the oblique-angle end is provided with a splayed Liang Chajin hole 201;

the connection of the foundation pit support beam section 1 and the foundation pit support splayed beam 2 comprises that after the two foundation pit support beam sections 1 are axially connected, the foundation pit support beam sections are butted with the bevel angle ends of the foundation pit support splayed beam 2 at the axial connection part, and the connection mode is as follows: the splayed Liang Chajin holes 201 are aligned with the transverse dowel holes 102 at the axial connection part of the two foundation pit support beam segments 1 one by one, and connecting steel bars 12 are arranged in the transverse dowel holes 102;

The peripheral standard area A and the internal standard area B are connected by a plurality of foundation pit support beam sections 1 with the same size, which are arranged in the peripheral standard area A or the internal standard area B; so as to achieve the purpose that the peripheral standard area A and the internal standard area B are matched with the corresponding foundation pit size.

When the peripheral standard area A and the internal standard area B are connected by using a plurality of foundation pit supporting beam sections 1 with the same length and cross section size and cannot be matched with the size of a foundation pit, a non-standard area C is arranged for connection, wherein the non-standard area C comprises a non-standard area foundation pit supporting beam section 11 with the length being less than 2 times that of the foundation pit supporting beam section 1, or comprises a non-standard area foundation pit supporting beam section 11 with the length being less than 2 times that of the foundation pit supporting beam section 1 and the foundation pit supporting beam section 1 so as to be matched with the corresponding foundation pit size, and other settings of the non-standard area foundation pit supporting beam section 11 are the same as those of the standard area foundation pit supporting beam section 1.

The crown beam 8 and the waist beam 6 are respectively provided with a bearing platform 5 and a bracket 7, and the foundation pit supporting beam section 1 in the peripheral standard area is placed on the bearing platform 5 fixed on the crown beam 8 or the waist beam 6; the foundation pit supporting splayed beam 2 in the peripheral standard area is placed on a bearing platform 5 fixed on a bracket 7; the jack 4 is arranged on the bearing platform 5 and is used for jacking and supporting the foundation pit supporting beam section 1 or the foundation pit supporting splayed beam 2; a tray 10 is arranged below the joint of the foundation pit supporting beam section 1, and the tray 10 is welded on the steel lattice column 9.

The number of the longitudinal dowel holes 101 is two, and the number of the transverse dowel holes 102 is one; the distance between two rows of longitudinal dowel holes 101 is equal to twice the distance between the transverse dowel holes 102 and the end face steel plate 104, the vertical distance between the adjacent longitudinal dowel holes 101 or the transverse dowel holes 102 is the same, the distance between the uppermost longitudinal dowel hole 101 and the upper edge of the beam sleeve 103 is equal to the distance between the lowermost transverse dowel hole 102 and the lower edge of the beam sleeve 103, the distance between two rows of splayed Liang Chajin holes 201 is equal to twice the distance between the transverse dowel holes 102 and the end face steel plate 104 of the foundation pit support beam section 1, the distance between the uppermost splayed Liang Chajin hole 201 and the upper edge of the foundation pit support splayed beam 2 is equal to the distance between the uppermost transverse dowel hole 102 and the upper edge of the foundation pit support beam section 1, and the distance between the vertically adjacent splayed Liang Chajin holes 201 is the same as the distance between the vertically adjacent transverse dowel holes 102.

The apertures of the transverse dowel holes 102, the longitudinal dowel holes 101 and the splayed Liang Chajin holes 201 are the same.

The crown beam 8 is provided with a first rope penetrating hole 3-1 for rope saw cutting, the first rope penetrating hole 3-1 is formed by embedding an L-shaped PVC pipe in the crown beam 8, two ends of the L-shaped PVC pipe are provided with openings, one end of the L-shaped PVC pipe is provided with an opening on the side surface of the crown beam 8, and the other end of the L-shaped PVC pipe is provided with an opening on the top surface of the crown beam 8; the waist beam 6 is provided with a second rope threading hole 3-2 for rope saw cutting, the second rope threading hole 3-2 is formed by vertically embedding a straight PVC pipe in the waist beam 6, two ends of the straight PVC pipe are provided with openings, one end of the straight PVC pipe is provided with an opening which is positioned on the top surface of the waist beam 6, the other end of the straight PVC pipe is provided with an opening which is positioned on the bottom surface of the waist beam 6, and the straight PVC pipe is embedded on one side of the waist beam 6 close to the supporting pile 13.

The bearing platform 5 is formed by welding a first steel plate 501, a second steel plate 503, a third steel plate 504 and a fourth steel plate 505, the planar shape of the first steel plate 501 and the second steel plate 503 is rectangular, the planar shape of the third steel plate 504 and the fourth steel plate 505 is trapezoid, and a concave pillow 506 for fixing the jack 4 is welded on the second steel plate 503.

A steel sheet 501 for welding cushion cap 5 pre-buried in roof beam 8 or waist rail 6, welding reinforcing bar 502 on the steel sheet 501, the face of steel sheet 501 is perpendicular to a steel sheet 502, the pre-buried direction of reinforcing bar 502 is perpendicular to the side of roof beam 8 or waist rail 6, and fixes on the steel reinforcement cage of roof beam 8 or waist rail 6 with the steel wire, bracket 7 shape is the triangular prism, bracket 7 sets up on roof beam 8 or waist rail 6, pre-buried in bracket 7's position has a steel sheet 501.

The branch parts of the steel lattice column 9 are angle steel, the decoration materials are steel plates, the tray 10 is welded on the steel plates, the tray 10 consists of a panel 10-1 and eight triangular steel plates 10-2, the decoration materials are not welded in the distance which is the same as the height of the foundation pit supporting beam section 1 above the tray which is not supported by the first path, the steel plates are used for reinforcing, the foundation pit supporting beam section 1 which is supported by the first path is directly placed on the tray 10 which is welded on the steel lattice column 9, the foundation pit supporting beam section 1 which is not supported by the first path passes through the steel lattice column 9 and is placed on the tray 10 which is welded on the steel lattice column 9.

1) After the hole is formed by rotary digging, constructing to form a supporting pile 13, a stand column pile and a steel lattice column 9;

2) After roughening the pile head of the support pile 13, carrying out steel bar binding work of the crown beam 8; the method comprises the steps of carrying out pre-burying operation of a first rope penetrating hole 3-1 of a crown beam 8 while binding reinforcing steel bars, fixing the first rope penetrating hole 3-1 through steel wires, setting the first rope penetrating hole 3-1 from a foundation pit angle point of 2.5 m-5 m, setting a first rope penetrating hole 3-1 every 2.5 m-5 m, and sealing by adopting gypsum; then, the steel bars 502 are welded on the first steel plate 501, and the welded steel bars 502 are fixed on the steel bar cage of the crown beam 8, and meanwhile, the first steel plate 501 is attached to the side face of the crown beam 8;

3) Carrying out formwork supporting work of the crown beam 8 and the bracket 7 on the crown beam 8, pouring concrete after formwork supporting is completed, and carrying out subsequent construction after concrete curing is completed;

4) Excavating earth to the elevation of the bottom of the first inner supporting beam; in order to facilitate welding of the tray 10 on the steel lattice column 9, the steel lattice column 9 is excavated at least 1m more deep; the bearing platform 5 on the crown beam 8 is conveniently welded, and the position of the bearing platform 5 is at least excavated 1m deep;

5) Welding a tray 10 on the steel lattice column 9;

6) The foundation pit supporting beam section 1 and the foundation pit supporting splayed beam 2 are transported to a design position by adopting a crane, the bearing pressure of the transverse foundation pit supporting beam section 1 and the longitudinal foundation pit supporting beam section 1 is analyzed, the foundation pit supporting beam section 1 and the foundation pit supporting splayed beam 2 which are supported at the middle position in the direction of bearing the larger pressure are assembled, and the pair of supports are assembled from the middle to two ends; firstly, mounting a foundation pit support beam section 1 of the pair of supports in an inner standard area A, then mounting a foundation pit support beam section 11 of the pair of supports in a non-standard area C, then mounting a foundation pit support beam section 1 of the pair of supports in a peripheral standard area B, then mounting a foundation pit support splay beam 2 of the pair of supports in the peripheral standard area B, mounting foundation pit support beam sections 1 of the pair of supports in the direction of smaller bearing pressure on two sides after the pair of supports are constructed, then mounting the pair of supports in the direction of larger bearing pressure on two adjacent pairs of supports in the direction of larger bearing pressure, and then mounting the foundation pit support beam sections 1 of the pair of supports in the direction of smaller bearing pressure on two sides, repeating the operation until the assembly construction of all the foundation pit support beam sections 1 and the foundation pit support splay beams 2 of the first inner support is completed, and the foundation pit support beam sections 1 are placed on a tray 10 at all beam column joints of the first inner support;

7) Welding a bearing platform 5 by utilizing a first steel plate pre-buried on a crown beam 8 or a bracket 7 of the crown beam 8, placing the uniform ends of a foundation pit supporting beam section 1 and a foundation pit supporting splayed beam 2 at the edge on the bearing platform 5, placing a jack 4 on a concave pillow 506 of the bearing platform 5, and jacking the jack 4 to form a first inner support;

8) Excavating earth to the elevation of the bottom of the supporting beam in the second channel; in order to facilitate welding of the tray 10 on the steel lattice column 9, the steel lattice column 9 is excavated at least 1m deep more; the bearing platform 5 on the crown beam 8 is conveniently welded, and the position of the bearing platform 5 is at least excavated 1m deep;

9) Welding a tray 10 on the steel lattice column 9;

10 Roughening the support pile 13, binding the reinforcing steel bars of the waist beam 6, embedding the second rope penetrating holes 3-2, fixing the second rope penetrating holes 3-2 through steel wires, setting the second rope penetrating holes 3-2 from the foundation pit angle point 2.5 m-5 m, setting one second rope penetrating hole 3-2 every 2.5 m-5 m, and sealing by gypsum; subsequently, the steel bars 502 are welded on the first steel plate 501, and the welded steel bars 502 are fixed on the steel bar cage of the wale 6;

11 Performing formwork supporting work of the waist beam 6 and the bracket 7 on the waist beam 6, pouring concrete after the formwork supporting is completed, and performing subsequent construction after the concrete curing is completed;

12 The method comprises the steps of) transporting a foundation pit support beam section 1 and a foundation pit support splay beam 2 to a designed position by adopting a crane, analyzing the bearing pressure of the transverse foundation pit support beam section 1 and the longitudinal foundation pit support beam section 1, firstly assembling the foundation pit support beam section 1 and the foundation pit support splay beam 2 of a pair of supports at the middle position in the direction of bearing pressure, assembling the pair of supports from the middle to two ends, firstly installing the foundation pit support beam section of the pair of supports in an internal standard area A, then assembling the foundation pit support beam section 11 of the pair of supports in a non-standard area C, then assembling the foundation pit support beam section 1 of the pair of supports in a peripheral standard area B, then assembling the foundation pit support splay beam 2 of the pair of supports in the peripheral standard area B, assembling the foundation pit support beam section 1 of the pair of supports in the direction of bearing pressure in the two sides, then assembling the support beam section 1 of the pair of supports in the direction of bearing pressure in the two adjacent directions of bearing pressure in the two sides, repeating the operation until all the foundation pit support beam sections 1 and the support beam sections of the pair of supports in the two sides bearing pressure in the direction of bearing pressure are assembled, and all the foundation pit support beams in the second path pass through a steel support beam frame 10;

13 Welding a bearing platform 5 by utilizing a first steel plate 501 pre-buried on a crown beam 8 or a bracket 7 of the crown beam 8, placing the uniform ends of a foundation pit supporting beam section 1 and a foundation pit supporting splayed beam 2 at the edge on the bearing platform 5, placing a jack 4 on a concave pillow 506 of the bearing platform 5, and jacking the jack 4 to form a second internal support;

Example 1:

As shown in fig. 15, a rectangular foundation pit is formed by arranging a cross-shaped inner support in a manner of being 148 long and m wide and 80m, 4 transverse pairs of supports and 8 longitudinal pairs of supports are adopted, 4 layers of the foundation pit inner support are designed, the sizes of foundation pit support beam sections are all the same, the section sizes of the foundation pit support beam sections are 1000-mm high and 800-mm wide, the lengths of the foundation pit support beam sections are 5000-mm, the sizes of the foundation pit support splayed beams are all the same, the section sizes of the foundation pit support splayed beams are 1000-mm high and 800-mm wide, the angle of an oblique angle end is 45 degrees, and the length is 6.98-m.

1) Designing a supporting pile diameter of 1.5 m, a column pile diameter of 1.8 m, rotary digging a hole to fill the supporting pile and the column pile, forming a hole by adopting a slurry protecting wall for rotary digging the pile, and arranging a long steel protecting cylinder at the upper part to avoid hole collapse at the top of the pile hole; the steel reinforcement cage of the support pile is transferred to the pile hole by adopting an automobile crane and a crawler crane, the steel reinforcement cage is lifted by utilizing the crawler crane, a guide pipe is arranged for pouring concrete, and the pile casing is pulled out while pouring according to the sleeve segmentation condition, so that the concrete is compact by vibrating up and down when lifting the guide pipe. The column adopts angle steel lattice column, branch parts of the steel lattice column adopt L75X 8 angle steel, the decoration material adopts No. 45 steel with the thickness of 1 cm, the section size length X width of the steel lattice column is 1.2 m X1.2 m, steel plates are not arranged at the lower layer supporting intersection point of the steel lattice column within the height range of 80 cm, the steel lattice column and column pile reinforcement cage are welded and fixed, then the steel lattice column pile is lowered to the designed elevation, and the steel lattice column pile adopts conduit grouting and earth filling after grouting; and a plurality of rotary pile digging machines can be adopted for simultaneous construction until the construction of the supporting piles and the upright piles is completed.

2) The cross section of the crown beam is wide in size multiplied by 1.2 m multiplied by 1m, the pile head of the support pile is subjected to roughening treatment, the steel bar cage of the crown beam is bound after roughening is finished, an L-shaped PVC plastic pipe with the diameter of 20 mm is embedded in the crown beam and is used as a threading hole for subsequent dismantling, one PVC pipe is embedded every 3m, gypsum hole sealing is adopted in the PVC pipe during embedding, the PVC pipe is vertically embedded at the position close to the outer edge of the crown beam, a Q390 steel plate with the length of 1m and the height of 1m and the thickness of 2 cm is adopted as a first steel plate, one side of the first steel plate is welded with HRB400 steel bars with the diameter of 20 mm, the first steel plate is placed at the correct position according to an internal support design drawing, the first steel plate is clung to the inner edge of the crown beam, and the first steel bars welded on the steel bar cage of the crown beam are bound by steel wires.

3) And (3) carrying out formwork supporting work of brackets on the crowns Liang Jiguan beams, pouring concrete after formwork supporting is completed, and carrying out subsequent construction after concrete curing is completed.

4) Excavating earth to the elevation of the first inner supporting bottom; in order to facilitate welding of trays on the steel lattice columns, the steel lattice columns are excavated 1m more deep; in order to facilitate welding of the bearing platform on the crown beam, more 1m parts are excavated at the bearing platform.

5) According to the bottom elevation of the first support, a tray is welded on a steel lattice column, a Q390 steel plate with the thickness of 2 cm is welded on the steel lattice column to form a tray panel with the plane size of 1.5m multiplied by 1.5m, eight Q390 isosceles right-angle steel plates with the thickness of 2 cm are selected, the right-angle side length of each right-angle side is 30 cm, one right-angle side is welded on the panel, and the other right-angle side is welded on the steel lattice column.

6) Prefabrication of the foundation pit support beam section and the foundation pit splayed beam is completed in a factory, and the prefabricated foundation pit support beam section and the foundation pit splayed beam are transported to a site for preparing and installing work; the foundation pit supporting beam section and the foundation pit supporting splayed beam are transported to a designed position by adopting a crane, and the supporting members are connected by adopting dowel bars; firstly, assembling a foundation pit supporting beam section and a foundation pit supporting splayed beam of the middle longitudinal opposite support, after the longitudinal opposite support construction is completed, assembling foundation pit supporting beam sections of which the two sides are transversely opposite support, then assembling two adjacent longitudinal opposite supports of the longitudinal opposite support, then assembling foundation pit supporting beam sections of which the two sides are transversely opposite support, and repeating the operation until the 4 transverse supports and 8 longitudinal support constructions of the first inner support are completed.

7) After all foundation pit supporting beam sections and foundation pit supporting splayed beams are installed, a bearing platform is welded at the pre-buried steel plate of the crown beam, a bearing platform bottom plate, namely a second steel plate, is welded on the pre-buried first steel plate by adopting a Q390 rectangular steel plate with the thickness of 2 cm and the length of 2m and the width of 1m, a third steel plate and a fourth steel plate of the bearing platform are respectively provided with a Q390 steel plate with the thickness of 2 cm and the width of 20 cm, one end of each bearing platform is welded on the first steel plate, the other end of each bearing platform is welded on the second steel plate, a jack is welded on the bearing platform bottom plate to fix a concave sleeper, the steel thickness of the concave sleeper is 1 cm, the steel is 45 steel, the supporting beam sections at the edge and the splayed Liang Junyi end are placed on the bearing platform, YDC4600 jacks are placed on the bearing platform, and the jacks stretch to complete the first support.

8) Excavating earth to the elevation of the supporting bottom in the second channel; in order to facilitate welding of trays on the steel lattice columns, the steel lattice columns are excavated 1m more deep; in order to facilitate welding of the bearing platform on the crown beam, more 1m parts are excavated at the bearing platform.

9) According to the bottom elevation of the second support, 2 cm thick Q390 steel plates are welded on the steel lattice columns to form a tray panel with the plane size of 1.5m multiplied by 1.5m, eight Q390 isosceles right-angle steel plates with the thickness of 2 cm are selected, the right-angle side length of each steel plate is 30 cm, one right-angle side is welded on the panel, and the other right-angle side is welded on the steel lattice columns.

10 The method comprises the steps of) roughening the underground diaphragm wall, binding a steel reinforcement cage of the waist beam after roughening, embedding a straight PVC plastic pipe with the diameter of 20 mm in the waist beam to serve as a threading hole for subsequent dismantling, embedding one PVC pipe every 3 m, vertically embedding the PVC pipe at the side of the waist beam close to the underground diaphragm wall by using gypsum hole sealing, selecting a Q390 steel plate with the length of 1m and the height of 1m and the thickness of 2 cm as a first steel plate, welding HRB400 steel bars with the diameter of 20 mm on one side of the first steel plate, placing the steel plates at the correct positions according to an internal support design drawing, tightly attaching the steel plates to the inner edge of the waist beam, and binding the steel bars welded on the steel plates on the steel reinforcement cage of the waist beam by using steel wires.

11 The formwork supporting work of the waist beam and the corbels on the waist beam is carried out, concrete is poured after the formwork supporting is completed, and subsequent construction is carried out after the concrete curing is completed.

12 The foundation pit supporting beam section and the foundation pit supporting splayed beam are transported to a design position by adopting a crane, and the supporting members are connected by adopting dowel bars; firstly, assembling a foundation pit supporting beam section and a foundation pit supporting splayed beam of the middle longitudinal opposite support, after the construction of the longitudinal opposite support is completed, assembling foundation pit supporting beam sections of which the two sides are transversely opposite support, then assembling two adjacent longitudinal opposite supports of the longitudinal opposite support, then assembling foundation pit supporting beam sections of which the two sides are transversely opposite support, and repeating the operation until the construction of 4 transverse supports and 8 longitudinal supports of the second inner support is completed.

13 After all foundation pit supporting beam sections and foundation pit supporting splayed beams of the second support are installed, a bearing platform is welded at a pre-buried first steel plate of the waist beam, a bearing platform bottom plate, namely a second steel plate, is welded on the pre-buried first steel plate by adopting a Q390 rectangular steel plate with the thickness of 2cm and the length of 2m and the width of 1m, a Q390 steel plate with the thickness of 2cm and the width of 20 cm is selected as a third steel plate and a fourth steel plate of the bearing platform, one end of the bearing platform is welded on the first steel plate, the other end of the bearing platform is welded on the second steel plate, a jack is welded on the bearing platform bottom plate, the thickness of steel of the concave pillow is 1 cm, steel is 45 steel, and the supporting beam sections and the splayed Liang Junyi ends at the edge are placed on the bearing platform, YDC4600 jacks are placed on the bearing platform, and the jacks stretch, so that the second support is completed.

14 Repeating steps 8), 9), 10), 11), 12), 13) to complete the installation work of the third support and the fourth support.

15 After the fourth support installation is completed, pouring the foundation slab.

Example 2

As shown in fig. 16, a rectangular foundation pit is formed by a length 146 m and a width 78 m, the inner support is in a cross arrangement, 4 transverse pairs of supports are adopted, 8 longitudinal pairs of supports are adopted, 4 layers of the foundation pit inner support are designed, the dimensions of foundation pit support beam sections are all the same, the cross section of the foundation pit support beam sections in a standard area is 1000 mm wide and 800 mm high, the length 5000 mm of the foundation pit support beam sections is the same, the cross section of the foundation pit support beam sections is 1000 mm wide and 800 mm high, the angle of the bevel end is 45 degrees, the length is 6.98 m, two rows of longitudinally parallel non-standard area beam sections and two rows of transversely parallel non-standard area beam sections are arranged, the cross section of the non-standard area beam sections is 1000 mm high and 800 mm, and the length 4000 mm of the foundation pit support beam sections are arranged.

6) Prefabrication of the foundation pit support beam section, the foundation pit splayed beam and the nonstandard area beam section is completed in a factory, and the prefabricated foundation pit splayed beam and the nonstandard area beam section are transported to a site for installation; the foundation pit supporting beam section and the foundation pit supporting splayed beam are transported to a designed position by adopting a crane, and the supporting members are connected by adopting dowel bars; firstly, assembling a foundation pit supporting beam section and a foundation pit supporting splayed beam of the middle longitudinal opposite support, after the longitudinal opposite support construction is completed, assembling foundation pit supporting beam sections of which the two sides are transversely opposite support, then assembling two adjacent longitudinal opposite supports of the longitudinal opposite support, then assembling foundation pit supporting beam sections of which the two sides are transversely opposite support, and repeating the operation until the 4 transverse supports and 8 longitudinal support constructions of the first inner support are completed.

7) After all foundation pit supporting beam sections, foundation pit supporting splayed beams and nonstandard area beam sections are installed, a bearing platform is welded at the pre-buried steel plate of the crown beam, a bearing platform bottom plate, namely a second steel plate, is welded on the pre-buried first steel plate by adopting a Q390 rectangular steel plate with the thickness of 2 cm and the length of 2m and the width of 1m, a third steel plate and a fourth steel plate of the bearing platform are respectively provided with a Q390 steel plate with the thickness of 2 cm and the width of 20cm, one end of the bearing platform is welded on the first steel plate, the other end of the bearing platform is welded on the second steel plate, a jack is welded on the bearing platform bottom plate, the steel thickness of the concave sleeper is 1cm, the steel is 45 steel, the supporting beam sections at the edge and the splayed Liang Junyi end are placed on the bearing platform, YDC4600 jacks are placed on the bearing platform, and the jacks stretch, and the first support is completed.

12A crane is adopted to lead the foundation pit supporting beam section, the foundation pit supporting splayed beam and the nonstandard area beam Duan Yun to the design position, and the supporting members are connected by dowel bars; firstly, assembling a foundation pit supporting beam section and a foundation pit supporting splayed beam of the middle longitudinal opposite support, after the construction of the longitudinal opposite support is completed, assembling foundation pit supporting beam sections of which the two sides are transversely opposite support, then assembling two adjacent longitudinal opposite supports of the longitudinal opposite support, then assembling foundation pit supporting beam sections of which the two sides are transversely opposite support, and repeating the operation until the construction of 4 transverse supports and 8 longitudinal supports of the second inner support is completed.

13 After all foundation pit supporting beam sections and foundation pit supporting splayed beams and nonstandard area beam sections of the second support are installed, a bearing platform is welded at a first pre-buried steel plate of the waist beam, a bearing platform bottom plate, namely a second steel plate, is welded on the first pre-buried steel plate by adopting a Q390 rectangular steel plate with the thickness of 2cm and the length of 2m and the width of 1m, a third steel plate and a fourth steel plate of the bearing platform are respectively a Q390 steel plate with the thickness of 2cm and the width of 20 cm, one end of the bearing platform is welded on the first steel plate, the other end of the bearing platform is welded on the second steel plate, finally a jack is welded on the bearing platform bottom plate to fix a concave sleeper, the steel thickness of the concave sleeper is 1cm, the steel is 45 steel, the supporting beam sections at the edge and the splayed Liang Junyi end are placed on the bearing platform, YDC4600 jacks are placed on the bearing platform, and extend by the jacks, and the second support is completed.

Example 3

As shown in fig. 17, in a certain L-shaped foundation pit, the upper side length of the foundation pit is 163 m, the left side length is 79 m, the left side length is 40m, the right side length is 119 m, the left side length is 106 m, the right side length is 57 m, the inner support of the foundation pit adopts a cross-shaped arrangement form, 6 transverse pairs of supports and 9 longitudinal pairs of supports are designed, 3 layers of the inner support of the foundation pit are designed, the dimensions of the foundation pit support beam sections are all the same, the cross-sectional dimensions of the foundation pit support beam sections in a standard area are 1000-mm wide and 800-mm high, the length of the foundation pit support beam sections is 5000-mm, the dimensions of the foundation pit support splayed beams are all the same, the cross-sectional dimensions of the foundation pit support splayed beams are 1000-mm high and 800-mm high, the angle of the bevel end is 45 degrees, the length is 6.98-m, a row of transversely parallel non-standard area beam sections are provided, the cross-sectional dimensions of the non-standard area beam sections are 1000-mm-high 800-mm, and the length of the foundation pit support beam sections is 3000-mm.

14 Repeating steps 8), 9), 10), 11), 12), 13) to complete the installation of the third support.

15 After the third support installation is completed, pouring the foundation slab.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. An assembled reinforced concrete foundation pit support system that is easy to dismantle, characterized in that: the support system comprises an outer standard area (A) and an inner standard area (B); the inner standard area is an orthogonal bracing system composed of a plurality of foundation pit support beam sections (1) of the same length and cross-sectional size; a beam sleeve (103) is provided on the surface of the foundation pit support beam section (1); a side steel plate (103-1) is provided on the beam sleeve (103); the pipe walls at both ends of a preset transverse embedded pipe are respectively welded to the hole walls of the side steel plates (103-1) on both sides to form a transverse reinforcement hole (102); an end steel plate (103-2) is provided on the beam sleeve (103); the pipe wall at one end of a preset longitudinal embedded pipe is welded to the inner wall of the hole of the end steel plate (103-2) to form a longitudinal reinforcement hole (101);

When two foundation pit support beam segments (1) are axially connected, the end steel plates (103-2) of the two foundation pit support beam segments (1) are seamlessly attached, the longitudinal reinforcement holes (101) of the two foundation pit support beam segments (1) are aligned one by one, and the longitudinal reinforcement holes (101) contain connecting steel bars (12); when four foundation pit support beam segments (1) are connected in a cross shape or three foundation pit support beam segments (1) are connected in a T shape, after the two foundation pit support beam segments (1) are axially connected, they are vertically connected with another one or two foundation pit support beam segments (1) at the axial connection, and at the vertical intersection, the longitudinal reinforcement holes (101) of one or two foundation pit support beam segments (1) are aligned one by one with the transverse reinforcement holes (102) at the axial connection of the two foundation pit support beam segments (1), and the transverse reinforcement holes (102) contain connecting steel bars (12);

An outer standard area is set in the area where the support system contacts the crown beam (8) or the waist beam (6), and the outer standard area includes N foundation pit support beam sections (1) perpendicular to the crown beam (8) and the waist beam (6) and foundation pit support crossbeams (2) arranged on both sides thereof;

The foundation pit supporting cross-shaped beam (2) has the same length and cross-sectional dimensions; one end is a right-angle end and the other end is an oblique-angle end; the surface of the foundation pit supporting cross-shaped beam (2) is provided with a cross-shaped beam sleeve (202), and the oblique-angle end is provided with a cross-shaped beam reinforcement hole (201);

The connection between the foundation pit support beam section (1) and the foundation pit support cross-beam (2) comprises that after the two foundation pit support beam sections (1) are axially connected, they are butted with the beveled ends of the foundation pit support cross-beam (2) at the axial connection, and the connection method is as follows: the cross-beam reinforcement holes (201) are aligned one by one with the transverse reinforcement holes (102) at the axial connection of the two foundation pit support beam sections (1), and connecting steel bars (12) are arranged in the transverse reinforcement holes (102);

The outer standard area (A) and the inner standard area (B) are connected by a plurality of foundation pit support beam sections (1) of the same size arranged inside the outer standard area (A) or the inner standard area (B); so that the outer standard area (A) and the inner standard area (B) are adapted to the corresponding foundation pit size.

2. The easily dismantled assembled reinforced concrete foundation pit support system according to claim 1 is characterized in that when the outer standard area (A) and the inner standard area (B) are connected by a plurality of foundation pit support beam segments (1) of the same length and cross-sectional size and cannot adapt to the size of the foundation pit, a non-standard area (C) is set for connection, and the non-standard area (C) includes a non-standard area foundation pit support beam segment (11) less than twice the length of the foundation pit support beam segment (1), or includes a non-standard area foundation pit support beam segment (11) less than twice the length of the foundation pit support beam segment (1) and a foundation pit support beam segment (1) to adapt to the corresponding foundation pit size, and the other settings of the non-standard area foundation pit support beam segment (11) are the same as those of the standard area foundation pit support beam segment (1).

3. The easily dismantled assembled reinforced concrete foundation pit support system according to claim 1 is characterized in that the crown beam (8) and the waist beam (6) are both provided with a cap (5) and a corbel (7), the foundation pit support beam section (1) of the outer standard area is placed on the cap (5) fixed to the crown beam (8) or the waist beam (6); and the foundation pit support cross-beam (2) of the outer standard area is placed on the cap (5) fixed to the corbel (7); a jack (4) is provided on the cap (5) for lifting and supporting the foundation pit support beam section (1) or the foundation pit support cross-beam (2); a tray (10) is provided below the connection of the foundation pit support beam section (1), and the tray (10) is welded to the steel lattice column (9).

4. The easily dismantled assembled reinforced concrete foundation pit support system according to claim 1 is characterized in that: the longitudinal reinforcing bar holes (101) are in two rows, and the transverse reinforcing bar holes (102) are in one row; the distance between the two rows of longitudinal reinforcing bar holes (101) is equal to twice the distance between the transverse reinforcing bar holes (102) and the end steel plate (103-2); the vertical spacing between adjacent longitudinal reinforcing bar holes (101) or transverse reinforcing bar holes (102) is the same; the distance between the uppermost longitudinal reinforcing bar hole (101) and the upper edge of the beam sleeve (103) is equal to the distance between the lowermost transverse reinforcing bar hole The distance between the two rows of the eight-shaped beam reinforcement holes (201) is equal to twice the distance between the transverse reinforcement holes (102) and the end steel plate (103-2) of the foundation pit support beam section (1). The distance between the uppermost eight-shaped beam reinforcement hole (201) and the upper edge of the foundation pit support eight-shaped beam (2) is equal to the distance between the uppermost transverse reinforcement hole (102) and the upper edge of the foundation pit support beam section (1). The spacing between the vertically adjacent eight-shaped beam reinforcement holes (201) is the same as the spacing between the vertically adjacent transverse reinforcement holes (102).

5. The easily dismantled assembled reinforced concrete foundation pit support system according to claim 1, characterized in that the diameters of the transverse reinforcement insertion holes (102), the longitudinal reinforcement insertion holes (101) and the S-beam reinforcement insertion holes (201) are the same.

6. The easily dismantled assembled reinforced concrete foundation pit support system according to claim 1 is characterized in that: a first rope threading hole (3-1) for rope saw cutting is arranged on the crown beam (8), and the first rope threading hole (3-1) is formed by an L-shaped PVC pipe pre-buried in the crown beam (8), and the L-shaped PVC pipe has openings at both ends, one end opening is located on the side surface of the crown beam (8), and the other end opening is located on the top surface of the crown beam (8); a second rope threading hole (3-2) for rope saw cutting is arranged on the waist beam (6), and the second rope threading hole (3-2) is formed by a straight PVC pipe vertically pre-buried in the waist beam (6), and the straight PVC pipe has openings at both ends, one end opening is located on the top surface of the waist beam (6), and the other end opening is located on the bottom surface of the waist beam (6).

7. The easily dismantled assembled reinforced concrete foundation pit support system according to claim 3 is characterized in that: the cap (5) is formed by welding a No. 1 steel plate (501), a No. 2 steel plate (503), a No. 3 steel plate (504), and a No. 4 steel plate (505); the No. 1 steel plate (501) and the No. 2 steel plate (503) are rectangular in plan shape; the No. 3 steel plate (504) and the No. 4 steel plate (505) are trapezoidal in plan shape; and a concave pillow (506) for fixing the jack (4) is welded on the No. 2 steel plate (503).

8. The easily dismantled assembled reinforced concrete foundation pit support system according to claim 7 is characterized in that: the No. 1 steel plate (501) used for welding the cap (5) is pre-buried in the crown beam (8) or the waist beam (6), the steel bar (502) is welded on the No. 1 steel plate (501), the steel bar (502) is perpendicular to the plate surface of the No. 1 steel plate (501), the pre-buried direction of the steel bar (502) is perpendicular to the side of the crown beam (8) or the waist beam (6), and is fixed to the steel cage of the crown beam (8) or the waist beam (6) with steel wire, the corbel (7) is in the shape of a straight triangular prism, the corbel (7) is arranged on the crown beam (8) or the waist beam (6), and the No. 1 steel plate (501) is pre-buried at the position of the corbel (7).

9. The easily dismantled assembled reinforced concrete foundation pit support system according to claim 3 is characterized in that: the branches of the steel lattice column (9) are angle steels, the tie materials are steel plates, and a tray (10) is welded thereon, the tray (10) is composed of a panel (10-1) and eight triangular steel plates (10-2), and no tie materials are welded within a distance at the same height as the foundation pit support beam section (1) above the tray that is not the first support, and then four angle steels are used to reinforce the four branches in this range; the first support is directly placed on the tray (10) at the top of the steel lattice column (9), and the non-first support passes through the steel lattice column (9) and is placed on the tray (10).

10. The construction method of the easily dismantled assembled reinforced concrete foundation pit support system according to any one of claims 1 to 9, characterized in that it comprises the following steps:

1) After the hole is drilled, support piles (13), column piles, and steel lattice columns (9) are formed;

2) After roughening the pile heads of the support piles (13), the steel bars of the crown beam (8) are tied; while tying the steel bars, the first rope threading hole (3-1) of the crown beam (8) is pre-buried, the first rope threading hole (3-1) is fixed by a steel wire, and the first rope threading hole (3-1) is set 2.5 m to 5 m from the corner point of the foundation pit, and then another first rope threading hole (3-1) is set every 2.5 m to 5 m, and the holes are sealed with plaster; then, steel bars (502) are welded on the No. 1 steel plate (501), and the welded steel bars (502) are fixed on the steel cage of the crown beam (8), while ensuring that the No. 1 steel plate (501) fits the side of the crown beam (8);

3) Formwork work is performed on the crown beam (8) and the corbel (7) on the crown beam (8). After the formwork is completed, concrete is poured. After the concrete is cured, subsequent construction is performed;

4) Excavate to the bottom elevation of the first inner support beam; to facilitate welding of the tray (10) on the steel lattice column (9), the excavation depth at least 1 m is increased at the location of the steel lattice column (9); to facilitate welding of the cap (5) on the crown beam (8), the excavation depth at least 1 m is increased at the location of the cap (5);

5) Welding a tray (10) onto the steel lattice column (9);

6) Use a crane to transport the foundation pit support beam section (1) and the foundation pit support cross-beam (2) to the designed position, analyze the pressure bearing size of the horizontal foundation pit support beam section (1) and the longitudinal foundation pit support beam section (1), first assemble the foundation pit support beam section (1) and the foundation pit support cross-beam (2) of the middle position of the pair of supports in the direction of greater pressure, and assemble the pair of supports from the middle to both ends; first install the foundation pit support beam section (1) of the pair of supports located in the inner standard area (A), then assemble the non-standard area foundation pit support beam section (11) of the pair of supports located in the non-standard area (C), and then assemble the foundation pit support beam section (11) of the pair of supports located in the outer standard area (B). ), then assemble the pit support eight-shaped beam (2) of the pair of supports located in the outer standard area (B), after the construction of the pair of supports is completed, assemble the pit support beam segments (1) of the supports in the direction of less pressure on both sides, then assemble the two adjacent supports in the direction of greater pressure, and then assemble the pit support beam segments (1) of the supports in the direction of less pressure on both sides, repeat the operation until the assembly construction of all the pit support beam segments (1) and the pit support eight-shaped beam (2) of the first inner support is completed, and the pit support beam segments (1) are placed on the pallet (10) at all the beam-column nodes of the first inner support;

7) Using a No. 1 steel plate pre-buried on the crown beam (8) or the corbel (7) of the crown beam (8), a cap (5) is welded, the foundation pit support beam section (1) at the edge and the foundation pit support cross beam (2) are both placed on the cap (5) at one end, a jack (4) is placed on the concave pillow (506) of the cap (5), and the jack (4) is extended to form a first internal support;

8) Excavate to the bottom elevation of the second inner support beam; to facilitate welding of the tray (10) on the steel lattice column (9), the excavation depth at least 1 m is increased at the location of the steel lattice column (9); to facilitate welding of the cap (5) on the crown beam (8), the excavation depth at least 1 m is increased at the location of the cap (5);

9) Welding a tray (10) onto the steel lattice column (9);

10) Performing roughening treatment on the support pile (13), performing steel bar binding work on the waist beam (6), and pre-embedding work on the second rope threading hole (3-2), the second rope threading hole (3-2) is fixed by a steel wire, and the second rope threading hole (3-2) is set from 2.5 m to 5 m away from the corner point of the foundation pit, and a second rope threading hole (3-2) is set every 2.5 m to 5 m, and sealed with plaster; then, welding steel bars (502) on the No. 1 steel plate (501), and fixing the welded steel bars (502) on the steel cage of the waist beam (6);

11) Formwork work is performed on the waist beam (6) and the upper corbel (7) of the waist beam (6), and after the formwork is completed, concrete is poured, and after the concrete is cured, subsequent construction is performed;

12) Use a crane to transport the foundation pit support beam section (1) and the foundation pit support cross-beam (2) to the designed position, analyze the pressure bearing of the horizontal foundation pit support beam section (1) and the longitudinal foundation pit support beam section (1), first assemble the foundation pit support beam section (1) and the foundation pit support cross-beam (2) of the middle position of the pair of supports in the direction of greater pressure, assemble the pair of supports from the middle to both ends, first install the foundation pit support beam section of the pair of supports located in the inner standard area (A), then assemble the non-standard area foundation pit support beam section (11) of the pair of supports located in the non-standard area (C), then assemble the foundation pit support beam section (1) of the pair of supports located in the outer standard area (B), and then assemble The pit support beam (2) is provided with the pair of supports located in the outer standard area (B). After the pair of supports is constructed, the pit support beam segments (1) on both sides of the pair of supports with less pressure are assembled, and then the two pairs of supports adjacent to the pair of supports with greater pressure are assembled, and then the pit support beam segments (1) on both sides of the pair of supports with less pressure are assembled, and the operation is repeated until the assembly construction of all the pit support beam segments (1) and the pit support beam (2) of the second inner support is completed. At all the beam-column nodes of the second inner support, the pit support beam segments (1) pass through the steel lattice columns (9) and are placed on the pallet (10);

13) The cap (5) is welded by using a No. 1 steel plate (501) pre-buried on the crown beam (8) or the corbel (7) of the crown beam (8), one end of the foundation pit support beam section (1) and the foundation pit support cross beam (2) at the edge are both placed on the cap (5), a jack (4) is placed on the concave pillow (506) of the cap (5), and the jack (4) is extended to form a second inner support;

14) Repeat the steps 8), 9), 10), 11), 12), and 13) to complete the construction of the remaining internal supports below the second internal support;

15) After the installation of the last support is completed, pour the foundation slab.