Construction method of inverse pulling system of temporary horizontal steel support of underground space by top-down method

Abstract

The application provides a construction method of a counter-pulling system of temporary horizontal steel support of underground space in a reverse construction method, which comprises the following steps: installing temporary horizontal steel support between a supporting structure and adjacent steel columns after the last layer of earthwork excavation of a foundation pit is completed; wrapping an outer steel plate at a connecting joint of the steel column and the temporary horizontal steel support, fixing a lock fixed end on both sides of the outer steel plate, respectively fixing one end of two prestressed cables on the corresponding lock fixed end; pulling the other end of the two prestressed cables obliquely upwards to the direction of the supporting structure, combining the two ends into one cable to pass through the B1 plate, then pulling the cable obliquely upwards to the direction of the steel column, fixing and tensioning the cable after passing through the B0 plate, and forming a prestressed cable counter-pulling system, which can effectively offset the lateral horizontal force caused by the temporary horizontal steel support, reduce the lateral deformation of the supporting structure caused by the "time-space effect", and ensure the safety of the underground structure in the foundation pit construction process in the reverse construction method.

Description

Technical Field

[0001] This invention relates to the field of reverse construction method for underground space construction technology. Background Technology

[0002] As an effective and economical means for sustainable urban underground space development and the construction of a resource-saving society, the reverse construction method is increasingly being used in projects such as basements of super high-rise buildings and underground transportation hubs. However, the reverse construction method often faces the problem of large lateral deformation of the support structure before the foundation slab is formed.

[0003] Therefore, the invention of a reverse tension system for temporary horizontal steel supports in underground spaces using the reverse construction method to solve the problem of large lateral deformation of the support structure before the bottom slab of the underground foundation pit is formed has become a technical problem that needs to be further improved and optimized in the construction industry. Summary of the Invention

[0004] The present invention aims to develop a construction method for a reverse tension system of temporary horizontal steel supports for underground spaces in the reverse construction method, thereby solving the problem of large lateral deformation of the support structure before the bottom slab of the underground foundation pit is formed in the reverse construction method.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A construction method for a reverse-construction method of a temporary horizontal steel support anti-tension system for underground space includes the following steps:

[0007] Step 1: After the last layer of earthwork excavation in the underground foundation pit is completed, temporary horizontal steel supports are installed between the support structure and the adjacent steel columns to transfer the lateral horizontal force of the support structure.

[0008] Step 2: Wrap a steel plate around the connection node between the steel column and the temporary horizontal steel support, and fix a locking end on each side of the outer steel plate. Fix one end of each of the two prestressed cables to the corresponding locking end.

[0009] Step 3: Pull the other ends of the two prestressed cables diagonally upward toward the support structure, combine them into one strand, pass through the B1 plate, and then pull diagonally upward toward the steel column. After passing through the B0 plate, fix and tension them to form a prestressed cable counter-tension system. After the prestressed cable counter-tension system is formed, it can effectively offset the lateral horizontal force brought by the temporary horizontal steel support, reduce the lateral deformation of the support structure caused by the "space-time effect", and ensure the safety of the underground structure during the construction of the foundation pit using the reverse construction method.

[0010] Preferably, in the above-mentioned construction method of the reverse-construction underground space temporary horizontal steel support anti-tension system, the outer steel plate includes three vertically arranged steel plate components, which are respectively arranged on the three sides of the steel column. Two of the steel plate components are parallel to the temporary horizontal steel support, and one end of each of the two steel plate components is connected to both ends of the other steel plate component. A locking end is symmetrically fixed on the two steel plate components.

[0011] Preferably, in the above-mentioned construction method of the anti-tension system of temporary horizontal steel support for underground space in reverse construction, the three vertically arranged steel plate members form a U-shaped structure, and the other steel plate member is set on the side of the steel column away from the temporary horizontal steel support.

[0012] Preferably, in the above-mentioned construction method of the reverse-construction underground space temporary horizontal steel support anti-tension system, in step 1, the end of the temporary horizontal steel support adopts the method of steel plate embedded parts and lower bracket.

[0013] Preferably, in the above-mentioned construction method of the reverse construction method for the anti-tension system of temporary horizontal steel support in underground space, a first through hole is opened on the B1 plate for two prestressed cables to pass through, and a second through hole is opened on the B0 plate for two prestressed cables to pass through.

[0014] Preferably, in the above-mentioned reverse construction method for the anti-tension system of temporary horizontal steel support in underground space, the prestressed cable and the steel column form a triangular structure.

[0015] Preferably, in the above-mentioned reverse construction method for the anti-tension system of temporary horizontal steel support in underground space, the first through hole is equidistant from the support structure and the steel column, and the second through hole is set close to the steel column.

[0016] Preferably, in the above-mentioned construction method of the reverse construction method for the anti-tension system of temporary horizontal steel support in underground space, the first through hole is set vertically.

[0017] Preferably, in the above-mentioned construction method of the reverse-construction underground space temporary horizontal steel support anti-tension system, the second through hole is set obliquely upward, and the upper end of the second through hole is closer to the steel column than the lower end of the second through hole.

[0018] As can be seen from the above-disclosed technical solutions, the beneficial effects of the present invention compared with the prior art are as follows:

[0019] This invention provides a construction method for a reverse-tension system of temporary horizontal steel supports in underground spaces using a reverse construction method. After the final layer of excavation in the underground foundation pit is completed, temporary horizontal steel supports are installed between the support structure and adjacent steel columns. Steel plates are wrapped around the connection nodes between the steel columns and the temporary horizontal steel supports. A locking device is fixed to each side of the outer steel plate, and one end of each of the two prestressed cables is fixed to the corresponding locking device. The other ends of the two prestressed cables are pulled obliquely upwards towards the support structure, combined into a single strand, passing through plate B1, and then pulled obliquely upwards towards the steel column, passing through plate B0, and then fixed and tensioned to form a prestressed cable reverse-tension system. The added temporary horizontal steel supports effectively transmit the stress from the support structure. Lateral horizontal forces serve as a reliable guarantee for transverse support during underground structure construction. The tensioning of prestressed cables at the B0 slab can offset the lateral horizontal forces transmitted from the temporary horizontal steel supports to the steel columns, forming an overall stable mechanical equilibrium system. This reduces the lateral deformation of the support structure before the underground foundation pit bottom slab is formed, ensuring the safety of the underground structure. After the prestressed cable counter-tension system is formed, it can effectively offset the lateral horizontal forces brought by the temporary horizontal steel supports, reducing the lateral deformation of the support structure caused by the "space-time effect," and ensuring the safety of the underground structure during the reverse construction method of the foundation pit. In addition, the installation process of the temporary horizontal steel supports and prestressed cables used in this invention is simple and convenient, with a short construction period, and does not occupy the absolute construction period of the bottom slab. Attached Figure Description

[0020] Figure 1 This is a schematic elevation view of the anti-tension system of temporary horizontal steel supports for underground spaces constructed using the reverse construction method.

[0021] Figure 2 This is a plan view of the reverse tension system of temporary horizontal steel supports for underground spaces constructed using the reverse construction method.

[0022] In the figure: 1-support structure, 2-steel column, 3-temporary horizontal steel support, 4-outer steel plate, 5-prestressed cable, 6-B0 plate, 7-B1 plate, 8-bottom plate, 9-rigging fixing end, 10-first through hole, 11-second through hole. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The technical content and features of the present invention will be described in detail below with reference to the listed embodiments and the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention. For ease of description, the terms "upper" and "lower" used below are consistent with the upper and lower directions in the accompanying drawings, but this should not be construed as a limitation of the technical solution of the present invention.

[0024] Please see Figures 1 to 2This embodiment discloses a construction method for a reverse-construction method of a temporary horizontal steel support anti-tension system in underground space, including the following steps:

[0025] Step 1: After the last layer of earthwork excavation of the underground foundation pit is completed, a temporary horizontal steel support 3 is installed between the support structure 1 and the adjacent steel column 2 to transfer the lateral horizontal force of the support structure 1.

[0026] Step 2: At the connection node between the steel column 2 and the temporary horizontal steel support 3, a steel plate 4 is wrapped around the outside. A locking end 9 is fixed on both sides of the steel plate 4. One end of each of the two prestressed cables 5 is fixed to the corresponding locking end 9.

[0027] Step 3: Pull the other ends of the two prestressed cables 5 diagonally upward toward the support structure 1, combine them into one strand, pass through the B1 slab 7 (i.e., the first basement floor slab), and then pull diagonally upward toward the steel column 2, pass through the B0 slab 6 (i.e., the top slab), fix and tension it to form a prestressed cable counter-tension system. After the prestressed cable counter-tension system is formed, it can effectively offset the lateral horizontal force brought by the temporary horizontal steel support 3, reduce the lateral deformation of the support structure 1 caused by the "space-time effect", and ensure the safety of the underground structure during the reverse construction method of the foundation pit.

[0028] This invention provides a construction method for a reverse-tension system of temporary horizontal steel supports in underground spaces using a reverse construction method. After the final layer of earthwork excavation in the underground foundation pit is completed, temporary horizontal steel supports 3 are installed between the support structure 1 and the adjacent steel columns 2. Steel plates 4 are wrapped around the connection nodes between the steel columns 2 and the temporary horizontal steel supports 3. A locking end 9 is fixed to each side of the outer steel plate 4, and one end of each of the two prestressed cables 5 is fixed to the corresponding locking end 9. The other ends of the two prestressed cables 5 are pulled upwards towards the support structure 1, combined into one strand, pass through plate B1 7, and then pulled upwards again towards the steel column 2, passing through plate B0 6 before being fixed and tensioned, forming a prestressed cable reverse-tension system. The added temporary horizontal steel supports 3 effectively transmit the support... The lateral horizontal force of structure 1 serves as a reliable guarantee for lateral support during underground structure construction. The tension of prestressed cable 5 at B0 plate 6 can offset the lateral horizontal force transmitted from temporary horizontal steel support 3 to steel column 2, forming an overall stable mechanical equilibrium system. This reduces the lateral deformation of support structure 1 before the underground foundation slab 8 is formed, ensuring the safety of the underground structure. After the prestressed cable counter-tension system is formed, it can effectively offset the lateral horizontal force brought by temporary horizontal steel support 3, reduce the lateral deformation of support structure 1 caused by the "space-time effect", and ensure the safety of the underground structure during the reverse construction method of foundation pit construction. In addition, the installation process of temporary horizontal steel support 3 and prestressed cable 5 used in this invention is simple and convenient, with a short construction period, and does not occupy the absolute construction period of the foundation slab 8.

[0029] Preferably, in the above-mentioned construction method of the reverse-construction underground space temporary horizontal steel support anti-tension system, the B0 plate 6, B1 plate 7 and bottom plate 8 are arranged sequentially from top to bottom.

[0030] Preferably, in the above-mentioned construction method of the anti-tension system of temporary horizontal steel support for underground space using the reverse construction method, the outer steel plate 4 includes three vertically arranged steel plate components. The three steel plate components are respectively arranged on the three sides of the steel column, wherein two steel plate components are parallel to the temporary horizontal steel support 3, and one end of the two steel plate components is connected to the two ends of the other steel plate component. A locking end 9 is symmetrically fixed on the two steel plate components, which is conducive to the tension of the two prestressed cables 5 through the B0 plate 6 to evenly offset the lateral horizontal force transmitted from the temporary horizontal steel support 3 to the steel column 2, thereby improving the stability of the entire anti-tension structure.

[0031] Preferably, in the above-mentioned reverse construction method for the anti-tension system of temporary horizontal steel supports in underground space, the three vertically arranged steel plate members form a U-shaped structure, and the other steel plate member is set on the side of the steel column 2 away from the temporary horizontal steel support 3. Compared with the "U"-shaped structure, which has steel plates 4 set around the steel column 2, the U-shaped structure saves a non-stressed steel plate member and reduces construction costs.

[0032] Preferably, in the above-mentioned construction method of the reverse-construction underground space temporary horizontal steel support anti-tension system, in step 1, the end of the temporary horizontal steel support 3 adopts the method of steel plate embedded parts and lower bracket.

[0033] Preferably, in the above-mentioned construction method of the reverse construction method for the anti-tension system of temporary horizontal steel support in underground space, a first through hole 10 is opened on the B1 plate 7 for two prestressed cables 5 to pass through, and a second through hole 11 is opened on the B0 plate 6 for two prestressed cables 5 to pass through.

[0034] Preferably, in the above-mentioned reverse construction method for the anti-tension system of temporary horizontal steel support in underground space, the prestressed cable 5 and the steel column 2 form a triangular structure, thereby forming an anti-tension structure.

[0035] Preferably, in the above-mentioned construction method of the reverse construction method for the anti-tension system of temporary horizontal steel support in underground space, the first through hole 10 is equidistant from the support structure 1 and the steel column 2, and the second through hole 11 is set close to the steel column 2. In this way, the anti-tension effect can be improved.

[0036] Preferably, in the above-mentioned construction method of the reverse-construction underground space temporary horizontal steel support anti-tension system, the first through hole 10 is set vertically.

[0037] Preferably, in the above-mentioned construction method of the reverse construction method for the anti-tension system of temporary horizontal steel support in underground space, the second through hole 11 is set obliquely upward, and the upper end of the second through hole 11 is closer to the steel column 2 than the lower end of the second through hole 11, which can further improve the anti-tension effect.

[0038] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A construction method for a reverse-construction method of a counter-tension system for temporary horizontal steel supports in underground spaces, characterized in that, Includes the following steps: Step 1: After the last layer of earthwork excavation in the underground foundation pit is completed, temporary horizontal steel supports are installed between the support structure and the adjacent steel columns to transfer the lateral horizontal force of the support structure. Step 2: Wrap a steel plate around the connection node between the steel column and the temporary horizontal steel support, and fix a locking end on each side of the outer steel plate. Fix one end of each of the two prestressed cables to the corresponding locking end. Step 3: Pull the other ends of the two prestressed cables diagonally upward toward the support structure, combine them into one strand, pass through the first basement floor slab, and then pull diagonally upward toward the steel column. After passing through the top slab, fix and tension them to form a prestressed cable reverse tension system.

2. The construction method of the reverse-construction method for the anti-tension system of temporary horizontal steel supports in underground space as described in claim 1, characterized in that, The outer steel plate includes three vertically arranged steel plate components, which are respectively set on the three sides of the steel column. Two of the steel plate components are parallel to the temporary horizontal steel support. One end of each of the two steel plate components is connected to both ends of the other steel plate component. A locking end is symmetrically fixed on the two steel plate components.

3. The construction method of the reverse-construction method for the anti-tension system of temporary horizontal steel supports in underground spaces as described in claim 2, characterized in that, The three vertically arranged steel plate components form a U-shaped structure, and the other steel plate component is located on the side of the steel column away from the temporary horizontal steel support.

4. The construction method of the reverse-construction method for the anti-tension system of temporary horizontal steel supports in underground spaces as described in claim 1, characterized in that, In step 1, the temporary horizontal steel support ends are constructed using embedded steel plates and lower brackets.

5. The construction method of the reverse-construction method for the anti-tension system of temporary horizontal steel supports in underground spaces as described in claim 1, characterized in that, A first through hole is provided on the basement floor slab for two prestressed cables to pass through, and a second through hole is provided on the top slab for two prestressed cables to pass through.

6. The construction method of the reverse-construction method for the anti-tension system of temporary horizontal steel supports in underground space as described in claim 5, characterized in that, The prestressed cable and the steel column form a triangular structure.

7. The construction method of the reverse-construction method for the anti-tension system of temporary horizontal steel supports in underground spaces as described in claim 5, characterized in that, The first through hole is equidistant from the support structure and the steel column, and the second through hole is located close to the steel column.

8. The construction method of the reverse-construction method for the anti-tension system of temporary horizontal steel supports in underground space as described in claim 5, characterized in that, The first through hole is set vertically.

9. The construction method of the reverse-construction method for the anti-tension system of temporary horizontal steel supports in underground space as described in claim 5, characterized in that, The second through hole is set at an angle upward, and the upper end of the second through hole is closer to the steel column than the lower end of the second through hole.

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