WO2022033503A1

WO2022033503A1 - Construction method for dismantling concrete supports of prefabricated subway station

Info

Publication number: WO2022033503A1
Application number: PCT/CN2021/111987
Authority: WO
Inventors: 刘晖; 胡云飞; 朱伯东; 胡学龙; 魏焰; 黄鹏; 王光伟; 刘远建; 高子明; 李雷; 张宝; 王超; 张永平; 徐文猛; 刘薇; 薛连; 李敏
Original assignee: 中铁八局集团昆明铁路建设有限公司; 中国中铁股份有限公司; 中铁八局集团有限公司
Priority date: 2020-08-11
Filing date: 2021-08-11
Publication date: 2022-02-17
Also published as: CN111926858A

Abstract

The present invention relates to the technical field of pile support system prefabricated station construction, and specifically relates to a construction method for dismantling concrete supports of a prefabricated subway station. The method comprises: hoisting several fixing bottom plate blocks in sequence, and tightening and locking the bottom plate blocks along the longitudinal depth direction; performing base grouting, fertilizer trough backfilling and inverted-arch backfilling; grouping according to several corresponding steel supports below first concrete supports, and dividing the concrete supports and the steel supports into a plurality of groups in the depth advancement direction; and splicing side wall blocks, middle plate blocks and top plate blocks in a group in succession according to the depth advancement direction, adding temporary supports in the construction advancement direction, and dismantling the steel supports and concrete supports in the group. By means of the disclosed construction method, the concrete supports may be dismantled simultaneously during the propulsive construction of the foundation pit and a roadway, and the original concrete supports and steel supports may be gradually dismantled when the bottom plate blocks, side wall blocks, top plate blocks and so on are spliced. The dismantling process is simple and more efficient, and is also safer and more reliable.

Description

A construction method for dismantling concrete supports of prefabricated subway stations

technical field

The invention relates to the technical field of station construction with a pile support system, in particular to a construction method for dismantling concrete supports of a prefabricated subway station.

Background technique

During the construction of the prefabricated subway station, the pre-support of the foundation pit and the roadway is completed through the first excavation construction of the foundation pit and the roadway, and then the floor block hoisting, base grouting, fertilizer tank backfilling, side wall assembly, middle plate assembly and roof plate are carried out. For construction such as assembly, it is also necessary to dismantle the pre-support and set up the long-term support.

Pre-support usually includes many concrete supports and steel structure supports, and the concrete supports are arranged at the top (first row) of the foundation pit or roadway, and the steel structure supports are arranged at the middle (second row) and bottom (third row) of the foundation pit or roadway. The concrete supports and steel structure supports are evenly arranged and grouped according to the distance according to one concrete support and multiple steel structure supports. Concrete support and steel structure support are set through pre-construction, providing great support force for foundation pit and roadway. Strict construction sequence and stress control are required during demolition. Only in this way can a safe and orderly dismantling be achieved, otherwise the uneven distribution of stress may lead to a roof fall accident or a hidden safety hazard. The existing dismantling methods are time-consuming, labor-intensive, and inefficient, resulting in a long construction period and low safety. This problem has always had a great impact on the construction of subway stations and has not been effectively solved.

Therefore, it is necessary to study and optimize the construction process to obtain a more reasonable technical solution and solve the deficiencies in the existing technology.

SUMMARY OF THE INVENTION

In order to overcome the defects of the prior art mentioned in the above content, the present invention provides a construction method for dismantling concrete supports of a prefabricated subway station, aiming to start the construction from the end of the foundation pit and the roadway and carry out the construction on the roadway. The setting of , middle and bottom plates, and the dismantling of supports are carried out at the same time to provide a safe and reliable guarantee for the construction of the roadway.

In order to achieve the above object, the technical scheme specifically adopted in the present invention is:

A construction method for dismantling concrete supports of a prefabricated subway station, the supports are gradually dismantled during the assembly construction process, including:

Hoist several fixed floor blocks in sequence, and tension and lock the floor blocks in the depth direction;

Carry out base grouting, fertilizer tank backfill and inverted arch backfill;

Group according to the corresponding steel supports below the first concrete support, and divide the concrete supports and steel supports into multiple groups in the depth direction; assemble the side wall blocks, middle blocks and roof blocks in sequence according to the depth advancing direction. Temporary supports were added in the forward direction and steel supports and concrete supports were removed within the group.

The dismantling method disclosed above is realized simultaneously in the process of advancing the construction of the foundation pit and the roadway, and the original concrete supports and steel supports can be gradually dismantled during the assembly of the floor blocks, side wall blocks, roof blocks, etc. The process is simple, the efficiency is higher, and it is safer and more reliable.

Further, the concrete supports and steel supports are evenly arranged in the depth direction. In order to facilitate disassembly, the grouping of concrete supports and steel supports is set during construction. Specifically, a feasible method is listed here. Scheme: Each set of supports includes a concrete support at the top, a steel support at the middle and a steel support at the lower part. Both the middle steel support and the lower steel support include at least two in the depth direction. As one of many feasible options, the advantage of this setting is that through the cooperation of one set of concrete supports and multiple sets of steel supports, the stress in the foundation pit and the roadway can be reasonably distributed, and the foundation pit and roadway can be reliably carried out. support, and can ensure sufficient construction space in the later stage.

Further, in order to improve the safety and reliability in the construction process, here is a specific and feasible solution: before assembling the side wall blocks, the middle plate and the top plate along the depth direction, at least one of the multiple supports of the lower steel supports shall be installed. Temporary support is set between the two parts. After the temporary support is set, the middle steel support and the lower steel support at the construction site are removed, and then the side wall blocks, the middle board and the roof board are assembled. When the temporary support is reached, the temporary support is removed.

Further, in order to improve the safety and reliability in the construction process, an additional specific and feasible solution is proposed here: before assembling the side wall blocks, the middle plate and the top plate along the depth direction, at least temporary supports are arranged at the concrete supports, After the temporary support is set, the concrete support at the construction site is removed, and then the side wall blocks, the middle block and the roof block are assembled.

Further, in the construction process, not only the bottom plate blocks need to be assembled and strengthened, but also the side wall blocks, the middle plate and the top plate. A number of side wall blocks, a number of middle panels and a number of top panels are tensioned and locked respectively.

Further, the side wall block needs to maintain a predetermined direction after tensioning and locking. Specifically, the outer side of the side wall block is provided with an enclosure pile. After the side wall block is assembled, the side wall block and the enclosure pile are connected and fastened. . The fence piles or the fence purlins can be connected and fastened to the side wall blocks, and the specific fastening method can be tightened by a jack.

Further, the concrete supports are arranged at the heights of the foundation pit and the roadway, and need to be supported and maintained during the demolition, and then hoisted and transported after demolition. Specifically, the following feasible solutions are given: when the concrete support is removed, at least two corbels are arranged under the concrete support, and both ends of the concrete support are cut simultaneously, and the concrete support falls on the corbel after being cut.

Further, the corbel can be made of various materials or structures. Here, in order to facilitate the cutting of the concrete support, a specific and feasible solution is given: the corbel is made of concrete, and a wire saw is used to cut the concrete support, and the corbel is There is a pre-embedded pipe on the top, and the wire saw passes through the pre-embedded pipe when cutting the concrete support.

Further, when hoisting the floor blocks, the specific construction operation methods are listed here: in the depth direction, the floor blocks are arranged in groups according to the number of rings, and the floor blocks are set in sequence, and then the floor blocks are hoisted ring by ring, tensioned and locked by ring, and 4 rings are assembled each time. Carry out a base grouting, and carry out a fertilizer tank backfill and an inverted arch backfill every 5 to 10 rings assembled.

Further, in the process of assembling the side wall plate, the middle plate and the top plate, the construction of the bottom plate can be carried out synchronously. Here is the following specific construction operation method: in the depth direction, set the bottom plate in groups according to the number of rings, and set them in sequence. After the floor block, carry out the backfilling of the fertilizer tank and the construction of the cast-in-place layer of the middle plate superimposition every 10 to 20 rings. After the assembly of the floor block is completed, remove the fixed end of the section steel combination, apply the reserved post-casting belt, and carry out the top plate. Backfill, restore the original ground.

Compared with the prior art, the present invention has the following beneficial effects:

The construction method disclosed in the present invention provides temporary support during the assembling process, does not affect the assembling process, and can also remove part of the pre-supported components. Through the construction method disclosed in the present invention, it can be realized synchronously in the process of advancing the construction of the foundation pit and the roadway. For the removal of concrete supports, the original concrete supports and steel supports can be gradually removed when assembling the floor blocks, side wall blocks, roof blocks, etc. The removal process is simple, more efficient, and safer and more reliable.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be It is regarded as a limitation of the scope. For those of ordinary skill in the art, other related drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is the schematic diagram of hoisting the first ring bottom plate block;

Fig. 2 is the schematic diagram of hoisting the second ring bottom plate block;

Figure 3 is a schematic diagram of longitudinal tensioning and locking of the bottom plate block;

Fig. 4 is the schematic diagram after the floor block construction is completed;

Fig. 5 is the schematic diagram of assembling the first ring side wall block, the middle block and the roof block;

Fig. 6 is the schematic diagram of dismantling the first steel support;

Fig. 7 is the schematic diagram of assembling the second ring and the third ring side wall block, middle block and roof block;

Figure 8 is a schematic diagram of adding a second temporary support at the steel support and removing the second steel support;

Fig. 9 is the schematic diagram of assembling the fourth ring and the fifth ring side wall block, middle block and roof block;

Figure 10 is a schematic diagram of adding a third temporary support at the steel support and removing the third steel support;

Figure 11 is a schematic diagram of assembling the sixth ring and the seventh ring side wall block, middle block and roof block;

Figure 12 is a schematic diagram of adding a fourth temporary support at the steel support and removing the fourth steel support;

Figure 13 is a schematic diagram of assembling the eighth ring and the ninth ring side wall block, middle block and roof block;

Figure 14 is a schematic diagram of construction completion;

Fig. 15 is the structural representation of corbel;

16 is a schematic cross-sectional view of the B-B section.

The corresponding meanings of the symbols in the accompanying drawings are: 1. Corbel; 2. Concrete support.

detailed description

The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

It should be noted here that the descriptions of these embodiments are used to help the understanding of the present invention, but do not constitute a limitation of the present invention. Specific structural and functional details disclosed herein are merely illustrative of example embodiments of the present invention. The present invention, however, may be embodied in many alternative forms and should not be construed as limited to the embodiments set forth herein.

Example

This embodiment is applied to a prefabricated subway station. In this embodiment, the foundation pit and the roadway are sequentially composed of a cast-in-place section with a length of 42 m, an assembly section with a length of 148 m, and a cast-in-place section with a length of 28 m. The foundation pits and roadways are mainly located in plain fill, silty clay, cohesive soil gravel, strongly weathered tuff, moderately weathered tuff and slightly weathered tuff. The foundation pits and roadways are mainly located in silty clay and cohesive soil gravel. In the sand, the base is located in strongly and moderately weathered tuff, and the anti-floating water level elevation is 12m.

The size of the cross-section of the concrete support to be removed is 1000mm×800mm, the length is 22m, and the weight of the concrete support is about 44t. Demolition of concrete supports is carried out in foundation pits and roadways from construction to assembly.

Specifically, the present embodiment discloses a construction method for dismantling concrete supports of a prefabricated subway station. During the assembly construction process, the supports are gradually dismantled, including:

Carry out base grouting, fertilizer tank backfill and inverted arch backfill;

Group according to the corresponding two steel supports below the first concrete support, and divide the concrete support and steel support into multiple groups in the depth direction; assemble the side wall block, middle plate and top plate in sequence according to the depth advancing direction. Temporary supports were added in the forward direction and steel supports and concrete supports were removed within the group.

As shown in Figure 1 to Figure 4, the specific steps can be as follows:

S01: Hoist the first ring bottom plate block A1, and tension and lock it longitudinally with the first ring fixed section steel bracket.

S02: The second step: hoist the second ring base plate block A2.

S03: Move the A2 block to the A1 direction, and longitudinally tension and lock the A2 block and the A1 block through the longitudinal relay steel rod.

S04: The bottom plate continues to be hoisted forward and ring by ring, and tensioned and locked by ring by ring. Base grouting is carried out once every 4 rings are assembled, and every 5 to 10 rings can be backfilled with fertilizer grooves on both sides of the bottom plate and inverted arch backfilling above the bottom plate. Complete the bottom plate assembly, grouting, backfilling and other processes.

Concrete supports and steel supports are evenly arranged in the depth direction. In order to facilitate disassembly, the grouping of concrete supports and steel supports is set during construction. Specifically, here is a feasible solution: each The group support includes a concrete support at the top, a steel support at the middle and a steel support at the lower part, and both the middle steel support and the lower steel support include at least two in the depth direction. As one of many feasible options, the advantage of this setting is that through the cooperation of one set of concrete supports and multiple sets of steel supports, the stress in the foundation pit and the roadway can be reasonably distributed, and the foundation pit and roadway can be reliably carried out. support, and can ensure sufficient construction space in the later stage.

For the concrete support located at the top, the first line is located at the end of the construction of the cast-in-place section, and the second line of concrete support meets it for 7.4m, followed by a concrete support evenly arranged every 8m; the steel support at the middle and bottom, the first One is set 3m away from the construction end of the cast-in-place section, and then a steel support is evenly set every 4m, and the middle steel support and the lower steel support are vertically aligned, and the second concrete support is aligned with the second steel support Bracing, the third concrete brace aligns with the fourth steel brace, the third concrete brace aligns with the sixth steel brace...and so on.

In order to improve the safety and reliability in the construction process, here is a specific and feasible solution: before assembling the side wall blocks, the middle plate and the top plate along the depth direction, at least temporarily set up temporary support between the multiple supports of the lower steel support. Support, after the temporary support is set, remove the middle steel support and the lower steel support at the construction site, and then assemble the side wall, middle and top panels. When the assembly reaches the temporary support, remove the temporary support.

The temporary support adopts steel support, which is arranged between two steel supports inside each group of supports, and the temporary support between the two steel supports is located in the middle position, and the distance between the nearest steel supports at the front and rear is 2m. And when temporary support is set, the distance between the first steel support closest to the construction position is 800mm from the side wall block, middle plate and roof plate, and the distance between the subsequent steel support and the side wall block, middle plate and roof plate is 1m.

In order to improve the safety and reliability in the construction process, an additional specific and feasible solution is proposed here: before assembling the side wall blocks, the middle plate and the top plate along the depth direction, at least temporary supports shall be provided at the concrete supports, and temporary supports shall be provided. After that, remove the concrete support at the construction site, and then assemble the side wall, middle and top panels. During construction, the position of the temporary support is pushed 1.6m from the concrete support to the construction position, and the distance between two adjacent temporary support brackets is 8m.

As shown in Figure 5 to Figure 14, the specific steps are as follows:

S05: Assemble the first ring side wall block B1, the middle block, and the top block C1 in sequence, and tension and lock them longitudinally with the fixed section steel bracket of the first ring respectively. The side wall blocks at the height of the middle slab and the steel purlins of the retaining piles are tightened by jacks, and temporary support is added before the support at the height of the middle slab is removed.

S06: Remove the first steel support G2-1 in the second row and the first steel support G3-1 in the third row to create a hoisting space for the second and third rings.

S07: Assemble the second ring and the side wall, middle plate and top plate of the third ring in sequence, and tension and lock them one by one. The side wall of the middle plate height and the steel purlin of the retaining pile are tightened by a jack.

S08: Add a steel support HC1 above the third ring roof plate C3, after applying prestress, remove the first row of the second concrete support H1-2; then remove the second row of the second steel support G2-2, Three rows of second steel support G3-2.

S09: Assemble the side wall, middle plate, and top plate of the fourth ring and the fifth ring in sequence, and tension and lock the rings one by one. The side wall of the middle plate height and the steel purlin of the retaining pile are tightened by a jack.

S10: Remove the third steel support G2-3 in the second row and the third steel support G3-3 in the third row in sequence.

S11: Assemble the side wall, middle plate, and top plate of the sixth ring and the seventh ring in sequence, and tension and lock them one by one. The side wall of the middle plate height and the steel purlin of the retaining pile are tightened by a jack.

S12: Add a steel support HC2 above the top plate C7 of the seventh ring. After applying prestress, remove the first row of the third concrete support H1-3; then remove the second row of the third steel support G2-3, The third row of three steel supports G3-3.

S13: Assemble the side walls, the middle plate and the top plate of the eighth ring and the ninth ring in sequence, and tension and lock the rings one by one. The side wall of the middle plate height and the steel purlin of the retaining pile are tightened by a jack. The subsequent assembly process repeats the above steps.

During the construction process, not only the bottom plate blocks need to be assembled and strengthened, but also the side wall blocks, the middle plate and the top plate. The wall blocks, some middle blocks and some top blocks are respectively tensioned and locked. The specific tensioning and locking method can adopt the conventional method in the industry.

After the side wall block is tensioned and locked, it needs to maintain a predetermined direction. Specifically, the outer side of the side wall block is provided with an enclosure pile. After the side wall block is assembled, the side wall block and the enclosure pile are connected and fastened. The fence piles or the fence purlins can be connected and fastened to the side wall blocks, and the specific fastening method can be tightened by a jack.

As shown in Figure 15 and Figure 16, the concrete supports are arranged at the heights of the foundation pit and roadway, and need to be supported and maintained during dismantling, and then hoisted and transported after dismantling. Specifically, the present embodiment adopts the following feasible solution: when the concrete support 2 is removed, at least two corbels 1 are arranged under the concrete support 2, and both ends of the concrete support 2 are cut at the same time. on leg 1.

A variety of materials or structures can be used for the corbel. Here, in order to facilitate the cutting of concrete support, this embodiment presents a specific and feasible solution: the corbel is made of concrete, and a wire saw is used to cut the concrete support. There is a pre-embedded pipe on the top, and the wire saw passes through the pre-embedded pipe when cutting the concrete support.

When hoisting the floor blocks, the specific construction operation methods are listed here: in the depth direction, set the floor blocks in groups according to the number of rings, set the floor blocks in sequence, hoist them one by one, tension and lock them one by one, and make a base for every 4 rings assembled. Grouting, every 5 to 10 rings are assembled to carry out backfilling of the fertilizer tank and backfilling of the inverted arch.

In the process of assembling the side wall panels, middle panels and top panels, the construction of the floor panels can be carried out simultaneously. The following specific construction operation methods are listed here: in the depth direction, set the floor panels in groups according to the number of rings, and then set the floor panels in sequence. , every 10 to 20 rings, carry out backfilling of the fertilizer tank and the construction of the cast-in-place layer of the middle plate. After the bottom plate is assembled, remove the fixed end of the steel combination, and apply the reserved post-casting belt of 1m, and carry out the backfill above the top plate. , to restore the original ground.

The above are the listed embodiments of the present invention, but the present invention is not limited to the above-mentioned optional embodiments. Those skilled in the art can arbitrarily combine the above-mentioned methods to obtain other various embodiments. Various other forms of implementation can be derived. The above specific embodiments should not be construed as limiting the protection scope of the present invention, which should be defined in the claims, and the description can be used to interpret the claims.

Claims

A construction method for dismantling concrete supports of prefabricated subway stations, characterized in that the supports are gradually dismantled during the assembly construction process, including:

Hoist several fixed floor blocks in sequence, and tension and lock the floor blocks in the depth direction;

Carry out base grouting, fertilizer tank backfill and inverted arch backfill;

Group according to the corresponding steel supports below the first concrete support, and divide the concrete supports and steel supports into multiple groups in the depth direction; assemble the side wall blocks, middle blocks and roof blocks in sequence according to the depth advancing direction. Temporary supports were added in the forward direction and steel supports and concrete supports were removed within the group.
The construction method for dismantling the concrete support of a prefabricated subway station according to claim 1, is characterized in that:

Each set of supports includes a concrete support at the top, a steel support at the middle and a steel support at the lower part, and each of the middle steel support and the lower steel support includes at least two in the depth direction.
The construction method for dismantling the concrete support of a prefabricated subway station according to claim 2, is characterized in that:

Before assembling the side wall block, middle block and roof block along the depth direction, set up temporary supports at least between the multiple supports of the lower steel supports. Assemble the side wall, middle and top panels. When the assembly reaches the temporary support, remove the temporary support.
The construction method for dismantling the concrete support of a prefabricated subway station according to claim 2, is characterized in that:

Before assembling the side wall, middle and top panels along the depth direction, set up temporary supports at least at the concrete supports. assembled.
The construction method for dismantling the concrete support of a prefabricated subway station according to claim 1, is characterized in that:

When assembling the side wall blocks, the middle block and the top block in sequence, tension and lock several side wall blocks, some middle blocks and some top blocks respectively in the depth direction.
The construction method for dismantling the concrete support of a fabricated subway station according to claim 1 or 5, characterized in that:

The outer side of the side wall block is provided with an enclosure pile, and after the side wall block is assembled, the side wall block and the enclosure pile are connected and fastened.
The construction method for dismantling the concrete support of a prefabricated subway station according to claim 1, is characterized in that:

When dismantling the concrete support, at least two corbels are arranged under the concrete support, and both ends of the concrete support are cut at the same time, and the concrete support falls on the corbel after being cut.
The construction method for dismantling the concrete support of a prefabricated subway station according to claim 7, characterized in that:

The corbel is made of concrete, and a wire saw is used to cut the concrete support. The corbel is provided with a pre-buried pipe, and the wire saw passes through the pre-buried pipe when cutting the concrete support.
The construction method for dismantling the concrete support of a prefabricated subway station according to claim 1, is characterized in that:

In the depth direction, set the floor blocks in groups according to the number of rings, set the floor blocks in sequence, and then hoist them one by one, stretch and lock them one by one, and perform base grouting once every 4 rings assembled, and once every 5 to 10 rings are assembled. Arch backfill.
The construction method for dismantling the concrete support of a prefabricated subway station according to claim 1, is characterized in that:

In the depth direction, set the floor blocks in groups according to the number of rings. After the floor blocks are set in sequence, the backfilling of the fertilizer tank and the construction of the cast-in-situ layer of the middle plate are carried out every 10 to 20 rings. Apply the reserved post-pouring belt, and backfill the top of the roof to restore the original ground.