Construction method for newly-built communication opening between underground space and existing subway station

Abstract

The invention provides a construction method for a newly-built communication port between an underground space and an existing subway station, and relates to the technical field of communication port construction, and the construction method comprises the following steps: arranging a downcast tube well, arranging a retaining wall, erecting an operation platform, breaking an underground diaphragm wall in sections and areas, building a temporary brick wall and a bottom plate cushion layer, performing waterproof construction, constructing structural reinforcing steel bars of the communication port, a template and concrete, and the like. The method is stable, reliable and high in safety, the construction period can be shortened, the construction cost is saved, the surrounding environment and noise pollution are reduced, and the environment-friendly and green construction requirements are met.

Description

Technical Field

[0001] The present invention relates to the technical field of the construction of connecting openings, and particularly to a construction method for a newly built connecting opening between an underground space and an existing subway station. Background Art

[0002] With the increasing development of urban civil buildings, newly built commercial complexes have gradually become a popular leisure and entertainment place for contemporary people. In order to facilitate the convenient travel of citizens and increase the passenger flow, newly built commercial complexes are generally set near subway stations, and connecting openings are set between the existing subway entrances and exits and the basements of newly built commercial complexes.

[0003] However, there are characteristics such as small space, dense spacing, complex retaining structures, high strength of diaphragm walls, thick and large wall steel bars with dense specifications, difficult demolition, and thick wall structures of the channel structures of existing subway stations between the underground space of newly built commercial complexes and existing rail transit structures. This has led to many construction difficulties, many unsafe factors, and great difficulty in water stoppage for the construction of newly built underground connecting openings, and there are great potential hazards of collapse, groundwater leakage, and displacement and deformation of subway tunnels. How to safely and efficiently demolish the diaphragm wall in a limited construction site to ensure one-time forming and meet the traffic function of the connecting opening of the subway station is a technical topic worthy of research. Summary of the Invention

[0004] In view of the above-mentioned prior art, the present invention proposes a construction method for a newly built connecting opening between an underground space and an existing subway station.

[0005] A construction method for a newly built connecting opening between an underground space and an existing subway station provided by the present invention includes the following steps: Step 1: Set dewatering wells: Set several first drainage holes on the retained diaphragm walls within a certain range on both sides of the diaphragm wall to be demolished; Set a number of dewatering wells outside one side of the retained diaphragm wall; Step 2: Set retaining walls: Build retaining walls at the edges of the top plates of the subway passage openings; Step 3: Build an operation platform: Build an operation platform inside the diaphragm wall to be demolished; Step 4: Demolish the diaphragm wall in sections and zones: The top of the diaphragm wall to be demolished and the diaphragm walls within a certain range on both sides are demolished by the laminated water drill method, and the remaining diaphragm walls are demolished by the wire saw cutting method; Step 5: Build temporary brick walls: Build temporary brick walls at the entrances and exits of the subway passage; Step 6: Construct the floor cushion and waterproofing: Remove the operation platform and carry out the construction of the floor cushion and waterproofing; Step 7: Construct the connecting opening structure steel bars, formwork and concrete: After the construction of the connecting opening structure, remove the retaining walls and temporary brick walls, and backfill the soil.

[0006] Preferably, in step 1, the aperture of the first water drainage hole is 30 mm, the hole spacing is 1 m * 1 m, and a water stop valve is arranged at the hole opening.

[0007] Preferably, in step 1, the depth of the dewatering pipe well is 15.2 m, a steel pipe with a diameter of 273 mm and a wall thickness of 3 mm is adopted, a 1 m sedimentation pipe is arranged at the bottom, the filter pipe is a bridge-type filter pipe of the same specification, a single-layer 60-mesh nylon filter screen is wrapped outside, the filter material is medium-coarse sand, backfilled to the groundwater level surface, and the original site soil is backfilled on it for well consolidation.

[0008] Preferably, in step 2, 15 mm thick 1:2 cement mortar is plastered on both the inner and outer sides of the retaining wall, a 30 mm second water drainage hole is arranged on the vertical surface, the hole spacing is 1 m * 1 m, a water stop valve is arranged inside the second water drainage hole, a brick masonry structural column of 670 mm * 670 mm is arranged every 4 m, and a C20 concrete coping is provided.

[0009] Preferably, in step 3, the height of the operation platform is 7.4 m, the length is 11.4 m, the width is 3.6 m, the longitudinal and transverse vertical rod spacing is 0.9 * 0.9 m, the horizontal rod step distance is 1.5 m, the height of the top safety railing is 1.5 m, and it is erected with Ф48×3.2 disk-socket steel pipes.

[0010] Preferably, in step 7, during the construction of the connection port structure, the formwork adopts 15 mm thick plywood, 40 * 40 * 2.5 mm square tube secondary ribs, and 100 * 50 * 3 mm square steel tube main ribs. Due to the rich groundwater in the surrounding area, P10 impermeable concrete is poured for the connection port structure, and post-grouting is carried out in local areas.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: A construction method for newly building a connection port between an underground space and an existing subway station provided by the present invention can safely and efficiently break a super-thick and super-high diaphragm wall in a limited construction space, and ensure the safe construction of the main structure of the underground connection port. The present invention can be used for effectively connecting and penetrating the ultra-deep underground space of a commercial complex with an existing subway station; the method is simple and practical to operate, and solves the construction problems of breaking the existing retaining structure and preventing leakage that are difficult to complete by conventional construction methods through a combined form of a laminated water drill method and a wire saw cutting method. It is stable and reliable, has high safety, shortens the construction period, saves construction costs, reduces the surrounding environment and noise pollution, and meets the requirements of environmental protection and green construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a plan view of a newly built connection port between an underground space and an existing subway station in an embodiment of the present invention.

[0013] Figure 2 is an elevation view of the diaphragm wall to be broken in an embodiment of the present invention.

[0014] Figure 3It is a schematic cross-sectional view of a newly built connection opening between the underground space and the existing subway station in an embodiment of the present invention.

[0015] In the figure, 1 is the diaphragm wall to be demolished; 2 is the first drain hole; 3 is the dewatering pipe well; 4 is the deformation joint; 5 is the temporary brick wall; 6 is the concrete capping beam; 7 is the diaphragm wall in Area I; 8 is the diaphragm wall in Area II; 9 is the diaphragm wall in Area III; 10 is the retaining wall; 11 is the operation platform; 12 is the second drain hole. Specific embodiments

[0016] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0017] Embodiment: As Figures 1-3 shown, a construction method for a newly built connection opening between the underground space and the existing subway station includes the following steps: Step 1: Set up dewatering pipe wells: Several first drain holes 2 with a pore diameter of 30 mm and a hole spacing of 1 m * 1 m are set on the retained diaphragm wall within 5 m on both sides of the diaphragm wall 1 to be demolished. A water stop valve is set at the hole opening and closed in time during heavy rain, rainstorm and other weather conditions; Two dewatering pipe wells 3 are set on the outside of one side of the retained diaphragm wall. The depth of the dewatering pipe well 3 is 15.2 m (the top elevation is -0.5 m and the bottom elevation is -15.7 m). A steel pipe with a diameter of 273 mm and a wall thickness of 3 mm is used. A 1 m sedimentation pipe is set at the bottom. The filter pipe is a bridge-type filter pipe of the same specification, wrapped with a single-layer 60-mesh nylon filter screen. The filter material is medium coarse sand and backfilled to the groundwater level, and the original site soil is backfilled on it to solidify the well to prevent a large amount of groundwater in the soil outside the diaphragm wall and the subway fat groove from flowing into the foundation pit of the subway passage opening during heavy rain and rainstorm; In this embodiment, the width of the underground connection opening is 9.0 m and the floor height is 6.15 m. Considering the construction of the steel bars and formwork of the side wall of the passage opening floor, the thickness of the diaphragm wall to be demolished is 1 m, the width is 10.75 m, and the height is 8.4 m; Step 2: Set up a retaining wall: A 480-mm-thick retaining wall 10 is built with solid bricks at the edge of the top plate of the subway passage opening to prevent the backfill soil from collapsing into the foundation pit of the connection opening; 15-mm-thick 1:2 cement mortar is plastered on both the inside and outside of the retaining wall 10. A 30-mm second drain hole 12 is set on the vertical surface with a hole spacing of 1 m * 1 m. A water stop valve is set inside the second drain hole 12. The backfill soil groundwater is discharged into the dewatering pipe well 3 through the second drain hole 12 and the water pipe. A brick structural column of 670 mm * 670 mm is set every 4 m, and a C20 concrete capping is provided; Step 3: Erect the operation platform: An operation platform 11 is erected inside the diaphragm wall 1 to be demolished. The operation platform 11 is 7.4 m high, 11.4 m long, and 3.6 m wide. The longitudinal and transverse vertical rod spacing is 0.9 * 0.9 m, the horizontal rod step distance is 1.5 m, and the height of the top guardrail is 1.5 m. It is erected with Ф48×3.2 formwork steel pipes; Step 4: Demolish the diaphragm wall in sections and zones: The diaphragm wall within 3 m at the top and 2 m on both sides of the diaphragm wall 1 to be demolished is demolished by the laminated water drill method, and the remaining diaphragm wall is demolished by the wire saw cutting method; Specifically, the demolition is divided into three zones. First, demolish the diaphragm wall 7 in Zone I and the diaphragm wall 8 in Zone II, and connect the floor slabs, roof slabs, and side walls of the two side passage openings. After the connecting port structure between the diaphragm wall 7 in Zone I and the diaphragm wall 8 in Zone II reaches the required strength, then demolish the diaphragm wall 9 in Zone III, and construct the floor slabs and roof slabs of the corresponding connecting ports to form a complete underground connecting port. The size of the diaphragm wall blocks is determined according to the lifting capacity of the tower crane or truck crane, and cutting lines are marked before demolition; Step 5: Build temporary brick walls: Temporary brick walls 5 are built at the subway passage entrances and exits to prevent subway passengers from entering the construction site. The temporary brick walls 5 are built with solid concrete bricks after the diaphragm wall 7 in Zone I is demolished. The width is 240 mm, the height is the same as the floor height of the subway passage opening, and the distance from the diaphragm wall to be demolished is 2 m; Step 6: Construction of the floor slab cushion and waterproofing: Demolish the operation platform 11 and carry out the construction of the floor slab cushion and waterproofing; Step 7: Construction of the connecting port structure's steel bars, formwork, and concrete: During the construction of the connecting port structure, the formwork uses 15-mm-thick plywood, 40*40*2.5-mm square tube secondary ribs, and 100*50*3-mm square steel tube main ribs. Since the groundwater is rich in the surrounding area, P10 impermeable concrete is poured for the connecting port structure, and post-grouting is carried out in local areas; After the construction of the connecting port structure, demolish the retaining wall 10 and the temporary brick wall 5, and backfill the soil.

[0018] The method of this embodiment can be used for the effective connection and penetration of the ultra-deep underground space of a commercial complex and an existing subway station; This method is simple and practical in operation. Through the combined form of the laminated water drill method and the wire saw cutting method, it solves the construction problems of demolishing the existing retaining structure and preventing leakage that are difficult to complete by conventional construction methods. It is stable, reliable, has high safety, shortens the construction period, saves construction costs, reduces the surrounding environment and noise pollution, and meets the requirements of environmental protection and green construction.

[0019] The above is only the implementation mode of the present invention, and it does not limit the patent scope of the present invention accordingly. All equivalent solutions made by using the content of the specification of the present invention, directly or indirectly applied in other related technical fields, are similarly within the patent protection scope of the present invention.

Claims

1. A construction method for a new connection opening between an underground space and an existing subway station, characterized in that, It includes the following steps: Step 1: Set up dewatering pipe wells: Set several first drainage holes (2) on the retained diaphragm walls within a certain range on both sides of the diaphragm wall (1) to be demolished; Set several dewatering pipe wells (3) on the outside of one side of the retained diaphragm wall; Step 2: Set up retaining walls: Build a retaining wall (10) at the edge of the top slab of the subway passage entrance; Step 3: Erect an operation platform: Erect an operation platform (11) inside the diaphragm wall (1) to be demolished; Step 4: Demolish the diaphragm wall in sections and areas: The top of the diaphragm wall (1) to be demolished and the diaphragm walls within a certain range on both sides are demolished by the laminated diamond drilling method, and the remaining diaphragm walls are demolished by the wire saw cutting method; Step 5: Build a temporary brick wall: Build a temporary brick wall (5) at the entrance and exit of the subway passage; Step 6: Construct the floor cushion and waterproofing: Demolish the operation platform (11) and carry out the construction of the floor cushion and waterproofing; Step 7: Construct the structural steel bars, formwork and concrete of the connection opening: After the construction of the connection opening structure, demolish the retaining wall (10) and the temporary brick wall (5), and backfill the soil.

2. The construction method for a new connection between an underground space and an existing subway station according to claim 1, characterized in that: In Step 1, the aperture of the first drainage hole (2) is 30mm, the hole spacing is 1m×1m, and a water stop valve is set at the hole opening.

3. The construction method for a new connection between an underground space and an existing subway station according to claim 1 or 2, characterized in that: In Step 1, the depth of the dewatering pipe well (3) is 15.2m, a steel pipe with a diameter of 273mm and a wall thickness of 3mm is used, a 1m sedimentation pipe is set at the bottom, the filter pipe is a bridge-type filter pipe of the same specification, a single-layer 60-mesh nylon filter screen is wrapped outside, the filter material is medium coarse sand, backfill to the groundwater level, and the original site soil is backfilled on it to fix the well.

4. The construction method of a new connection opening between an underground space and an existing subway station according to claim 1 or 2, characterized in that, In Step 2, 15mm thick 1:2 cement mortar is plastered on both the inside and outside of the retaining wall (10), and second drainage holes (12) with an aperture of 30mm are set on the vertical surface, the hole spacing is 1m×1m, a water stop valve is set inside the second drainage hole (12), a brick-built structural column of 670mm×670mm is set every 4m, and a C20 concrete coping is provided.

5. The construction method for a new connection between an underground space and an existing subway station according to claim 1 or 2, characterized in that: In Step 3, the height of the operation platform (11) is 7.4m, the length is 11.4m, the width is 3.6m, the longitudinal and transverse vertical rod spacing is 0.9×0.9m, the horizontal rod step distance is 1.5m, the height of the top guardrail is 1.5m, and it is erected with Ф48×3.2 formwork-connected steel pipes.

6. The construction method of a new connection opening between an underground space and an existing subway station according to claim 1 or 2, characterized in that, In Step 7, during the construction of the connection opening structure, the formwork uses 15mm thick plywood, 40×40×2.5mm square tube secondary ribs, and 100×50×3mm square steel tube main ribs. Due to the rich groundwater in the surrounding area, P10 impermeable concrete is poured for the connection opening structure, and post-grouting is carried out in some areas.

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