A construction method for building a cross-river subway underground station

Abstract

The application provides a construction method for building a cross-river subway underground station, relates to the field of rail transit construction technology, and aims at the problems of low construction efficiency and poor long-term operation reliability of the cross-river subway underground station. After a cofferdam is arranged, the cofferdam at the upstream is used as a construction road, the upstream cofferdam is directly used for construction during the construction of the supporting structure, the strength of the cofferdam is increased and the anti-seepage capacity of the cofferdam is improved, the temporary supporting structure in the foundation pit supporting structure is designed as a permanent structure, the anti-floating capacity of the underground subway station is improved, the waste of construction materials is greatly reduced, the reliability requirement of long-term operation of the station is met, a diversion pipe is arranged to guide the river water, the drainage requirement is met, and the flood control requirement is met.

Description

Technical Field

[0001] This invention relates to the field of rail transit construction technology, specifically to a construction method for building underground subway stations across rivers. Background Technology

[0002] As urban rail transit networks become increasingly dense and more numerous, the construction of subway stations presents numerous challenges during station site planning and construction, such as the construction of underground subway stations spanning rivers. The construction of such stations will face a series of issues, including pre-construction river diversion, river flow management, material transportation via temporary access roads, flood control risks during construction, foundation pit sealing and dewatering, post-construction structural buoyancy resistance, and riverbed erosion.

[0003] By employing existing technologies, such as constructing sluice gates or dams, or utilizing pumping systems for water level control, and to ensure smooth construction, it is necessary to consider how to transport the necessary materials and equipment. Generally, containers and conveyor belts are used to transport materials and equipment from land to the construction site. To cope with the buoyancy pressure caused by rising groundwater levels, reinforcement measures can be taken, such as deep anchor bolts and anti-uplift piles, to improve the stability and anti-buoyancy capacity of the station structure. However, traditional water level control methods are insufficient to meet drainage and flood control requirements. The construction process for the anti-buoyancy structures is complex, prolonging construction time and making it difficult to meet the construction schedule requirements, while also increasing project investment. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a construction method for building underground subway stations across rivers. After setting up a cofferdam, the upstream cofferdam also serves as a construction access road. During the construction of the support structure, construction is carried out directly on the upstream cofferdam, increasing the strength of the cofferdam and improving its anti-seepage ability. The temporary support structure in the foundation pit support mechanism is designed as a permanent structure, improving the anti-buoyancy ability of the subway station and greatly reducing the waste of construction materials. A diversion pipe is set up to divert river water, meeting the needs of drainage and flood control.

[0005] The purpose of this invention is to provide a construction method for building underground subway stations across rivers, which includes the following scheme:

[0006] Construct a diversion pipe to connect the upstream and downstream of the river channel above the station area; construct an upstream cofferdam for the river channel upstream of the station area and a downstream cofferdam for the river channel downstream.

[0007] The first support structure is constructed at the upstream cofferdam, and the second support structure is constructed on the downstream cofferdam side near the station.

[0008] The station foundation pit was excavated in stages, and a supporting structure was constructed.

[0009] A protective structure was constructed at the bottom of the foundation pit, and the main structure of the station was then constructed.

[0010] A connecting force transmission plate is installed on the top surface of the main structure to establish a reliable connection between the connecting force transmission plate, the first support structure, the first support structure, and the second support structure.

[0011] The riverbed structure was restored, and the portion of the first support structure above the riverbed surface was removed. The upstream cofferdam, downstream cofferdam, and diversion pipe were also removed.

[0012] Furthermore, diversion pipes are arranged on both sides of the river channel, avoiding the river channel area above the station.

[0013] Furthermore, a construction access road is provided for the upstream cofferdam, and the first support structure passes through the upstream cofferdam and inserts into the riverbed.

[0014] Furthermore, during the excavation of the foundation pit, the upstream cofferdam of the first support structure near the station was removed, and a temporary retaining wall was constructed on top of the first support structure. The temporary retaining wall was then dismantled along with the first support structure.

[0015] Furthermore, the phased excavation of the station foundation pit and the construction of the supporting structure include:

[0016] The excavation within the station foundation pit area was carried out to the location of the first supporting structure, where a reinforced concrete supporting structure was constructed and served as a permanent structure.

[0017] The station foundation pit was excavated in stages, with steel supports installed after each stage of excavation, until the pit was excavated to the bottom.

[0018] Furthermore, the protective structure includes a protective layer and a waterproof layer; a protective structure is also provided on the top of the main structure of the station.

[0019] Furthermore, the main structure of the construction station includes:

[0020] The base slab was constructed on the protective structure, and some side walls and structural columns of the main station structure were also constructed.

[0021] Remove part of the supporting structure and retain the first supporting structure at the top of the pit, construct the remaining side walls and structural columns of the station's main structure, and then construct the top slab.

[0022] Furthermore, the restoration of the riverbed structure includes:

[0023] Impermeable clay was used for backfilling, up to the top of the first supporting structure.

[0024] Construct a paving structure on the riverbed to restore it.

[0025] Furthermore, the first support structure connects the cap beam and the anti-buoyancy top beam, and the first support structure connects the first support structure and the second support structure to form an integral structure.

[0026] Furthermore, the first support structure includes a first support body and a first water-stop curtain, with the first support body located between the first water-stop curtain and the main structure of the station; the second support structure includes a second support body and a second water-stop curtain, with the second support body located between the second water-stop curtain and the main structure of the station.

[0027] Alternatively, both the first and second support structures may be impermeable support structures.

[0028] Compared with the prior art, the advantages and positive effects of this invention are:

[0029] (1) In view of the current problems of low construction efficiency and poor long-term operational reliability of cross-river underground subway stations, after setting up a cofferdam, the upstream cofferdam also serves as a construction access road. During the construction of the support structure, the upstream cofferdam is directly constructed to increase the strength of the cofferdam and improve its anti-seepage ability. The temporary support structure and temporary support structure in the foundation pit support mechanism are designed as permanent structures to improve the anti-buoyancy ability of the underground subway station, greatly reduce the waste of construction materials, meet the reliability requirements of long-term operation of the station, and set up a diversion pipe to divert river water to meet drainage needs and flood control requirements.

[0030] (2) It improved the safety of the construction of the underground subway station across the river, avoided certain construction risks, shortened the construction period, reduced the impact on the existing river channel, and reduced the area and time occupied by the river channel.

[0031] (3) The reinforced concrete connecting force transfer plate structure can increase the structural counterweight, which is beneficial to the overall anti-buoyancy of the station structure; it increases the structural stiffness, which is beneficial to the uniform distribution and transmission of the buoyancy generated by the station; as an important protective layer for the station structure, it is beneficial to resist the scouring effect of the riverbed. At the same time, the reinforced concrete connecting force transfer plate structure connects the support structure, reinforced concrete support structure, anti-buoyancy capping beam and crown beam to form an integral anti-buoyancy structure cover, which is snapped on the top of the station structure, holding and wrapping the station structure, achieving the best anti-buoyancy effect, and having the best control effect on the deformation and movement of the underground subway station structure, thereby improving the structural safety of the riverbed station for long-term use and ensuring the reliability of the safe operation of the subway.

[0032] (4) The diversion pipes are arranged on both sides of the river channel, avoiding the river channel area above the station, reducing construction procedures, reducing construction difficulty, and avoiding construction risks caused by the diversion pipes.

[0033] (5) It provides a safe, reliable, economical and reasonable construction method for the construction of underground subway stations across rivers. It does not require the installation of anti-buoyancy structures (such as anti-uplift piles) on the station structure. It has the advantages of strong feasibility, fewer construction procedures and better results, high utilization rate of engineering materials and less waste, and reduced project cost. Attached Figure Description

[0034] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0035] Figure 1 This is a schematic diagram of the underground station in an embodiment of the present invention.

[0036] Figure 2 This is a schematic diagram showing the distribution of underground stations and waterways in an embodiment of the present invention.

[0037] Figure 3 This is a schematic diagram showing the relative positions of the subway station and the river in the vertical direction in an embodiment of the present invention.

[0038] Figure 4 This is a schematic diagram of the arrangement of the guide pipe in an embodiment of the present invention.

[0039] Figure 5 This is a schematic diagram of the construction of the upstream and downstream cofferdams in an embodiment of the present invention.

[0040] Figure 6 This is a schematic diagram of the construction of the water-stop curtain and support structure in an embodiment of the present invention.

[0041] Figure 7 This is a schematic diagram of the construction of the anti-buoyancy pressure top beam in an embodiment of the present invention.

[0042] Figure 8 This is a schematic diagram of the steel support construction during the excavation of the foundation pit in an embodiment of the present invention.

[0043] Figure 9 This is a schematic diagram of the construction of a portion of the main station structure in an embodiment of the present invention.

[0044] Figure 10 This is a schematic diagram of the construction of the station roof slab in an embodiment of the present invention.

[0045] Figure 11 This is a schematic diagram of the connection force transmission plate being installed in an embodiment of the present invention.

[0046] In the diagram: 1. Main structure; 2. Top slab; 3. Side wall; 4. Bottom slab; 5. Structural column; 6. Protective layer; 7. Waterproof layer; 8.1. First support structure; 8.2. Second support structure; 9.1. First water-stop curtain; 9.2. Second water-stop curtain; 10. Crown beam; 11. Anti-buoyancy pressure top beam; 12. Reinforced concrete support; 13. Connecting force transmission plate; 14. Riverbed paving structure; 15. Riverbed; 16. Water level line; 17. Riverbank; 18.1. Upstream cofferdam; 18.2. Downstream cofferdam; 19.1. Temporary retaining wall one; 19.2. Temporary retaining wall two; 20. Steel support; 21. Diversion pipe. Detailed Implementation

[0047] Example 1

[0048] In a typical embodiment of the present invention, such as Figures 1-11 As shown, a construction method for building underground subway stations across rivers is presented.

[0049] As urban rail transit networks become increasingly dense and more and more subway stations are built, many challenges arise during the planning and construction of station locations. For the construction of underground subway stations that cross rivers, there are problems such as complex construction of anti-buoyancy structures and poor resistance to scouring of the riverbed at 15°C on the station roof, which affect the construction efficiency and long-term operational reliability of underground stations.

[0050] Based on this, this embodiment provides a construction method for building underground subway stations across rivers. By designing some temporary supports and temporary support structures in the foundation pit support mechanism as permanent structures, the demolition and waste of temporary support structures in the foundation pit of the underground subway station can be reduced, and the ability of the station structure to resist the buoyancy of water can be improved, thereby improving the station construction efficiency.

[0051] The following section, with reference to the accompanying drawings, details the construction methods used for building underground subway stations across rivers.

[0052] See Figure 1 Construction methods for building underground subway stations across rivers include:

[0053] Construct diversion pipe 21 to connect the upstream and downstream of the station area, and construct upstream cofferdam 18.1 upstream of the station area and downstream cofferdam 18.2 downstream;

[0054] The first support structure 8.1 and the first water-stop curtain 9.1 were constructed at the upstream cofferdam 18.1, and the second support structure 8.2 and the second water-stop curtain 9.2 were constructed on the side of the downstream cofferdam 18.2 near the station.

[0055] The station foundation pit was excavated in stages, and a supporting structure was constructed.

[0056] A protective structure was constructed at the bottom of the foundation pit, and the main structure 1 of the station was constructed.

[0057] A connecting force transmission plate 13 is installed between the top surfaces of the main structure 1 to establish a connection between the connecting plate, the main structure 1, the first support 8.1, and the second support 8.2;

[0058] The riverbed structure was restored, and the portions of the first retaining wall 8.1 and the first water-stop curtain 9.1 located above the riverbed surface were removed. The upstream cofferdam 18.1, the downstream cofferdam 18.2, and the diversion pipe 21 were also removed.

[0059] In the construction of underground subway stations spanning rivers, intercepting and diverting river water before construction is a crucial issue. Therefore, this embodiment employs a diversion pipe 21 to divert river water, achieving drainage and flood control purposes and reducing flood safety risks during construction. Figure 2 and Figure 3 As shown, the diversion pipes 21 are distributed on both sides of the river channel to avoid the river channel area above the station, thus meeting the flood control requirements of the river channel under extreme weather conditions such as heavy rain.

[0060] Meanwhile, to ensure the smooth progress of construction, it is necessary to consider how to transport the materials and equipment required for construction. Traditionally, containers, conveyor belts, and other temporary access equipment are used to transport materials and equipment from land to the construction site, but this still requires crossing the river. In this embodiment, the upstream cofferdam 18.1 and the river embankment 17 jointly intercept the upstream water body of the river. A construction access road is set up on the upstream cofferdam 18.1, and the first support structure passes through the upstream cofferdam 18.1 and extends below the riverbed. After the upstream cofferdam 18.1 is set up upstream of the station area, the upstream cofferdam 18.1 can serve as a construction access road, facilitating the transportation of materials and equipment across the river.

[0061] To cope with the buoyancy pressure caused by rising groundwater levels, current reinforcement measures include deep anchor bolts and pile foundation reinforcement, but these also increase the complexity of construction. In this embodiment, a combined permanent and temporary design concept is adopted, designing some temporary supports and temporary support structures in the foundation pit support mechanism as permanent structures. This reduces the waste and demolition of temporary support structures in the underground subway station foundation pit, greatly improves the station's ability to resist buoyancy, significantly reduces the waste of construction materials, and saves project costs.

[0062] Since the subway station is located below the riverbed 15 and the water level 16 is above the station roof slab 2, the station roof slab 2 is subject to scouring by the riverbed 15 as the station operates for a long time, which can easily lead to leakage and erosion damage to the station. In this embodiment, a waterproof layer 7 and a protective layer 6 are provided at the location of the station roof slab 2. At the same time, it is also covered with impermeable clay. The scouring resistance of the underground station roof surface is improved by the riverbed paving structure 14.

[0063] like Figure 1As shown, the main structure 1 of the station consists of a top slab 2, side walls 3, bottom slab 4, and structural columns 5. The first support structure includes a capping beam 10, an anti-buoyancy pressure top beam 11, and a reinforced concrete support 12, which connects the first support structure, capping beam 10, anti-buoyancy pressure top beam 11, connecting force transmission plate 13, and the second support structure, serving as a permanent structure to resist the buoyancy of groundwater as a whole.

[0064] Combination Figures 1-11 This paper provides a detailed introduction to the construction methods used to build underground subway stations across rivers.

[0065] Step 1: Figure 4 , Figure 5 As shown, construction should be carried out during the dry season of the river as much as possible. Several diversion pipes 21 should be constructed on both sides of the river to ensure smooth drainage during heavy rain and extreme weather conditions, and to meet flood control requirements. An upstream cofferdam 18.1 and a downstream cofferdam 18.2 should be constructed within the area on both sides of the station. The upstream cofferdam 18.1 serves as flood control and a construction access road, while the downstream cofferdam 18.2 mainly serves as flood control.

[0066] Step Two: Figure 6 As shown, the first support structure of the station is constructed at the upstream cofferdam 18.1, and the second support structure is constructed on one side of the downstream cofferdam 18.2.

[0067] Step 3: Figure 7 As shown, part of the upstream cofferdam 18.1 on one side of the first support structure of the station was excavated, and the station foundation pit was excavated to the position of the first support structure, and reinforced concrete support structure 12 was constructed.

[0068] Step Four: Figure 8 As shown, the excavation within the station foundation pit extends to 0.5m below the second support structure, where steel supports of 20mm are installed.

[0069] Step 5: Figure 9 As shown, the station foundation pit is excavated to the bottom of the pit, and the protective layer 6, waterproof layer 7, base slab 4, side wall 3 of part of the station main structure 1, and structural column 5 of part of the station main structure 1 are constructed.

[0070] Step Six: Figure 10 As shown, steel support 20 is removed, and the side wall 3 of part of the main station structure 1, the structural column 5 of part of the main station structure 1, the top slab 2 of the main station structure 1, the waterproof layer 7 of the main station structure 1, and the protective layer 6 of the main station structure 1 are constructed.

[0071] Step Seven: Figure 11As shown, a connecting force transmission plate 13 is constructed above the top slab 2 of the main structure 1 of the underground station. The connecting force transmission plate 13 is a reinforced concrete structure that serves to transmit force and prevent erosion. Impermeable clay is used to backfill the soil up to the top surface of the first supporting structure, and the riverbed paving structure 14 is constructed.

[0072] Step 8: Figure 11 As shown, temporary retaining walls 19.1 and 19.2 above the top surface of the first supporting structure were demolished, part of the first support structure was demolished, the upstream cofferdam 18.1 and the downstream cofferdam 18.2 were demolished, several diversion channels on both sides of the river were demolished, the river channel was restored, and the main structure of the underground station across the river was completed.

[0073] It is understood that this embodiment is based on a single-story underground station with two supporting structures. The station is a multi-story underground structure. When more supporting structures are set, the excavation is carried out in stages within the station foundation pit. Except for the first supporting structure which uses reinforced concrete support 12, steel support 20 is installed after each excavation until the station foundation pit is excavated to the bottom.

[0074] The first support structure includes a first support body 8.1 and a first water-stop curtain 9.1, with the first support body 8.1 located between the first water-stop curtain 9.1 and the main station structure 1; the second support structure includes a second support body 8.2 and a second water-stop curtain 9.2, with the second support body 8.2 located between the second water-stop curtain 9.2 and the main station structure 1.

[0075] Optionally, the support structure can be constructed using support piles or support walls. When using support walls, the support walls themselves are impermeable, and a water-stop curtain is not required. During the excavation of the foundation pit, after removing the upstream cofferdam 18.1 on the side of the first support structure closest to the station, a temporary retaining wall is constructed on top of the first support structure. The temporary retaining wall is removed along with the first support structure. The first support structure 8.1 and the first water-stop curtain 9.1 are set at the upstream cofferdam 18.1, which can prevent upstream water from seeping through the upstream cofferdam 18.1.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A construction method for building underground subway stations across rivers, characterized in that, include: Construct a diversion pipe to connect the upstream and downstream of the river channel above the station area; construct an upstream cofferdam for the river channel upstream of the station area and a downstream cofferdam for the river channel downstream. The first support structure is constructed at the upstream cofferdam, and the second support structure is constructed on the downstream cofferdam side near the station. The phased excavation of the station foundation pit and the construction of the supporting structure include: excavating within the station foundation pit to the position of the first supporting structure, constructing a reinforced concrete supporting structure as a permanent structure; and excavating within the station foundation pit in phases, with steel supports constructed after each phase of excavation, until the station foundation pit is excavated to the bottom. A protective structure was constructed at the bottom of the foundation pit, and the main structure of the station was then constructed. A connecting force transmission plate is installed on the top surface of the main structure to establish a reliable connection between the connecting force transmission plate, the first support structure, the first support structure, and the second support structure. Restoring the riverbed structure involves removing the portion of the first support structure above the riverbed surface, as well as dismantling the upstream and downstream cofferdams and diversion pipes. The main structure of the construction station includes: The base slab was constructed on the protective structure, and some side walls and structural columns of the main station structure were also constructed. Remove part of the supporting structure and retain the first supporting structure at the top of the foundation pit, construct the remaining side walls and structural columns of the main station structure, and then construct the top slab; The first support structure includes a cap beam, an anti-buoyancy top beam, and reinforced concrete supports. The first support structure connects the first support structure and the second support structure to form an integral structure.

2. The construction method for building an underground subway station across a river as described in claim 1, characterized in that, Diversion pipes are installed on both sides of the river channel, avoiding the river channel area above the station.

3. The construction method for building an underground subway station across a river as described in claim 1, characterized in that, A construction access road is set up for the upstream cofferdam, and the first support structure passes through the upstream cofferdam and inserts into the riverbed.

4. The construction method for building an underground subway station across a river as described in claim 3, characterized in that, When excavating the foundation pit, the upstream cofferdam of the first support structure near the station was removed, and a temporary retaining wall was constructed on top of the first support structure. The temporary retaining wall was then removed along with the first support structure.

5. The construction method for building an underground subway station across a river as described in claim 1, characterized in that, The protective structure includes a protective layer and a waterproof layer; a protective structure is also installed on the top of the main structure of the station.

6. The construction method for building an underground subway station across a river as described in claim 1, characterized in that, The restoration of the riverbed structure includes: Impermeable clay was used for backfilling, up to the top of the first supporting structure. Construct a paving structure on the riverbed to restore it.

7. The construction method for building an underground subway station across a river as described in claim 1, characterized in that, The first support structure includes a first support body and a first water-stop curtain, with the first support body located between the first water-stop curtain and the main structure of the station; the second support structure includes a second support body and a second water-stop curtain, with the second support body located between the second water-stop curtain and the main structure of the station. Alternatively, both the first and second support structures may be impermeable support structures.

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