Shield launching method suitable for water-rich sand layer non-expanded-end shield launching well subway station

Abstract

The invention discloses a subway station shield launching method suitable for a water-rich sand layer non-expanded-end shield launching well, and relates to the technical field of subway station shield machine launching construction, the method comprises the following steps: S1, a station main body construction stage construction process: firstly completing station east half-range top plate and fender post construction; then main body foundation pit supports are erected, and earthwork is excavated; reinforcing the slurry soil body again; s2, a construction procedure of a corner post construction stage: firstly chiseling off a fender post; then, a soil retaining steel plate also serving as a column formwork is constructed; the corner columns are constructed again, and the shield ring beams are left; finally, when the concrete reaches the strength, the temporary columns are chiseled away; s3, a construction procedure in a shield construction stage; and S4, a construction procedure of a later side wall construction stage. The problem that starting and receiving of the shield tunneling machine are affected by urban land occupation conditions is solved, and construction safety and construction quality are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of shield machine starting construction at subway stations, and more particularly to the technical field of a shield starting method for subway stations with a shield starting shaft without an enlarged end in a water-rich sand layer. Background Art

[0002] Most subway stations are built in the city center. Due to the limited construction space conditions, open excavation (partial cover excavation) and sequential construction methods are mostly adopted during the construction phase. The foundation pit support system adopts bored cast-in-place piles + hanging mesh sprayed anchors + internal support system, and sprayed concrete and steel mesh are used as the primary support system between the piles in the pit.

[0003] Shield machine launch and reception require the reservation of expanded shield shafts at both ends of the station. The station shield shaft must be approximately 2m larger than the standard section width to accommodate shield machine launch and reception operations. If the station construction location is limited by environmental factors such as pipelines, buildings, and roads, shield shafts cannot be constructed, failing to meet shield machine construction requirements and impacting shield machine launch and reception operations.

[0004] The present invention aims to solve the problem that the shield shaft cannot be formed due to the restrictive conditions of the surrounding environment of the station, which in turn affects the shield construction. It provides a construction method after removing some retaining piles and partial side walls in the station, which solves the problem that the starting and receiving of the shield machine are affected by the urban land conditions, and ensures construction safety and quality. Summary of the Invention

[0005] The purpose of the present invention is: in order to solve the above technical problems, the present invention provides a shield starting method for subway stations with shield starting shafts without enlarged ends in water-rich sand layers.

[0006] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0007] The present invention provides a shield starting method for a subway station with a shield starting shaft without an enlarged end in a water-rich sand layer, comprising the following steps:

[0008] S1. Construction process of the main station construction phase:

[0009] First, the roof and retaining piles of the eastern half of the station were completed; then, the main foundation pit supports were erected and earthwork was excavated; then, the main structure of the station and temporary columns were constructed, while conditions for the construction of corner columns were reserved; then, the main structure of the shield shaft was completed; and finally, the soil was reinforced by horizontal grouting.

[0010] S2, corner column construction phase construction process:

[0011] First, remove the retaining piles; then construct the retaining steel plates that also serve as column formwork; then construct the corner columns and the remaining shield ring beams; finally, after the concrete reaches the required strength, remove the temporary columns;

[0012] S3, Shield construction phase construction process:

[0013] First, some retaining piles were removed and welded steel plates were laid. Then, the shield tunnel went down the right line and moved horizontally to the left line. Finally, the left line shield tunnel began to advance.

[0014] S4, construction process of the side wall construction stage:

[0015] First, the left-line shield construction is completed; then the negative ring is removed, and finally the side wall structure and the post-cast shield ring beam are cast. In one embodiment, in step S1, the station main construction phase specifically includes the following:

[0016] S11. Construction of the underground third floor of the station: Construction of the underground third floor floor slab and underground third floor side walls (12 meters of the side walls on the left line will be reserved for later construction). Simultaneously, temporary columns and part of the shield ring beam will be constructed on the underground third floor side walls. End side beams will be constructed on the top of the underground third floor side walls.

[0017] S12. Construction of the underground second floor of the station: Construct the underground second floor floor slab and the underground second floor side walls. End beams are installed at the ends of the underground second floor slab. When constructing the underground second floor slab, remove the piles in the end beam range (②). The contact surface between the underground second floor slab and the soil is fully paved with steel plates (which also serve as formwork). The end beams are constructed in one go, and corner column steel bar connectors are reserved in the end beams.

[0018] S13. Construction of the underground first floor of the station: Construction of the underground first floor bottom plate and the underground first floor side wall. After the construction of the underground first floor bottom plate is completed, deep hole grouting reinforcement is carried out on the soil outside the pile drilling range.

[0019] In one embodiment, in step S13, during deep hole grouting reinforcement, since grouting needs to be performed below the water level, in order to ensure soil reinforcement and water-stopping effects, the grouting depth is 6 m outside the pile, and the grouting range is 3 m above the end beam and 1 m below the corner column.

[0020] In one embodiment, in step S13, a double slurry of water glass and cement slurry is used, and the grouting pressure is controlled at 0.5 MPa to 1.0 MPa.

[0021] In one embodiment, in step S2, during the construction process of the corner column construction phase, after the horizontal grouting reinforcement is completed, the retaining piles are chiseled out, and the excavation is chiseled out three times from bottom to top, followed by full laying of 10 mm thick steel plate support (also serving as column formwork), the steel plate is anchored and connected to the retaining piles, and the corner column reinforced concrete construction is carried out in sections, and the remaining shield ring beam is constructed at the same time.

[0022] In one embodiment, in step S3, during the shield starting phase construction process, after the corner column construction is completed, the encroaching part of the retaining pile is chiseled out, and the retaining pile range is fully reinforced with 10 mm thick steel plates. The steel plates are made in blocks (2 m × 0.2 m) and fully welded. As a water-stopping and reinforcement measure, the steel plates and the retaining piles are connected with expansion bolts. The horizontal spacing of the bolts is 1.3 m and the vertical spacing is 0.4 m. After the corner columns meet the strength requirements, the temporary columns are removed and the shield construction begins.

[0023] In one embodiment, in step S4, in the construction process of the subsequent side wall construction phase, after the shield construction is completed and the negative ring is removed, the remaining permanent side wall is constructed to complete the construction task.

[0024] The beneficial effects of the present invention are as follows:

[0025] The present invention is rationally designed, and includes the following construction procedures: the station main body construction phase, the corner column construction phase, the shield construction phase, and the subsequent side wall construction phase; it aims to solve the problem that the shield shaft cannot be formed and the shield machine starting space is insufficient due to the influence of the surrounding environmental restrictions of the station, thereby affecting the shield machine's initial construction. It provides a construction method in which some retaining piles are chiseled out in the station and some side walls of the station are built afterwards, solves the problem that the shield machine's initialization and reception are affected by the urban land conditions, solves the construction process difficulty of the shield machine's smooth starting and exit from the shaft, and ensures construction safety and quality.

[0026] The aim is to solve the problem of force conversion in the main structure of the station. A method is provided to construct temporary columns during the construction of the station structure to temporarily bear the vertical bearing capacity of the station. After the main structure of the station is completed, permanent corner columns are constructed using the hidden excavation method to permanently bear the vertical bearing capacity of the station. At the same time, the temporary columns are removed to solve the problem of structural force conversion.

[0027] Aiming to solve the problem of water leakage on the side walls of retaining piles in water-rich sand layers, 10mm thick steel plates are laid throughout the retaining pile area. The steel plates are rigidly connected to the retaining piles, and combined with horizontal grouting reinforcement outside the retaining piles, the soil is consolidated and a local water-stop curtain is formed. This provides a solution to prevent side wall leakage from affecting construction, while also strengthening the retaining piles. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1The present invention is a process flow chart of a shield starting method for a subway station with a shield starting shaft without an expanded end in a water-rich sand layer.

[0030] Figure 2 This is a schematic diagram of the shield machine working after construction is completed.

[0031] Figure 3 It is a schematic diagram of the construction process during the main construction phase of the station.

[0032] Figure 4 yes Figure 3 Cross-sectional view from the top direction.

[0033] Figure 5 yes Figure 3 Elevation section view of .

[0034] Figure 6 It is a schematic diagram of the construction process during the corner column construction phase.

[0035] Figure 7 yes Figure 6 Cross-sectional view from the top direction.

[0036] Figure 8 yes Figure 6 A sectional view in the elevation direction.

[0037] Figure 9 It is a schematic diagram of the construction process during the shield construction phase.

[0038] Figure 10 yes Figure 9 A partial cross-sectional view of .

[0039] Figure 11 yes Figure 9 A cross-sectional view in the top direction.

[0040] Figure 12 yes Figure 9 A sectional view in the elevation direction.

[0041] Figure 13 It is a schematic diagram of the construction process in the later side wall construction stage.

[0042] Figure 14 yes Figure 13 Top view of . DETAILED DESCRIPTION

[0043] To make the technical problems, technical solutions, and technical effects of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0045] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. In addition, the terms "first," "second," etc. are used only to distinguish the descriptions and are not to be understood as indicating or implying relative importance.

[0046] In the description of the embodiments of the present invention, it should be noted that the terms "inside", "outside", "upper", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0047] Example 1

[0048] like Figures 1 to 2 As shown, this embodiment provides a shield starting method for a subway station with a shield starting shaft without an enlarged end in a water-rich sand layer, comprising the following steps:

[0049] S1. Construction process of the main station construction phase:

[0050] First, the roof and retaining piles of the eastern half of the station were completed; then, the main foundation pit supports were erected and earthwork was excavated; then, the main structure of the station and temporary columns were constructed, while conditions for the construction of corner columns were reserved; then, the main structure of the shield shaft was completed; and finally, the soil was reinforced by horizontal grouting.

[0051] S2, corner column construction phase construction process:

[0052] First, remove the retaining piles; then construct the retaining steel plates that also serve as column formwork; then construct the corner columns and the remaining shield ring beams; finally, after the concrete reaches the required strength, remove the temporary columns;

[0053] S3, Shield construction phase construction process:

[0054] First, some retaining piles were removed and welded steel plates were laid. Then, the shield tunnel went down the right line and moved horizontally to the left line. Finally, the left line shield tunnel began to advance.

[0055] S4, construction process of the side wall construction stage:

[0056] First, the left-line shield construction was completed; then the negative ring was removed, and finally the side wall structure and post-cast shield ring beam were poured.

[0057] Example 2

[0058] like Figures 3 to 5 As shown, this embodiment is further optimized based on the embodiment 1, specifically:

[0059] In step S1, the station main construction phase specifically includes the following procedures:

[0060] S11. Construction of the underground third floor of the station: Construction of the underground third floor floor slab and underground third floor side walls (12 meters of the side walls on the left line will be reserved for later construction). Simultaneously, temporary columns and part of the shield ring beam will be constructed on the underground third floor side walls. End side beams will be constructed on the top of the underground third floor side walls.

[0061] S12. Construction of the underground second floor of the station: Construct the underground second floor floor slab and the underground second floor side walls. End beams are installed at the ends of the underground second floor slab. When constructing the underground second floor slab, remove the piles in the end beam range (②). The contact surface between the underground second floor slab and the soil is fully paved with steel plates (which also serve as formwork). The end beams are constructed in one go, and corner column steel bar connectors are reserved in the end beams.

[0062] S13. Construction of the underground first floor of the station: Construction of the underground first floor bottom plate and the underground first floor side wall. After the construction of the underground first floor bottom plate is completed, deep hole grouting reinforcement is carried out on the soil outside the pile drilling range.

[0063] During deep hole grouting reinforcement, grouting is required below the water level. To ensure soil reinforcement and water-stopping effects, the grouting depth is 6m outside the pile, the grouting range is 3m above the end beam, and the bottom is 1m below the corner column. Water glass + cement slurry is used as a double slurry, and the grouting pressure is controlled at 0.5Mpa ~ 1.0Mpa.

[0064] Example 3

[0065] like Figures 6 to 8 As shown, this embodiment is further optimized based on embodiment 2, specifically:

[0066] In step S2, during the construction process of the corner column construction phase, after the horizontal grouting reinforcement is completed, the retaining piles are chiseled out, and the excavation is chiseled out three times from bottom to top, followed by full laying of 10mm thick steel plate support (also serving as column formwork), the steel plate is anchored and connected to the retaining piles, and the corner column reinforced concrete construction is carried out in sections, and the remaining shield ring beams are constructed at the same time.

[0067] Example 4

[0068] like Figures 9 to 12 As shown, this embodiment is further optimized based on embodiment 2, specifically:

[0069] In step S3, during the construction process of the shield starting stage, after the construction of the corner column is completed, the encroaching part of the retaining pile is chiseled out, and the retaining pile range is fully reinforced with 10mm thick steel plates. The steel plates are made in blocks (2m×0.2m) and fully welded. As a water-stopping and reinforcement measure, the steel plates and the retaining piles are connected with expansion bolts. The horizontal spacing of the bolts is 1.3m and the vertical spacing is 0.4m. After the corner column meets the strength requirements, the temporary column is removed and the shield construction begins.

[0070] Example 5

[0071] like Figures 13 and 14 As shown, this embodiment is further optimized based on embodiment 2, specifically:

[0072] In step S4, in the construction process of the subsequent side wall construction phase, after the shield construction is completed and the negative ring is removed, the remaining permanent side wall is constructed to complete the construction task.

Claims

1. A shield starting method for subway stations with no expanded end shield starting shaft in water-rich sand layers, characterized in that: The process includes the following steps: S1. Construction process of the main construction phase of the station: First, the roof and retaining piles of the eastern half of the station were completed; then, the main foundation pit supports were erected and earthwork was excavated; then, the main structure of the station and temporary columns were constructed, while conditions for the construction of corner columns were reserved; then, the main structure of the shield shaft was completed; and finally, the soil was reinforced by horizontal grouting. S2, corner column construction phase construction process: First, remove the retaining piles; then construct the retaining steel plates that also serve as column formwork; then construct the corner columns and the remaining shield ring beams; finally, after the concrete reaches the required strength, remove the temporary columns; S3, Shield construction phase construction process: First, some retaining piles were removed and welded steel plates were laid. Then, the shield tunnel went down the right line and moved horizontally to the left line. Finally, the left line shield tunnel began to advance. S4, construction process of the side wall construction stage: First, the left-line shield construction was completed; then the negative ring was removed, and finally the side wall structure and post-cast shield ring beam were poured.

2. The shield starting method for a subway station with a shield starting shaft without an enlarged end in a water-rich sand layer according to claim 1 is characterized in that: In step S1, the main construction phase of the station specifically includes the following contents: including the station underground third floor, the station underground second floor and the station underground first floor S11. Construction of the underground third floor of the station: Construction of the underground third floor floor slab and underground third floor side walls. Simultaneously, construction of temporary columns and part of the shield ring beam on the underground third floor side walls. Construction of end side beams on the top of the underground third floor side walls. S12. Construction of the underground second floor of the station: The underground second floor floor slab and the underground second floor side walls are constructed. The ends of the underground second floor floor slab are provided with end beams. When constructing the underground second floor slab, the end beams are partially chiseled out. The contact surface between the underground second floor floor slab and the soil is fully paved with steel plates. The end beams are constructed in one go, and corner column steel bar connectors are reserved in the end beams. S13. Construction of the underground first floor of the station: Construction of the underground first floor bottom plate and the underground first floor side wall. After the construction of the underground first floor bottom plate is completed, deep hole grouting reinforcement is carried out on the soil outside the pile drilling range.

3. The shield starting method for a subway station with a shield starting shaft without an enlarged end in a water-rich sand layer according to claim 2, characterized in that: In step S13, during deep hole grouting reinforcement, grouting is required below the water level. To ensure soil reinforcement and water-stopping effects, the grouting depth is 6m outside the pile, and the grouting range is 3m above the end beam and 1m below the corner column.

4. The shield starting method for a subway station with a shield starting shaft without an enlarged end in a water-rich sand layer according to claim 2 is characterized in that: In step S13, a double slurry of water glass and cement slurry is used, and the grouting pressure is controlled at 0.5 MPa to 1.0 MPa.

5. The shield starting method for a subway station with a shield starting shaft without an enlarged end in a water-rich sand layer according to claim 3 is characterized in that: In step S2, during the construction process of the corner column construction phase, after the horizontal grouting reinforcement is completed, the retaining piles are chiseled out, and the excavation is chiseled out three times from bottom to top, followed by full paving of 10mm thick steel plates for support. The steel plates are anchored and connected to the retaining piles, and the reinforced concrete construction of the corner columns is carried out in sections, and the remaining shield ring beams are constructed at the same time.

6. The shield starting method for a subway station with a shield starting shaft without an enlarged end in a water-rich sand layer according to claim 4 is characterized in that: In step S3, during the construction process of the shield starting stage, after the construction of the corner column is completed, the encroaching part of the retaining pile is chiseled out, and the retaining pile range is fully reinforced with 10mm thick steel plates. The steel plates are made in blocks and fully welded. As a water-stopping and reinforcement measure, the steel plates and the retaining piles are connected with expansion bolts. The horizontal spacing of the bolts is 1.3m and the vertical spacing is 0.4m. After the corner column meets the strength requirements, the temporary column is removed and the shield construction begins.

7. The shield starting method for a subway station with a shield starting shaft without an enlarged end in a water-rich sand layer according to claim 6, characterized in that: In step S4, in the construction process of the subsequent side wall construction phase, after the shield construction is completed and the negative ring is removed, the remaining permanent side wall is constructed to complete the construction task.

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