A method for treating backfill soil with anti-sinking piles in dark excavation areas

Abstract

The invention discloses a method for treating backfill soil with anti-sinking piles in a dark excavation interval, and the steps are: excavating and supporting the first section of the dark excavation interval in a set dark excavation interval tunnel along the direction of vehicle travel, and then supporting a plurality of arch frames at intervals in the dark excavation interval along the direction of vehicle travel; drilling holes and driving anti-sinking pile foundations at set anti-sinking pile foundation positions in the dark excavation interval between two adjacent inverted arch frames; spraying concrete on all inverted arch frames and all arch ring arch frames to form initial support; then laying a waterproof layer on the initial support; and pouring a secondary lining on the waterproof layer. The invention allows the force during tunnel construction and later operation to be transmitted to the underground by the anti-sinking piles, safely and smoothly passing through the backfill layer, and ensuring safety and stability during construction and operation.

Description

Technical Field

[0001] The invention relates to a method for processing backfill soil, in particular to a method for processing backfill soil using anti-sinking piles in a dark excavation interval. Background Art

[0002] The section is the area between two stations in urban rail transit. It can be used as a bridge on the ground or as a tunnel underground. Tunnels are divided into dark excavation and open excavation. Open excavation is directly excavated from the ground and backfilled after construction, while dark excavation is directly drilled and excavated underground. Dark excavation section tunnels passing through cities often encounter backfill layers. The treatment of tunnel crossing backfill soil sinking generally adopts treatment measures such as replacement and grouting reinforcement. Deep underground excavation and replacement are prone to risks such as stepping on the air and roof collapse. Large-scale grouting reinforcement is not economical and cannot guarantee safety and stability during operation after completion. In the context of rapid urban development, urban backfill areas are common. Underground section tunnels often need to pass through special strata such as backfill areas. Ordinary replacement and grouting methods can only ensure safe crossing during construction, but cannot guarantee safe operation during operation. They are expensive, and the overall backfill area of ​​the tunnel will still sink and settle. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for treating backfill soil with anti-sinking piles in dark-cut sections that realizes pile foundation construction in a dark-cut tunnel and is safer, more economical and has a longer service life and safely and smoothly crosses the backfill area.

[0004] A method for treating backfill soil with anti-sinking piles in a dark excavation area according to the present invention comprises the following steps:

[0005] Step 1: excavate and support the first section of the dark excavation interval in the set dark excavation interval tunnel along the vehicle travel direction, and then support multiple arch frames at intervals in the dark excavation interval along the vehicle travel direction, each arch frame is supported according to the tunnel contour of the dark excavation interval, and each arch frame is a closed loop formed by an upper arch ring arch frame and a lower inverted arch frame;

[0006] Step 2: Drill holes at the set anti-sinking pile foundation positions in the dark excavation interval between two adjacent inverted arch frames and drive in anti-sinking pile foundations, wherein the bottom end of each anti-sinking pile foundation is embedded in the underground hard rock layer, and the reserved length of the pile head of the anti-sinking pile foundation can form an integral body with the initial support of the inverted arch bottom plate to be constructed and the secondary lining construction of the inverted arch bottom plate, and the diameter of the anti-sinking pile foundation is 35-45 cm;

[0007] Step 3, spraying concrete on all the inverted arch frames so that all the inverted arch frames and the concrete form an inverted arch bottom plate initial support, spraying concrete on all the arch ring arch frames so that all the arch ring arch frames and the concrete form an arch ring part initial support, the inverted arch bottom plate initial support and the arch ring part initial support form a closed ring initial support; then laying the inverted arch bottom plate part waterproof layer on the inverted arch bottom plate initial support and laying the arch ring part waterproof layer on the arch ring part initial support, the inverted arch bottom plate part waterproof layer and the arch ring part waterproof layer form a closed ring waterproof layer;

[0008] Step 4: pouring the secondary lining of the inverted arch bottom plate on the waterproof layer of the inverted arch bottom plate, so that the anti-sinking piles, the initial support of the inverted arch bottom plate and the secondary lining of the inverted arch bottom plate form a whole, pouring the secondary lining of the arch ring part on the waterproof layer of the arch ring part, the secondary lining of the inverted arch bottom plate and the secondary lining of the arch ring part form a closed ring secondary lining, the anti-sinking pile foundation, the secondary lining of the inverted arch bottom plate and the secondary lining of the arch ring part form an integral force and protection, and are located in the underground hard rock layer;

[0009] Step 5. Repeat steps 1 to 4 to continue excavating and supporting along the forward direction of the dark excavation tunnel and carry out the next section of construction until the dark excavation tunnel is crossed.

[0010] The present invention uses anti-sinking piles to treat backfill soil, and uses small-diameter pile foundations before the construction of the inverted arch frame in the tunnel. The reduction in the diameter of the pile foundation makes it unnecessary to use large equipment to enter the narrow underground tunnel, and a small engineering drilling machine such as a geological drilling machine can be used to form a hole. The pile bottom is embedded in the hard rock layer, and the pile head is deeply embedded in the inverted arch to form a whole, so that the force during the tunnel construction and the later operation period is transmitted to the underground by the anti-sinking piles, and the backfill layer is safely and smoothly passed through, ensuring safety and stability during construction and operation. The problem of sinking in the backfill area of ​​the dark excavated tunnel and the problem that the equipment cannot operate due to the narrow site for pile foundation construction in the tunnel are solved. Compared with conventional replacement filling, grouting reinforcement and other measures, it is safer, more economical, and has a longer service life, and realizes the construction of pile foundations in the dark excavated tunnel, and safely and smoothly passes through the backfill area. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the accompanying drawings described below are only some embodiments. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0012] Figure 1 This is a side view of the dark-cut section tunnel treated with anti-sinking piles;

[0013] Figure 2 It is a plan view of the tunnel in the dark excavation section treated with anti-sinking piles;

[0014] Figure 3 This is the front view of the tunnel in the dark excavation section treated with anti-sinking piles;

[0015] Figure 4 Schematic diagram of excavation support arch construction in step 1 of the present invention;

[0016] Figure 5-1 A schematic plan view of the relationship between the position of the anti-sinking pile foundation and the invert arch frame in step 2 of the present invention;

[0017] Figure 5-2 Schematic diagram of the relationship between the anti-sinking pile head and the inverted arch floor in step 2 of the present invention

[0018] Figure 6 Schematic diagram of initial support and waterproof layer closing into a ring in step three of the present invention;

[0019] Figure 7 Schematic diagram of performing step 4 of the present invention, wherein the secondary lining is closed into a ring and forms an integral body with the anti-sinking pile foundation and is located in a hard rock layer;

[0020] Figure 8 Schematic diagram of tunnel excavation and support cycle for dark-cut section tunneling in step five of the present invention.

[0021] 1-arch ring and arch frame, 2-inverted arch frame, 3-initial support of inverted arch bottom plate, 4-initial support of arch ring part, 5-secondary lining of inverted arch bottom plate, 6-secondary lining of arch ring part, 7-partial waterproof layer of inverted arch bottom plate, 8-waterproof layer of arch ring part, 9-anti-sinking pile foundation, 10-blind excavation section tunnel. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] As shown in the accompanying drawings, a method for treating backfill soil with anti-sinking piles in a dark excavation area of ​​the present invention comprises the following steps:

[0024] Step 1: Follow the direction of the vehicle (such as Figure 8 The first section of the dark excavation section is excavated and supported in the set dark excavation section tunnel 10, and then a plurality of arch frames are supported in the dark excavation section at intervals along the vehicle travel direction. Each arch frame is supported according to the contour of the tunnel 10 in the dark excavation section. Each arch frame is a closed loop formed by an upper arch ring arch frame 1 and a lower inverted arch frame 2, as shown in FIG. Figure 4 .

[0025] Step 2: Drill holes and drive anti-sinking pile foundations 9 at the set anti-sinking pile foundation positions in the dark excavation interval between two adjacent inverted arch frames 2. The bottom end of each anti-sinking pile foundation 9 is embedded in the underground hard rock layer. The reserved length of the pile head of the anti-sinking pile foundation 9 can form a whole with the initial support 3 of the inverted arch bottom plate to be constructed and the secondary lining 5 of the inverted arch bottom plate. The diameter of the anti-sinking pile foundation is 35-45 cm.

[0026] Step 3: Figure 6 As shown, concrete is sprayed on all the inverted arch frames 2 so that all the inverted arch frames 2 and the concrete form an inverted arch bottom plate initial support 3, and concrete is sprayed on all the arch ring arch frames 1 so that all the arch ring arch frames 1 and the concrete form an arch ring part initial support 4, and the inverted arch bottom plate initial support 3 and the arch ring part initial support 4 form a closed ring initial support. Then, an inverted arch bottom plate part waterproof layer 7 is laid on the inverted arch bottom plate initial support 3, and an arch ring part waterproof layer 8 is laid on the arch ring part initial support 4, and the inverted arch bottom plate part waterproof layer 7 and the arch ring part waterproof layer 8 form a closed ring waterproof layer.

[0027] Step 4: Figure 7 As shown, the secondary lining 5 of the inverted arch bottom plate is cast on the waterproof layer 7 of the inverted arch bottom plate, so that the anti-sinking piles 9, the initial support 3 of the inverted arch bottom plate and the secondary lining 5 of the inverted arch bottom plate form a whole, and the secondary lining 6 of the arch ring part is cast on the waterproof layer 8 of the arch ring part. The secondary lining 5 of the inverted arch bottom plate and the secondary lining 6 of the arch ring part form a closed ring secondary lining, and the anti-sinking pile foundation 9, the secondary lining 5 of the inverted arch bottom plate and the secondary lining 6 of the arch ring part form an integral force and protection, and are located in the hard rock layer underground.

[0028] Step 5: Repeat steps 1 to 4 to continue excavating and supporting along the forward direction of the dark-cut tunnel 10, and carry out the next section of construction until the dark-cut tunnel is crossed.

[0029] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment, it is not used to limit the present invention. Any technician familiar with this patent can make some changes or modify the technical contents suggested above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the solution of the present invention.

Claims

1. A method for treating backfill soil with anti-sinking piles in a dark excavation area, characterized in that The following steps are involved: Step 1: excavating and supporting the first section of the dark excavation interval in a set dark excavation interval tunnel (10) along the direction of vehicle travel, and then supporting a plurality of arch frames at intervals in the dark excavation interval along the direction of vehicle travel, each arch frame being supported according to the contour of the dark excavation interval tunnel (10), and each arch frame being a closed loop formed by an upper arch ring arch frame (1) and a lower inverted arch frame (2); Step 2: drilling holes at the set anti-sinking pile foundation positions in the dark excavation interval between two adjacent inverted arch frames (2) and driving anti-sinking pile foundations (9), wherein the bottom end of each anti-sinking pile foundation is embedded in the underground hard rock layer, and the reserved length of the pile head portion of the anti-sinking pile foundation (9) can form an integral body with the initial support (3) of the inverted arch bottom plate to be constructed and the secondary lining (5) of the inverted arch bottom plate, and the diameter of the anti-sinking pile foundation is 35-45 cm; Step 3: spraying concrete on all the inverted arch frames (2) so that all the inverted arch frames (2) and the concrete form an inverted arch bottom plate initial support (3), spraying concrete on all the arch ring arch frames (1) so that all the arch ring arch frames (1) and the concrete form an arch ring part initial support (4), the inverted arch bottom plate initial support (3) and the arch ring part initial support (4) form a closed ring initial support; then laying an inverted arch bottom plate partial waterproof layer (7) on the inverted arch bottom plate initial support (3) and laying an arch ring part waterproof layer (8) on the arch ring part initial support (4), the inverted arch bottom plate partial waterproof layer (7) and the arch ring part waterproof layer (8) form a closed ring waterproof layer; Step 4: pouring the secondary lining (5) of the inverted arch bottom plate on the waterproof layer (7) of the inverted arch bottom plate, so that the anti-sinking pile (9) and the initial support (3) of the inverted arch bottom plate and the secondary lining (5) of the inverted arch bottom plate form a whole, pouring the secondary lining (6) of the arch ring part on the waterproof layer (8) of the arch ring part, the secondary lining (5) of the inverted arch bottom plate and the secondary lining (6) of the arch ring part form a closed ring secondary lining, the anti-sinking pile foundation (9) and the secondary lining (5) of the inverted arch bottom plate and the secondary lining (6) of the arch ring part form a whole force and protection, and are located in the underground hard rock layer; Step 5: Repeat steps 1 to 4 to continue excavating and supporting along the forward direction of the dark excavation section tunnel (10) and carry out the next section of construction until the dark excavation section is crossed.

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