Earth pressure balance shield machine filling type starting method

Abstract

The present invention relates to a method for starting a earth pressure balance shield machine by filling the bin. Dense plastic foam blocks are filled in the soil bin of the shield body until the back of the cutter head of the shield cutter head; after the shield machine is started and in place, the water level at the end is lowered below the construction water level; the shield cutter head is rotated to cut the working face, and the soil enters the soil bin and the plastic foam blocks; when the sensed pressure of the soil pressure sensor is 2.2 - 2.3 bar, or when the depth of the soil bin entering the end is about 2 / 3 of the depth of the soil bin, it is considered that the pressure balance state is achieved in the soil bin and the working face is stable; the screw conveyor is started, and the plastic foam blocks in contact with the screw blade are crushed and discharged; under the action of the throwing force of the soil, the self-weight of the soil and the self-weight of several plastic foam blocks, the plastic foam blocks above gradually fall, are crushed by the screw blade and discharged with the soil; the newly entered soil in the soil bin can establish a new pressure balance. Compared with the traditional method for strengthening the soil at the end, the technical solution of the present invention has low cost, short working hours and low labor intensity.

Description

Technical Field

[0001] The present invention belongs to the technical field of shield construction, and particularly relates to a filling-type starting method for an earth pressure balance shield machine. Background Art

[0002] The starting of a shield machine is a crucial link in shield construction. The construction risk is high, and it is easy to cause phenomena such as water inrush and sand inrush. In severe cases, it can lead to conditions such as end settlement and collapse.

[0003] When an earth pressure balance shield machine starts, the key control is to keep the end face of the heading face stable. Affected by the design of the soil chamber, there is no filler in the soil chamber space of a conventional shield machine. When starting, the cutter head cuts the heading face, and the soil needs to be filled into the soil chamber first to establish soil pressure before it can maintain soil pressure balance with the heading face. The soil chamber space is relatively large, which is likely to cause the collapse of the soil body on the heading face. Therefore, it is necessary to reinforce the soil at the end to maintain the stability of the soil body.

[0004] To reinforce the soil at the end, generally, methods such as jet grouting reinforcement or freezing reinforcement are adopted to reinforce the soil and keep the soil stable when the shield machine enters the end. The above-mentioned conventional reinforcement methods need to use a large amount of cement slurry to reinforce the soil, which has a long working time, high cost, and a large amount of manual work. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to make up for the deficiencies of the prior art and provide a filling-type starting method for an earth pressure balance shield machine with low cost and short working hours.

[0006] To solve the above technical problem, the technical solution of the present invention is as follows:

[0007] A filling-type starting method for an earth pressure balance shield machine includes the following steps:

[0008] S1: Fix the shield cutter head to the main bearing in the shield body, and a soil pressure sensor is arranged in the soil chamber of the shield body;

[0009] S2: Fill a number of pre-prepared plastic foam blocks into the soil chamber of the shield body to form a plastic foam filling unit. The filling space is a cavity surrounded by the chamber wall, the shield shell, and the back of the cutter head of the shield cutter head. The plastic foam blocks need to avoid the rotation space of the cutter head bracket and shall not interfere with the rotation of the shield cutter head;

[0010] The filling sequence of a number of plastic foam blocks is: from bottom to top and from back to front;

[0011] The filling method of a number of plastic foam blocks is: the plastic foam blocks close to the chamber wall of the soil chamber are cemented to the chamber wall, and the adjacent plastic foam blocks before and after are fixedly connected by nail shooting;

[0012] S3: The shield machine is in place for starting, and a dewatering well is used to lower the water level at the end to below the construction water level;

[0013] S4: Push the shield machine forward until the cutter head of the shield machine touches the heading face, rotate the cutter head of the shield machine to cut the heading face, the soil enters the soil bin behind the back of the cutter head, and the soil squeezes the plastic foam blocks;

[0014] S5: When the sensed pressure of the soil pressure sensor is 2.2 - 2.3 bar, or when the depth of the soil bin entering the end is about 2 / 3 of the depth of the soil bin, it is considered that the pressure balance state is reached in the soil bin and the heading face is stable; start the screw conveyor, the screw conveyor enters the soil bin through the screw conveyor feed inlet, and the plastic foam blocks in direct contact with the screw blades of the screw conveyor are crushed and discharged by the screw conveyor; under the action of the throwing force of the soil, the self-weight of the soil and the self-weight of several plastic foam blocks, the bonding between the plastic foam blocks and the bin wall is damaged, and the plastic foam blocks above gradually fall, are crushed by the screw blades of the screw conveyor and discharged with the soil; the newly entered soil in the soil bin can establish a new pressure balance.

[0015] Further, the main component of the plastic foam block is polystyrene, and the density is 0.974 g / cm 3 。

[0016] Further, the size of the plastic foam block is 80 cm × 80 cm × 5 cm, and during the filling process, the plastic foam block is cut according to the shape requirements.

[0017] The beneficial effects that the present invention can achieve are as follows: By filling the soil bin of the shield machine with plastic foam filling units, the pressure balance of the heading face is ensured when the shield machine enters the end, and the stability of the heading face is ensured; compared with the traditional method of strengthening the end soil body, the labor intensity is small, the costs for cement, mechanical equipment, labor, etc. required for strengthening the end soil body are saved, and the disadvantages such as a large amount of cement consumption and long construction time of jet grouting piles are improved. Description of the Drawings

[0018] Figure 1 is the three-dimensional schematic diagram after the plastic foam filling unit is filled in the embodiment of the present invention;

[0019] Figure 2 is Figure 1 the front view of

[0020] Figure 3 is the installation schematic diagram of the shield body and the cutter head of the shield machine without filling the plastic foam filling unit in the embodiment of the present invention;

[0021] Figure 4 is Figure 3 the front view of

[0022] Figure 5 is the internal structure schematic diagram of the soil bin of the shield body in the embodiment of the present invention;

[0023] Figure 6 isFigure 5 Front view;

[0024] Figure 7 is a schematic structural view of a shield cutter head in an embodiment of the present invention;

[0025] Figure 8 is a front view schematic diagram of a plastic foam filling unit in an embodiment of the present invention;

[0026] Figure 9 is a three-dimensional schematic diagram of a plastic foam filling unit in an embodiment of the present invention;

[0027] In the figure: 1 - shield body, 101 - bin wall, 102 - shield shell, 103 - screw feeder inlet, 104 - main bearing, 105 - earth pressure sensor;

[0028] 2 - shield cutter head, 201 - cutter head, 202 - back of cutter head, 203 - cutter head mounting plate, 204 - cutter head bracket;

[0029] 3 - plastic foam filling unit, 301 - plastic foam block. Detailed implementation manners

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners. Embodiment

[0031] The method for starting a soil pressure balance shield machine by filling the bin includes the following steps:

[0032] S1: As shown in Figure 3 and Figure 4 , fixedly connect the cutter head mounting plate 203 of the shield cutter head 2 with the main bearing 104 in the shield body 1, and an earth pressure sensor 105 is provided in the soil bin of the shield body 1;

[0033] S2: Prepare a number of plastic foam blocks 301 in advance. The main component of the plastic foam blocks 301 is polystyrene, and the density is 0.974 g / cm 3 , and the size of the plastic foam blocks 301 is 80 cm × 80 cm × 5 cm;

[0034] Fill a number of plastic foam blocks 301 in the soil bin of the shield body 1 to form a plastic foam filling unit 3. The filling space is a cavity surrounded by the bin wall 101, the shield shell 102, and the back surface 202 of the cutter head 201 of the cutter head. Fill the cavity densely, but the plastic foam blocks 301 need to avoid the rotation space of the cutter head bracket 204 and shall not interfere with the rotation of the shield cutter head 2;

[0035] The filling order of the number of plastic foam blocks 301 is: from bottom to top, from back to front;

[0036] The filling method of several plastic foam blocks 301 is as follows: the plastic foam blocks 301 close to the soil bin wall 101 are cemented to the wall 101, and the adjacent plastic foam blocks 301 are fixedly connected by shooting nails with a nail gun;

[0037] During the filling process, the plastic foam blocks 301 are cut according to the shape requirements.

[0038] : The shield machine is launched and positioned, and the water level at the end is lowered to below the construction water level by using a dewatering well;

[0039] S4: Push the shield machine until the shield cutter head 2 contacts the working face, rotate the shield cutter head 2 to cut the working face, the soil enters the soil bin behind the back of the cutter head 202, and the soil squeezes the plastic foam blocks 301;

[0040] S5: When the sensed pressure of the soil pressure sensor 105 is 2.2 - 2.3 bar, or when the depth of the soil bin entering the end is about 2 / 3 of the depth of the soil bin, it is considered that the pressure balance state is reached in the soil bin and the working face is stable; start the screw conveyor, the screw conveyor enters the soil bin through the screw conveyor feed inlet 103, and the plastic foam blocks 301 in direct contact with the screw blades of the screw conveyor are crushed and discharged by the screw conveyor; under the action of the soil throwing-in force, the self-weight of the soil and the self-weight of several plastic foam blocks 301, the cementation between the plastic foam blocks 301 and the wall 101 is damaged, and the plastic foam blocks 301 above gradually fall, are crushed by the screw blades of the screw conveyor and discharged with the soil; the newly entered soil in the soil bin can establish a new pressure balance.

[0041] In the description of the present invention, the words indicating the orientation or position relationship such as "inside", "outside", "above", "below", "front", "rear", etc. are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0042] The above is only one implementation manner of the present invention, and the protection scope of the present invention is not limited to the above embodiments. It should be pointed out that for those of ordinary skill in the art in this technical field, several improvements and refinements made without departing from the idea of the present invention are within the protection scope of the present invention.

Claims

1. Earth pressure balance shield tunneling machine filling bin starting method, characterized in that: It includes the following steps: S1: Fix the shield cutter head (2) to the main bearing (104) in the shield body (1). A soil pressure sensor (105) is provided in the soil bin of the shield body (1). S2: Fill a number of pre-prepared plastic foam blocks (301) in the soil bin of the shield body (1) to form a plastic foam filling unit (3). The filling space is a cavity surrounded by the bin wall (101), the shield shell (102), and the back surface (202) of the shield cutter head (2). The plastic foam blocks (301) need to avoid the rotation space of the cutter head bracket (204) and shall not prevent the rotation of the shield cutter head (2). The filling sequence of a number of plastic foam blocks (301) is: from bottom to top and from back to front. The filling method of a number of plastic foam blocks (301) is: The plastic foam blocks (301) close to the soil bin wall (101) are cemented to the bin wall (101), and the adjacent plastic foam blocks (301) before and after are fixedly connected by nail shooting. S3: The shield machine is launched and positioned, and the water level at the end is lowered below the construction water level by using a dewatering well. S4: Push the shield machine until the shield cutter head (2) contacts the working face, and rotate the shield cutter head (2) to cut the working face. The soil enters the soil bin behind the back surface (202) of the cutter head, and the soil squeezes the plastic foam blocks (301). S5: When the sensed pressure of the soil pressure sensor (105) is 2.2 - 2.3 bar, or when the depth of the soil bin entering the end is about 2 / 3 of the soil bin depth, it is considered that the pressure balance state is reached in the soil bin and the working face is stable. Start the screw conveyor. The screw conveyor enters the soil bin through the screw conveyor feed port (103). The plastic foam blocks (301) in direct contact with the screw blades of the screw conveyor are crushed and discharged by the screw conveyor. Under the action of the soil throwing-in force, the self-weight of the soil, and the self-weight of a number of plastic foam blocks (301), the cementation between the plastic foam blocks (301) and the bin wall (101) is damaged, and the upper plastic foam blocks (301) gradually fall, are crushed by the screw blades of the screw conveyor, and are discharged with the soil. The newly entered soil in the soil bin can establish a new pressure balance. The main component of the plastic foam block (301) is polystyrene, and the density is 0.974 g / cm 3 ; The size of the plastic foam block (301) is 80 cm × 80 cm × 5 cm. During the filling process, the plastic foam block (301) is cut according to the shape requirements.

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