Upper-soft and lower-hard stratum earth pressure balance shield end-free reinforcing starting warehouse building method and reinforcing warehouse head

Abstract

The invention discloses an upper-soft and lower-hard stratum earth pressure balance shield end-free reinforcement starting warehouse building method, which comprises the following steps of: mounting a short sleeve (1) on a tunnel portal steel ring (10) by using bolt connection according to a shield tail sealing and synchronous grouting principle, enabling a cutter head to penetrate through the short sleeve (1) by assembling a negative ring duct piece by a shield tunneling machine, and stopping the machine when the cutter head is about to completely break a tunnel portal enclosure structure (8); the shield tail grease and the mud-proof effect are injected through the grease injection hole (6) and the grouting hole (7) reserved in the short sleeve (1) respectively, the shield tail grease, the steel wire tail brush (4), the rubber curtain cloth and the folding pressing plate (12) form a plurality of sealing defense lines, and the mud-proof effect flows into a soil bin through a shield body gap under the effect of grouting pressure. After the space of the soil bin is filled, the full bin state is kept, the tunnel portal enclosure structure (8) continues to be completely broken, when the cutterhead cuts into the undisturbed stratum of the end, the pressure of the soil bin is solid soil pressure, the purpose of building the bin in advance is achieved, and the space of deformation of a starting tunneling tunnel face towards the soil bin is eliminated.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel construction, and in particular to a method for starting building a warehouse with an earth pressure balance shield without end head reinforcement in a soft upper and hard lower stratum. Background Art

[0002] During the initial construction of the earth pressure balance shield, when the cutterhead breaks through the retaining structure (8) at the tunnel entrance, the end stratum is exposed, and its structure, acting load and stress change. At this time, the amount of slag in the soil bin is limited, and the solid earth pressure has not yet been fully established. For strata with poor self-stability, especially when the end strata are soft on the top and hard on the bottom, it is impossible to maintain the water and soil balance of the tunnel face by relying solely on air support, and sliding damage is very likely to occur.

[0003] The patent number is 202110294958.6, and a public specification published on June 11, 2021 discloses a device and method for preventing water-rich strata from gushing out and improving the efficiency of shield tunneling. The patent belongs to the field of tunnel shield construction technology and can solve the problems of ground collapse, shield machine flooding, tunnel collapse, and casualties that are prone to occur when the shield machine is crossing water-rich strata. The tunneling device includes a belt conveyor, a spiral conveyor located above the belt conveyor, and a sump and side discharge sump located at the bottom of the belt conveyor. The tunneling method includes: draining water from the soil bin, establishing solid earth pressure, improving soil bin slag, advancing the shield machine, preventing gushing and rapid pressure relief, and starting the drainage and slag removal system. The present invention can effectively reduce the pressure in the soil bin and prevent gushing from occurring. At the same time, it can effectively prevent the accumulation of slag and muddy water at the bottom of the shield machine and fall to the outside of the belt conveyor. There is no need for manual regular cleaning, thereby improving the efficiency of shield tunneling.

[0004] In order to avoid the risk of end stratum collapse, the end stratum is usually reinforced before the shield starts. The more commonly used methods include high-pressure rotary jetting, deep mixing, horizontal deep hole grouting, freezing and precipitation stabilization stratum methods. Not only are the construction costs high and the cycle long, but they may also be limited by factors such as underground pipelines or technological levels, resulting in the problem of no end reinforcement conditions or poor reinforcement effects. Summary of the invention

[0005] The present invention aims to provide a method for initially building a bunker without end head reinforcement of an earth pressure balance shield machine in soft upper and hard lower strata, which can eliminate the deformation space of the initial excavation heading facing the bunker.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: a method for starting and building a warehouse without end head reinforcement in an earth pressure balance shield in a soft upper and hard lower stratum, the steps are as follows:

[0007] S1: The starting end of the shield machine is in soft upper and hard lower strata. When the shield machine is selected and designed, the cutterhead is equipped with a roller cutter;

[0008] S2: Install a short sleeve in the well;

[0009] S3: Short sleeve wire tail brush to apply hand-applied shield tail grease;

[0010] S4: The shield machine stops when the remaining 20 to 30 cm of the tunnel enclosure structure remains;

[0011] S5: During advancement, short sleeve grease and mud effect injection are carried out simultaneously;

[0012] S6: After the short sleeve grease cavity and soil bin are filled, the shield machine continues to excavate with a full bin state.

[0013] In S2, a short sleeve is installed in the well, the bottom block is installed first, and a plain concrete base is poured at the bottom and a grouting pipe and a grease injection pipe are pre-buried, and then the left, right and top blocks are installed in sequence, followed by welding the bottom block and two steel wire tail brushes at the connection between the blocks, and finally the rubber curtain and the folding plate are installed, and the inner support is removed.

[0014] In S4, the shield machine advances and uses a roller cutter to directly cut the tunnel portal enclosure structure, and stops when there are 20 to 30 cm left.

[0015] In S5, a shield tail grease pump is used to inject pumpable shield tail grease through the short sleeve grease injection hole. At the same time, a mud effect pump is used to inject mud effect through the short sleeve grouting hole to fill the soil bin and establish solid soil pressure.

[0016] In S6, after the short sleeve grease cavity and the soil bin are filled with the injected medium, the shield machine continues to advance with a full bin, completely breaks through the tunnel door enclosure structure and cuts into the original stratum at the end.

[0017] The mud effect is a mixture of liquid A and liquid B, wherein the ratio of liquid A is mud effect powder: water = 300kg: 885L, and liquid B is water glass with a Baume degree of 40°Bé, and the ratio of liquid A: liquid B = 20:1 (volume ratio).

[0018] A reinforced bunker head is used in a method for reinforcing a bunker without an end head in an earth pressure balance shield with soft upper and hard lower strata. The method comprises a short sleeve, which is divided into four adjacent blocks. The blocks form a cylinder. The blocks are provided with reserved holes, which are divided into grease injection holes and grouting holes arranged in front and rear rings.

[0019] The blocks are divided into a top block, a left block, a right block and a bottom block. The blocks are connected by flanges, and rubber sealing pads are arranged at the connection points of the blocks.

[0020] Steel wire tail brushes are welded on the top block, the left block and the right block. The steel wire tail brushes are inclined, and inner supports are arranged on the inner sides of the blocks.

[0021] An inner lining wall is arranged on the enclosure structure, a tunnel door steel ring is arranged inside the inner lining wall, the blocks are connected to the tunnel door steel ring by bolts, and a rubber sealing pad is arranged at the connection.

[0022] The technical effect of the present invention is as follows: a short sleeve is designed by referring to the principle of shield tail sealing and synchronous grouting, and is installed on the steel ring of the tunnel portal through bolt connection. The shield machine allows the cutter head to pass through the short sleeve by assembling negative ring segments. When the cutter head is about to completely break through the tunnel portal retaining structure, the machine is stopped, and shield tail grease and mud-breaking effect are respectively injected through the grease injection hole and grouting hole reserved in the short sleeve. The shield tail grease, wire tail brush, rubber curtain and folding pressure plate form multiple sealing defense lines. The mud-breaking effect flows into the soil bin through the gap of the shield body under the action of grouting pressure, fills the soil bin space, and then maintains a full bin state to continue to completely break through the tunnel portal retaining structure. When the cutter head cuts into the original stratum at the end, the soil bin pressure is real soil pressure, thereby achieving the purpose of building the bin in advance and eliminating the space for deformation of the soil bin facing the heading at the beginning of excavation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] This specification includes the following drawings, which show the following contents:

[0024] Figure 1 This is a structural schematic diagram of a reinforced warehouse head according to the present invention;

[0025] Figure 2 for Figure 1 A schematic diagram of a block structure for strengthening the warehouse head;

[0026] Figure 3 for Figure 1 Schematic diagram of a plain concrete base for reinforcing the warehouse head.

[0027] Markings in the figure are: 1. Short sleeve; 2. Block; 201. Top block; 202. Left block; 203. Right block; 204. Bottom block; 3. Flange; 4. Wire tail brush; 5. Inner support; 6. Grease injection hole; 7. Grouting hole; 8. Enclosure structure; 9. Lining wall; 10. Portal steel ring; 11. Plain concrete base; 12. Rubber curtain and folding pressure plate; 13. Bottom plate. DETAILED DESCRIPTION

[0028] The specific implementation methods of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention and facilitating their implementation.

[0029] A method for starting and building a warehouse without end head reinforcement of an earth pressure balance shield in soft upper and hard lower strata, the steps are as follows:

[0030] S1: The starting end of the shield machine is in soft upper and hard lower strata. When the shield machine is selected and designed, the cutterhead is equipped with a roller cutter;

[0031] S2: Install a short sleeve 1 in the well;

[0032] S3: Short sleeve 1 wire tail brush 4 smear hand-applied shield tail grease;

[0033] S4: The shield machine stops when the remaining 20 to 30 cm of the tunnel enclosure structure 8 is reached;

[0034] S5: Grease and mud effect injection of short sleeve 1 are carried out simultaneously during advancement;

[0035] S6: After the grease cavity and soil bin of short sleeve 1 are filled, the shield machine continues to excavate with a full bin.

[0036] Taking full advantage of the structure and functional characteristics of the earth pressure balance shield, a short sleeve 1 sealing system is designed to ensure the stability of the heading face by building a warehouse in advance. The short sleeve 1 has a simple structure, is easy to install and disassemble, is reusable, has multiple sealing lines of defense, is safe and reliable, and the grease and mud-killing effect injection systems and channels are independent of each other, so they can be constructed at the same time, which speeds up the construction speed. There is no need for end reinforcement, which saves the cost and time of end reinforcement construction.

[0037] In S2, a short sleeve 1 is installed in the well, and the bottom block 204 is installed first, and a plain concrete base 11 is poured at the bottom and a grouting pipe and a grease injection pipe are pre-buried. A bottom plate 13 is provided at the bottom of the plain concrete base 11, and then the left, right and top blocks 201 are installed in sequence, and then the bottom block 204 and two steel wire tail brushes 4 at the connection of each block 2 are welded, and finally the rubber curtain and the folding pressure plate 12 are installed, and the inner support 5 is removed; the split structure is simple to install and easy to transfer to the well for installation, and it can be disassembled and removed from the well after use, and can be used repeatedly.

[0038] In S4, the shield machine advances and uses a roller cutter to directly cut the portal enclosure structure 8, and stops when there are 20 to 30 cm left.

[0039] In S5, the shield tail grease pump of the shield machine is used to inject pumpable shield tail grease through the grease injection hole 6 of the short sleeve 1. At the same time, a mud effect pump is used to inject mud effect through the grouting hole 7 of the short sleeve 1 to fill the soil bin and establish solid soil pressure. By injecting mud effect and grease into the soil bin, solid soil pressure is established, the purpose of building the bin in advance is achieved, and the space for deformation of the soil bin facing the initial excavation heading is eliminated.

[0040] In S6, after the grease cavity and soil bin of the short sleeve 1 are filled with the injected medium, the shield machine continues to advance with a full bin, completely breaks through the tunnel portal retaining structure 8 and cuts into the original stratum at the end; it gradually digs underground, and advances to the next location after establishing solid soil pressure at one location, seeking gradual progress to reduce the occurrence of dangerous situations.

[0041] The mud effect is a mixture of liquid A and liquid B, in which the ratio of liquid A is mud effect powder: water = 300kg:885L, and liquid B is water glass with a Baume degree of 40°Bé, and the volume ratio of liquid A: liquid B = 20:1; it can effectively improve the compactness.

[0042] See also Figure 1-3 A reinforcement bunker head is used in a method for reinforcing the initial bunker of an earth pressure balance shield with soft upper and hard lower strata without an end head, comprising a short sleeve 1, the short sleeve 1 is divided into four adjacent blocks 2, the blocks 2 form a cylinder, and reserved holes are arranged on the blocks 2, the reserved holes are divided into grease injection holes 6 and grouting holes 7 arranged in front and rear rings; shield tail grease and mud effect are respectively injected through the grease injection holes 6 and grouting holes 7 reserved by the short sleeve 1, the shield tail grease, wire tail brush 4, rubber curtain and folding pressure plate 12 form multiple sealing defense lines, and the mud effect flows into the soil bunker through the gap of the shield body under the action of grouting pressure, fills the soil bunker space, and then maintains a full bunker state to continue to completely break the tunnel door enclosure structure 8, when the cutter head cuts into the original stratum at the end, the soil bunker pressure is solid soil pressure, the purpose of building the bunker in advance is achieved, and the space for deformation of the soil bunker facing the initial excavation heading is eliminated.

[0043] The block 2 is divided into a top block 201, a left block 202, a right block 203 and a bottom block 204. The blocks 2 are connected by flanges 3, and rubber sealing pads are arranged at the connection points of the blocks 2. The split structure is easy to install and convenient to transfer to the underground for installation. After use, it can be split and then removed from the well and can be used repeatedly.

[0044] A wire tail brush 4 is welded on the top block 201, the left block 202 and the right block 203. The wire tail brush 4 is inclined. An inner support 5 is provided on the inner side of the block 2. The block 2 is supported by the inner support 5 to reduce the possibility of breakage.

[0045] An inner lining wall 9 is provided on the enclosure structure 8, and a tunnel door steel ring 10 is provided inside the inner lining wall 9. The block 2 and the tunnel door steel ring 10 are connected by bolts, and a rubber sealing pad is provided at the connection. The installation is simple and the strength is high, and the damage caused by vibration is reduced by adding a rubber sealing pad.

[0046] The technical effect of the present invention is as follows: a short sleeve 1 is designed by referring to the principle of shield tail sealing and synchronous grouting, and is installed on the tunnel portal steel ring 10 through bolt connection. The shield machine makes the cutter head pass through the short sleeve 1 by assembling negative ring segments. When the cutter head is about to completely break through the tunnel portal retaining structure 8, the machine is stopped. Shield tail grease and mud-breaking effect are respectively injected through the grease injection hole 6 and the grouting hole 7 reserved in the short sleeve 1. The shield tail grease, wire tail brush 4, rubber curtain and folding pressure plate 12 form multiple sealing defense lines. The mud-breaking effect flows into the soil bin through the gap of the shield body under the action of grouting pressure, fills the soil bin space, and then maintains a full bin state to continue to completely break through the tunnel portal retaining structure 8. When the cutter head cuts into the original stratum at the end, the soil bin pressure is real soil pressure, thereby achieving the purpose of building the bin in advance and eliminating the space for deformation of the soil bin facing the heading at the beginning of excavation.

[0047] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for starting and building a warehouse with an earth pressure balance shield without end head reinforcement in soft upper and hard lower strata, characterized in that: Here are the steps: S1: The starting end of the shield machine is in soft upper and hard lower strata. When the shield machine is selected and designed, the cutterhead is equipped with a roller cutter; S2: Install a short sleeve (1) in the well; S3: Short sleeve (1) wire tail brush (4) smears hand-applied shield tail grease; S4: The shield machine stops when the remaining length of the tunnel portal retaining structure (8) is 20 to 30 cm; S5: while advancing, grease and mud-reducing effect are injected into the short sleeve (1) simultaneously; S6: After the grease chamber and soil bin of the short sleeve (1) are filled, the shield machine continues to excavate with the bin full.

2. The method for starting and building a warehouse with an earth pressure balance shield without end head reinforcement in soft upper and hard lower strata according to claim 1 is characterized in that: In S2, a short sleeve (1) is installed in the well, the bottom block (204) is installed first, and a plain concrete base (11) is poured at the bottom and a grouting pipe and a grease injection pipe are pre-buried, and then the left, right and top blocks (201) are installed in sequence, and then the two steel wire tail brushes (4) at the connection between the bottom block (204) and each block (2) are welded, and finally the rubber curtain and the folding plate (12) are installed, and the inner support (5) is removed.

3. The method for starting and building a warehouse with an earth pressure balance shield without end head reinforcement in soft upper and hard lower strata according to claim 1 is characterized in that: In S4, the shield machine advances, and uses a roller cutter to directly cut the tunnel portal enclosure structure (8), and stops when 20 to 30 cm is left.

4. A method for starting a warehouse without end-head reinforcement of an earth pressure balance shield in soft upper and hard lower strata according to claim 1, characterized in that: In S5, a shield tail grease pump is used to inject pumpable shield tail grease through the grease injection hole (6) of the short sleeve (1). At the same time, a mud effect pump is used to inject mud effect through the grouting hole (7) of the short sleeve (1) to fill the soil bin and establish solid soil pressure.

5. The method for starting and building a warehouse with an earth pressure balance shield without end head reinforcement in soft upper and hard lower strata according to claim 1 is characterized in that: In S6, after the grease cavity and soil bin of the short sleeve (1) are filled with the injected medium, the shield machine continues to advance in a full bin state, completely breaking through the tunnel door enclosure structure (8) and then cutting into the original stratum at the end.

6. The method for starting and building a warehouse with an earth pressure balance shield without end head reinforcement in soft upper and hard lower strata according to claim 4 is characterized by: The mud effect is a mixture of liquid A and liquid B, in which the ratio of liquid A is mud effect powder: water = 300kg: 885L, and liquid B is water glass with a Baume degree of 40°Bé, and the ratio of liquid A: liquid B = 20:1 (volume ratio).

7. A reinforced warehouse head, applied to any one of claims 1 to 6, characterized in that: The invention comprises a short sleeve (1), wherein the short sleeve (1) is divided into four adjacent blocks (2), wherein the blocks (2) form a cylinder, and the blocks (2) are provided with reserved holes, wherein the reserved holes are divided into grease injection holes (6) and grouting holes (7) arranged in a front and rear annular pattern.

8. The reinforced warehouse head according to claim 1, characterized in that: The blocks (2) are divided into a top block (201), a left block (202), a right block (203) and a bottom block (204); the blocks (2) are connected via flanges (3); and rubber sealing pads are provided at the connection points of the blocks (2).

9. A reinforced warehouse head according to claim 2, characterized in that: A steel wire tail brush (4) is welded to the top block (201), the left block (202) and the right block (203); the steel wire tail brush (4) is in an inclined shape; and an inner support (5) is provided on the inner side of the block (2).

10. A reinforced warehouse head according to claim 1 or 2, characterized in that: The enclosure structure (8) is provided with an inner lining wall (9), a tunnel door steel ring (10) is provided inside the inner lining wall (9), the blocks (2) and the tunnel door steel ring (10) are connected by bolts, and a rubber sealing pad is provided at the connection.

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