Water-rich alteration zone open type TBM stuck machine escape method

Abstract

The invention discloses a water-rich alteration zone open-type TBM (Tunnel Boring Machine) stuck escape method which comprises the following steps: advanced geological forecast, chemical pouring, advanced pipe shed driving, coring work room opening for coring construction, after coring is completed, assisting TBM escape by trying to rotate a cutterhead, stretch and retract a shield and retreat a TBM, and recovering tunneling. And the above steps are circulated until the TBM tunnels and passes through the machine clamping section. According to the method, the collapse body of the shield is cleaned from the rear part of the shield by using the coring tool, and the step of manually drilling into the upper part of the shield to clean the collapse body of the shield is avoided, so that the safety risk of personnel in the jamming and escape construction process is greatly reduced, and the construction efficiency is improved. The pipe shed is moved backwards, the design structure size of the working chamber is reduced, and the height difference between the inclination angle of the pipe shed and the shield is used as the construction space of the coring working chamber, so that the excavation workload of the working chamber is greatly reduced, the safety risk is reduced, and the construction efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and in particular to a method for releasing a stuck open TBM in a water-rich altered zone. Background Technique

[0002] As an efficient tunnel boring equipment, a Tunnel Boring Machine (TBM) has significant advantages in the construction of long tunnels. However, under complex geological conditions, the TBM may encounter problems of getting stuck during tunneling, which seriously affects the construction progress and safety. The causes of the stuck machine problem are diverse, such as complex geological conditions, insufficient equipment adaptability, improper construction operations, etc. For example, after a certain tunnel TBM advanced to a water-rich altered zone, a series of collapses occurred, causing the shield to be squeezed and locked by the collapsed body, resulting in the shutdown of the TBM equipment. At the same time, large pieces of gravel in the collapsed body and the consolidation effect of the collapsed body caused the cutter head to get stuck and stop rotating. Therefore, it is particularly important to develop an effective method for releasing a stuck TBM.

[0003] Among the existing methods for releasing a stuck TBM, methods such as excavating side pilot tunnels, pre-injecting grout, and equipment modification are relatively commonly used. Although these methods can solve the stuck machine problem to a certain extent, each has certain limitations. For example, the method of excavating side pilot tunnels requires manual excavation, with high construction difficulty and low efficiency; although the pre-injection grouting method can improve the integrity and strength of the rock mass, the grouting effect is greatly affected by geological conditions; the equipment modification method needs to be carried out in the design stage, and the modification cost is relatively high.

[0004] Therefore, it is necessary to propose a method for releasing a stuck open TBM in a water-rich altered zone to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for releasing a stuck open TBM in a water-rich altered zone to solve the problems of high construction difficulty and low efficiency, great influence by geological conditions, and high modification cost of the existing TBM stuck machine release methods.

[0006] The present invention provides a method for releasing a stuck open TBM in a water-rich altered zone, including:

[0007] Step 1, advanced geological prediction. The advanced geological prediction adopts a construction method mainly based on advanced drilling, supplemented by seismic wave reflection method and complex frequency conductivity technology; within the range of 8 o'clock to 11 o'clock at the TBM shield tail, a fully hydraulic anchor drill is used to drill 1 to 3 advanced exploration holes with a length of 15 to 20 m and a diameter of φ120 mm at an external insertion angle of 30 to 45°.

[0008] Step 2: Chemically grout the positions of the TBM cutter head, shield, and shield tail to fill and block water in the fractures of the broken rock mass, and at the same time reinforce the collapsed bodies above the shield and in front of the cutter head;

[0009] Step 3: The starting point of the pipe shed construction is at the position 5 m behind the shield tail. Control the external insertion angle at 10°, and the length of the guiding pipe is 2 m to ensure the drilling angle of the drill rig. A total of 40 holes are drilled in the direction from 10 o'clock to 14 o'clock for the advanced pipe shed. The circumferential spacing is 30 cm, the maximum drilling depth is 20 m, and the rock penetration depth is not less than 3 m. Use the space between the pipe shed and the shield as the core sampling working chamber;

[0010] Step 4: Open a core sampling working chamber within 2 m behind the shield tail. The longitudinal length of the core sampling working chamber is 2 m, and the circumferential direction is from the 10 o'clock position to the 14 o'clock position. The height of the core sampling working chamber is 60.5 cm to 39.0 cm; Use a 150 water drill to conduct core sampling construction on the consolidated body at the top of the shield. The drilling diameter is 240 mm, and the maximum core sampling depth is 6 m;

[0011] Step 5: After the core sampling is completed, assist the TBM to get out of trouble by trying to rotate the cutter head, extend and retract the shield, and retract the TBM, and resume tunneling;

[0012] Step 6: Repeat Steps 1 to 5 until the TBM tunnels through the stuck machine section.

[0013] Further, in Step 2, the chemical grouting material consists of two components: polyether polyol and isocyanate.

[0014] Further, in Step 2, grout in the order from bottom to top. After forming a closed space, re-drill holes for grouting; The initial pressure of the grouting pressure is 0 MPa, and the termination pressure is 5 MPa.

[0015] Further, in Step 3, the 40 holes include 35 normal holes and 5 densified holes. The circumferential length of the densified area is 2 m. Determine the densified part according to the surrounding rock conditions detected by drilling. The densified holes are located between two normal holes.

[0016] Further, in Step 4, the arch replacement of the core sampling working chamber is carried out according to the plan of removing four sets of arch frames and reinstalling four sets of arch frames. The newly replaced four sets of arch frames use HW175 steel, and the longitudinal spacing is 60 cm.

[0017] The present invention has the following beneficial effects: A method for releasing a stuck open TBM in a water-rich altered zone according to the present invention, compared with the traditional method of manually cleaning and releasing the shield extrusion pressure by means of pilot tunnel excavation and enlargement, uses a core-taking tool to clean the shield collapse body from behind the shield, avoiding the step of manually drilling above the shield to clean the shield collapse body, thereby greatly reducing the personnel safety risk during the stuck TBM release construction process and improving the construction efficiency. The traditional release method requires constructing a pipe shed working chamber closely behind the shield and reserving an artificial working space between the pipe shed and the shield; the present invention moves the pipe shed backward, reduces the design structure size of the working chamber, and uses the height difference generated by the pipe shed inclination and the shield as the construction space for the core-taking working chamber, greatly reducing the excavation workload of the working chamber, reducing the safety risk and improving the construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a flow chart of a method for releasing a stuck open TBM in a water-rich altered zone provided by the present invention;

[0020] Figure 2 It is a schematic diagram of a method for releasing a stuck open TBM in a water-rich altered zone provided by the present invention.

[0021] Illustration: 1 - Cutter head; 2 - Pipe shed; 3 - Original construction arch; 4 - Core-taking working chamber; 5 - Replaced arch; 6 - Core-taking hole; 7 - Collapse body. SPECIFIC EMBODIMENTS

[0022] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments. It should be pointed out that the following detailed description is illustrative and is intended to provide further description of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0023] The present invention proposes a combined method of grouting reinforcement and core drilling by a core drill. By horizontally taking cores after reinforcing the loose body to remove the collapse body above the TBM cutter head and shield, this method has the advantages of simple construction procedures, low safety risk, and high construction efficiency compared with the pilot tunnel excavation and enlargement method; it optimizes the deficiency of the traditional stuck TBM release plan for large-scale excavation of the shield top, greatly reducing the stuck TBM release processing time and improving the stuck TBM release efficiency.

[0024] Please refer to Figure 1 and Figure 2 A method for the stuck TBM to break free in an open water-rich altered zone provided by an embodiment of the present invention includes:

[0025] Step 1, advanced geological prediction. The advanced geological prediction mainly adopts advanced drilling, supplemented by the seismic wave reflection method (Tunnel Geology Prediction, TGP) and the complex frequency conductivity technology (Complex Frequency Conductivity, CFC). In the range of 8 o'clock to 11 o'clock at the TBM shield tail, a full-hydraulic anchoring drill is used to drill 1 to 3 advanced exploration holes with a length of 15 to 20 m and a diameter of φ120 mm at an external insertion angle of 30° to 45°.

[0026] Specifically, the advanced exploration holes play a role in exploring the surrounding rock structure in front of the cutterhead and in the upper left.

[0027] Step 2, chemically grout the positions of the TBM cutterhead, shield and shield tail to fill and block water in the fractures of the broken rock mass, and at the same time reinforce the collapsed bodies above the shield and in front of the cutterhead.

[0028] Specifically, the chemical grouting material consists of two components: polyether combination and isocyanate. Reinforce the collapsed bodies 7 above the shield and in front of the cutterhead 1 to prepare for the cleaning of the shield and cutterhead collapsed bodies. The grouting is carried out in the order from bottom to top. After forming a closed space, re-drill holes for grouting. The initial pressure of the grouting pressure is 0 MPa, and the termination pressure is 5 MPa. According to the actual situation on site, raise the grouting pressure to the maximum allowable pressure of 5 MPa to ensure the compactness of grouting and increase the effective diffusion range. After the chemical grouting starts, continuous grouting should be carried out without interruption. High-foaming chemical grouting is used for chemical grouting, and the chemical grouting must be filled completely, and the cutterhead is protected by normal-pressure foaming.

[0029] Step 3, the starting point of the pipe shed construction is at the position 5 m behind the shield tail. The external insertion angle is controlled at 10°, and the length of the guide pipe is 2 m to ensure the drilling angle of the drill. A total of 40 holes are drilled in the direction from 10 o'clock to 14 o'clock for the advanced pipe shed, with a circumferential spacing of 30 cm. The maximum drilling depth is 20 m, and the rock penetration depth is not less than 3 m. The space between the pipe shed and the shield is used as a core-taking working room.

[0030] Specifically, the pipe shed 2 is as Figure 2 shown. The 40 holes include 35 normal holes and 5 encrypted holes. The encrypted circumferential length is 2 m. The encrypted part is determined according to the surrounding rock conditions detected by drilling. The encrypted holes are located between two normal holes.

[0031] Step 4: A coring workroom is opened within a range of 2 m from the tail of the shield. The longitudinal length of the coring workroom is 2 m, and circumferentially, it ranges from the 10 o'clock position to the 14 o'clock position. The height of the coring workroom is from 60.5 cm to 39.0 cm. Core sampling construction of the consolidated body at the top of the shield is carried out using a 150 diamond drill. The drilling diameter is 240 mm, and the maximum core sampling depth is 6 m.

[0032] Specifically, by using a 150 diamond drill to carry out core sampling construction of the consolidated body at the top of the shield, with a drilling diameter of 240 mm and a maximum core sampling depth of 6 m, the purpose of safely stripping the collapsed body above the shield is achieved.

[0033] The coring workroom 4 and the coring holes 6 are as Figure 2 shown. The height of the coring workroom from 60.5 cm to 39.0 cm is the height after removing the arch frame. The arch replacement in the coring workroom is carried out according to the plan of demolishing four sets of arch frames and reinstalling four sets of arch frames. The newly replaced four sets of arch frames use HW175 steel, with a longitudinal spacing of 60 cm. The four sets of arch frames to be demolished are shown in Figure 2 the original construction arch frame 3, and the four sets of newly replaced arch frames are shown in Figure 2 the replaced arch frame 5.

[0034] Step 5: After core sampling is completed, the TBM is assisted to get out of trouble by trying to rotate the cutter head, extend and retract the shield, and retract the TBM, and then tunneling is resumed.

[0035] Step 6: Repeat Steps 1 to 5 until the TBM tunnels through the stuck section.

[0036] As can be seen from the above embodiments, compared with the traditional method of manually cleaning and releasing the shield extrusion pressure by means of pilot tunnel excavation, the method of the present invention significantly reduces the construction safety risk by using the core sampling method, simplifies the construction process steps, and can greatly reduce the time consumption and improve the safety of personnel. The present invention innovates the construction method of the coring workroom. Compared with the traditional pipe shed workroom, this method has the advantages of small structural size and fast and convenient construction.

[0037] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for escaping a stuck TBM in an open water-rich alteration zone, characterized in that: include: Step 1: Advanced geological prediction, which adopts the construction method of advanced drilling as the main method, supplemented by seismic wave reflection method and complex frequency conductivity technology; a fully hydraulic anchor drilling rig is used within the range of 8 to 11 points of the TBM shield tail, and 1 to 3 advanced exploration holes with a length of 15 to 20 meters and a diameter of 120 mm are drilled at an external insertion angle of 30 to 45 degrees; Step 2: Chemical injection is performed on the TBM cutterhead, shield, and shield tail to fill and seal the cracks in the broken rock mass, while reinforcing the collapsed mass above the shield and in front of the cutterhead. Step 3: The starting point of the pipe shed construction is 5m from the shield tail, and the external insertion angle is controlled at 10°. The length of the guide pipe is 2m to ensure the drilling angle of the drill rig; a total of 40 holes are drilled from 10 o'clock to 14 o'clock in the advance pipe shed, with a circumferential spacing of 30cm, a maximum drilling depth of 20m, and a rock penetration depth of not less than 3m. The space between the pipe shed and the shield is used as a coring studio; Step 4: Open a coring studio within 2m of the tail of the shield. The vertical length of the coring studio is 2m, and the circumferential direction is from 10 o'clock to 14 o'clock. The height of the coring studio is 60.5cm to 39.0cm. Use a 150 water drill to coring the top consolidation body of the shield. The drilling diameter is 240mm and the maximum coring depth is 6m. Step 5: After coring is completed, the TBM is assisted to escape and resume excavation by trying to rotate the cutter head, extend the shield, and retreat the TBM. Step six, repeat steps one to five until the TBM excavation passes the stuck section.

2. A method for escaping a stuck TBM in an open water-rich alteration zone according to claim 1, characterized in that: In step 2, the chemical injection material consists of two components: a combined polyether and an isocyanate.

3. A method for escaping a stuck TBM in an open water-rich alteration zone according to claim 1, characterized in that: In step 2, sequential pouring from bottom to top is adopted to form a closed space, and then new holes are made for grouting; the initial grouting pressure is 0 MPa and the ending pressure is 5 MPa.

4. A method for escaping a stuck TBM in an open water-rich alteration zone according to claim 1, characterized in that: In step three, the 40 holes include 35 normal holes and 5 encrypted holes with an encrypted circumferential length of 2m. The encrypted positions are determined based on the surrounding rock conditions ascertained by drilling, and the encrypted holes are located between two normal holes.

5. A method for escaping a stuck TBM in an open water-rich alteration zone according to claim 1, characterized in that: In step 4, the arch replacement of the core sampling studio is carried out according to the plan of dismantling four arch frames and reinstalling four arch frames. The new four arch frames are made of HW175 steel with a longitudinal spacing of 60cm.

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