A method of preventing the outer wall of a freeze wellbore shaft tunnel boring machine from falling off during tunneling

Abstract

The application discloses a method for preventing the outer layer well wall from falling off during the shaft sinking of a shaft sinking machine in a frozen shaft, which is installed in the shaft sunk by using a common method, and after installation and debugging, the lower part of the frozen shaft is sunk to the design depth by the shaft sinking machine in a way of a cycle operation every 6 m, an annular groove is constructed in each cycle, the annular groove is integrally poured with the outer layer well wall, and finally, a permanent wall seat is constructed; by the method, the anchor rod constructed on the shaft and the annular groove arranged at the bottom of each cycle can increase the supporting force of the outer layer well wall after pouring, the shaft is sprayed except the groove, the frozen wall can be effectively protected, the freezing of the frozen wall is reduced, and the friction between the outer layer well wall is increased; the application can effectively prevent the outer layer well wall from falling off due to the insufficient friction of the smooth shaft under the frozen condition during the shaft sinking by the shaft sinking machine.

Description

Technical Field

[0001] This invention relates to the field of special shaft sinking technology in mining. Specifically, it relates to a method for preventing the outer layer of the shaft wall from detaching during the excavation of a frozen shaft tunneling machine. Background Technology

[0002] Traditionally, shafts constructed using the freezing method are primarily excavated manually or by blasting, a method known as the "freezing + drilling and blasting" method. When using this method, the shaft walls become uneven after excavation, resulting in significant friction between the excavated outer shaft wall and the shaft walls. This effectively prevents the outer shaft wall from detaching, eliminating the need for additional measures to prevent it from falling off.

[0003] However, when using a shaft boring machine (TBM) to excavate a shaft under frozen conditions, the shaft walls after excavation are very smooth, resulting in a very low coefficient of friction between the shaft walls and the outer shaft wall used in later construction. This friction is insufficient to withstand the weight of the outer shaft wall. Furthermore, during the TBM excavation process, the frozen wall is exposed for a long time, leading to severe thawing and significant creep. Without effective measures, there is a high risk of the outer shaft wall detaching during construction, potentially causing an engineering accident. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide a method for preventing the outer well wall from falling off during the excavation of a frozen shaft tunneling machine, ensuring the safety, reliability and stability of the outer well wall.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A method for preventing the outer wall of a frozen shaft tunneling machine from detaching during tunneling includes the following steps:

[0007] S1 will be excavated in the already excavated frozen shaft using a vertical shaft tunneling machine in a cyclic operation until it reaches the designed depth;

[0008] After S2 reaches the designed depth, the permanent wall seat will be constructed to complete the construction of the outer well wall.

[0009] The job steps in each loop of step S1 include:

[0010] After the S11 shaft tunneling machine reaches a construction footage of 6m, the shaft tunneling machine stops normal tunneling, and the anchor drilling rig on the tunneling machine is used to construct the first anchor bolt at the upper shaft wall, with the tail of the first anchor bolt exposed.

[0011] After the first anchor bolt of S12 is completed, the telescopic cutting head set on the upper part of the tunneling machine constructs an annular groove on the shaft wall, and constructs a second anchor bolt in the middle of the annular groove. The tail of the second anchor bolt is exposed and aligned with the end of the first anchor bolt.

[0012] S13 adopts steel wire mesh to connect all the first anchor rods into a whole, and then performs shotcrete treatment on the shaft sides except the grooves to form a shotcrete layer with a certain thickness;

[0013] S14, after the shotcrete is finished, the outer shaft wall steel bars are bound, the tail parts of the first anchor rods and the second anchor rods are connected to the shaft wall steel bars, and then the outer shaft wall of a circulation section is formed by pouring together with the annular grooves.

[0014] Further, the method for preventing the outer shaft wall from falling off during the shaft sinking of the shaft sinking machine in the frozen shaft further comprises the step S0 of installing the shaft sinking machine in the frozen shaft: two annular wall seats are arranged at a distance of 10 m and 5 m from the shaft mouth of the frozen shaft, and the two annular wall seats are constructed together with the outer shaft wall when the shaft wall at the shaft mouth is poured.

[0015] Further, the annular wall seat has a depth of 300 mm and a height of 300 mm.

[0016] Further, in the step S12, the annular groove has a height of 500 mm and a depth of 300 mm.

[0017] Further, the first anchor rod has a depth of not more than 600 mm, the first anchor rod has a layout size of 300 mm*300 mm, the first anchor rod is arranged in a plum blossom form, and a 200 mm long anchor rod is reserved at the tail part of the first anchor rod; the second anchor rod has a depth of 300 mm and an anchor rod spacing of 300 mm, and a 500 mm long anchor rod is reserved at the tail part of the second anchor rod.

[0018] Further, in the step S13, the steel wire mesh is hung at half of the reserved length of the tail part of the first anchor rod; the shotcrete layer has a thickness of 150 mm, and the shotcrete strength is C20.

[0019] The technical scheme of the present application has the following beneficial technical effects:

[0020] By adopting the method of the present application, the anchor rods constructed on the shaft sides and the annular grooves arranged at each circulation bottom can increase the supporting force on the poured outer shaft wall, the shotcrete is performed on the shaft sides except the grooves, the frozen wall can be effectively protected, the freezing of the frozen wall is reduced, and the friction between the outer shaft wall is increased; the present application can effectively prevent the outer shaft wall from falling off due to the insufficient friction of the smooth shaft sides when the shaft sinking machine is used to sink under the frozen condition. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Fig. 1 is a structural schematic view after the step S11 of the present application is finished;

[0022] Figure 2 Fig. 2 is a structural schematic view after the step S12 of the present application is finished;

[0023] Figure 3 It is a structural schematic diagram after the construction of one S13 step of the present application;

[0024] Figure 4 It is a structural schematic diagram after the construction of one S14 step of the present application;

[0025] Figure 5 It is a structural schematic diagram after the construction of two S11 steps of the present application;

[0026] Figure 6 It is a sectional schematic diagram at the position of the first anchor rod of the embodiment of the present application.

[0027] The reference signs in the figure are as follows: 1-well slope, 2-annular wall seat, 3-first anchor rod, 4-annular groove, 5-second anchor rod, 6-steel mesh, 7-spraying layer, 8-well wall steel bar, 9-outer layer well wall. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0029] As shown in Figures 1 to 6 a method for preventing the outer layer well wall 9 from falling off during the shaft sinking of the frozen shaft by the shaft sinking machine, which is installed in the shaft sunk by the common method, and after the installation and debugging are completed, the lower part of the frozen shaft is sunk by the shaft sinking machine, and specifically includes the following steps:

[0030] As shown in Figure 1 S0, the shaft sinking machine is installed in the frozen shaft: one annular wall seat 2 is arranged at each of positions 10 m and 5 m away from the well mouth of the frozen shaft, the annular wall seat 2 has a depth of 300 mm and a height of 300 mm; when pouring the well wall at the well mouth, the two annular wall seats 2 are constructed together with the outer layer well wall 9 to increase the support force of the upper well wall and the stability of the well wall;

[0031] S1, the shaft sinking machine is used to sink in the excavated frozen shaft in a cyclic operation mode, the shaft sinking machine is sunk in a cyclic operation mode of every 6 m, and the sinking is performed until the design depth is reached;

[0032] The operation steps in each cycle in step S1 include:

[0033] S11, after the construction footage of the shaft sinking machine reaches 6 m, the shaft sinking machine stops normal sinking, the anchor rod drill machine on the shaft sinking machine is used to construct the first anchor rod 3 at the upper well slope 1, the tail of the first anchor rod 3 is exposed, and a 200 mm long anchor rod is reserved at the tail of the first anchor rod 3; Figure 1Structure diagram after the construction of the first anchor rod 3 in the cycle located at the top of the frozen shaft is completed, Figure 1 H0 in the figure represents the depth required for the installation of the shaft boring machine;

[0034] S12 After the construction of the first anchor rod 3 is completed, the telescopic cutting head arranged on the upper part of the boring machine is used to construct an annular groove 4 on the shaft side 1, the height of the annular groove 4 is 500 mm, and the depth is 300 mm; after the construction of the annular groove 4 is completed, a circle of second anchor rods 5 is constructed at the middle position of the annular groove 4, and the tail of the second anchor rod 5 is exposed to be aligned with the end of the first anchor rod 3; Figure 2 Structure diagram after the construction of the second anchor rod 5 in the cycle located at the top of the frozen shaft is completed;

[0035] S13 After the construction of all the anchor rods is completed, steel wire mesh 6 is used to connect all the first anchor rods 3 into a whole, the steel wire mesh 6 is hung at the half of the reserved length of the tail of the first anchor rod 3, that is, the steel wire mesh 6 is hung at the position 100 mm away from the outside of the shaft side 1; then, the shaft side 1 except the groove is subjected to shotcreting treatment to form a shotcreting layer 7 with a thickness of 150 mm, and the shotcreting strength is C20; the shotcreting is performed on the exposed frozen wall in the boring process in time, which can reduce the exposure time of the frozen wall, reduce the creep of the frozen wall, and ensure the stability of the frozen wall in the boring process; Figure 3 Structure diagram after the shotcreting treatment in the cycle located at the top of the frozen shaft is completed;

[0036] S14 After the shotcreting is completed, the reinforcement 8 of the outer shaft wall 9 is bound to connect the tails of the first anchor rod 3 and the second anchor rod 5 to the reinforcement 8 of the shaft wall; then, the outer shaft wall 9 of a cycle section is poured together with the annular groove 4; Figure 4 Structure diagram after the pouring of the outer shaft wall 9 in the cycle located at the top of the frozen shaft is completed; Figure 6 Cross-sectional view of the position of the first anchor rod 3 after the pouring of the outer shaft wall 9 in the cycle operation; Figure 5 Structure diagram after the construction of the first anchor rod 3 in another layer after the start of the next cycle operation is completed; when the reinforcement 8 of the outer shaft wall 9 is bound, the reserved part of the tail of the first anchor rod 3 and the second anchor rod 5 is connected to the reinforcement 8 of the outer shaft wall 9 by T-shaped welding, and after the binding of all the reinforcements is completed, the outer shaft wall 9 is poured; the reinforcement 8 of the outer shaft wall 9 is connected to the tails of all the anchor rods, the annular groove 4 is integrally poured with the outer shaft wall 9, provides support force for the outer shaft wall 9, and prevents the outer shaft wall 9 from sliding downward;

[0037] After one cycle operation is completed, the shaft boring machine starts the next cycle boring, and the construction process of S11-S14 is repeated every 6 m until the boring reaches the designed depth;

[0038] After S2 reaches the designed depth, the permanent wall seat is constructed according to the design document, and the construction of the outer shaft wall 9 is completed.

[0039] Before the shaft sinking machine is installed in step S0, since it is at the shaft mouth, the problem of shaft wall falling is not considered, but when the ordinary method is used to construct the upper part of the shaft, it is different from the conventional ordinary method construction, the main difference is that when the shaft mouth is constructed, the width and depth of the locking ring are each increased by 2m than when the ordinary method is constructed, and the construction quality requirement is more strict.

[0040] In one specific embodiment, the diameters of the first anchor rod 3 and the second anchor rod 5 used in the cyclic operation are 14-20mm, the length of the first anchor rod 3 is 800, the depth of the first anchor rod 3 does not exceed 600mm, the layout size of the first anchor rod 3 is 300mm*300mm, and the first anchor rod 3 is arranged in a plum blossom form; the depth of the second anchor rod 5 is 300mm, and the anchor rod spacing is 300mm.

[0041] By using the method of the present application, the shotcrete is sprayed at the shaft side 1 except the groove, which can effectively protect the frozen wall, reduce the freezing of the frozen wall, and increase the friction between the outer shaft wall 9; the reinforcement 8 of the outer shaft wall 9 is connected with all the anchor rod tails, and the annular groove 4 is integrally poured with the outer shaft wall 9, which can all provide support force for the outer shaft wall 9 to prevent the outer shaft wall 9 from sliding downward; the present application can effectively prevent the outer shaft wall 9 from falling off due to insufficient friction of the smooth shaft side 1 when the shaft sinking machine is used to excavate under the freezing condition.

[0042] Obviously, the above embodiments are only examples for clearly illustrating, and are not limitation to the embodiments. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, all the embodiments need not and cannot be exhausted. The obvious changes or variations derived therefrom are still within the protection scope of the patent application claims.

Claims

1. A method of preventing the falling of a freezing shaft shaft sinking machine excavation of an outer shaft lining (9), characterized in that, It comprises the following steps: S1: using a shaft excavator to excavate in a cycle mode in the excavated frozen shaft until the design depth is reached; S2: after reaching the design depth, constructing a permanent wall seat and completing the construction of the outer shaft wall (9); Each cycle in step S1 comprises the following steps: S11: after the shaft excavator has constructed a 6m long section, the shaft excavator stops normal excavation, and an anchor rod drill on the shaft excavator constructs a first anchor rod (3) at the upper shaft side (1), with the tail of the first anchor rod (3) exposed; S12: after the first anchor rod (3) is constructed, a retractable cutting head on the upper part of the shaft excavator constructs an annular groove (4) on the shaft side (1) and constructs a circle of second anchor rods (5) in the middle of the annular groove (4), with the tails of the second anchor rods (5) exposed to align with the ends of the first anchor rods (3); S13: using a steel mesh (6) to connect all the first anchor rods (3) into a whole, and then performing shotcrete treatment on the shaft side (1) except the groove to form a shotcrete layer (7) of a certain thickness; S14: after the shotcrete is completed, the tails of the first anchor rods (3) and the second anchor rods (5) are connected to the shaft wall reinforcement (8) by binding the reinforcement (8) of the outer shaft wall (9), and then the annular groove (4) is poured together to form an outer shaft wall (9) of a cycle section.

2. The method of preventing the excavation of the outer shaft lining (9) from the freeze wellbore shaft jumbo to be excavated according to claim 1, characterized in that, It further comprises step S0: installing a shaft excavator in the frozen shaft: two annular wall seats (2) are arranged 10m and 5m away from the shaft mouth of the frozen shaft, and the two annular wall seats (2) are constructed together with the outer shaft wall (9) when pouring the shaft wall at the shaft mouth.

3. The method of preventing the excavation of the outer shaft lining (9) from the freeze wellbore shaft jumbo to be excavated according to claim 2, characterized in that, The annular wall seat (2) has a depth of 300mm and a height of 300mm.

4. The method of preventing the excavation of the outer shaft lining (9) from falling off the freeze well shaft shaft jumbo according to claim 1, characterized in that, In step S12, the annular groove (4) has a height of 500mm and a depth of 300mm.

5. The method of preventing the excavation of the outer shaft lining (9) from falling off the freezing shaft shaft jumbo according to claim 1, characterized in that, The depth of the first anchor rod (3) is not more than 600mm, the first anchor rod (3) has a layout size of 300mm x 300mm, the first anchor rod (3) is arranged in a quincunx pattern, and the tail of the first anchor rod (3) is reserved with a 200mm long anchor rod; the second anchor rod (5) has a depth of 300mm and an anchor rod spacing of 300mm, and the tail of the second anchor rod (5) is reserved with a 500mm long anchor rod.

6. The method of preventing the excavation of the outer shaft lining (9) from falling off the freeze well shaft shaft jumbo according to claim 1, characterized in that, In step S13, the steel mesh (6) is hung at half the length of the reserved length of the tail of the first anchor rod (3); the shotcrete layer (7) has a thickness of 150mm and a shotcrete strength of C20.

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