A method for initial support and arch replacement in soft rock with large deformation

Abstract

This invention discloses a method for replacing the arch support in the initial support structure during large deformation in soft rock, comprising the following steps: measuring and obtaining the deformation length of the initial support arch frame within the tunnel, recording it as the surrounding rock deformation segment; dividing the surrounding rock deformation segment into at least two construction areas and a connecting area connecting the two construction areas; dismantling the initial support arch frame in one of the construction areas and the connecting area to form a first installation area; installing a first support arch frame in the first installation area; dismantling the initial support arch frame in the other construction area, forming a second installation area with the connecting area; and installing a second support arch frame in the second installation area. This invention aims to solve the problem of deformation encroachment in the support system structure within the Xiaguan Tunnel.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, specifically to a method for initial support and arch replacement in soft rock with large deformation. Background Technology

[0002] The Xiaguan Tunnel passes through an area with extremely high ground stress and complex surrounding rock geology. The rock has poor bearing capacity, and the settlement rate during construction is much greater than the convergence value, which causes damage to the support system. The I-beams are twisted and deformed, and the surrounding rock is greatly deformed, thus destroying the surrounding rock support system. Summary of the Invention

[0003] The main objective of this invention is to propose a method for initial support arch replacement in soft rock with large deformation, which aims to solve the problem of deformation and limit of the support system structure in Xiaguan Tunnel.

[0004] To achieve the above objectives, this invention proposes a method for initial support and arch replacement in soft rock with large deformation, comprising the following steps:

[0005] The deformation length of the initial support arch in the tunnel is measured and recorded as the deformation section of the surrounding rock;

[0006] The surrounding rock deformation section is divided into at least two construction areas and a connecting area connecting the two construction areas;

[0007] Remove the initial support arches of the construction area and the connecting area to form the first installation area;

[0008] Install the first arch support frame in the first installation area;

[0009] The initial support arch frame of the other construction area is removed, and the other construction area and the connecting area form a second installation area;

[0010] Install the second support arch frame in the second installation area.

[0011] Optionally, the step of installing the first support arch frame in the first installation area includes:

[0012] In the first installation area, the surrounding rock encroaching on the initial support arch is removed in order to widen the tunnel to the first design outline.

[0013] The surrounding rock surface of the first installation area was reinforced with shotcrete.

[0014] The first support arch is installed in the first installation area of ​​the shotcrete according to the preset support strength parameters.

[0015] Optionally, the step of installing the second support arch frame in the second installation area includes:

[0016] In another construction area, the surrounding rock encroaching on the initial support arch is removed to widen the tunnel to the first design profile.

[0017] The surrounding rock surface of the other construction area was reinforced with shotcrete.

[0018] The second support arch is installed in the connecting area according to the preset profile of the tunnel, and the second support arch is installed in another construction area according to the first design profile.

[0019] Optionally, after the steps of installing the second support arch frame in the connecting area according to the preset contour of the tunnel, and installing the second support arch frame in another construction area according to the first design contour, the method further includes:

[0020] In one construction area, the first support arch is sprayed with concrete to the predetermined outline, and in another construction area, the second support arch is sprayed with concrete to the predetermined outline.

[0021] Optionally, after the step of reinforcing the surrounding rock surface of the first installation area with shotcrete, the following steps are included:

[0022] Install construction anchors and locking guide pipes in uncured concrete.

[0023] Optionally, after the step of installing the construction anchors and locking guide pipes in the uncured concrete, the following steps are included:

[0024] The connection strength of the construction anchor rod and the locking foot guide pipe in the concrete that has solidified after a second preset time period is tested.

[0025] Optionally, after the step of installing the first support arch frame in the first installation area, the method further includes:

[0026] The first arch support frame was reinforced;

[0027] Observe whether the first arch support frame deforms after the first preset time period;

[0028] If so, then remove the first arch support frame of the deformed part;

[0029] If not, install steel mesh and connecting bars on the first arch support frame and spray concrete.

[0030] Optionally, before the step of dismantling the initial support arch of one of the construction areas and the connecting areas to form the first installation area, the method further includes:

[0031] Reinforce the initial support arch frame adjacent to the first installation area.

[0032] Optionally, the step of reinforcing the initial support arch adjacent to the first installation area includes:

[0033] Level the concrete surface of the initial support arch frame adjacent to the first installation area;

[0034] I-beams are used as temporary protective arches, which are in contact with the concrete surface of the initial support arch adjacent to the first installation area.

[0035] Optionally, after the step of installing the second support arch frame in the second installation area, the method further includes:

[0036] Dismantle the aforementioned temporary protective measures;

[0037] Waterproofing treatment is applied to the initial support arch frame, the first support arch frame, and the second support arch frame in the undeformed part of the tunnel.

[0038] An embodiment of the present invention provides a method for initial support and arch replacement in soft rock with large deformation. The method involves measuring and recording the deformation length of the initial support arch within the tunnel as a surrounding rock deformation segment; dividing the surrounding rock deformation segment into at least two construction areas and a connecting area connecting the two construction areas; dismantling the initial support arch in one construction area and the connecting area to form a first installation area; installing a first support arch in the first installation area; dismantling the initial support arch in the other construction area, forming a second installation area with the connecting area; and installing a second support arch in the second installation area. In this embodiment, the surrounding rock deformation segment is constructed in segments to reduce construction risks caused by surrounding rock deformation while ensuring construction quality. By dividing the surrounding rock deformation section into multiple construction areas and a connecting area between two adjacent construction areas, the following method is used to illustrate that the surrounding rock deformation section has two construction areas and one connecting area. First, the initial support arches of one construction area and the connected area can be dismantled. Due to the small dismantling area and the support provided by the remaining initial support arches of the surrounding rock deformation section, the surrounding rock will not experience rapid collapse and subsidence during the dismantling. Therefore, after dismantling, the first support arch is installed in this area to re-stabilize it. Then, the initial support arches of the other construction area are dismantled, and the second support arch is installed in the second installation area. The first and second support arches are overlapped in the connecting area, thereby increasing the support strength in the connecting area and improving the connection strength between the first and second support arches. In other words, the above construction method can solve the problem of deformation and encroachment of the support system structure in the Xiaguan Tunnel. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0040] Figure 1 This is a schematic flowchart of an embodiment of the initial support and arch replacement method for large deformation in soft rock provided by the present invention.

[0041] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0043] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0044] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0045] The Xiaguan Tunnel passes through an area with extremely high ground stress and complex surrounding rock geology. The rock has poor bearing capacity, and the settlement rate during construction is much greater than the convergence value, which causes damage to the support system. The I-beams are twisted and deformed, and the surrounding rock is greatly deformed, thus destroying the surrounding rock support system.

[0046] In view of this, the present invention proposes a method for initial support and arch replacement in soft rock with large deformation. Figure 1 This is one embodiment of the present invention.

[0047] Please see Figure 1 The method for initial support and arch replacement in soft rock with large deformation includes the following steps:

[0048] Step S1: Measure and obtain the deformation length of the initial support arch in the tunnel, and record it as the surrounding rock deformation segment;

[0049] Step S2: Divide the surrounding rock deformation section into at least two construction areas and a connecting area connecting the two construction areas;

[0050] Step S3: Remove the initial support arch of the construction area and the connecting area to form the first installation area;

[0051] Step S4: Install the first support arch frame in the first installation area;

[0052] Step S5: Remove the initial support arch frame of the other construction area, and the other construction area and the connecting area form a second installation area;

[0053] Step S6: Install the second support arch frame in the second installation area.

[0054] An embodiment of the present invention provides a method for initial support and arch replacement in soft rock with large deformation. The method involves measuring and recording the deformation length of the initial support arch within the tunnel as a surrounding rock deformation segment; dividing the surrounding rock deformation segment into at least two construction areas and a connecting area connecting the two construction areas; dismantling the initial support arch in one construction area and the connecting area to form a first installation area; installing a first support arch in the first installation area; dismantling the initial support arch in the other construction area, forming a second installation area with the connecting area; and installing a second support arch in the second installation area. In this embodiment, the surrounding rock deformation segment is constructed in segments to reduce construction risks caused by surrounding rock deformation while ensuring construction quality. By dividing the surrounding rock deformation section into multiple construction areas and a connecting area between two adjacent construction areas, the following method is used to illustrate that the surrounding rock deformation section has two construction areas and one connecting area. First, the initial support arches of one construction area and the connected area can be dismantled. Due to the small dismantling area and the support provided by the remaining initial support arches of the surrounding rock deformation section, the surrounding rock will not experience rapid collapse and subsidence during the dismantling. Therefore, after dismantling, the first support arch is installed in this area to re-stabilize it. Then, the initial support arches of the other construction area are dismantled, and the second support arch is installed in the second installation area. The first and second support arches are overlapped in the connecting area, thereby increasing the support strength in the connecting area and improving the connection strength between the first and second support arches. In other words, the above construction method can solve the problem of deformation and encroachment of the support system structure in the Xiaguan Tunnel.

[0055] It is understood that the number of construction areas and connection areas is determined according to the actual length of the surrounding rock deformation section, and is not limited here.

[0056] Further, step S4: the step of installing the first support arch frame in the first installation area includes:

[0057] Step S41: Remove the surrounding rock that encroaches on the initial support arch in the first installation area to widen the tunnel to the first design outline.

[0058] Step S42: Reinforce the surrounding rock surface of the first installation area with shotcrete;

[0059] Step S43: Install the first support arch in the first installation area of ​​the shotcrete according to the preset support strength parameters.

[0060] Wherein, the first design profile is larger than the preset profile of the tunnel. After the initial support arch frame located in the first installation area is removed, the surrounding rock encroaching on the initial support arch frame can be chiseled away to reserve an installation space suitable for the installation of the first support arch frame. The surface of the chiseled surrounding rock is sprayed with concrete for initial fixation. After the concrete solidifies, the first support arch frame can be installed on the surface of the concrete according to the preset support strength parameters to support the first installation area.

[0061] Further, step S6: the step of installing the second support arch frame in the second installation area includes:

[0062] Step S61: In another construction area, the surrounding rock encroaching on the initial support arch is removed to widen the tunnel to the first design profile.

[0063] Step S62: Reinforce the surrounding rock surface of the other construction area with shotcrete;

[0064] Step S63: Install the second support arch frame in the connecting area according to the preset contour of the tunnel, and install the second support arch frame in another construction area according to the first design contour.

[0065] Similarly, after the first support arch is installed in the first installation area, the initial support arch located in the other construction area is removed, and the surrounding rock encroaching on the initial support arch in the other construction area is chiseled away, thereby reserving an installation space suitable for the installation of the second support arch. The surface of the chiseled surrounding rock is sprayed with concrete for initial fixation. After the concrete is fixed, the second support arch can be installed on the surface of the concrete and the inside of the first support arch according to the preset support strength parameters. At this time, the outline formed by the overlapping of the first support arch and the second support arch in the connecting area is the preset outline of the tunnel.

[0066] Further, after step S63: installing the second support arch frame in the connecting area according to the preset contour of the tunnel, and installing the second support arch frame in another construction area according to the first design contour, the method further includes:

[0067] Step S7: In the construction area, spray concrete onto the first support arch to the preset outline, and in another construction area, spray concrete onto the second support arch to the preset outline.

[0068] After the first and second support arches are reconstructed in the two construction areas and the connecting area, since the size of the tunnel's preset outline and the first design outline are different, it is necessary to level the first and second support arches located in the two construction areas and spray concrete onto them to the preset outline of the tunnel in the two construction areas, thereby completing the reconstruction of the surrounding rock deformation section. At the same time, since the concrete layer in the two construction areas is relatively thick, it can further stabilize the two construction areas.

[0069] Further, after step S42: the step of reinforcing the surrounding rock surface of the first installation area with shotcrete, the following is included:

[0070] Step S421: Install construction anchors and locking guide pipes in the uncured concrete.

[0071] The first support arch is installed in the first installation area by installing construction anchors and locking guide pipes in the uncured concrete. Similarly, in the other construction area, the second support arch is installed by installing construction anchors and locking guide pipes in the uncured concrete. In the connection area, the first and second support arches are connected for installation.

[0072] Further, after step S421: installing the construction anchor and locking guide pipe in the uncured concrete, the following is included:

[0073] Step S422: Test the connection strength of the construction anchor rod and the locking foot guide pipe in the concrete that has solidified after the second preset time period.

[0074] After installing the construction anchor rods and locking foot guide pipes in the uncured concrete, it is necessary to test the connection strength of the construction anchor rods and locking foot guide pipes to avoid instability during the installation of the first support arch.

[0075] Further, after step S4: installing the first support arch frame in the first installation area, the method further includes:

[0076] Step S451: Reinforce the first arch support frame;

[0077] Step S452: Observe whether the first arch support frame deforms after the first preset time period;

[0078] Step S45:3: If so, remove the first arch support frame of the deformed part;

[0079] Step S454: If not, install the steel mesh and connecting bars on the first support arch frame and spray concrete.

[0080] The first support arch is installed in the first installation area, and the first support arch is reinforced with sprayed concrete. After a first preset time period, the first support arch is observed to see if it is deformed. If it is deformed, the deformed part is measured again, removed, and the first support arch is reinstalled. If it is not deformed, steel mesh and connecting bars are installed on the first support arch, and sprayed concrete is used to complete the final fixation.

[0081] Further, before step S3: dismantling the initial support arch of the construction area and the connecting area to form the first installation area, the method further includes:

[0082] Step S231: Reinforce the initial support arch frame adjacent to the first installation area.

[0083] In this embodiment, by reinforcing the initial support arch adjacent to the first installation area, it is possible to avoid increased stress on the initial support arch adjacent to the first installation area after the initial support arch in the first installation area is removed, thereby preventing deformation.

[0084] Further, step S231: the step of reinforcing the initial support arch adjacent to the first installation area includes:

[0085] Step S2311: Level the concrete surface of the initial support arch adjacent to the first installation area;

[0086] Step S2312: Use I-beams to make a temporary arch support, which is in contact with the concrete surface of the initial support arch adjacent to the first installation area.

[0087] In the technical solution of this embodiment, by leveling the concrete surface of the initial support arch adjacent to the first installation area and using I-beams as temporary protective arches, the temporary protective arches can be tightly attached to the concrete surface of the initial support arches, eliminating the need to fill the gap between the temporary protective arches and the concrete surface of the initial support arches. This makes the operation convenient and facilitates safe construction in the later stages.

[0088] Further, after step S6: installing the second support arch frame in the second installation area, the method further includes:

[0089] Step S7: Remove the temporary protective equipment;

[0090] Step S8: Waterproofing treatment is applied to the initial support arch frame, the first support arch frame, and the second support arch frame in the undeformed part of the tunnel.

[0091] In this embodiment, after reconstructing the support system for the deformed section of the surrounding rock, the temporary support can be removed, and the deformed section of the surrounding rock can be waterproofed to prevent water penetration and reduce the service life of the first support arch and the second support arch.

[0092] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for soft rock large deformation initial support intruding arch replacement, characterized in that, Includes the following steps: The deformation length of the initial support arch in the tunnel is measured and recorded as the deformation section of the surrounding rock; The surrounding rock deformation section is divided into at least two construction areas and a connecting area connecting the two construction areas; Remove the initial support arches of the construction area and the connecting area to form the first installation area; Install the first arch support frame in the first installation area; The initial support arch frame of the other construction area is removed, and the other construction area and the connecting area form a second installation area; Install the second support arch frame in the second installation area; The step of installing the first support arch frame in the first installation area includes: In the first installation area, the surrounding rock encroaching on the initial support arch is removed in order to widen the tunnel to the first design outline. The surrounding rock surface of the first installation area was reinforced with shotcrete. The first support arch is installed in the first installation area of ​​the shotcrete according to the preset support strength parameters. The step of installing the second support arch frame in the second installation area includes: In another construction area, the surrounding rock encroaching on the initial support arch is removed to widen the tunnel to the first design profile. The surrounding rock surface of the other construction area was reinforced with shotcrete. The second support arch is installed in the connecting area according to the preset outline of the tunnel, and the second support arch is installed in another construction area according to the first design outline. The first design profile is larger than the preset profile of the tunnel.

2. The method for initial support and arch replacement in soft rock with large deformation as described in claim 1, characterized in that, After the steps of installing the second support arch frame in the connecting area according to the preset contour of the tunnel, and installing the second support arch frame in another construction area according to the first design contour, the method further includes: In one construction area, the first support arch is sprayed with concrete to the predetermined outline, and in another construction area, the second support arch is sprayed with concrete to the predetermined outline.

3. The method for initial support and arch replacement in soft rock with large deformation as described in claim 1, characterized in that, After the step of reinforcing the surrounding rock surface of the first installation area with shotcrete, the following steps are included: Install construction anchors and locking guide pipes in uncured concrete.

4. The method for initial support and arch replacement in soft rock with large deformation as described in claim 3, characterized in that, After the steps of installing construction anchors and locking guide pipes in uncured concrete, the following are included: The connection strength of the construction anchor rod and the locking foot guide pipe in the concrete that has solidified after a second preset time period is tested.

5. The method for initial support and arch replacement in soft rock with large deformation as described in claim 1, characterized in that, After the step of installing the first support arch frame in the first installation area, the method further includes: The first arch support frame was reinforced; Observe whether the first arch support frame deforms after the first preset time period; If so, then remove the first arch support frame of the deformed part; If not, install steel mesh and connecting bars on the first arch support frame and spray concrete.

6. The method for initial support and arch replacement in soft rock with large deformation as described in claim 1, characterized in that, Before the step of dismantling the initial support arch of the construction area and the connecting area to form the first installation area, the method further includes: Reinforce the initial support arch frame adjacent to the first installation area.

7. The method for initial support and arch replacement in soft rock with large deformation as described in claim 6, characterized in that, The step of reinforcing the initial support arch adjacent to the first installation area includes: Level the concrete surface of the initial support arch frame adjacent to the first installation area; I-beams are used as temporary protective arches, which are in contact with the concrete surface of the initial support arch adjacent to the first installation area.

8. The method for initial support and arch replacement in soft rock with large deformation as described in claim 7, characterized in that, Following the step of installing the second support arch frame in the second installation area, the following steps are also included: Remove the temporary protective arch; Waterproofing treatment is applied to the initial support arch frame, the first support arch frame, and the second support arch frame in the undeformed part of the tunnel.

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