Method for safely repairing tunnel slump cavity through shed shell type structure
By inserting anchor rods in the tunnel collapse area and spraying concrete to form a shed shell, the problem of low safety for construction workers during tunnel construction is solved, and a safer tunnel collapse repair effect is achieved.
Patent Information
- Application Number
- CN202510041946.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-10
- Publication Date
- 2025-04-11
AI Technical Summary
In the arch replacement operation of large deformation sections of tunnel soft rock, collapse is easily induced when the top surrounding rock is weak. The safety of construction workers in the existing technology is low during the repair process.
The safety restoration method of shed-shell structure is adopted. By inserting the first layer of anchor rod along the longitudinal direction of the tunnel, the collapse chamber is divided into the upper chamber and the lower chamber, spray concrete to seal the gap to form the shed, and an arch frame and steel mesh are installed below to support the shed to ensure construction safety.
The construction safety is effectively improved, and the slight rockfall in the collapse cavity is not threatened by the safety of construction workers through the support of the shed shell. The construction workers below are better protected through the stable shed shell and arch structure.
Smart Images
Figure CN119801575A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of tunnel construction, and in particular to a method for safely repairing a tunnel collapse cavity using a shed shell structure. Background Art
[0002] During the arch replacement operation in the soft rock section of the tunnel with large deformation, the collapse cavity is easily induced when the top surrounding rock is weak. The repair of the collapse cavity requires replacing the support and filling and sealing the collapse cavity, so that the tunnel can be rebuilt and form a stable structure.
[0003] There are many solutions for the treatment of collapsed holes in the prior art. However, these solutions all require construction workers to enter the collapsed hole area to carry out construction without effective protection in the collapsed hole area, which is less safe. Summary of the invention
[0004] The purpose of the present invention is to provide a method for safely repairing a tunnel collapse cavity using a shed shell structure, which can carry out construction more safely.
[0005] The embodiments of the present invention are implemented by the following technical solutions:
[0006] A method for safely repairing a tunnel collapse cavity using a shed shell structure comprises the following steps:
[0007] S1: inserting a plurality of first-layer anchor rods obliquely upward from one side of the collapsed cavity into the cavity wall of the collapsed cavity along the longitudinal direction of the tunnel; the plurality of first-layer anchor rods are distributed along the circumference of the tunnel so that the plurality of first-layer anchor rods divide the collapsed cavity into an upper cavity and a lower cavity;
[0008] S2: Applying a steel composite mesh on a plurality of first-layer anchor rods and spraying concrete to close the gaps between the plurality of first-layer anchor rods to form a shed shell;
[0009] S3: Install the first arch frame below the collapse cavity and install the steel mesh and shotcrete;
[0010] S4: Install the second arch frame and the steel mesh below the collapse cavity, and apply shotcrete between the first and second arch frames except for the second layer of anchor bolts;
[0011] S5: Along the longitudinal direction of the tunnel, the second layer of anchor rods is applied obliquely upward from the second arch frame, and the parts within the range of the second layer of anchor rods are sprayed with concrete; a number of second layer anchor rods are distributed along the circumference of the tunnel;
[0012] S6: Remove the original first arch and deformed initial support at the other end of the collapsed cavity, install the third arch frame and install steel mesh and shotcrete to seal the lower part of the lower chamber;
[0013] S7: injecting concrete into the lower chamber and the upper chamber in sequence to fill the collapsed cavity;
[0014] S8: Remove the second arch and deformed initial support at the other end of the collapsed cavity, install the fourth arch frame and install the steel mesh and shotcrete;
[0015] S9: Continue to dismantle and replace the initial supports of the deformed section one by one along the longitudinal direction of the tunnel;
[0016] S10: After the upper chamber is filled with concrete that reaches 100% strength, the temporary steel frame is removed and the shed shell and the portion of shotcrete that has invaded the initial support design boundary are cleared.
[0017] Furthermore, step S1 also includes using a wet spraying robot to spray concrete to protect the inner wall of the collapse cavity and the construction of a temporary protective arch. 2-3 steel arch frames are installed under the initial support of the original tunnel at both ends of the collapse cavity as temporary protective arches, and the protective arches are connected with angle steels; a temporary protective arch close to the collapse cavity is used as an anchor positioning steel frame, and anchor positioning holes are set on the anchor positioning steel frame, and circumferential reinforcement steel bars are added within the range of the anchor positioning steel frame.
[0018] Furthermore, step S2 also includes: installing a delivery pump pipe through the first layer of anchor rods into the upper chamber; applying a steel composite mesh on a number of first layer anchor rods and spraying concrete to form a shed shell by connecting the steel composite mesh with the first layer anchor rods to form a whole; the steel composite mesh is formed by overlapping a φ6.5mm steel mesh with a spacing of 200×200mm and a φ3.5mm steel wire mesh with a spacing of 50mm×50mm, wherein the steel wire mesh is located above the steel mesh.
[0019] Furthermore, step S6 also includes: pre-burying a delivery pump pipe between the second arch frame and the third arch frame for pouring concrete into the lower chamber.
[0020] Furthermore, step S7 also includes: filling the lower chamber with C25 concrete; after the concrete filled in the lower chamber reaches 70% strength, filling the upper chamber with C25 concrete in layers to a height of about 2.0m above the tunnel vault excavation line, and if there is still space, blowing sand to fill it until it is full; the layered filling of C25 concrete is carried out in layers according to the secondary pouring process, wherein the first pouring of concrete is controlled to be 0.5m above the tunnel vault excavation line.
[0021] Furthermore, the first-layer anchor rods and the second-layer anchor rods are both hollow self-advancing anchor rods, and cement-water glass double liquid slurry is pressed into the first-layer anchor rods and the second-layer anchor rods after drilling and installation.
[0022] Furthermore, the external insertion angle of the first layer of anchor rods is controlled by leaving a clear height of about 50mm between the anchor rods and the first arch frame, and the spacing between adjacent anchor rods along the circumference of the tunnel is 200mm; the external insertion angle and spacing of the second layer of anchor rods are controlled according to the normal advance support design values.
[0023] Furthermore, the temporary arch frame is provided with a through hole in cooperation with each first-layer anchor rod, so that each first-layer anchor rod is plugged into one through hole.
[0024] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects:
[0025] The method for safely repairing a collapsed tunnel cavity with a shed shell structure of the present invention first uses a drilling rig to drill the first-layer anchor rod from one end of the collapsed cavity to the other end, so that one end of the first-layer anchor rod extends into the surrounding rock and is supported. A plurality of first-layer anchor rods can form a barrier to separate the collapsed cavity into an upper chamber and a lower chamber. The gaps between the plurality of first-layer anchor rods can be closed by spraying concrete, thereby forming a closed shed shell. At this point, construction personnel can enter the bottom of the collapsed cavity to perform operations such as replacing the arch frame. Due to the support of the shed shell, slight rockfalls at the collapsed cavity will not threaten the safety of construction personnel.
[0026] The temporary arch also supports the upper and lower parts of the first layer of anchor rods, making the shed shell more stable and thus better protecting the construction workers below. The anchor rods are self-propelled, so that grouting can be done directly after the anchor rods are drilled into place, unlike the risk of surrounding rock falling off caused by pulling out the drill rods after drilling. At the same time, before the first layer of anchor rods are drilled, concrete will be sprayed on the inner wall of the collapsed cavity to better prevent the surrounding rock from falling during construction. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 Schematic diagram of the distribution of the first layer of anchor rods and the second layer of anchor rods in the tunnel.
[0028] Figure 2 for Figure 1 A magnified schematic diagram of middle a.
[0029] Figure 3 Schematic diagram of the distribution of several first-layer anchor rods.
[0030] Figure numerals: 1-tunnel, 101-replaced arch section, 102-largely deformed arch section that has not been replaced, 2-upper chamber, 3-lower chamber, 4-first layer of anchor rods, 5-first arch frame, 6-second arch frame, 7-temporary arch protection, 701-anchor rod positioning steel frame, 8-second layer of anchor rods, 9-steel composite mesh. DETAILED DESCRIPTION
[0031] After tunnel construction, large deformation or even collapse may occur. During the repair process, the original arch frame needs to be replaced and the collapsed cavity needs to be filled. Figure 1 As shown, position 101 is the replaced arch segment, and position 102 is the arch segment with large deformation that has not been replaced.
[0032] like Figure 1-Figure 3 As shown, the present invention provides a tunnel 1 arch collapse hole shed shell type repair method, comprising the following steps:
[0033] S1: Insert a plurality of first-layer anchor rods 4 obliquely upward from one side of the collapsed cavity into the cavity wall of the collapsed cavity along the longitudinal direction of the tunnel 1. The plurality of first-layer anchor rods 4 are distributed along the circumference of the tunnel 1 so that the plurality of first-layer anchor rods 4 divide the collapsed cavity into an upper cavity 2 and a lower cavity 3. Figure 1 As shown in FIG. 1 , the drilling rig is on the right side of the collapsed hole area of the tunnel 1, and it drills the first layer anchor rods 4 at a 35 degree angle to the horizontal plane. The cavity on the upper right of the first layer anchor rods 4 is the upper chamber 2, and the cavity on the lower left is the lower chamber 3. The distribution of several first layer anchor rods 4 is shown in FIG. Figure 3 As shown, the upper chamber 2 and the lower chamber 3 are separated.
[0034] S2: A steel composite mesh 9 is applied on the first layer anchor rods 4 and concrete is sprayed. The concrete adheres to the steel composite mesh 9 and the first layer anchor rods 4, thereby blocking the gaps between the first layer anchor rods 4 to form a shed shell. After hardening, the concrete has a certain strength and can block the debris falling from the inner wall of the upper chamber 2. Before spraying concrete, the collapsed cavity needs to be pre-buried and backfilled with C15 concrete pumping pipes and exhaust pipes.
[0035] S3: Install the first arch frame 5 below the collapsed cavity and install a steel mesh and shotcrete between the first arch frame 5 and the arch frame on the right, so that the space between the two is closed into a shell.
[0036] S4: Install the second arch frame 6 below the collapse cavity and install the longitudinal connecting steel bars and steel mesh, and apply the initial support shotcrete of the tunnel outside the range of the advance anchor, that is, the shotcrete between the first and second arch frames except the range of the second layer of anchor.
[0037] S5: Along the longitudinal direction of the tunnel 1, the second layer of anchor rods 8 are installed obliquely upward from the second arch frame 6, and the area within the range of the second layer of anchor rods 8 is sprayed with concrete to seal the lower part of the lower chamber 3. A plurality of second layer anchor rods 8 are inserted into the cavity wall of the collapsed cavity. The installation direction of the plurality of second layer anchor rods 8 in the surrounding rock is as follows: Figure 1 As shown. The surrounding rock on the upper left side can be stabilized by the second layer of anchor rods 8. A plurality of second layer anchor rods 8 are distributed along the circumference of the tunnel 1, and the distribution pattern is the same as that of a plurality of first layer anchor rods 4. Since the space between the second arch frame 6 and the first arch frame 5 has not been closed, the second anchor rod drilling can be conveniently performed.
[0038] S6: Remove the original first arch and deformed initial support at the other end of the collapsed cavity, install the third arch frame and install steel mesh and shotcrete to seal the lower part of the lower chamber.
[0039] S7: Concrete is poured into the upper chamber 2 and the lower chamber 3 to fill the upper chamber 2 and the lower chamber 3. Specifically, the upper chamber 2 and the lower chamber 3 are first poured with C15 concrete to a depth of 0.5 meters. Then C25 concrete is poured and the thickness of C25 concrete is not greater than 2.5 meters. If there is still space, sand is blown to fill it up.
[0040] S8: Remove the second arch guard and deformed initial support at the other end of the collapsed cavity, install the fourth arch frame and install the steel mesh and shotcrete.
[0041] S9: Continue to replace the initial supports of the deformed section one by one along the longitudinal direction of the tunnel.
[0042] S10: After the upper chamber is filled with concrete that reaches 100% strength, the temporary steel frame is removed and the shed shell and the portion of shotcrete that has invaded the initial support design boundary are cleared.
[0043] The tunnel 1 arch collapse hole shed shell type repair method of the present invention first uses a drilling rig to drill the first layer anchor rod 4 from one end of the collapsed cavity to the other end, so that one end of the first layer anchor rod 4 extends into the surrounding rock and is supported. A plurality of first layer anchor rods 4 can form a barrier to separate the collapsed cavity into an upper chamber 2 and a lower chamber 3. The gaps between the plurality of first layer anchor rods 4 can be closed by spraying concrete to form a closed shed shell. At this time, construction personnel can enter the bottom of the collapsed cavity to perform operations such as arch frame replacement. Due to the support of the shed shell, slight rockfalls at the collapsed cavity will not threaten the safety of construction personnel.
[0044] In this embodiment, step S1 also includes: spraying concrete to protect the inner wall of the collapsed cavity and the construction of the temporary arch protection 7 with a wet spraying manipulator, and the construction of the anchor rod positioning steel frame 701. 2-3 steel arch frames are installed under the original tunnel initial support at both ends of the collapsed cavity as temporary arch protection 7. Figure 1 As shown, the temporary arch protection 7 is set inside the uncollapsed tunnel 1. The arch protections are connected with angle steels; a temporary arch protection close to the collapsed cavity is used as an anchor rod positioning steel frame 701, and anchor rod positioning holes are set on the anchor rod positioning steel frame 701, and annular reinforcement steel bars are added within the range of the anchor rod positioning steel frame 701. The lower ends of several first-layer anchor rods 4 are connected to the temporary arch frame 701. Specifically, the temporary arch protection 7 is slightly smaller than the arch frame of the tunnel 1, and it can be stretched and supported in the tunnel 1. The anchor rod positioning steel frame 701 is provided with a through hole to cooperate with each first-layer anchor rod 4, so that each first-layer anchor rod 4 is inserted into a through hole. During drilling, each first-layer anchor rod 4 is inserted into its corresponding through hole and drilled. After drilling into place, the first-layer anchor rod 4 is fixedly connected to the anchor rod positioning steel frame 701 by welding or the like. This makes the upper end of the first-layer anchor rod 4 inserted into the surrounding rock and supported by the surrounding rock, and the lower end is supported by the anchor rod positioning steel frame 701. This makes the shed shell more stable and thus better protects the construction workers below.
[0045] In this embodiment, step S2 also includes: installing a delivery pump pipe through the first layer anchor rods 4 into the upper chamber 2, applying a steel composite mesh 9 on a number of first layer anchor rods 4 and spraying concrete, and connecting them with the first layer anchor rods 4 to form a shed shell; the steel composite mesh 9 is formed by overlapping a φ6.5mm steel mesh 9 with a spacing of 200×200mm and a φ3.5mm steel wire mesh with a spacing of 50mm×50mm, wherein the steel wire mesh is located above the steel mesh.
[0046] In this embodiment, step S6 also includes: pre-burying a delivery pump pipe between the second arch frame and the third arch frame for pouring concrete into the lower chamber.
[0047] In this embodiment, step S7 also includes: filling the lower chamber with C25 concrete; after the concrete filled in the lower chamber reaches 70% strength, filling the upper chamber with C25 concrete in layers to a height of about 2.0m above the tunnel vault excavation line, and if there is still space, blowing sand to fill it until it is full; the layered filling of C25 concrete is carried out in layers according to the secondary pouring process, wherein the first pouring of concrete is controlled to be 0.5m above the tunnel vault excavation line.
[0048] In this embodiment, the first layer anchor rod 4 and the second layer anchor rod 8 are both self-propelled anchor rods. After the self-propelled anchor rod is drilled into place, grouting and other operations can be carried out. There is no need to pull it out and reinsert the anchor rod. This reduces the loosening and falling off of the surrounding rock caused by the drill rod being pulled out. The external insertion angle of the first layer anchor rod 4 is 35 degrees and the spacing between adjacent anchor rods along the circumference of the tunnel 1 is 20 cm. The external insertion angle of the second layer anchor rod 8 is 17 degrees and the spacing between adjacent anchor rods along the circumference of the tunnel 1 is 20 cm. The first layer anchor rod 4 and the second layer anchor rod 8 are both φ51 hollow self-propelled anchor rods.
[0049] In this embodiment, the external insertion angle of the first layer of anchor rods 4 is controlled by leaving a clear height of about 50 mm between the anchor rods and the first arch frame 5, and the spacing between adjacent anchor rods along the circumference of the tunnel is 200 mm; the external insertion angle and spacing of the second layer of anchor rods 8 are controlled according to the normal advanced support design values.
[0050] In this embodiment, after the first layer of anchor rods 4 and the second layer of anchor rods 8 are drilled, cement-water glass double liquid slurry is pressed into both. From both sides to the middle, two-sequence holes are constructed, and the whole hole is grouted at one time. The grouting pressure is 1.0MPa, and pure pressure grouting is used. The first sequence hole is controlled according to the grouting amount. When the grouting amount reaches or approaches the estimated grouting amount, the grouting of this hole can be ended; the second sequence hole is controlled according to the grouting pressure. When the grouting pressure reaches the design pressure, the grouting amount is gradually reduced, and finally less than 1L / min·m, and maintained for more than 10 minutes, the grouting of this hole can be ended.
Claims
1. A method for safely repairing a tunnel collapse cavity using a shed shell structure, comprising the following steps: S1: inserting a plurality of first-layer anchor rods obliquely upward from one side of the collapsed cavity into the cavity wall of the collapsed cavity along the longitudinal direction of the tunnel; the plurality of first-layer anchor rods are distributed along the circumference of the tunnel so that the plurality of first-layer anchor rods divide the collapsed cavity into an upper cavity and a lower cavity; S2: Applying a steel composite mesh on a plurality of first-layer anchor rods and spraying concrete to close the gaps between the plurality of first-layer anchor rods to form a shed shell; S3: Install the first arch frame below the collapse cavity and install the steel mesh and shotcrete; S4: Install the second arch frame and the steel mesh below the collapse cavity, and apply shotcrete between the first and second arch frames except for the second layer of anchor bolts; S5: Along the longitudinal direction of the tunnel, the second layer of anchor rods is applied obliquely upward from the second arch frame, and the parts within the range of the second layer of anchor rods are sprayed with concrete; a number of second layer anchor rods are distributed along the circumference of the tunnel; S6: Remove the original first arch and deformed initial support at the other end of the collapsed cavity, install the third arch frame and install steel mesh and shotcrete to seal the lower part of the lower chamber; S7: injecting concrete into the lower chamber and the upper chamber in sequence to fill the collapsed cavity; S8: Remove the second arch and deformed initial support at the other end of the collapsed cavity, install the fourth arch frame and install the steel mesh and shotcrete; S9: Continue to dismantle and replace the initial supports of the deformed section one by one along the longitudinal direction of the tunnel; S10: After the upper chamber is filled with concrete that reaches 100% strength, the temporary steel frame is removed and the shed shell and the portion of shotcrete that has invaded the initial support design boundary are cleared.
2. The method for safely repairing tunnel collapse using a shed-shell structure according to claim 1 is characterized in that: Step S1 also includes using a wet spraying manipulator to spray concrete to protect the inner wall of the collapse cavity and the construction of a temporary protective arch. 2-3 steel arch frames are installed under the original tunnel initial support at both ends of the collapse cavity as temporary protective arches, and the protective arches are connected with angle steels; a temporary protective arch close to the collapse cavity is used as an anchor positioning steel frame, and anchor positioning holes are set on the anchor positioning steel frame, and circumferential reinforcement steel bars are added within the range of the anchor positioning steel frame.
3. The method for safely repairing tunnel collapse using a shed-shell structure according to claim 2 is characterized in that: Step S2 also includes: installing a delivery pump pipe through the first layer of anchor rods into the upper chamber; applying a steel composite mesh on a number of first layer anchor rods and spraying concrete to form a shed shell by connecting the steel composite mesh with the first layer anchor rods to form a whole; the steel composite mesh is formed by overlapping a φ6.5mm steel mesh with a spacing of 200×200mm and a φ3.5mm steel wire mesh with a spacing of 50mm×50mm, wherein the steel wire mesh is located above the steel mesh.
4. The method for safely repairing tunnel collapse using a shed-shell structure according to claim 3 is characterized in that: Step S6 also includes: pre-burying a delivery pump pipe between the second arch frame and the third arch frame for pouring concrete into the lower chamber.
5. The method for safely repairing tunnel collapse using a shed-shell structure according to claim 4 is characterized in that: Step S7 also includes: filling the lower chamber with C25 concrete; after the concrete in the lower chamber reaches 70% strength, filling the upper chamber with C25 concrete in layers to a height of about 2.0m above the tunnel vault excavation line, and if there is still space, blowing sand to fill it until it is full; the layered filling of C25 concrete is carried out in layers according to the secondary pouring process, wherein the first pouring of concrete is controlled to be 0.5m above the tunnel vault excavation line.
6. The method for safely repairing tunnel collapse using a shed-shell structure according to claim 5 is characterized in that: The first layer anchor rods and the second layer anchor rods are both hollow self-advancing anchor rods. After the first layer anchor rods and the second layer anchor rods are drilled, cement-water glass double liquid slurry is pressed into them.
7. The method for safely repairing tunnel collapse using a shed-shell structure according to claim 6 is characterized in that: The external insertion angle of the first layer of anchor rods is controlled by leaving a clear height of about 50mm between the anchor rods and the first arch frame, and the spacing between adjacent anchor rods along the circumference of the tunnel is 200mm; the external insertion angle and spacing of the second layer of anchor rods are controlled according to the normal advanced support design values.
8. The method for safely repairing tunnel collapse using a shed-shell structure according to claim 7 is characterized in that: The temporary arch frame is provided with through holes in cooperation with each first-layer anchor rod, so that each first-layer anchor rod is plugged into one through hole.