Soft rock tunnel upward slope grouting structure for enhancing stability of underneath passing existing gabion

Abstract

The utility model provides a soft rock tunnel upward slope grouting structure for enhancing the stability of an underneath passing existing gabion, and relates to the field of upward slope reinforcement. First-class grouting holes and second-class grouting holes are formed in a gabion laying area, the first-class grouting holes are obliquely formed in the lower middle portion of the gabion laying area relative to the horizontal plane and deep into a sliding body, and the second-class grouting holes are perpendicularly and horizontally formed in the upper portion of the gabion laying area and penetrate through gabions, the sliding body and a potential sliding belt. The grouting unit is used for being inserted into the first type of grouting holes and the second type of grouting holes for grouting, and the first type of grouting holes and the second type of grouting holes are formed to be used for being filled with different kinds of grout, fixing a stone cage and slip mass contact area and a potential slip band, so that cooperative stress of the stone cage and the soft rock stratum is achieved; in addition, the sleeve valve pipe is provided with the duckbill valve, slurry can be effectively prevented from flowing back into the sleeve valve pipe, efficient reinforcement of the deep rock mass is achieved, and the stability of the gabion can be effectively enhanced through combination of the duckbill valve and the sleeve valve pipe.

Description

Technical Field

[0001] This utility model relates to the field of slope reinforcement, and in particular to a grouting structure for soft rock tunnels that pass under existing gabions to enhance their stability. Background Technology

[0002] In soft rock strata, the layers from the surface inwards are sliding bodies, potential slip zones, and slip beds. Because the sliding of sliding bodies and the underlying potential slip zones can easily lead to poor slope stability, gabion structures are commonly used for slope protection in soft rock strata. To address the risk of gabion contact surface voids and slope slippage, traditional grouting reinforcement typically employs vertical drilling or evenly distributed perforated holes. However, vertical drilling can easily damage the gabion structure, and the grout is difficult to directionally fill the voided areas at the bottom of the gabion. While perforated holes can reinforce deep rock masses, they cannot simultaneously address the synergistic stress distribution between the gabion and the soft rock slope. Therefore, to achieve better grouting reinforcement, the grouting structure needs to be optimized based on the existing gabion structure. Utility Model Content

[0003] This utility model provides a grouting structure for the uphill slope of a soft rock tunnel to enhance the stability of existing gabions. Its purpose is to solve the problem that existing grouting reinforcement structures cannot take into account the coordinated stress of the gabions and the uphill slope.

[0004] To achieve the above objectives, embodiments of this utility model provide a grouting structure for the uphill slope of a soft rock tunnel used to enhance the stability of tunnels passing under existing gabions, comprising:

[0005] Gabions are used to lay on the sliding body;

[0006] A first type of grouting hole and a second type of grouting hole are provided in the area where the gabion is laid. A number of first type grouting holes are inclined to the horizontal plane and are located in the middle and lower part of the area where the gabion is laid. The first type of grouting holes penetrate the gabion and extend into the sliding body. A number of second type grouting holes are perpendicular to the horizontal plane and are located in the upper part of the area where the gabion is laid. The second type of grouting holes penetrate the gabion, the sliding body and the potential slip zone.

[0007] The grouting unit is used to insert into the first type of grouting hole and the second type of grouting hole for grouting.

[0008] Preferably, the first type of grouting hole extends downward through the upper surface of the sliding body by n meters, where n is a positive number less than the minimum thickness of the sliding body, and the angle between the first type of grouting hole and the horizontal plane is 45°-60°.

[0009] Preferably, a number of first-type grouting holes are arranged in a stepped fan shape from top to bottom in the area where the gabion is laid. The stepped fan shape includes multiple concentric virtual arcs with increasing radii. Each first-type grouting hole is arranged on a virtual arc, and the hole spacing of the first-type grouting holes located on the same virtual arc is 1.4-1.7 times the grout diffusion radius.

[0010] The central angle corresponding to the virtual arc is 60°-90°.

[0011] Preferably, the portion of the first type of grouting hole located below the gabion is injected with modified epoxy chemical grout through the grouting unit, while the portion of the first type of grouting hole located inside the gabion is injected with quick-setting cement grout mixed with 5% expansion agent through the grouting unit.

[0012] Preferably, the second type of grouting holes are staggered in a quincunx pattern, and the second type of grouting holes are inserted through the lower surface of the potential slip zone and extend downwards by m meters, where m is a positive number.

[0013] Preferably, the plum blossom shape includes several virtual straight lines from top to bottom, and each of the second type of grouting holes is arranged at intervals on each virtual straight line, and in two adjacent virtual straight lines, the second type of grouting hole on one virtual straight line is located between two second type of grouting holes on the other virtual straight line.

[0014] Preferably, the second type of grouting hole is injected with ultrafine cement slurry through a grouting unit.

[0015] Preferably, the grouting unit includes a sleeve valve tube, which includes an inner layer and an outer layer spaced apart. Grout outlet holes are provided in the radial direction of the inner and outer layers. A duckbill valve is provided on the grout outlet hole located on the inner layer. The other end of the duckbill valve extends out of the outer layer. The space between the inner and outer layers is used to fill shell material to form an inner material layer. The space between the outer layer and the gabion, sliding body, or potential sliding zone or slide bed is used to fill shell material to form an outer material layer.

[0016] The above-mentioned solution of this utility model has the following beneficial effects:

[0017] In this application, by setting up first-type grouting holes and second-type grouting holes to fill different grouts, the contact area between the gabion and the sliding body and the potential slip zone are consolidated, thereby achieving synergistic stress between the gabion and the soft rock strata. In addition, the duckbill valve on the sleeve valve pipe can effectively prevent the grout from flowing back into the sleeve valve pipe, thereby achieving efficient reinforcement of the deep rock mass (the rock mass below the gabion). Through the synergistic stress between the gabion and the slope and the reinforcement of the deep rock mass, the stability of the gabion is effectively enhanced.

[0018] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the arrangement of the first and second types of grouting holes;

[0020] Figure 2 This is a schematic diagram of drilling the first type of grouting hole on the gabion;

[0021] Figure 3 This is a schematic diagram of drilling holes for the second type of grouting holes on a gabion;

[0022] Figure 4 This is a cross-sectional view of the grouting unit.

[0023] [Explanation of Labels in the Attached Image]

[0024] 01-Sliding body, 02-Potential slip zone, 03-Sliding bed,

[0025] 10 - Gabion, 20 - Type I grouting hole, 30 - Type II grouting hole

[0026] 41-Inner layer, 42-Outer layer, 43-Duckbill valve, 44-Inner material layer, 45-Outer material layer. Detailed Implementation

[0027] To make the technical problems, technical solutions and advantages of this utility model clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0028] like Figure 1 As shown, the embodiment of this utility model provides a grouting structure for the uphill slope of a soft rock tunnel to enhance the stability of existing gabions. The uphill slope consists of a sliding body 01, a potential slip zone 02, and a sliding bed 03 from the surface to the inside. The sliding body 01 has poor stability due to its own structure, while the potential slip zone 02 has the risk of slippage. Therefore, in the prior art, gabions 10 are usually laid at an angle on the surface of the sliding body 01 to stabilize the soft rock strata.

[0029] Based on this, a first type of grouting hole 20 and a second type of grouting hole 30 are set up. By injecting different grouts into the first type of grouting hole 20 and the second type of grouting hole 30, the gabion 10 and the soft rock strata are subjected to synergistic stress and the reinforcement of the deep rock mass are achieved.

[0030] To better illustrate the technical solution of this application, the layer below where the gabion 10 is laid is defined as the deep layer.

[0031] Within the area where the gabion 10 is laid, there are first-type grouting holes 20 and second-type grouting holes 30. The first-type grouting holes 20 are drilled at an angle downwards to the horizontal plane, and their depth extends into the sliding body 01. Several first-type grouting holes 20 are located in the lower middle part of the gabion 10 laying area. The second-type grouting holes 30 are drilled vertically downwards to the horizontal plane, and their depth penetrates the gabion 10, the sliding body 01, the potential sliding zone 02, and extends to the sliding bed 03. Several second-type grouting holes 30 are located above the gabion 10 laying area, that is, above the first-type grouting holes 20.

[0032] Grouting units are inserted into the first type of grouting hole 20 and the second type of grouting hole 30. The grouting units are used to inject grout into the first type of grouting hole 20 and the second type of grouting hole 30.

[0033] To ensure the grouting and curing effect of the first type of grouting hole 20, the first grouting hole extends downward to a distance of n meters after passing through the upper surface of the sliding body 01, where n is a positive number less than the minimum thickness of the sliding body 01, thus ensuring that the lower end of the first type of grouting hole 20 is located inside the sliding body 01. The angle α between the first type of grouting hole 20 and the horizontal plane is 45°-60°.

[0034] By using first-type grouting holes 20 at an angle of 45-60°, the drilling path passes through the gabion 10 and extends into the sliding body 01, allowing the grout to diffuse directionally along the included angle α to the void area where the gabion 10 and the sliding body 01 meet. This thoroughly fills the interface voids that are difficult to cover with traditional vertical holes, thereby improving the bond strength between the gabion 10 and the sliding body 01. This effectively solves the problems of slippage and void formation of the gabion 10, ensuring that the two work together to bear the load.

[0035] In this embodiment, the first type of grouting hole 20 extends downward 1-2 meters after passing through the upper surface of the slide body 01, ensuring that the lower end of the first type of grouting hole 20 is located inside the slide body 01.

[0036] Reference Figure 1 and Figure 2As shown, several first-type grouting holes 20 are provided, arranged in a stepped fan shape from top to bottom within the area where the gabion 10 is laid. The stepped fan shape includes several virtual arcs, each with a common center, and the radius of the virtual arcs increases outwards from the center. The central angle of each virtual arc is 60°-90°. These first-type grouting holes 20 are arranged on various virtual arcs, forming a fan-shaped circular array. The portion of the first-type grouting holes 20 located below the gabion 10 is injected with modified epoxy chemical grout through grouting units, while the portion located inside the gabion 10 is injected with quick-setting cement grout mixed with 5% expansion agent. The spacing between the first-type grouting holes 20 located on the same virtual arc is 1.4-1.7 times the radius of the grout diffusion range, and the distance between adjacent virtual arcs is 2-5 meters. Preferably, the hole spacing of the first type of grouting hole 20 is based on the radius of the larger diffusion range in the modified epoxy chemical grout and the quick-setting cement grout with 5% expansion agent.

[0037] The modified epoxy chemical grout and the quick-setting cement grout with 5% expansion agent are both existing products, and their composition will not be described in detail.

[0038] When injecting quick-setting cement grout with 5% expansion agent, the grouting pressure is 0.5-1.0 MPa. When injecting modified epoxy chemical grout, the pressure is increased to 1.5 MPa.

[0039] The deep layer below the gabion 10 is reinforced with high-pressure chemical grout, which not only avoids the grout erosion and damage to the gabion 10 structure, but also ensures that the deep cracks are fully filled.

[0040] Reference Figure 1 and Figure 3 The aforementioned second type of grouting holes 30 are arranged in a staggered, quincunx pattern within the area where the gabion 10 is laid. The second type of grouting holes 30 penetrate the lower surface of the potential slip zone 02 and extend downwards by m meters, where m is a positive number. That is, the lower end of the second type of grouting holes 30 is located inside the slide bed 03.

[0041] The second type of grouting holes 30 are arranged in a staggered quincunx pattern. After grouting, the grout overlaps along the diffusion radius to form a continuous reinforcement network, covering the potential slip zone 02 and significantly improving the shear strength of the potential slip zone 02. The lower end of the second type of grouting holes 30 is located inside the sliding bed 03. After the grout solidifies, it can block the overall slip path of the uphill slope.

[0042] The aforementioned plum blossom shape includes several virtual straight lines from top to bottom, with each type of second-class grouting hole 30 spaced out on each virtual straight line. One type of second-class grouting hole 30 on one straight line is located between two type of second-class grouting holes 30 on another virtual straight line adjacent to it.

[0043] In this embodiment, the hole spacing on the same virtual straight line is 1.5-3m, and the spacing between adjacent virtual straight lines is 0.8-1.2 times the hole spacing.

[0044] The second type of grouting hole 30 is used to inject ultrafine cement grout with a particle size ≤10μm. The initial grouting pressure is 0.3MPa, gradually increased to a final pressure of 2.0MPa. The second type of grouting hole 30 is constructed in a staggered sequence to prevent the grouting pressure from overlapping and causing the slide bed 03 to split. Grouting of the first type of grouting hole 20 is carried out 24 hours after the completion of grouting of the second type of grouting hole 30.

[0045] Reference Figure 4 The aforementioned grouting unit includes a sleeve valve tube, which comprises an inner layer 41 and an outer layer 42 spaced apart. A gap is formed radially between the inner layer 41 and the outer layer 42. Grout outlet holes are also provided radially between the inner layer 41 and the outer layer 42. A duckbill valve 43 is installed on the grout outlet hole of the inner layer 41, with one end connected to the grout outlet hole of the inner layer 41 and the other end extending through the grout outlet hole of the outer layer 42. The gap between the inner layer 41 and the outer layer 42 is used to fill the casing material to form an inner material layer 44, while the outer layer 42 and the external rock mass are filled with casing material to form an outer material layer 45. Since the grouting unit is used to insert into the first type of grouting hole 20 and the second type of grouting hole 30, the external rock mass can be a gabion 10, a sliding body 01, or a potential slip zone 02 or a sliding bed 03.

[0046] During construction, the grouting unit is lowered into either the first type of grouting hole 20 or the second type of grouting hole 30. The casing material is then filled into the gap between the inner layer 41 and the outer layer 42, and between the outer layer 42 and the external rock mass, forming an inner material layer 44 and an outer material layer 45. Grouting is performed after the casing material solidifies. During grouting, the grout is injected in stages through the grouting pipe into the sleeve valve pipe. The grout pressure opens the duckbill valve 43, causing it to diffuse radially outwards. After grouting, the pressure inside the sleeve valve pipe decreases, and the duckbill valve 43 automatically closes under the pressure of the external grout, effectively preventing grout backflow. After the inner material layer 44 and the outer material layer 45 solidify, they form a ring-shaped barrier, restricting the axial flow of the grout.

[0047] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A grouting structure for the uphill slope of a soft rock tunnel used to enhance the stability of an existing gabion, characterized in that: include: Gabion (10) is used to lay on the sliding body (01); A first type of grouting hole (20) and a second type of grouting hole (30) are provided in the area where the gabion (10) is laid. A number of the first type of grouting holes (20) are inclined to the horizontal plane and are located in the middle and lower part of the area where the gabion (10) is laid. The first type of grouting holes (20) penetrate the gabion (10) and extend into the sliding body (01). A number of the second type of grouting holes (30) are perpendicular to the horizontal plane and are located in the upper part of the area where the gabion (10) is laid. The second type of grouting holes (30) penetrate the gabion (10), the sliding body (01) and the potential slip zone (02). The grouting unit is used to insert into the first type of grouting hole (20) and the second type of grouting hole (30) for grouting.

2. The grouting structure for soft rock tunnel slopes used to enhance the stability of existing gabions as described in claim 1, characterized in that: The first type of grouting hole (20) extends downward n meters through the upper surface of the sliding body (01), where n is a positive number less than the minimum thickness of the sliding body (01), and the angle between the first type of grouting hole (20) and the horizontal plane is 45°-60°.

3. The grouting structure for soft rock tunnel slopes used to enhance the stability of existing gabions as described in claim 2, characterized in that: A number of first-type grouting holes (20) are arranged in a stepped fan shape from top to bottom in the area where the gabion (10) is laid. The stepped fan shape includes multiple concentric virtual arcs with increasing radii. Each first-type grouting hole (20) is arranged on the virtual arc, and the hole spacing of the first-type grouting holes (20) located on the same virtual arc is 1.4-1.7 times the grout diffusion radius. The central angle corresponding to the virtual arc is 60°-90°.

4. The grouting structure for soft rock tunnel slopes used to enhance the stability of existing gabions as described in claim 3, characterized in that: The portion of the first type of grouting hole (20) located below the gabion (10) is injected with modified epoxy chemical grout through the grouting unit, while the portion of the first type of grouting hole (20) located inside the gabion (10) is injected with quick-setting cement grout mixed with 5% expansion agent through the grouting unit.

5. The grouting structure for soft rock tunnel slopes used to enhance the stability of existing gabions as described in claim 1, characterized in that: The second type of grouting hole (30) is staggered in a plum blossom shape. The second type of grouting hole (30) passes through the lower surface of the potential slip zone (02) and extends downward by m meters, where m is a positive number.

6. The grouting structure for soft rock tunnel slopes used to enhance the stability of existing gabions as described in claim 5, characterized in that: The plum blossom shape includes several virtual straight lines from top to bottom. Each of the second type of grouting holes (30) is arranged at intervals on each virtual straight line. In two adjacent virtual straight lines, the second type of grouting hole (30) on one virtual straight line is located between two second type of grouting holes (30) on the other virtual straight line.

7. The grouting structure for soft rock tunnel slopes used to enhance the stability of existing gabions as described in claim 6, characterized in that: The second type of grouting hole (30) injects ultrafine cement slurry through the grouting unit.

8. The grouting structure for soft rock tunnel slopes used to enhance the stability of existing gabions as described in claim 1, characterized in that: The grouting unit includes a sleeve valve tube, which includes an inner layer (41) and an outer layer (42) spaced apart. Grout outlet holes are provided in the radial direction of the inner layer (41) and the outer layer (42). A duckbill valve (43) is provided on the grout outlet hole on the inner layer (41). The other end of the duckbill valve (43) extends out of the outer layer (42). The space between the inner layer (41) and the outer layer (42) is used to fill shell material to form an inner material layer (44). The space between the outer layer (42) and the gabion (10), the sliding body (01), or the potential sliding zone (02) or the sliding bed (03) is used to fill shell material to form an outer material layer (45).

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