Waterproof partition structure of water-rich karst tunnel

Abstract

The utility model discloses a water-rich karst tunnel waterproof partition structure which comprises a grouting hole formed in surrounding rock and used for being matched with a grouting device to conduct grouting operation, a primary support and a secondary lining are sequentially arranged on the outer side of the surrounding rock from inside to outside, a waterproof layer is arranged between the primary support and the secondary lining, and the secondary lining is arranged between the primary support and the secondary lining. The waterproof layer comprises a flexible rubber cushion layer, non-woven geotextile and a waterproof roll. On the basis of a traditional waterproof layer structure, the flexible rubber cushion layer which has large elasticity and can be tightly attached to the surface of a primary support and the waterproof roll is used for replacing traditional non-woven geotextile, and therefore the purpose that the flexible rubber cushion layer can be tightly attached to the surface of the primary support and the waterproof roll while the traditional mature and reliable construction technology is not obviously changed is achieved. The purposes of sealing the gap between the primary support and the secondary lining and reducing longitudinal water mixing of karst water are achieved, the defects that traditional tunnel waterproof measures are insufficient in water pressure resistance and prone to leakage, and then traffic safety is seriously affected are overcome, and the later maintenance difficulty and maintenance cost of the karst tunnel are remarkably reduced.

Description

Technical Field

[0001] The utility model relates to the field of karst tunnel waterproofing, in particular to a waterproof partition structure for a water-rich karst tunnel. Background Art

[0002] A large amount of karst water develops in the surrounding rock of water-rich karst tunnels. However, the location, volume, and pressure of this water are difficult to accurately locate and measure due to the random development of the unfavorable karst geological bodies. This results in many areas of karst tunnels being without adequate waterproofing measures and drainage pipes to isolate and drain the karst water. During later operations, undrained karst water will continue to accumulate behind the waterproof membrane and, under pressure, flow longitudinally and transversely along the tunnel, transmitting water pressure. In areas with weak support, karst water may fracture the tunnel's secondary lining, break through the waterproof membrane, and leak into the tunnel through the cracks, causing slippery road surfaces, damp lining surfaces, and the loss of fire-retardant coatings or equipment on the lining surface, seriously affecting driving safety and tunnel durability.

[0003] In actual engineering, a structural measure is urgently needed to isolate different karst water development areas from each other, so as to control the karst water behind the lining within a relatively independent range with high support structure strength, and avoid karst water leakage and damage to weak support parts. Utility Model Content

[0004] The technical problem to be solved by the present invention is to provide a water-rich karst tunnel waterproof partition structure in response to the deficiencies of the above-mentioned existing technologies, so as to make up for the shortcomings of traditional tunnel waterproof measures such as insufficient water pressure resistance, easy leakage and thus serious impact on driving safety, thereby significantly reducing the difficulty and cost of later maintenance of karst tunnels, and the construction is convenient and low-cost, which has great promotion and application value.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A waterproof partition structure for a water-rich karst tunnel comprises grouting holes formed in the surrounding rock for grouting with grouting equipment. Primary support and secondary lining are sequentially provided on the outer side of the surrounding rock from the inside out. A waterproof layer is provided between the primary support and the secondary lining. The waterproof layer comprises a flexible rubber cushion, a non-woven geotextile, and a waterproof roll.

[0007] The number of the secondary linings is set to be multiple, and a joint is reserved between two adjacent secondary linings;

[0008] The waterproof roll is applied on the secondary lining, and the non-woven geotextile is applied on the primary support;

[0009] The initial support is provided with a groove at the position corresponding to the joint, and the flexible rubber pad is embedded in the groove;

[0010] A partition gap is reserved between two adjacent sections of the non-woven geotextile;

[0011] A back-sticking waterstop and a middle-embedded waterstop are provided between two adjacent sections of the secondary lining.

[0012] Preferably, the back-sticking waterstop is embedded on the inner wall of the secondary lining, and the embedded waterstop is embedded inside the secondary lining.

[0013] Preferably, the back-stick waterstop includes an outer strip, a limit block and an extension strip. Multiple extension strips are vertically arranged on one side of the outer strip, and a limit block is integrally arranged on the other end of the extension strip. The outer strip is distributed parallel to the embedded waterstop and are both arranged perpendicular to the joint.

[0014] Preferably, the width of the limiting block is greater than the width of the extension belt.

[0015] Preferably, a first accommodating cavity and a second accommodating cavity are respectively opened on the inner side and inside of the secondary lining, which are used for casting a back-sticked waterstop and a middle-buried waterstop respectively.

[0016] Preferably, the back-sticking waterstop and the embedded waterstop are cast with modified clay cement slurry to resist karst water pressure.

[0017] Preferably, the initial support and secondary lining are formed by cement casting.

[0018] Preferably, the extension lengths of both sides of the flexible rubber cushion layer on the two sections of secondary lining are both ≥10 cm, and both sides of the flexible rubber cushion layer are overlapped and covered on the non-woven geotextiles on both sides respectively.

[0019] Preferably, the number of the grouting holes is set to multiple groups, the number of grouting holes in each group is set to multiple, and the grouting holes in each group are arranged in a plum blossom shape.

[0020] The utility model has the following beneficial effects:

[0021] By replacing the traditional non-woven geotextile with a flexible rubber cushion layer that has great elasticity and can closely adhere to the surface of the primary support and waterproof membrane on the basis of the traditional waterproof layer structure, the purpose of sealing the gap between the primary support and the secondary lining and reducing the vertical flow of karst water is achieved without significantly changing the traditional mature and reliable construction process. The surrounding rock grouting measures are adopted through the grouting holes to fill the joints and cracks of the surrounding rock, thereby enhancing the strength of the surrounding rock, improving the bearing capacity of the surrounding rock, reducing the risk of cracking and damage of the support structure, and reducing the permeability of the surrounding rock at the junction of different waterproof intervals, thereby achieving the purpose of reducing the vertical flow of karst water in the surrounding rock between different waterproof intervals.

[0022] The waterproof partition structure provided by the utility model can make up for the shortcomings of traditional tunnel waterproofing measures such as insufficient water pressure resistance, easy leakage and serious impact on driving safety, thereby significantly reducing the difficulty and cost of later maintenance of karst tunnels. It is also convenient to construct and low-cost, and has great promotion and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the cross-sectional structure of the waterproof partition structure (partial section) proposed by the present invention.

[0024] Figure 2 for Figure 1 Enlarged view of the structure of part A in the middle.

[0025] Figure 3 This is a schematic diagram of the casting structure of the back-sticking waterstop in the utility model.

[0026] Among them are:

[0027] Grouting hole; 2. Initial support; 3. Flexible rubber cushion; 4. Non-woven geotextile; 5. Waterproof membrane; 6. Back-attached waterstop; 7. Embedded waterstop; 8. Secondary lining; 9. Joint; 10. Groove;

[0028] 01. Surrounding rock;

[0029] 61. Outer belt; 62. Limit block; 63. Extension belt. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and specific preferred embodiments.

[0031] In the description of the present invention, it should be understood that the terms "left side," "right side," "upper," "lower," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Terms such as "first" and "second" do not indicate the importance of a component and therefore should not be construed as limiting the present invention. The specific dimensions used in this embodiment are merely for illustrative purposes and do not limit the scope of protection of the present invention.

[0032] like Figure 1-3 As shown, a waterproof partition structure for a water-rich karst tunnel includes a grouting hole 1 opened in a surrounding rock 01 for performing grouting operations in conjunction with grouting equipment. A primary support 2 and a secondary lining 8 are sequentially arranged on the outer side of the surrounding rock 01 from the inside out. A waterproof layer is provided between the primary support 2 and the secondary lining 8. The waterproof layer includes a flexible rubber cushion 3, a non-woven geotextile 4, and a waterproof membrane 5.

[0033] The number of secondary linings 8 is set to be multiple, and a joint 9 is reserved between two adjacent secondary linings 8;

[0034] The waterproofing membrane 5 is applied on the secondary lining 8, and the non-woven geotextile 4 is applied on the primary support 2;

[0035] A groove 10 is provided at the position of the initial support 2 corresponding to the joint 9, and the flexible rubber pad 3 is embedded in the groove 10;

[0036] A partition gap is reserved between two adjacent sections of non-woven geotextile 4;

[0037] A back-attached waterstop 6 and a middle-buried waterstop 7 are provided between two adjacent sections of secondary lining 8 .

[0038] Specifically, the back-sticking waterstop 6 is embedded on the inner wall of the secondary lining 8 , and the embedded waterstop 7 is embedded inside the secondary lining 8 .

[0039] like Figure 3 As shown, the back-stick waterstop 6 includes an outer strip 61, a limit block 62 and an extension strip 63. A plurality of extension strips 63 are vertically arranged on one side of the outer strip 61, and a limit block 62 is integrally arranged at the other end of the extension strip 63. The outer strip 61 is distributed parallel to the embedded waterstop 7, and both are arranged perpendicular to the joint 9; the width of the limit block 62 is greater than the width of the extension strip 63.

[0040] Specifically, a first accommodating cavity and a second accommodating cavity are respectively opened on the inner side and inside of the secondary lining 8, which are used for casting the back-attached waterstop 6 and the embedded waterstop 7 respectively.

[0041] Specifically, the back-sticking waterstop 6 and the embedded waterstop 7 are cast with modified clay cement slurry to resist karst water pressure.

[0042] Specifically, the initial support 2 and the secondary lining 8 are formed by pouring cement.

[0043] Specifically, the extension lengths of both sides of the flexible rubber cushion layer 3 on the two sections of secondary lining 8 are both ≥10 cm, and both sides of the flexible rubber cushion layer 3 are overlapped and covered on the non-woven geotextiles 4 on both sides.

[0044] Specifically, the number of grouting holes 1 is set to multiple groups, the number of grouting holes 1 in each group is set to multiple, and the grouting holes 1 in each group are arranged in a plum blossom shape.

[0045] Specifically, the surface unevenness of the initial support 2 is ≤±3cm, and the surface flatness of the initial support 2 is ≤1 / 6.

[0046] The process of constructing the waterproof partition structure of the water-rich karst tunnel provided by the utility model is as follows:

[0047] Step 1: Determine the location of the waterproof partition, which includes the following steps:

[0048] Step 1A: Determine the degree of karst water development in the excavation area based on geological survey data and excavation findings. For example, geological survey data and excavation findings for a karst tunnel on a highway under construction show that the entire tunnel is located in the vertical seepage zone-seasonal variation zone. In particular, the karst water inflow revealed by excavation in a certain section A reaches about 800m 3 / d, the water pressure does not exceed 0.1MPa, and water drips or flows out of the cave wall during excavation, it can be determined that the karst water development level in excavation section A is relatively developed; in the adjacent section B, the karst water inflow revealed by excavation reaches about 3000m 3 / d, it can be determined that the karst water development level in excavation section B is developed.

[0049] Step 1B: Divide the tunnel longitudinally into waterproof zones according to the karst water development degree determined in step 1A, with different karst water development degrees corresponding to different waterproof zones.

[0050] In this embodiment, the karst water development level of section A is relatively developed, and the karst water development level of section B is developed, and the sections are divided into two different waterproof zones A and B.

[0051] Step 1C: In the waterproof partition on the side of the boundary between different waterproof partitions determined in step 1B where karst water is relatively less developed, a section of the relatively intact surrounding rock 01 is selected as the location for the waterproof partition. The joint 9 in the middle of the waterproof partition must be combined with adjacent joints 9 such as construction joints and expansion joints. The length of the waterproof partition is determined based on the karst water inflow and water pressure at the location.

[0052] In this embodiment, the karst water in Section A is relatively underdeveloped, so a section in Section A where the surrounding rock 01 is relatively intact is selected as the construction location of the waterproof partition, and the joint 9 in the middle of the waterproof partition is sewn and set with the construction seam.

[0053] The relationship between karst water inflow, water pressure and waterproof partition length is:

[0054] A. When the karst water inflow is ≤100m 3 / d and water pressure ≤0.01MPa, the waterproof partition length is 3m;

[0055] B. When the karst water inflow is greater than 10000m 3 / d or water pressure ≤0.5MPa, the waterproof partition length is 5m;

[0056] C. When the karst water inflow is 100-10000m 3 / d or when the water pressure is 0.01-0.5MPa, the length of the waterproof partition is interpolated according to the relationship between the water inflow, water pressure and the length of the waterproof partition in A and B, and the larger value is taken.

[0057] In this example, the karst water inflow in Section A reaches about 800m 3 / d, the interpolation result is 3+(5-2) / (10000-100)×(800-100)=3.14m, and the actual waterproof partition length is 3.2m.

[0058] Step 2: Grouting the surrounding rock 01, specifically including the following steps:

[0059] Step 2A: At the construction location of the waterproof partition determined in step 1, within the length of the waterproof partition, grouting holes 1 are arranged in a full-circle plum blossom pattern. Specific layout data include the spacing between the grouting holes 1, the position of the grouting holes 1, the number of the grouting holes 1, and the diameter of the grouting holes 1. The spacing between the grouting holes 1, the position of the grouting holes 1, and the number of the grouting holes 1 are determined based on the karst water inflow and water pressure at the location.

[0060] The relationship between karst water inflow, water pressure, grouting hole spacing, grouting hole position, and the number of grouting holes is as follows:

[0061] A. When the karst water inflow is ≤100m 3 / d and water pressure ≤0.01MPa, the grouting holes are spaced 1m apart and arranged in a plum blossom shape;

[0062] B. When the karst water inflow is greater than 10000m 3 / d or when the water pressure is ≤0.5MPa, the grouting holes are spaced 0.5m apart and arranged in a plum blossom shape;

[0063] C. When the karst water inflow is 100-10000m 3 / d or when the water pressure is 0.01-0.5MPa, the spacing between grouting holes 1 is interpolated according to the relationship between the water inflow, water pressure and the spacing between grouting holes 1 in A and B, and the larger value is taken, and the arrangement is in a plum blossom shape.

[0064] In this example, the karst water inflow in Section A reaches about 800m 3 / d, interpolation is 1+(0.5-1) / (10000-100)×(800-100)=0.96m, and the actual spacing of grouting holes 1 is determined to be 1.0m.

[0065] Step 2B, drilling: Drill each grouting hole determined in step 2A, with a drilling depth of no less than 3m; the type of grouting fluid is determined based on the karst water inflow and water pressure at the location.

[0066] The relationship between karst water inflow, water pressure and grouting fluid type is:

[0067] A. When the karst water inflow is ≤1000m 3 / d and water pressure ≤0.1MPa, use ordinary Portland cement paste with a water-cement ratio of 2:1-1:1;

[0068] B. When the karst water inflow is greater than 1000m 3 / d or water pressure>0.1MPa, use ordinary Portland cement slurry with a water-cement ratio of 2:1-1:1, add 5% water glass by weight of cement, the water glass concentration is 35°Bé, and the water glass modulus is 2.4.

[0069] In this example, the karst water inflow in Section A reaches about 800m 3 / d, using ordinary Portland cement paste with a water-cement ratio of 2:1-1:1.

[0070] Step 2C, grouting: using grouting equipment, place a grouting pipe in the grouting hole 1, install a grouting plug, and start grouting. When the grouting volume reaches the set value or the grouting pressure increases to 1.5 MPa or above, stop grouting, remove the grouting pipe, and seal the grouting hole 1;

[0071] Step 2D, inspection and grouting: After grouting of all grouting holes 1 is completed, check the grouting effect; if the grouting effect is not good, additional grouting is required.

[0072] Step 3: Implement tunnel initial support 2;

[0073] Step 4: Laying the flexible rubber cushion layer 3 and the non-woven geotextile 4: First, clean and level the surface of the initial support 2, and lay the flexible rubber cushion layer 3 and the non-woven geotextile 4;

[0074] Step 5, laying waterproof membrane 5: Lay the waterproof membrane 5 on the outer layer of the flexible rubber cushion 3 and non-woven geotextile 4 laid in step 4;

[0075] Step 6: Apply back-attached waterstop 6, embedded waterstop 7 and secondary lining 8.

[0076] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all fall within the scope of protection of the present invention.

Claims

1. A waterproof partition structure for a water-rich karst tunnel, comprising a grouting hole (1) opened on a surrounding rock (01), used for performing grouting operations in conjunction with a grouting device, wherein an initial support (2) and a secondary lining (8) are sequentially arranged on the outer side of the surrounding rock (01) from the inside to the outside, and a waterproof layer is arranged between the initial support (2) and the secondary lining (8), characterized in that: The waterproof layer comprises a flexible rubber cushion layer (3), a non-woven geotextile (4) and a waterproof roll (5); The number of the secondary linings (8) is set to be multiple, and a joint (9) is reserved between two adjacent secondary linings (8); The waterproof coiled material (5) is applied on the secondary lining (8), and the non-woven geotextile (4) is applied on the initial support (2); The initial support (2) is provided with a groove (10) at a position corresponding to the joint (9), and the flexible rubber cushion layer (3) is embedded in the groove (10); A partition gap is reserved between two adjacent sections of the non-woven geotextile (4); A back-attached waterstop (6) and a middle-buried waterstop (7) are provided between two adjacent sections of the secondary lining (8).

2. The waterproof partition structure for a water-rich karst tunnel according to claim 1, characterized in that: The back-sticking waterstop (6) is embedded on the inner wall of the secondary lining (8), and the embedded waterstop (7) is embedded inside the secondary lining (8).

3. The waterproof partition structure for a water-rich karst tunnel according to claim 1, characterized in that: The back-sticking waterstop (6) comprises an outer strip (61), a limit block (62) and an extension strip (63). A plurality of extension strips (63) are vertically arranged on one side of the outer strip (61), and a limit block (62) is integrally arranged on the other end of the extension strip (63). The outer strip (61) is distributed parallel to the embedded waterstop (7) and is both arranged perpendicular to the joint (9).

4. The waterproof partition structure for a water-rich karst tunnel according to claim 3, characterized in that: The width of the limiting block (62) is greater than the width of the extension belt (63).

5. The waterproof partition structure for a water-rich karst tunnel according to claim 3, characterized in that: A first accommodating cavity and a second accommodating cavity are respectively provided on the inner side and inside of the secondary lining (8), and are used for casting a back-attached waterstop (6) and a middle-buried waterstop (7), respectively.

6. The waterproof partition structure for a water-rich karst tunnel according to claim 5, characterized in that: The back-attached waterstop (6) and the embedded waterstop (7) are cast using modified clay cement slurry to resist karst water pressure.

7. The waterproof partition structure for a water-rich karst tunnel according to claim 1, characterized in that: The initial support (2) and secondary lining (8) are formed by cement casting.

8. The waterproof partition structure for a water-rich karst tunnel according to claim 1, characterized in that: The extension lengths of both sides of the flexible rubber cushion layer (3) on the two sections of secondary lining (8) are both ≥10 cm, and both sides of the flexible rubber cushion layer (3) are respectively overlapped and covered on the non-woven geotextiles (4) on both sides.

9. The waterproof partition structure for a water-rich karst tunnel according to claim 1, characterized in that: The number of the grouting holes (1) is set to multiple groups, the number of the grouting holes (1) in each group is set to multiple, and the grouting holes (1) in each group are arranged in a plum blossom shape.

10. The waterproof partition structure for a water-rich karst tunnel according to claim 1, characterized in that: The surface unevenness of the initial support (2) is ≤±3cm, and the surface flatness of the initial support (2) is ≤1 / 6.

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