Structure of the avoidance type of impervious curtain in the karst area encountering the filled soil cave

Abstract

The application discloses a kind of karst region meets filling soil cave to avoid type anti-seepage curtain structure, including the upper layer grouting hole, middle layer grouting hole and lower layer grouting hole being arranged in the area outside filling soil cave, the upper layer grouting hole is formed into first vertical curtain by drilling grouting downwards, the middle layer grouting hole is formed into first horizontal curtain by drilling grouting upstream, and second vertical curtain is formed by drilling grouting downwards, the lower layer grouting hole is formed into second horizontal curtain or annular curtain by drilling grouting around, and third vertical curtain is formed by drilling grouting downwards, wherein, first horizontal curtain and first vertical curtain overlap, and second horizontal curtain or annular curtain and second vertical curtain overlap.The application is convenient for construction, low investment, short construction period, high construction safety; the curtain formed by drilling grouting in the above grouting hole in rock mass, the anti-seepage material is uniform, the type is single, avoids the overlap of soil anti-seepage and rock mass anti-seepage, and improves the anti-seepage effect.

Description

Technical Field

[0001] This invention relates to the field of water conservancy engineering technology, and in particular to a seepage prevention curtain structure that avoids karst caves filled with soil in karst areas. Background Technology

[0002] In water conservancy projects, dams are permanent water-retaining structures in water conservancy hubs. To ensure the safety of the structure itself and to prevent large amounts of water from seeping downstream through the dam foundation and the banks, anti-seepage grouting curtains are often installed. The grouting curtains are generally constructed inside the grouting tunnels. To prevent seepage around the dam, the grouting curtain and the grouting tunnels need to be extended a certain length into the mountainside.

[0003] In karst regions, the development of karst is controlled by lithology and closely related to geological structure. The formation of karst caves is unpredictable, and it's difficult to completely avoid them during building layout. Therefore, karst caves may be encountered during underground cavern construction, including grouting caves used to form anti-seepage curtains. The causes of karst cave formation are complex, and their scale and filling methods vary. Large-scale karst caves pose a significant threat to the construction safety of grouting caves and the operational stability of the curtain, necessitating treatment. The treatment method is highly dependent on the size, shape, and filling material properties of the karst cave. The relative position of the karst cave and the grouting cave sometimes greatly influences the treatment plan, even playing a decisive role. Especially when the karst cave has a large planar area and considerable depth, the treatment plan significantly impacts investment and construction period. However, the success of the treatment directly affects the success or failure of the anti-seepage project and even the entire key project. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a seepage-proof curtain structure for encountering karst caves filled with soil in karst areas, specifically employing the following technical solution:

[0005] The present invention describes a seepage-proof curtain structure for avoiding soil-filled karst caves in karst areas, comprising:

[0006] The system includes an upper grouting cave, a middle grouting cave, and a lower grouting cave located outside the karst cave in the backfill soil. The upper grouting cave is drilled downwards to form a first vertical curtain. The middle grouting cave is drilled upstream to form a first horizontal curtain and drilled downwards to form a second vertical curtain. The lower grouting cave is drilled around to form a second horizontal curtain or annular curtain and drilled downwards to form a third vertical curtain. The first horizontal curtain overlaps with the first vertical curtain, and the second horizontal curtain or annular curtain overlaps with the second vertical curtain.

[0007] The upper grouting hole is located above the karst cave in the filling soil, and the lower grouting hole is located below the karst cave in the filling soil. The middle grouting hole consists of an end section, a clearance section, and a transition section. The end section is coplanar with the corresponding upper and lower grouting holes. The clearance section is located on the downstream side of the karst cave in the filling soil. The transition section is used to connect the end section and the clearance section.

[0008] The end section, the avoidance section, and the transition section are set at the same height. The two end sections are set along the same line. The avoidance section is parallel to the end section. The line connecting the transition section and the end section is set at an angle of 45-60°.

[0009] The distance between the avoidance section and the end section is 8-10m, and the minimum distance between the tunnel wall of the avoidance section and the outline of the karst cave filled with soil is not less than 1 times the excavation width of the middle grouting tunnel.

[0010] Within the area of ​​the end section, the boreholes of the first and second vertical curtains are both inclined upwards at 5-7°, while the boreholes of the third vertical curtain are vertically downwards; the lower grouting hole grouts the surrounding boreholes to form a second horizontal curtain, and the horizontal and vertical lengths of the overlaps between the first vertical curtain and the first horizontal curtain, and between the second vertical curtain and the second horizontal curtain are both 5m.

[0011] Within the avoidance section, the boreholes of the first vertical curtain are inclined at 5-7° to the downstream side, the boreholes of the second vertical curtain are inclined at 5-7° to the upstream side, and the boreholes of the third vertical curtain are vertically downward; the first horizontal curtain extends into the soil of the filling karst cave, and the overlap length of the first vertical curtain through the first horizontal curtain is 5m; the lower grouting hole grouts the surrounding boreholes to form an annular curtain, and the length of the annular curtain is 10-15m, and the overlap length between it and the second vertical curtain is 5-10m.

[0012] Within the transition section, the boreholes of the first vertical curtain gradually transition from an upstream inclination of 5-7° to a downstream inclination of 5-7°, or vice versa, with the angle difference between adjacent boreholes not exceeding 0.5°; the boreholes of the second vertical curtain are inclined upstream at 5-7°, while the boreholes of the third vertical curtain are vertically downward; the horizontal and vertical lengths at the overlap between the first vertical curtain and the first horizontal curtain are both 5m; the lower grouting hole grouts the surrounding boreholes to form an annular curtain, and the length of the annular curtain is 10-15m, with an overlap length of 5-10m with the second vertical curtain.

[0013] The present invention provides a seepage-proof curtain structure for encountering karst caves filled with soil in karst areas. This structure is convenient to construct, has low investment, and a short construction period. It employs a three-layer grouting tunnel system, with the middle layer avoiding the karst caves, allowing all grouting tunnels to be constructed within the rock mass, thus improving construction safety. The curtain formed by drilling and grouting through these grouting tunnels within the rock mass has a uniform seepage-proof material and a single type, avoiding overlap between soil and rock seepage prevention and improving the seepage-proofing effect. Because the grouting tunnels and seepage-proof curtain avoid the karst caves, it is possible to avoid treating the cave filling material, reducing the adverse effects on construction caused by the uncertainty of the cave filling material. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention.

[0015] Figure 2 yes Figure 1 AA section view.

[0016] Figure 3 yes Figure 1 BB cross-section diagram.

[0017] Figure 4 yes Figure 1 CC cross-section view. Detailed Implementation

[0018] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. These embodiments are implemented based on the technical solution of the present invention, and detailed implementation methods and specific construction processes are given. However, the scope of protection of the present invention is not limited to the following embodiments.

[0019] like Figure 1-4 As shown, the karst region avoidance seepage prevention curtain structure for encountering backfilled soil caves in the present invention includes an upper grouting cave 1, a middle grouting cave 2, and a lower grouting cave 3 located outside the backfilled soil cave M. The upper grouting cave 1 is drilled downwards to form a first vertical curtain 4. The middle grouting cave 2 is drilled upstream to form a first horizontal curtain 5 and a lower vertical curtain 6. The lower grouting cave 3 is drilled around to form a second horizontal curtain 71 or an annular curtain 72 and a lower vertical curtain 8. The first horizontal curtain 5 overlaps with the first vertical curtain 4, and the second horizontal curtain 71 or annular curtain 72 overlaps with the second vertical curtain 6.

[0020] Specifically, the upper grouting hole 1 is located above the backfill karst cave M, the lower grouting hole 3 is located below the backfill karst cave M, and the middle grouting hole 2 consists of two end sections 21, one avoidance section 22, and two transition sections 23. The end sections 21 are coplanar with the corresponding upper grouting holes 1 and lower grouting holes 3 above and below them. The avoidance section 22 is located on the downstream side of the backfill karst cave M, and the transition sections 23 are used to connect the end sections 21 and the avoidance section 22. The end sections 21, avoidance sections 22, and transition sections 23 are set at the same height. The two end sections 21 are collinear. The avoidance section 22 is parallel to the two end sections 21, and the distance M1 between the avoidance section 22 and the end sections 21 is 8-10m. The minimum distance M2 between the wall of the avoidance section 22 and the outline of the backfill karst cave M is not less than 1 times the excavation width of the middle grouting hole 2, which is generally 4-5m. The two transition sections 23 are connected to the end section 21 and the avoidance section 22 by inclined holes, and the angle α between the line connecting each transition section 23 and the end section 21 is 45-60°.

[0021] Within the area of ​​end section 21, the boreholes of the first vertical curtain 4 and the second vertical curtain 6 are both inclined upwards at 5~7°, while the boreholes of the third vertical curtain 8 are vertically downwards; the lower grouting hole 3 grouts the surrounding boreholes to form a second horizontal curtain 71, and the horizontal length L1 and vertical length L2 of the overlap between the first vertical curtain 4 and the first horizontal curtain 5, and between the second vertical curtain 6 and the second horizontal curtain 71 are both 5m.

[0022] Within the area of ​​the avoidance section 22, the boreholes of the first vertical curtain 4 are inclined at 5-7° to the downstream side, the boreholes of the second vertical curtain 6 are inclined at 5-7° to the upstream side, and the boreholes of the third vertical curtain 8 are vertically downward; the first horizontal curtain 5 extends into the soil of the filling karst cave M, and the overlap length L3 of the first vertical curtain 4 through the first horizontal curtain 5 is 5m; the lower grouting cave 3 grouts the surrounding boreholes to form an annular curtain 72, and the length of the annular curtain 72 is 10-15m, and the overlap length L4 between it and the second vertical curtain 6 is 5-10m.

[0023] Within the area of ​​transition section 23 (including the left and right sections), the boreholes of the first vertical curtain 4 in the left section gradually transition from an upward inclination of 5-7° to a downward inclination of 5-7°, and the boreholes of the first vertical curtain 4 in the right section gradually transition from a downward inclination of 5-7° to an upward inclination of 5-7°, with the angle difference between adjacent boreholes in each section not exceeding 0.5°; the boreholes of the second vertical curtain 6 in both the left and right sections are inclined upwards at 5-7°, while the boreholes of the third vertical curtain 8 are vertically downwards; the horizontal and vertical lengths at the overlap between the first vertical curtain 4 and the first horizontal curtain 5 are both 5m; the lower grouting hole 3 grouts around the surrounding boreholes to form an annular curtain 72, and the length of the annular curtain 72 is 10-15m, with an overlap length of 5-10m with the second vertical curtain 6.

[0024] The seepage-avoiding curtain structure for encountering karst caves in karst areas, as described in this invention, can avoid the adverse effects of karst caves on the seepage-proof structure and improve the seepage-proof effect and safety of the curtain.

[0025] It should be noted that in the description of this invention, terms such as "front," "rear," "left," "right," "vertical," "horizontal," "inner," and "outer" indicating orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

Claims

1. A structure of a barrier-type curtain for avoiding a filled soil cave in a karst area, characterized in that: The upper grouting hole, the middle grouting hole and the lower grouting hole arranged outside the filled soil cave, the upper grouting hole is drilled downward to form a first vertical curtain, the middle grouting hole is drilled upward to form a first horizontal curtain and drilled downward to form a second vertical curtain, and the lower grouting hole is drilled around to form a second horizontal curtain or an annular curtain and drilled downward to form a third vertical curtain, wherein the first horizontal curtain overlaps with the first vertical curtain, and the second horizontal curtain or the annular curtain overlaps with the second vertical curtain; The upper grouting hole is arranged above the filled soil cave, the lower grouting hole is arranged below the filled soil cave, the middle grouting hole is composed of a head section, an avoiding section and a transition section, the head section is arranged in the same plane with the corresponding upper grouting hole and lower grouting hole, the avoiding section is arranged on the downstream side of the filled soil cave, and the minimum distance between the hole wall of the avoiding section and the profile line of the filled soil cave is not less than 1 times the excavation width of the middle grouting hole, and the transition section is used for connecting the head section and the avoiding section; the distance between the avoiding section and the head section is 8-10 m; The head section, the avoiding section and the transition section are arranged in the same height, the two head sections are arranged in the same line, the avoiding section and the head section are parallel to each other, and the transition section and the head section are arranged at an angle of 45-60°. In the area where the avoiding section is located, the drill holes of the first vertical curtain are arranged to be inclined to the downstream side by 5-7°, the drill holes of the second vertical curtain are arranged to be inclined to the upstream side by 5-7°, and the drill holes of the third vertical curtain are arranged vertically downward; the first horizontal curtain extends into the soil body of the filled soil cave, and the overlapping length of the first vertical curtain through the first horizontal curtain is 5 m; the lower grouting hole is drilled around to form an annular curtain, and the length of the annular curtain is 10-15 m, and the overlapping length of the annular curtain and the second vertical curtain is 5-10 m.

2. The avoidance type anti-seepage curtain structure that karst region meets filling soil cave according to claim 1, its characterized in being: In the area where the head section is located, the drill holes of the first vertical curtain and the second vertical curtain are arranged to be inclined to the upstream side by 5-7°, and the drill holes of the third vertical curtain are arranged vertically downward; the lower grouting hole is drilled around to form a second horizontal curtain, and the horizontal length and the vertical length of the overlapping part of the first vertical curtain and the first horizontal curtain and the overlapping part of the second vertical curtain and the second horizontal curtain are both 5 m.

3. The avoiding type anti-seepage curtain structure encountering filled soil karst cave in karst area according to claim 1, characterized in that: In the area where the transition section is located, the drill holes of the first vertical curtain are gradually transitioned from being arranged to be inclined to the upstream side by 5-7° to being arranged to be inclined to the downstream side by 5-7°, or from being arranged to be inclined to the downstream side by 5-7° to being arranged to be inclined to the upstream side by 5-7°, and the angle difference between adjacent drill holes is not greater than 0.5°; the drill holes of the second vertical curtain are arranged to be inclined to the upstream side by 5-7°, and the drill holes of the third vertical curtain are arranged vertically downward; the horizontal length and the vertical length of the overlapping part of the first vertical curtain and the first horizontal curtain are both 5 m; the lower grouting hole is drilled around to form an annular curtain, and the length of the annular curtain is 10-15 m, and the overlapping length of the annular curtain and the second vertical curtain is 5-10 m.

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