Dam construction method based on underground multi-karst cave geology

Abstract

The invention discloses a dam construction method based on underground multi-karst cave geology, which comprises the following steps: firstly, carrying out reinforcement treatment on karst caves, filling a first-stage dam body, carrying out auxiliary curtain grouting operation on the first-stage dam body, then filling a second-stage dam body on the basis of the first-stage dam body, and constructing at the top of the second-stage dam body towards a foundation to construct a core wall; and meanwhile, the pre-buried pipe body for main curtain grouting is synchronously pre-buried in the core wall construction process, so that secondary drilling operation of main curtain grouting is not needed, and after core wall construction is completed, main curtain grouting operation is carried out in the foundation through the pre-buried pipe body. According to the damming method, due to the fact that filling of the second-stage dam body is completed firstly, the overall weight of the dam is almost completed, the foundation is tamped through the dead weight of the dam, the karst cave is driven to collapse in advance, then the core wall is built, the core wall cannot be affected by collapse of the karst cave, the quality of the core wall is higher, and the construction efficiency is improved. The design standard is met, and the problem of deformation caused by collapse of the karst cave is avoided.

Description

Technical Field

[0001] This invention relates to the field of dams, and in particular to a dam construction method based on geology with multiple underground karst caves. Background Technology

[0002] A dam is a large-scale water conservancy project. Current dam construction technology follows a standard pattern: first, a core wall (i.e., a seepage barrier) is built, and then the dam body is constructed on top of this core wall. However, this method is not suitable for certain geological conditions, namely, those with numerous underground karst caves. When there are many karst caves in the foundation, even if some larger caves are reinforced, many smaller ones cannot be fully reinforced. In a dam construction method where the core wall is built first and then the dam body is filled, the sheer weight of the dam causes the karst areas to collapse due to gravity, leading to foundation settlement and deformation of the core wall, thus affecting the overall quality of the dam. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide a dam construction method that involves first constructing the dam and then building the core wall.

[0004] The technical solution adopted by this invention to solve the problem is: a dam construction method based on underground karst geology, comprising the following arrangement:

[0005] S1. Detect the location of the underground cave;

[0006] S2. Complete the dam surface clearing and foundation treatment site leveling work, drill holes to connect the karst cave, inject grout into the karst cave to fill the karst cave and thus complete the karst cave reinforcement treatment;

[0007] S3. First, fill the dam body to establish the first-phase dam body. The height of the first-phase dam body is the flood control height. At the top of the first-phase dam body, perform secondary curtain grouting on the foundation.

[0008] S4. After the secondary curtain grouting of the first-phase dam body is completed, check whether the secondary curtain grouting is qualified. If it is qualified, continue to fill the dam body on the basis of the first-phase dam body to the designed main height of the dam body to form the second-phase dam body.

[0009] S5. Construct a core wall extending to a predetermined depth to the bottom of the foundation at the top of the second-phase dam body, and simultaneously embed pre-embed pre-embedded pipes for main curtain grouting during the construction of the core wall, wherein the depth of both the main curtain grouting and the secondary curtain grouting is greater than the depth of the core wall.

[0010] S6. After the core wall is constructed, the main curtain grouting operation is carried out into the foundation through the pre-embedded pipes, wherein the main curtain grouting is parallel to the secondary curtain grouting.

[0011] S7. Check whether the grouting of the core wall and main curtain wall is qualified. After it is qualified, the second phase of the dam body is filled and the slope protection, wave wall, dam top road and drainage ditch are constructed.

[0012] As a further improvement to the above technical solution, the area of ​​the main curtain grouting filling foundation partially overlaps with the area of ​​the secondary curtain grouting filling foundation.

[0013] As a further improvement to the above technical solution, after step S is completed, the second-phase dam body needs to be left to stand for a period of time before step S is carried out.

[0014] As a further improvement to the above technical solution, the core wall is a shaped concrete core wall.

[0015] The beneficial effects of this invention are as follows: First, the karst cave is reinforced, then the first-stage dam body is constructed by filling in the dam. After the first-stage dam body is constructed, secondary curtain grouting is performed. After the secondary curtain grouting is completed, the second-stage dam body is constructed on the basis of the first-stage dam body. After the second-stage dam body is completed, the core wall is constructed on the top of the second-stage dam body facing the foundation. Simultaneously, the pre-embedded pipes for the main curtain grouting are pre-embedded during the construction of the core wall, thus eliminating the need for secondary drilling for the main curtain grouting. After the core wall construction is completed, the main curtain grouting is performed into the foundation through the pre-embedded pipes. After completion, the second-stage dam body is filled in, and ancillary facilities such as slope protection, wave walls, dam crest roads, and drainage ditches are constructed. Under this dam construction method, because the second phase of dam body filling is completed first, the basic structure of the dam is completed first, and the overall weight is almost complete. Thus, the foundation is compacted by the dam's own weight, thereby causing the karst caves to collapse in advance. Then the core wall is built. In this way, the core wall will not be affected by the collapse of the karst caves. Therefore, the quality of the core wall is higher, meets the design standards, and will not cause deformation problems due to the collapse of the karst caves. Attached Figure Description

[0016] The present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments.

[0017] Figure 1 This is a schematic diagram of the foundation structure before construction.

[0018] Figure 2 This is a structural schematic diagram of the first phase of the dam.

[0019] Figure 3 A schematic diagram of the structure after the secondary curtain grouting construction of the first-phase dam body;

[0020] Figure 4 This is a schematic diagram of the second-phase dam structure;

[0021] Figure 5 A schematic diagram of the structure after the core wall and main curtain wall of the second-phase dam have been grouted. Detailed Implementation

[0022] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0023] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not 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 limiting this invention.

[0024] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, the number of indicated technical features, or the order of the indicated technical features. In the description of this invention, unless otherwise explicitly defined, terms such as "set," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of these terms in this invention based on the specific content of the technical solution.

[0025] Reference Figures 1 to 5 A dam construction method based on underground karst geology includes the following arrangement:

[0026] S1. Locate the underground cavern 1;

[0027] S2. Complete the dam surface clearing and foundation treatment site leveling work, drill holes to connect to karst cave 1, inject grout into karst cave 1 to fill karst cave 1 and thus complete the reinforcement treatment of karst cave 1;

[0028] S3. First, fill the dam body to establish the first-phase dam body 2. The height of the first-phase dam body 2 is the flood control height. Then, perform secondary curtain grouting 3 on the foundation at the top of the first-phase dam body 2.

[0029] S4. After the secondary curtain grouting 3 is completed in the first phase dam body 2, check whether the secondary curtain grouting 3 is qualified. If it is qualified, continue to fill the dam body on the basis of the first phase dam body 2 to the designed main height of the dam body to form the second phase dam body 4.

[0030] S5. Construct a core wall 5 extending to a predetermined depth at the bottom of the foundation by constructing it on the top of the second-phase dam body 4. Preferably, the core wall 5 is a shaped concrete core wall. During the construction of the core wall 5, pre-embedded pipes for the main curtain grouting 6 are simultaneously pre-embedded. The depths of the main curtain grouting 6 and the secondary curtain grouting 3 are both greater than the depth of the core wall 5.

[0031] S6. After the core wall 5 is constructed, the main curtain grouting 6 is carried out on the foundation through the pre-embedded pipe body, wherein the main curtain grouting 6 is parallel to the secondary curtain grouting 3.

[0032] S7. Check whether the core wall 5 and main curtain grouting 6 are qualified. After they are qualified, fill the second phase dam body 4 and carry out the construction of slope protection, wave wall, dam top road and drainage ditch.

[0033] First, the karst cave 1 is reinforced, then the first-phase dam 2 is constructed by filling in the dam body. After the first-phase dam 2 is constructed, the secondary curtain grouting 3 is carried out. After the secondary curtain grouting 3 is completed, the second-phase dam 4 is constructed on the basis of the first-phase dam 2. After the second-phase dam 4 is completed, the core wall 5 is constructed on the top of the second-phase dam 4 facing the foundation. Since the construction of the core wall 5 requires excavation, the pre-embedded pipes for the main curtain grouting 6 can be pre-embedded during the excavation process of the core wall 5, thus eliminating the need for secondary drilling for the main curtain grouting 6. After the construction of the core wall 5 is completed, the main curtain grouting 6 is carried out into the foundation through the pre-embedded pipes. After completion, the second-phase dam 4 is filled in, and the ancillary facilities such as slope protection, wave walls, dam crest roads, and drainage ditches are constructed. Under this dam construction method, since the second phase of dam body 4 is filled in first, the basic structure of the dam is completed first, and the overall weight is almost complete. Thus, the foundation is compacted by the dam's own weight, thereby causing the karst cave 1 to collapse in advance. Then the core wall 5 is constructed. In this way, the core wall 5 will not be affected by the collapse of the karst cave 1. Therefore, the quality of the core wall 5 is higher, meets the design standards, and will not cause deformation problems due to the collapse of the karst cave 1.

[0034] In this scheme, it is preferable that the area of ​​the main curtain grouting 6 filling the foundation partially overlaps with the area of ​​the secondary curtain grouting 3 filling the foundation, thereby consolidating them into one to further form a continuous water-blocking curtain.

[0035] In this scheme, considering that the collapse of the karst cave 1 takes a certain amount of time, it is preferable that after step S4 is completed, the second-phase dam body 4 should be left to stand for a period of time to ensure that the foundation of the collapsed karst cave 1 is compacted before proceeding with step S5.

[0036] The main technical feature disclosed in this invention is that the dam body is constructed first, followed by the construction of the core wall 5. This addresses the problem of foundation settlement caused by the collapse of karst caves 1 in areas with multiple karst caves 1, which in turn affects the quality of the core wall 5. As for the structural features of the dam, these have already been described in existing technologies, such as transition cushion layer, filter material layer, reverse filter layer, rockfill layer, slope protection structure, and wave wall, etc. Therefore, this solution will not elaborate on them in detail.

[0037] Meanwhile, the construction methods of curtain grouting and core wall 5 are also conventional technologies in the existing technology, so they will not be explained in detail in this plan.

[0038] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct or indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A dam construction method based on underground karst geology, characterized in that, The following arrangements are included: S1. Detect the location of the underground cave (1); S2. Complete the dam clearing and foundation treatment site leveling work, drill holes to connect the karst cave (1), inject grout into the karst cave (1) to fill the karst cave (1) and thus complete the reinforcement treatment of the karst cave (1); S3. First, fill the dam body to establish the first-phase dam body (2). The height of the first-phase dam body (2) is the flood control height. At the top of the first-phase dam body (2), perform secondary curtain grouting (3) on the foundation. S4. After the secondary curtain grouting (3) of the first-phase dam body (2) is completed, check whether the secondary curtain grouting (3) is qualified. If it is qualified, continue to fill the dam body on the basis of the first-phase dam body (2) to the main height of the dam body design to form the second-phase dam body (4); S5. Construct a core wall (5) extending to a predetermined depth at the bottom of the foundation by constructing the top of the second-phase dam body (4), and simultaneously embed the pre-embedded pipe body for the main curtain grouting (6) during the construction of the core wall (5), wherein the depth of the main curtain grouting (6) and the secondary curtain grouting (3) are both greater than the depth of the core wall (5). S6. After the core wall (5) is constructed, the main curtain grouting (6) is carried out on the foundation through the pre-embedded pipe body, wherein the main curtain grouting (6) is parallel to the secondary curtain grouting (3); S7. Check whether the core wall (5) and main curtain grouting (6) are qualified. After they are qualified, fill the second phase dam body (4) and carry out the construction of slope protection, wave wall, dam top road and drainage ditch.

2. The dam construction method based on underground karst geology as described in claim 1, characterized in that: The area where the main curtain grouting (6) fills the foundation partially overlaps with the area where the secondary curtain grouting (3) fills the foundation.

3. The dam construction method based on underground karst geology as described in claim 1, characterized in that: After step S4 is completed, the second-phase dam body (4) needs to be left to stand for a period of time before step S5 is carried out.

4. A dam construction method based on underground karst geology as described in claim 1, characterized in that: The core wall (5) is a shaped concrete core wall (5).

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