Concrete gravity dam structure suitable for Xigeda stratum

Abstract

The utility model belongs to the technical field of hydraulic engineering, and relates to a concrete gravity dam structure suitable for Xigeda stratum.The concrete gravity dam structure comprises a dam body, a cushion layer, a main tooth wall, an auxiliary tooth wall and an anti-seepage wall which are all made of concrete in a pouring mode, the anti-seepage wall is buried in the stratum, the longitudinal section of the main tooth wall is in an inverted trapezoid shape, and the bottom face of the main tooth wall is connected to the anti-seepage wall; the at least one auxiliary tooth wall is arranged in the direction from the upstream to the downstream, and a gap is formed between the auxiliary tooth wall and the main tooth wall; the dam body is arranged on the cushion layer, and the longitudinal section of the dam body is triangular; a back pressure platform is further arranged on the cushion layer and connected to the dam body, and a drainage ditch is arranged at the joint of the back pressure platform and the dam body. A first drainage hole is further formed in the dam body, a second drainage hole is formed in the back pressure platform, and the first drainage hole is communicated with the second drainage hole. Therefore, the technical problem that in the prior art, a concrete gravity dam is difficult to construct under the soft foundation condition of the Xigeda stratum is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of water conservancy engineering, and specifically relates to a concrete gravity dam structure suitable for the Xigeda stratum. Background Art

[0002] The Xigeda Formation is distributed from the south to the northwest of Sichuan. It is a set of stillwater river-lake sedimentary strata composed mainly of fine sandstone, siltstone, argillaceous siltstone and silty argillaceous interlayers. Due to its semi-diagenetic characteristics of being like soil but not soil, like rock but not rock, it has engineering properties such as soft lithology, extremely low strength and extremely poor stability.

[0003] With the acceleration of modern water network construction in Sichuan Province and the continuous rise of water conservancy and hydropower engineering construction, many dam projects will face the basic conditions of the Xigeda stratum. When building a gravity dam on a weak foundation, it is difficult to remove the soft foundation of the overburden layer on the surface, and the bearing capacity of the soft clay soil at the bottom of Xigeda is low, so it is easy to have local shear failure or even the danger of overall sliding, and the settlement of the dam body and the uneven settlement of the foundation are large, which is easy to cause cracks in the dam body. At the same time, there are few examples of gravity dams built directly on the overburden layer, and the design specifications have not involved it. There are also few similar projects in the world, so it is impossible to provide reference and reference for water conservancy project construction.

[0004] In view of the above problems, a more reasonable technical solution needs to be provided to adapt to the soft foundation conditions of the Xigeda formation, so that the concrete gravity dam constructed thereby can achieve the purpose of safety protection. Utility Model Content

[0005] The utility model aims to provide a concrete gravity dam structure suitable for the Xigeda stratum, so as to solve the technical problem in the prior art that it is difficult to construct a dam body under the soft foundation condition of the Xigeda stratum.

[0006] In order to achieve the above-mentioned purpose, the utility model provides a concrete gravity dam structure suitable for the Xigeda stratum, the stratum having a relative upstream and downstream. The concrete gravity dam structure comprises: a dam body, a cushion layer, a main tooth wall, an auxiliary tooth wall and an impermeable wall, all of which are made of concrete casting, wherein the impermeable wall is buried in the stratum, and the longitudinal section of the main tooth wall is an inverted trapezoid and its bottom surface is connected to the impermeable wall;

[0007] The auxiliary tooth wall is provided with at least one and is arranged in the direction from upstream to downstream, and a spacing is provided between the auxiliary tooth wall and the main tooth wall; the dam body is arranged on the cushion layer, and the longitudinal cross-section of the dam body is triangular; a back pressure platform is also provided on the cushion layer, and the back pressure platform is connected to the dam body, and a drainage ditch is provided at the connection between the two;

[0008] Wherein, the dam body is further provided with a first drainage hole, the back pressure platform is provided with a second drainage hole, and the first drainage hole is connected to the second drainage hole.

[0009] In a possible design, the first drainage hole extends downward from the top surface of the dam body at the same slope as the upstream slope, and extends into the stratum; the back pressure platform has an inclined guide surface, and the second drainage hole extends along the inclined direction of the guide surface and is connected to a preset discharge pipe in the drainage ditch.

[0010] In a possible design, the guide surface has a depression angle of 2.5-4%.

[0011] In a possible design, the dam body includes an upstream dam surface facing upstream and a downstream dam surface facing downstream, the upstream slope surface is in a folded shape, including a vertical section and an inclined section, wherein the slope ratio of the slope surface in the area where the inclined section is located below the fold point is 1:n1, wherein n1 is 0.3 to 0.35;

[0012] The downstream dam surface slope ratio is 1:n2, wherein n2 is 0.8-0.75.

[0013] In a possible design, the height of the dam body is H1, and H1≤30m; a plane is provided on the top of the dam body, and the width of the plane is B1, and B1≥3m.

[0014] In a possible design, the concrete gravity dam structure further includes a cushion seat, and the cushion seat is arranged on both sides of the dam body;

[0015] The width of the cushion is B2, and B2≥3.5m; the thickness of the cushion is H2, and H2≥3.5;

[0016] / and, H2=B2.

[0017] In a possible design, the thickness of the main tooth wall is B3, and B3 is 0.8-1.2 m; the slope ratio on both sides of the main tooth wall is 1:n3, and n3 is 0.4-0.6; the height of the main tooth wall is H3, and H3 is 2-3 m.

[0018] In a possible design, the longitudinal cross-section of the auxiliary tooth wall is square, wherein the thickness of the auxiliary tooth wall is B4, B4 is 0.8-1m; the height of the auxiliary tooth wall is H4, H4=0.8-1m;

[0019] / and, H4 = B4;

[0020] / And, when the auxiliary tooth walls are provided in two groups, one group is arranged at the dam heel near the upstream of the dam body, and the other group is arranged at the dam toe near the downstream of the dam body. The distance between the two auxiliary tooth walls is 5 to 8m.

[0021] In a possible design, the thickness of the cushion layer is H5, and H5 is 1 to 1.5 m.

[0022] In a possible design, pedestals are provided on both sides of the dam body, and a back-pressure platform formed by rockfill is arranged on the downstream dam surface side and the pedestals, wherein the top surface width of the back-pressure platform is B5, and B5 is 8 to 12 m; the height of the back-pressure platform is H6, and H6 is 0.3 to 0.4H1, and the slope ratio of the back-pressure platform is 1:n4, and n4 is 1.7 to 2; wherein H1 is the height of the dam body, and H1≤30 m.

[0023] Through the above technical solution, by setting up the main tooth wall and the auxiliary tooth wall, the anti-sliding stability of the dam body can be increased. Through the concrete pad, the foundation contact surface can be expanded, the water weight can be increased, the uneven settlement of the foundation can be reduced, and the anti-sliding stability of the dam body (including the dam body) can be increased; then, by slowing down the upstream and downstream slopes of the concrete gravity dam body profile, the dam bottom width is increased, the foundation pressure is reduced, the profile symmetry is improved, and the internal stress distribution of the dam body is more uniform, which increases the anti-sliding stability of the dam body. The design of the counter-pressure platform effectively reduces the uneven settlement of the foundation caused by the center of gravity of the dam body being biased upstream, thereby utilizing its weight-bearing effect to improve the anti-sliding stability of the dam body, and ultimately achieves the purpose of protecting the permanent safety of the concrete gravity dam built on the Xigeda formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A schematic structural diagram of a concrete gravity dam structure suitable for the Xigeda formation provided by the utility model in one embodiment.

[0026] In the above drawings: 1-dam body, 2-cushion, 3-main tooth wall, 4-auxiliary tooth wall, 5-anti-seepage wall, 6-back pressure platform, 71-first drainage hole, 72-second drainage hole, 8-seat, 9-discharge pipe. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that although the description of these embodiments is used to help understand the present invention, it does not constitute a limitation of the present invention.

[0028] The specific structural and functional details disclosed herein are only used to describe the exemplary embodiments of the present invention. However, the present invention can be embodied in many alternative forms, and it should not be understood that the present invention is limited to the embodiments set forth herein.

[0029] According to a specific embodiment of the present disclosure, a concrete gravity dam structure suitable for the Xigeda formation is provided, which is suitable for the operation conditions of water storage upstream and no water storage downstream. Figure 1 is one embodiment thereof.

[0030] See also Figure 1 As shown, the concrete gravity dam structure suitable for the Xigeda stratum includes: a dam body 1, a cushion layer 2, a main tooth wall 3, an auxiliary tooth wall 4 and an anti-seepage wall 5, all of which are made of concrete pouring, wherein the anti-seepage wall 5 is buried in the stratum, and the longitudinal section of the main tooth wall 3 is an inverted trapezoid and its bottom surface is connected to the anti-seepage wall 5, thereby improving the anti-sliding stability of the dam body through the main tooth wall 3 and the anti-seepage wall 5; at least one auxiliary tooth wall 4 is provided and arranged in a direction from upstream to downstream, and a spacing is provided between the auxiliary tooth wall 4 and the main tooth wall 3, which is beneficial to further improve the anti-sliding stability of the dam body; the dam body 1 is arranged on the cushion layer 2, The longitudinal cross-section of the dam body 1 is triangular, and the design of the cushion layer 2 is beneficial to better leveling the dam body 1 and improving the accuracy of the construction position and construction projects. Based on the structural design of the dam body 1, the upstream and downstream slopes can be slowed down and the dam bottom width can be increased. A back pressure platform 6 is also provided on the cushion layer 2, and the back pressure platform 6 is connected to the dam body 1, and a drainage ditch is provided at the connection between the two, so as to facilitate timely and effective removal of accumulated water and improve the anti-slip stability of the dam body. Among them, a first drainage hole 71 is also provided on the dam body 1, and a second drainage hole 72 is provided on the back pressure platform 6, and the first drainage hole 71 is connected to the second drainage hole 72.

[0031] Through the above technical solution, by setting the main tooth wall 3 and the auxiliary tooth wall 4, the anti-sliding stability of the dam body 1 can be increased. Through the concrete pad 8, the foundation contact surface can be expanded, the water weight can be increased, the uneven settlement of the foundation can be reduced, and the anti-sliding stability of the dam body (including the dam body 1) can be increased; then, by slowing down the upstream and downstream slopes of the concrete gravity dam body 1, the dam bottom width is increased, the foundation pressure is reduced, the section symmetry is improved, and the internal stress distribution of the dam body is more uniform, thereby increasing the anti-sliding stability of the dam body. The design of the counter-pressure platform 6 effectively reduces the uneven settlement of the foundation caused by the center of gravity of the dam body being biased upstream, thereby utilizing its weight-bearing effect to improve the anti-sliding stability of the dam body, and ultimately achieving the purpose of protecting the permanent safety of the concrete gravity dam built on the Xigeda formation.

[0032] In the present disclosure, the first drainage hole 71 extends downward from the top surface of the dam body 1 at the same slope as the upstream slope, and extends into the stratum; the back pressure platform 6 has an inclined guide surface, and the second drainage hole 72 extends along the inclined direction of the guide surface and is connected to the preset discharge pipe 9 in the drainage ditch. This design can guide water to gather under the action of gravity and finally discharge to other areas outside the dam body, thereby ensuring smooth discharge of accumulated water and avoiding accumulation.

[0033] Specifically, the inclination angle of the diversion surface is 2.5-4%, so that the impact on the dam body can be reduced while ensuring that the surface water is smoothly diverted. In the present disclosure, the inclination angle of the reverse flow surface is 3%.

[0034] In one embodiment provided by the present disclosure, the dam body 1 includes an upstream dam surface facing upstream and a downstream dam surface facing downstream, and the upstream slope surface is in a folded shape, including a vertical section and an inclined section, wherein the slope ratio of the slope surface in the area where the inclined section is located below the fold point is 1:n1, wherein n1 is 0.3 to 0.35. This arrangement can make the stress distribution inside the dam body more uniform and reduce the uneven settlement generated on the thick overburden.

[0035] The slope ratio of the downstream dam surface is 1:n2, where n2 is 0.8 to 0.75. When designing, it can be selected based on the stability and stress requirements and combined with the upstream dam slope.

[0036] For example, in the present disclosure, n1 is 0.35 and n2 is 0.8. In addition, n1 can also be any suitable data such as 0.3, 0.32, 0.34, etc., and n2 can also be any suitable data such as 0.75, 0.76, 0.78, etc.

[0037] Furthermore, the height of the dam body 1 is H1, and H1≤30m. Specifically, those skilled in the art can determine the height of the dam body 1 according to the actual engineering conditions such as the upstream water storage level and wave height, for example, setting it to any suitable data such as 30m, 28m, 27m, etc. The top of the dam body 1 is provided with a plane, and the width of the plane is B1, and B1≥3m. Specifically, the width is determined according to the application and traffic requirements, for example, setting it to any suitable data such as 3m, 4m, etc.

[0038] In an embodiment provided by the present disclosure, the concrete gravity dam structure further includes a cushion seat 8, which is arranged on both sides of the dam body 1. Specifically, during construction, concrete is poured in a vertical formwork, and the cushion seat 8 is arranged on both sides of the dam heel and the dam toe of the dam body 1, and is poured together with the dam body 1 structure at the same elevation to increase the dam bottom width, reduce uneven foundation settlement, and increase the anti-sliding stability of the dam body by using the water weight acting on the upper part of the cushion seat 8 structure.

[0039] The width of the cushion 8 is B2, and B2≥3.5m, for example, 3.5m or 4m. The thickness of the cushion 8 is H2, and H2≥3.5, for example, 4m or 5m. It should be noted that the thickness of the cushion 8 refers to the parameter in the height direction.

[0040] Furthermore, the width of the cushion 8 can be set to be consistent with the thickness value. That is, H2 = B2. For example, the width of the cushion 8 is set to 4m, and the thickness of the cushion 8 is also set to 4m.

[0041] In the present disclosure, the thickness of the main tooth wall 3 is B3, and B3 is 0.8 to 1.2 m. Specifically, the thickness of the main tooth wall 3 refers to the size parameter of the main tooth wall 3 relative to the dam body 1 (i.e., in the direction from upstream to downstream). In the present disclosure, B3 is 1 m. In other embodiments, it is set to any suitable value such as 0.8 m, 0.9 m, 1.1 m, 1.2 m, etc. The slope ratio on both sides of the main tooth wall 3 is 1:n3, and n3 is 0.4 to 0.6. Specifically, n3 is 0.5. Of course, n3 can also be set to any suitable value such as 0.4, 0.6, etc. The height of the main tooth wall 3 is H3, and H3 is 2 to 3 m. Specifically, H3 is 2.5. Of course, H3 can also be set to any suitable value such as 2 m, 3 m, etc.

[0042] In one embodiment provided by the present disclosure, the longitudinal cross-section of the auxiliary tooth wall 4 is square, wherein the thickness of the auxiliary tooth wall 4 is B4, and B4 is 0.8 to 1 m. Specifically, B4 is 1 m. Of course, B4 can also be set to any suitable value such as 0.8 m, 0.9 m, etc. The height of the auxiliary tooth wall 4 is H4, and H4=0.8 to 1 m. Specifically, H4 is 1 m. Of course, H4 can also be set to any suitable value such as 0.8 m, 0.9 m, etc.

[0043] Furthermore, the width of the auxiliary tooth wall 4 can be set to be consistent with the thickness value. That is, H4 = B4. For example, the width of the auxiliary tooth wall 4 is set to 1m, and the thickness of the cushion seat 8 is also set to 1m.

[0044] Furthermore, when the auxiliary tooth walls 4 are provided in two groups, one group is arranged at the dam heel near the upstream of the dam body 1, and the other group is arranged at the dam toe near the downstream of the dam body 1, and the spacing between the two auxiliary tooth walls 4 is 5 to 8 meters, thereby improving the anti-sliding stability of the gravity dam. The spacing between the auxiliary tooth walls 4 can be referenced according to the height and width of the dam body 1.

[0045] In an embodiment provided in the present disclosure, the thickness of the cushion layer 2 is H5, and H5 is 1 to 1.5 m. Specifically, the cushion layer 2 is cast using a concrete formwork, arranged on the upstream auxiliary tooth wall 4 and the downstream auxiliary tooth wall 4, and cast and formed at the same time, which is convenient for later processing and leveling, thereby ensuring the stability and reliability of the structure and position of the cushion layer 2. In the present disclosure, the thickness of the cushion layer 2 is 1.5 m. In other embodiments, the thickness of the cushion layer 2 is any suitable value such as 1 m, 1.2 m, 1.4 m, etc.

[0046] In one embodiment provided in the present disclosure, cushion seats 8 are provided on both sides of the dam body 1, and a back-pressure platform 6 formed by rockfill is arranged on the downstream dam surface side and on the cushion seats 8, wherein the top surface width of the back-pressure platform 6 is B5, and B5 is 8 to 12 m. In the present disclosure, B5 is 10 m. In other embodiments, B5 is 8 m, 9 m, 11 m, and 12 m. The height of the back-pressure platform 6 is H6, and H6 is 0.3 to 0.4 H1. The slope ratio of the back-pressure platform 6 is 1:n4, and n4 is 1.7 to 2; wherein H1 is the height of the dam body 1, and H1 ≤ 30 m. This arrangement can effectively reduce the uneven settlement of the foundation caused by the center of gravity of the dam body being biased upstream, and utilize its weight-carrying effect to improve the anti-sliding stability of the dam body.

[0047] A longitudinal C20 concrete drainage ditch is arranged on the surface of the back pressure platform 6 to help drain the accumulated water from the backflow surface; a PVC discharge pipe 9 is buried in the back pressure platform 6 to drain the seepage water in the dam and on the surface of the platform to form a drainage system, thereby reducing the uplift pressure of the concrete gravity dam structure 1.

[0048] Furthermore, transverse joints may be provided in the above concrete gravity dam structure, with a joint width of 20 mm and a joint spacing of generally 15 to 20 m.

[0049] It should be noted that the utility model is not limited to the above optional implementations, and anyone can derive other various forms of products under the inspiration of the utility model. The above specific implementations should not be understood as limiting the scope of protection of the utility model. The scope of protection of the utility model shall be based on the definition in the claims, and the description can be used to interpret the claims.

Claims

1. A concrete gravity dam structure suitable for the Xigeda formation, the formation having a relative upstream and downstream, characterized in that: The concrete gravity dam structure comprises: a dam body, a cushion layer, a main tooth wall, an auxiliary tooth wall and an anti-seepage wall, all of which are made of concrete. The anti-seepage wall is buried in the stratum, and the longitudinal section of the main tooth wall is in an inverted trapezoidal shape and its bottom surface is connected to the anti-seepage wall. The auxiliary tooth wall is provided with at least one and is arranged in the direction from upstream to downstream, and a spacing is provided between the auxiliary tooth wall and the main tooth wall; the dam body is arranged on the cushion layer, and the longitudinal cross-section of the dam body is triangular; a back pressure platform is also provided on the cushion layer, and the back pressure platform is connected to the dam body, and a drainage ditch is provided at the connection between the two; Wherein, the dam body is further provided with a first drainage hole, the back pressure platform is provided with a second drainage hole, and the first drainage hole is connected to the second drainage hole.

2. The concrete gravity dam structure suitable for the Xigeda formation according to claim 1 is characterized in that: The first drainage hole extends downward from the top surface of the dam body, maintaining the same slope as the upstream slope, and extends into the stratum; the back pressure platform has an inclined guide surface, and the second drainage hole extends along the inclined direction of the guide surface and is connected to a preset discharge pipe in the drainage ditch.

3. The concrete gravity dam structure suitable for the Xigeda formation according to claim 2 is characterized in that: The inclination angle of the guide surface is 2.5-4%.

4. The concrete gravity dam structure suitable for the Xigeda formation according to claim 1 is characterized in that: The dam body comprises an upstream dam surface facing upstream and a downstream dam surface facing downstream, the upstream slope surface is in a folded shape, comprising a vertical section and an inclined section, wherein the slope ratio of the slope surface in the area where the inclined section is located below the fold point is 1:n1, wherein n1 is 0.3 to 0.35; The slope ratio of the downstream dam surface is 1:n2, wherein n2 is 0.8 to 0.

75.

5. The concrete gravity dam structure applicable to the Xigeda formation according to any one of claims 1 to 4, characterized in that: The height of the dam body is H1, and H1≤30m; a plane is provided on the top of the dam body, and the width of the plane is B1, and B1≥3m.

6. The concrete gravity dam structure suitable for the Xigeda formation according to claim 1 is characterized in that: The concrete gravity dam structure further comprises a cushion seat, and the cushion seat is arranged on both sides of the dam body; The width of the cushion is B2, and B2 ≥ 3.5m; the thickness of the cushion is H2, and H2 ≥ 3.5; / and, H2=B2.

7. The concrete gravity dam structure suitable for the Xigeda formation according to claim 1 is characterized in that: The thickness of the main tooth wall is B3, and B3 is 0.8-1.2m; the slope ratio on both sides of the main tooth wall is 1:n3, and n3 is 0.4-0.6; the height of the main tooth wall is H3, and H3 is 2-3m.

8. The concrete gravity dam structure suitable for the Xigeda formation according to claim 1 is characterized in that: The longitudinal section of the auxiliary tooth wall is square, wherein the thickness of the auxiliary tooth wall is B4, B4 is 0.8-1m; the height of the auxiliary tooth wall is H4, H4=0.8-1m; / and, H4 = B4; / And, when the auxiliary tooth walls are provided in two groups, one group is arranged at the dam heel near the upstream of the dam body, and the other group is arranged at the dam toe near the downstream of the dam body. The distance between the two auxiliary tooth walls is 5 to 8m.

9. The concrete gravity dam structure suitable for the Xigeda formation according to claim 1 is characterized in that: The thickness of the cushion layer is H5, and H5 is 1 to 1.5 m.

10. The concrete gravity dam structure suitable for the Xigeda formation according to claim 1, characterized in that: There are pedestals on both sides of the dam body, and a back-pressure platform formed by rockfill is arranged on the downstream dam surface side and the pedestals, wherein the top surface width of the back-pressure platform is B5, and B5 is 8 to 12 m; the height of the back-pressure platform is H6, and H6 is 0.3 to 0.4H1, and the slope ratio of the back-pressure platform is 1:n4, and n4 is 1.7 to 2; wherein H1 is the height of the dam body, and H1≤30 m.

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