Gravity dam anti-seismic reinforcing structure for foundation surface inclined downstream
By using prestressed anchor cables and U-shaped concrete groove reinforced structures in the gravity dam with a downstream foundation surface tilt, the problem of poor stability of the gravity dam under strong earthquakes is solved, and the effect of anti-slip and compressive resistance is achieved, reducing investment cost.
Patent Information
- Application Number
- CN202420870520.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-25
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2034-04-25
AI Technical Summary
In hydraulic buildings, gravity dams with a foundation surface tend to be downstream are difficult to maintain stability under strong earthquakes, and due to terrain limitations or geological defects, horizontal or upstream tendency excavation cannot be carried out, resulting in an increased risk of slip failure in the dam section. , the prior art is difficult to effectively resist seismic reinforcement.
The structure of prestressed anchor cable is reinforced, including the installation of prestressed anchor cables in the foundation corridor, the anchor head is located on the ground, the anchor end is located in the foundation, the vertical force is increased by prestressed tension, and the upper and lower dam foundation drainage is set on the inclined foundation surface The corridor and grouting hole are combined with the U-shaped concrete groove to perform the post-dam pressure weight to reduce the lifting pressure and dam toe pressure stress.
It effectively improves the anti-slip capacity of the dam body after earthquake, reduces the dam foundation lifting pressure and dam toe pressure stress during earthquakes, enhances the overall stability of the dam body, saves investment, and maximizes the use of local materials.
Smart Images
Figure CN222206225U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a gravity dam in a hydraulic structure, in particular to an earthquake-resistant reinforcement structure of a gravity dam with a foundation surface inclined toward downstream. Background Art
[0002] Southwest my country is rich in hydropower resources and is also an earthquake-prone area. A large number of concrete gravity dams have been built in this area, such as Xiangjiaba, Guandi, and Dawei. The Changle-Zhao'an earthquake zone along the coast of Fujian Province in my country has experienced a major earthquake. A series of large and medium-sized gravity dams have been built along the coast of Fujian Province, such as Dongzhang, Fengtou, and Shuikou. So far, many gravity dams around the world have experienced sliding failures. For example, in 1900, the Austin Gravity Dam in the United States, 20.7m, had a 152m-long dam section sliding; in 1928, the St. Francis Gravity Dam in the United States, 62m, collapsed at midnight, killing more than 600 people. According to incomplete statistics, there are more than 30 large and medium-sized dams in China that have failed to discover geological defects in time, resulting in design changes, delays in construction, supplementary surveys, and later anti-sliding reinforcement. Once a gravity dam loses stability under the action of an earthquake, it will lose its water storage function, endanger personal safety, and swallow up economic achievements. Therefore, the seismic stability of gravity dams is extremely important.
[0003] When excavating the foundation of a gravity dam, due to terrain restrictions or geological defects, some dam sections cannot be excavated horizontally or inclined upstream, but have to be inclined downstream. For example, the 8# and 9# dam sections of Dongzhang Reservoir and the 4# dam section of Fengtou Reservoir. Under strong earthquakes, the downstream inclination of the foundation surface is more unfavorable to the stability of the gravity dam and the dam toe pressure stress. Therefore, it is necessary to take seismic reinforcement measures for gravity dams with downstream inclinations of the foundation surface. Utility Model Content
[0004] The technical problem to be solved by the utility model is to provide a seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream, so as to solve the problems raised in the background technology.
[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is as follows: a seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream, characterized in that it includes a prestressed anchor cable, the gravity dam includes a dam body, a foundation corridor is arranged in the dam body, the anchor head at the top of the prestressed anchor cable is located on the ground of the foundation corridor, and the anchor end at the bottom is located in the foundation, and the prestressed anchor cable is tensioned with prestress.
[0006] Preferably, the dam body and the foundation are provided with grouting holes and foundation drainage holes extending from the ground of the foundation corridor to the foundation, a grouting curtain is formed around the grouting holes, the anchor head at the top of the prestressed anchor cable is located between the grouting hole head and the foundation drainage hole head of the foundation corridor, and the prestressed anchor cable is located as a whole between the grouting curtain and the foundation drainage hole.
[0007] Preferably, the prestressed anchor cables are perpendicular to the ground of the foundation corridor.
[0008] Preferably, the end of the foundation drainage hole of the foundation corridor is lower than the anchor end of the prestressed anchor cable.
[0009] Preferably, the foundation corridor is 4-5m higher than the foundation surface, and the anchor end needs to penetrate 3-4m into the foundation.
[0010] Preferably, it also includes an upper dam foundation drainage corridor and a lower dam foundation drainage corridor arranged on the inclined foundation surface between the dam body and the foundation, the bottom surface of the upper dam foundation drainage corridor extending toward the foundation is provided with upper dam foundation drainage holes, and the bottom surface of the lower dam foundation drainage corridor extending toward the foundation is provided with lower dam foundation drainage holes.
[0011] Preferably, the bottom elevation of the upper dam foundation drainage gallery is level with the dam heel, and the bottom elevation of the lower dam foundation drainage gallery is level with the dam toe.
[0012] Preferably, the end of the drainage hole in the lower dam foundation is lower than the end of the drainage hole in the upper dam foundation, and the dam body and the foundation are provided with grouting holes and foundation drainage holes extending from the ground of the foundation corridor to the foundation, the end of the grouting hole is lower than the end of the grouting hole, and the end of the drainage hole in the upper dam foundation is lower than the end of the foundation drainage hole.
[0013] Preferably, a dam rear weight is provided at the end of the dam body, and the dam rear weight is a concrete U-shaped groove.
[0014] Preferably, the ballast behind the dam is connected to the dam body through anchor rods.
[0015] From the above description, it can be seen that the seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream provided by the utility model has the following beneficial effects:
[0016] (1) The establishment of prestressed anchor cables in the foundation corridor can effectively increase the vertical force on the sliding surface and improve the anti-sliding ability of the dam body during earthquakes. Compared with prestressed anchor cables on the dam top, it can save more investment.
[0017] (2) A double dam foundation drainage corridor is set up on the inclined foundation surface. The drainage holes are deeper into the dam foundation than the horizontal dam foundation drainage holes and are deeper relative to the curtain position. This can more effectively discharge the seepage behind the curtain, thereby reducing the dam foundation uplift pressure during an earthquake and being more conducive to the stability of the dam body.
[0018] (3) A U-shaped concrete trough is used behind the dam for weighting. Construction waste can be placed in the U-shaped trough to maximize the use of local materials and reduce investment. The upstream side of the U-shaped trough is connected to the dam body through anchor rods. The dam body and the weight behind the dam form a whole, which increases the width of the dam bottom, reduces the compressive stress on the dam toe during an earthquake, and prevents the bedrock at the dam toe from being crushed. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 Schematic diagram of the seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream. DETAILED DESCRIPTION
[0020] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific implementation methods.
[0021] As shown in the figure, the utility model is a seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream, including a prestressed anchor cable 1. The gravity dam includes a dam body 2, and a foundation corridor 3 is arranged in the dam body 2. The anchor head 11 at the top of the prestressed anchor cable 1 is located on the ground of the foundation corridor 3, and the anchor end 12 at the bottom is located in the foundation 4. The prestressed anchor cable 1 is tensioned by prestressing. An asphalt well is arranged on the upstream side of the dam body 2, and water-stop copper sheets are arranged before and after the asphalt well. A drainage well is arranged inside the dam body 2. In order to achieve the large vertical force required to maintain stability, the anchor cable needs to be prestressed, which is beneficial to the seismic stability of the dam body 2. The prestressed anchor cable 1 is set up in the foundation corridor 3, which can effectively increase the vertical force on the sliding surface and improve the anti-sliding ability of the dam body 2 during earthquakes. Compared with the prestressed anchor cable 1 on the top of the dam, it can save more investment.
[0022] The dam body 2 and the foundation 4 are provided with grouting holes 5 and foundation drainage holes 6 extending from the ground of the foundation gallery 3 to the foundation 4, and a grouting curtain 7 is formed around the grouting hole 5. The anchor head 11 at the top of the prestressed anchor cable 1 is located between the head of the grouting hole 5 of the foundation gallery 3 and the head of the foundation drainage hole 6, and the prestressed anchor cable 1 is located as a whole between the grouting curtain 7 and the foundation drainage hole 6. In order to create a dry anchor end 12 environment, the anchor cable should be located between the curtain grouting and the foundation drainage hole 6 of the foundation gallery 3.
[0023] The prestressed anchor cable 1 is perpendicular to the ground of the foundation gallery 3. The prestressed anchor cable 1 is an anchor cable driven vertically into the foundation 4 from the ground of the foundation gallery 3.
[0024] The end of the foundation drainage hole 6 of the foundation gallery 3 is lower than the anchor end 12 of the prestressed anchor cable 1. In order to create a dry anchor end 12 environment, the foundation drainage hole 6 of the foundation gallery 3 should be located below the anchor end 12.
[0025] The foundation corridor 3 is 4-5m higher than the foundation surface, and the anchor end 12 needs to be 43-4m deep into the foundation. In order to anchor the prestressed effect, the anchor end 12 needs to be deep into the foundation 4. The anchor end 12 is driven into the foundation 4 behind the curtain, and the anchor head 11 is on the ground of the foundation corridor 3, which is more conducive to the seismic stability of the dam body 2.
[0026] The seismic reinforcement structure for the gravity dam with the foundation surface inclined downstream also includes an upper dam foundation drainage gallery 8 and a lower dam foundation drainage gallery 10 arranged on the inclined foundation surface between the dam body 2 and the foundation 4. The bottom surface of the upper dam foundation drainage gallery 8 extends toward the foundation 4 and is provided with an upper dam foundation drainage hole 11, and the bottom surface of the lower dam foundation drainage gallery 10 extends toward the foundation 4 and is provided with a lower dam foundation drainage hole 12. The double dam foundation drainage galleries are arranged front and back on the inclined foundation surface. Through the dam foundation drainage holes driven into the foundation 4, the seepage water that has penetrated behind the curtain and has not been discharged by the foundation drainage holes 6 is discharged into the dam foundation drainage gallery in a timely manner in layers, and then pumped away, so as to reduce the uplift pressure of the dam foundation, which is beneficial to the seismic stability of the dam body 2.
[0027] The bottom elevation of the upper dam foundation drainage gallery 8 is level with the dam heel, and the bottom elevation of the lower dam foundation drainage gallery 10 is level with the dam toe.
[0028] The end of the lower dam foundation drainage hole 12 is lower than the end of the upper dam foundation drainage hole 11. Grouting holes 5 and foundation drainage holes 6 extending from the ground of the foundation gallery 3 to the foundation 4 are provided in the dam body 2 and the foundation 4. The end of the grouting hole 5 is lower than the end of the grouting hole 5, and the end of the upper dam foundation drainage hole 11 is lower than the end of the foundation drainage hole 6. The seepage water that penetrates into the curtain and is not discharged by the foundation drainage hole 6 is pumped away through the upper dam foundation drainage hole 11 and the lower dam foundation drainage hole 12 in turn. By setting up a double dam foundation drainage gallery on the inclined foundation surface, the upper dam foundation drainage hole 11 and the lower dam foundation drainage hole 12 are deeper into the dam foundation than the foundation water hole, and are deeper relative to the grouting curtain 7, which can more effectively discharge the seepage water behind the curtain, thereby reducing the dam foundation uplift pressure during an earthquake and being more conducive to the stability of the dam body 2.
[0029] The end of the dam body 2 is provided with a dam back weight 13, which is a concrete U-shaped groove. The U-shaped concrete groove is used for weighting behind the dam. The groove can be filled with construction waste soil and blocks to increase the dam back weight 13, and can maximize the use of local materials and reduce investment. The bottom of the U-shaped groove has a certain width, which can increase the sliding area and thus play an anti-slip role, and can increase the width of the dam bottom, thereby reducing the dam toe compressive stress, preventing the dam toe foundation 4 from being crushed, which is beneficial to the seismic stability of the dam body 2.
[0030] The ballast 13 behind the dam is connected to the dam body 2 through an anchor rod 14. The upstream side of the U-shaped groove is connected to the dam body 2 through the anchor rod 14 so that the dam body 2 and the ballast become one, thereby increasing the integrity.
[0031] The above are only some specific implementation methods of the utility model, but the design concept of the utility model is not limited to this. Any non-substantial changes to the utility model using this concept shall be deemed as an infringement of the protection scope of the utility model.
Claims
1. A seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream. Features: The gravity dam comprises a prestressed anchor cable, wherein the dam body is provided with a foundation corridor, the anchor head at the top of the prestressed anchor cable is located on the ground of the foundation corridor, and the anchor end at the bottom is located in the foundation, and the prestressed anchor cable is tensioned by using prestress.
2. The seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream according to claim 1, Features: The dam body and the foundation are provided with grouting holes and foundation drainage holes extending from the ground of the foundation gallery to the foundation, a grouting curtain is formed around the grouting holes, the anchor head at the top of the prestressed anchor cable is located between the grouting hole head and the foundation drainage hole head of the foundation gallery, and the prestressed anchor cable is located as a whole between the grouting curtain and the foundation drainage hole.
3. The seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream according to claim 1 or 2, Features: The prestressed anchor cable is perpendicular to the ground of the foundation corridor.
4. The seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream according to claim 1, Features: The end of the foundation drainage hole of the foundation gallery is lower than the anchor end of the prestressed anchor cable.
5. The seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream according to claim 1, Features: The foundation corridor is 4-5m higher than the foundation surface, and the anchor end needs to penetrate 3-4m into the foundation.
6. The seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream according to claim 1, Features: It also includes an upper dam foundation drainage corridor and a lower dam foundation drainage corridor arranged on the inclined foundation surface between the dam body and the foundation, the bottom surface of the upper dam foundation drainage corridor extending toward the foundation is provided with upper dam foundation drainage holes, and the bottom surface of the lower dam foundation drainage corridor extending toward the foundation is provided with lower dam foundation drainage holes.
7. The seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream according to claim 6, Features: The bottom elevation of the upper dam foundation drainage corridor is level with the dam heel, and the bottom elevation of the lower dam foundation drainage corridor is level with the dam toe.
8. The seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream according to claim 6, Features: The end of the drainage hole in the lower dam foundation is lower than the end of the drainage hole in the upper dam foundation. The dam body and the foundation are provided with grouting holes and foundation drainage holes extending from the ground of the foundation corridor to the foundation. The end of the grouting hole is lower than the end of the grouting hole, and the end of the drainage hole in the upper dam foundation is lower than the end of the foundation drainage hole.
9. The seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream according to claim 1, Features: A dam rear weight is provided at the end of the dam body, and the dam rear weight is a concrete U-shaped groove.
10. The seismic reinforcement structure for a gravity dam with a foundation surface inclined downstream according to claim 1, Features: The dam rear weight is connected to the dam body through anchor rods.