Gravity dam downstream folding slope preset anti-seismic structure and anti-seismic method thereof

Abstract

The invention discloses a gravity dam downstream folding slope preset anti-seismic structure and an anti-seismic method thereof, the anti-seismic structure comprises a dam body and a restorer, the dam body is provided with a slot, and the restorer is arranged in the dam body. The crack forming direction and the dam body deformation direction during an earthquake are guided through preset slotting, and the destructive effect of the earthquake on the dam body is relieved. The deformation of the dam body is mainly concentrated in the preset slotting area, so that the overall structure of the dam body is protected, the structural damage of the dam body is reduced, and the dam body can be conveniently repaired according to the actual condition of a crack after an earthquake, and the function of the dam body is recovered. On the basis of a preset seam, in order to further improve the anti-seismic property of the dam body and ensure the safety of overall operation of the dam, a memory alloy restorer is additionally arranged, deformation of the dam body can be restored to a certain degree through the shape memory effect of shape memory alloy, the workload and cost of post-earthquake repair are reduced, and the dam body is protected from being damaged. Therefore, the anti-seismic performance of the dam body and the overall operation safety of the dam are further enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of water conservancy and hydropower engineering, and particularly relates to a preset seismic structure with a downstream slope break of a gravity dam and a seismic resistance method therefor. Background Art

[0002] For a long time, the prediction of crack development in a dam body has always been an important problem in the field of seismic performance analysis of concrete dams. The downstream slope break of a gravity dam is the area where the gravity dam is most vulnerable to damage and develop cracks under earthquake action. The crack development of a concrete dam under earthquake action is not only affected by various factors such as material properties, structural design, and construction quality, but also involves many factors such as the randomness and uncertainty of seismic dynamics. Traditional analysis methods are often difficult to accurately predict the initiation, propagation path of cracks and their impact on the overall performance of the dam body. Therefore, how to effectively predict and control the crack development of a concrete dam under earthquake action has become an urgent problem to be solved in the field of seismic resistance of water conservancy projects.

[0003] Technical reasons for this problem: ① Complexity of earthquake action: The multi-directional action (horizontal, vertical) and non-uniformity of seismic waves make the downstream slope break part of the gravity dam bear a complex stress state and is prone to cracks. The duration and intensity of ground motion have a significant impact on the dynamic response of the dam body, and existing design methods are difficult to accurately simulate the response of the dam body under earthquake action. ② Weak links in the dam body structure: The amplification effect of ground motion acceleration in the upper part of the dam is obvious, and the downstream slope break part is usually designed as a relatively thin structure, and its crack resistance performance is relatively weak.

[0004] Solutions and deficiencies of the prior art:

[0005] ① Prestressed anchor cable reinforcement, by setting prestressed anchor cables inside the dam body to increase the anti-sliding ability of the dam body. For example, the patent application document with the application number CN2024020870520.7 proposes a seismic reinforcement structure for a gravity dam with a downstream inclined foundation surface, and the anti-sliding ability of the dam body is improved through prestressed anchor cables. Deficiencies of this document: Although prestressed anchor cables can effectively increase the anti-sliding ability of the dam body, their ability to recover the deformation of the dam body after an earthquake is limited, and the construction is complex and the cost is high.

[0006] ② Double dam foundation drainage galleries, by setting double dam foundation drainage galleries to drain the seepage water behind the curtain and reduce the uplift pressure of the dam foundation. For example, the double dam foundation drainage gallery design mentioned in the patent application document with the application number CN2024020870520.7. Deficiencies of this document: Although the drainage gallery can effectively reduce the uplift pressure of the dam foundation, it mainly only has an effect on the middle and lower parts of the dam body, and the control of dam body cracks and the effect of post-earthquake deformation recovery are not obvious, and the construction difficulty is relatively large.

[0007] ③ The transverse joint grouting technology enhances the connection strength between dam sections and reduces the tensile stress under earthquake action by setting spherical keyway molds at the transverse joints and grouting. For example, the patent application document with the application number CN2024010455117.2 proposes a transverse joint spherical keyway grouting structure. The deficiency of this document is that although the transverse joint grouting technology can enhance the connection strength between dam sections, its ability to restore the deformation of the dam body after an earthquake is limited, and strict control of the grouting quality is required during the construction process.

[0008] Although the existing reinforcement measures have improved the seismic resistance of the dam body to a certain extent, their ability to restore the deformation of the dam body after an earthquake is limited, it is difficult to restore the initial state of the dam body, and insufficient attention is paid to the seismic safety of the weak parts of the dam neck. Therefore, an anti-seismic structure is needed to overcome the problems existing in the field of seismic performance analysis of hydraulic engineering. Summary of the Invention

[0009] The present invention provides a preset anti-seismic structure for the downstream slope of a gravity dam and its anti-seismic method, which solves the technical problems that the downstream slope of the gravity dam is prone to damage under earthquake conditions and the crack development is difficult to predict.

[0010] The present invention is achieved through the following technical solutions.

[0011] A preset anti-seismic structure for the downstream slope of a gravity dam provided by the present invention includes a dam body and a reset device. A slit is provided on the dam body, and the reset device is arranged inside the dam body.

[0012] Preferably, the reset device includes a first connection panel, a second connection panel and a plurality of connection cables. One end of the connection cable is connected through the first connection panel, and the other end of the connection cable is connected through the second connection panel. The reset device is arranged near the slit.

[0013] Preferably, the connection cable is tightly connected to the first connection panel through a first bolt, and the connection cable is tightly connected to the second connection panel through a second bolt.

[0014] Preferably, the slit is located between the first connection panel and the second connection panel, and the connection cable passes through the slit.

[0015] Preferably, the width of the slit is greater than the widths of the first connection panel and the second connection panel.

[0016] Preferably, the materials of the first connection panel, the second connection panel and the connection cable are all alloys.

[0017] Preferably, the alloy includes one or two of Ti-Al-Cr alloy and Ni-Ti alloy.

[0018] Preferably, the slit is horizontally arranged at the junction of the vertical surface and the inclined surface of the dam body.

[0019] Preferably, a water baffle is arranged at the opening of the slit.

[0020] An earthquake resistance method for a preset earthquake resistance structure of a downstream slope of a gravity dam includes the following steps:

[0021] When the dam body is built, slits and reset devices are preset. The dam body is combined into a dam through multiple connections. Under normal working conditions, the slits and the reset devices arranged in cooperation with them are in the initial in-situ state. The water baffle forms a sealing protection for the slits, blocking the infiltration of external water bodies;

[0022] When an earthquake occurs, the dam body area undergoes directional deformation based on the preset slit expansion path, and the reset device restricts the displacement of the dam body through the tensile deformation of the connecting cable;

[0023] After the earthquake action terminates, the reset device drives the deformation interface of the slit to achieve closing and reset through the shape recovery driving force generated by the connecting cable. This self-resetting process restores the dam body structure to its initial geometric shape.

[0024] The beneficial effects of the present invention are as follows:

[0025] 1. The present invention guides the direction of crack formation and the deformation direction of the dam body during an earthquake by presetting slits, reducing the destructive effect of the earthquake on the dam body. The deformation of the dam body is mainly concentrated in the preset slit area, which is beneficial to protecting the overall structure of the dam body, thereby reducing the structural damage of the dam body and facilitating the repair according to the actual situation of the cracks after the earthquake and restoring the function of the dam body.

[0026] 2. On the basis of presetting slits, in order to further improve the earthquake resistance performance of the dam body and ensure the safety of the overall operation of the dam, a shape memory alloy reset device is installed. Through the shape memory effect of the shape memory alloy, the deformation of the dam body can be reset to a certain extent, reducing the workload and cost of post-earthquake repair, thereby further enhancing the earthquake resistance performance of the dam body and the safety of the overall operation of the dam.

[0027] 3. The preset shape memory alloy reset horizontal joint earthquake resistance technology for the downstream slope of the gravity dam provided by the present invention has a simple structure, convenient construction and installation, and relies on the excellent corrosion resistance and fatigue resistance of the shape memory alloy, and can work stably for a long time under harsh environmental conditions without frequent replacement or complex maintenance operations, providing a new solution for the earthquake resistance design of the gravity dam. Description of the Drawings

[0028] Figure 1 is a three-dimensional schematic diagram of the present invention;

[0029] Figure 2 is a cross-sectional schematic diagram of the present invention;

[0030] Figure 3It is a schematic cross-sectional view of the reset device of the present invention;

[0031] Figure 4 It is a three-dimensional schematic diagram of the reset device of the present invention;

[0032] In the figure: 1 - slit, 2 - reset device, 201 - first connection panel, 202 - second connection panel, 203 - connection cable, 204 - first bolt, 205 - second bolt, 3 - water baffle, 4 - dam body, 401 - vertical surface, 402 - inclined surface. Specific embodiments

[0033] The technical solution of the present invention will be further described below, but the scope of protection claimed is not limited thereto.

[0034] Example:

[0035] As Figures 1 to 4 shown, an earthquake-resistant structure with a preset downstream slope of a gravity dam includes a dam body 4 and a reset device 2. A slit 1 is provided on the dam body 4, and the reset device 2 is arranged inside the dam body 4.

[0036] The reset device 2 includes a first connection panel 201, a second connection panel 202 and a plurality of connection cables 203. One end of the connection cable 203 is connected through the first connection panel 201, and the other end of the connection cable 203 is connected through the second connection panel 202. The reset device 2 is arranged near the slit 1.

[0037] The connection cable 203 is tightly connected to the first connection panel 201 through the first bolt 204, and the connection cable 203 is tightly connected to the second connection panel 202 through the second bolt 205.

[0038] The slit 1 is located between the first connection panel 201 and the second connection panel 202, and the connection cable 203 passes through the slit 1.

[0039] The width of the slit 1 is greater than the widths of the first connection panel 201 and the second connection panel 202. The first connection panel 201 and the second connection panel 202 are aligned with the slit 1 and arranged in parallel.

[0040] The materials of the first connection panel 201 and the second connection panel 202 are both Ti - Al - Cr alloy, and the material of the connection cable 203 is Ni - Ti alloy. Ti - Al - Cr alloy and Ni - Ti alloy are shape memory alloys and can recover their initial shapes after a certain deformation.

[0041] The slit 1 is horizontally arranged at the junction of the vertical surface 401 and the inclined surface 402 of the dam body 4. The stress at this position is relatively high during an earthquake, and the setting of the slit 1 is convenient for controlling the propagation path of cracks.

[0042] A water baffle 3 is arranged at the opening of the slit 1.

[0043] An earthquake resistance method for a preset seismic structure with a downstream slope break in a gravity dam, comprising the following steps:

[0044] When the dam body 4 is constructed, a slit 1 and a reset device 2 are preset. The reset device 2 is cast and embedded in the dam body 4. Multiple dam bodies 4 are connected and combined to form a dam to control the length of crack generation. Under normal working conditions, the slit 1 and the reset device 2 arranged in cooperation therewith are in the in-situ initial state. The water retaining plate 3 is prepared from a high waterproof polymer compound to form a sealing protection for the slit 1 and prevent external water from seeping in;

[0045] When an earthquake occurs, the dam body 4 area generates directional and controllable deformation based on the preset expansion path of the slit 1. The reset device 2 restricts the displacement of the dam body 4 through the tensile deformation of the connecting cable 203, dissipates seismic energy through the plastic deformation of the shape memory alloy material, and effectively limits the structural displacement within the preset safety threshold;

[0046] After the earthquake action terminates, the reset device 2 generates a shape recovery driving force based on the phase change characteristics of the shape memory alloy through the connecting cable 203, and drives the deformation interface of the slit 1 to achieve progressive closing and resetting. This self-resetting process enables the dam body 4 structure to initially return to the initial geometric shape, providing a reliable structural basis for subsequent safety assessment and necessary repair measures.

Claims

1. A preset seismic structure with a downstream slope break for a gravity dam, characterized in that: It includes a dam body (4) and a reset device (2). A slit (1) is provided on the dam body (4), and the reset device (2) is arranged inside the dam body (4).

2. The preset seismic structure with a downstream slope break of a gravity dam according to claim 1, characterized in that: The reset device (2) includes a first connection panel (201), a second connection panel (202) and a plurality of connection cables (203). One end of each connection cable (203) is connected through the first connection panel (201), and the other end of the connection cable (203) is connected through the second connection panel (202). The reset device (2) is arranged near the slit (1).

3. The aseismic structure with a pre-set downstream slope break for a gravity dam according to claim 2, characterized in that: The connection cable (203) is tightly connected to the first connection panel (201) through a first bolt (204), and the connection cable (203) is tightly connected to the second connection panel (202) through a second bolt (205).

4. The preset anti-seismic structure with a downstream slope break of a gravity dam according to claim 2, characterized in that: The slit (1) is located between the first connection panel (201) and the second connection panel (202), and the connection cable (203) is arranged through the slit (1).

5. The preset seismic structure with a downstream slope break of a gravity dam according to claim 2, characterized in that: The width of the slit (1) is greater than the widths of the first connection panel (201) and the second connection panel (202).

6. The aseismic structure with a pre - set downstream slope break of a gravity dam according to claim 2, characterized in that: The materials of the first connection panel (201), the second connection panel (202) and the connection cable (203) are all alloys.

7. The aseismatic structure with a pre-set downstream slope break for a gravity dam according to claim 6, characterized in that: The alloy includes one or two of Ti-Al-Cr alloy and Ni-Ti alloy.

8. The preset seismic structure with a downstream slope break of a gravity dam according to claim 1, characterized in that: The slit (1) is horizontally arranged at the junction of the vertical surface (401) and the inclined surface (402) of the dam body (4).

9. The preset seismic structure with a downstream slope break of a gravity dam according to claim 1, characterized in that: A water retaining plate (3) is arranged at the opening of the slit (1).

10. An earthquake-resistant method for the earthquake-resistant structure with a preset downstream slope break of a gravity dam as described in any one of claims 1-9, characterized in that, It includes the following steps: When the dam body (4) is constructed, the slit (1) and the reset device (2) are preset. Multiple dam bodies (4) are connected and combined to form a dam. Under normal working conditions, the slit (1) and the reset device (2) arranged in cooperation with it are in the in-situ initial state, and the water retaining plate (3) forms a sealed protection for the slit (1) to prevent external water from seeping in; When an earthquake occurs, the dam body (4) area undergoes directional deformation based on the preset expansion path of the slit (1), and the reset device (2) restricts the displacement of the dam body (4) through the tensile deformation of the connection cable (203); After the earthquake action terminates, the reset device (2) drives the deformation interface of the slit (1) to close and reset through the shape recovery driving force generated by the connection cable (203). This self-resetting process restores the structure of the dam body (4) to its initial geometric shape.

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