Anti-seismic concrete gravity dam and construction method thereof

Abstract

The present application relates to the technical field of concrete gravity dam, in particular to an anti-seismic concrete gravity dam and a construction method thereof. The dam body main body comprises a plurality of dam body units arranged in sequence along the dam axis direction, and a concave-convex connecting interface is arranged between the bottom of the dam body unit and the dam foundation; a first flexible connecting layer is arranged at the concave-convex connecting interface; a second flexible connecting layer is used for buffering the relative displacement of the dam section and dissipating vibration energy; an inertia energy dissipation unit comprises a damping counterweight block for absorbing and dissipating seismic energy; and a seepage-proof water-stopping unit comprises a first water-stopping element, a second water-stopping element and a third water-stopping element. The first flexible connecting layer, the second flexible connecting layer and the inertia energy dissipation unit gradually reduce the transmission of seismic energy, the mechanical embedded effect of the concave-convex connecting interface is used to ensure the anti-sliding stability, and the annular seepage-proof system formed by the two water-stopping elements of the transverse joint and the bottom water-stopping element ensures the seepage-proof closure, so that the three functions of shock absorption, anti-sliding and seepage-proof under strong earthquake are realized.

Description

Technical Field

[0001] This invention relates to the field of concrete gravity dam technology, and more specifically, to an earthquake-resistant concrete gravity dam and its construction method. Background Technology

[0002] As inland hydropower resources become increasingly saturated, my country's hydropower construction focus has gradually shifted to high-altitude, high-seismic-intensity regions such as the Northwest and Southwest. Concrete gravity dams, as one of the three traditional dam types (gravity dams, arch dams, and earth-rock dams), have undergone long-term engineering practice, and their design and construction techniques are quite mature. However, under high seismic intensity conditions, the seismic fortification of gravity dams remains a prominent challenge. The main difficulty lies in the fact that gravity dams rely on their own weight to maintain anti-sliding and anti-overturning stability, and the dam body and foundation are usually rigidly connected to ensure good contact and overall stress distribution. While this rigid connection is beneficial for strengthening the dam foundation bond, under seismic action, the vibrational energy of the bedrock is transmitted upwards to the dam body with almost no attenuation, resulting in a significant amplification of the dam body's dynamic response. However, if the bond between the dam body and the bedrock is poor, it can easily lead to contact leakage and even concentrated seepage channels, threatening the safety of the project. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides an earthquake-resistant concrete gravity dam and its construction method, which solves the problems of rigid connection of gravity dams leading to no attenuation of seismic energy transmission and drastic amplification of dam dynamic response, as well as the difficulty in simultaneously ensuring anti-sliding stability and seepage prevention at the contact surface when flexible seismic measures are introduced.

[0004] On one hand, the present invention provides an earthquake-resistant concrete gravity dam, comprising: The dam body is a main body comprising multiple dam body units arranged sequentially along the dam axis. Each dam body unit comprises multiple dam segments arranged sequentially along the upstream and downstream directions. A concave-convex connection interface is provided between the bottom of the dam body unit and the dam foundation. The connecting unit includes a first flexible connecting layer and a second flexible connecting layer. The first flexible connecting layer is disposed at the concave-convex connecting interface to isolate the transmission of seismic energy. The second flexible connecting layer is disposed between adjacent dam sections within the same dam body unit to buffer the relative displacement of the dam sections and dissipate vibration energy. An inertial energy dissipation unit is located inside the dam section in the middle of the dam body unit. The inertial energy dissipation unit includes a damping counterweight for absorbing and dissipating seismic energy. The seepage-proof and water-stopping unit includes a first water-stopping component, a second water-stopping component, and a third water-stopping component. The first water-stopping component and the second water-stopping component are both disposed at the transverse joint between adjacent dam body units. The first water-stopping component is disposed on the water-facing side of the adjacent dam body unit at the transverse joint, and the second water-stopping component is disposed between adjacent dam sections of the adjacent dam body units at the transverse joint. The third water-stopping component is horizontally disposed between the dam foundation and the main body of the dam.

[0005] Preferably, each dam unit includes dam section A, dam section C and dam section B arranged sequentially along the upstream and downstream directions, and the inertial energy dissipation unit is located inside dam section C.

[0006] Preferably, the second water-stopping element includes a rubber water-stop and a spare rubber water-stop; the rubber water-stop is located on the backwater side of the adjacent A dam section and on the backwater side of the adjacent B dam section; the spare rubber water-stop is located on at least one side of the adjacent C dam section; both the first water-stopping element and the third water-stopping element are copper water-stopping elements, the first water-stopping element is located on the water-facing side of the adjacent A dam section and on the water-facing side of the adjacent B dam section, the third water-stopping element is located in the concrete cushion layer and close to the bedrock of the dam foundation, and both ends of the third water-stopping element are respectively connected to the corresponding first water-stopping element to form a closed annular anti-seepage ring.

[0007] Preferably, both the first flexible connecting layer and the second flexible connecting layer include a rubber damping layer, multiple springs, and multiple connecting steel plates; each spring is embedded inside the rubber damping layer, and both ends of the spring extend outside the rubber damping layer and are respectively connected to the corresponding connecting steel plate, and the connecting steel plate extends into the corresponding concrete component to achieve anchoring; the rubber waterstop of the second waterstop and the rubber damping layer of the first flexible connecting layer are sealed together by vulcanization welding.

[0008] Preferably, the rubber damping layer of the second flexible connecting layer is further provided with a waterproof flange, which is fitted and covers the joint between the rubber damping layer and the corresponding concrete component.

[0009] Preferably, the first flexible connecting layer is laid at the concave-convex connecting interface and forms a sawtooth structure with the concave-convex connecting interface. The first flexible connecting layer is provided with a reserved opening for concrete pouring, and the reserved opening is sealed by a sealing component after the pouring is completed.

[0010] Preferably, the inertial energy dissipation unit includes: A damping counterweight chamber is located inside the C-section dam, and the damping counterweight block is suspended on the side wall of the damping counterweight chamber. A limiter is provided on the side wall of the damping counterweight chamber to limit the swing amplitude of the damping counterweight block.

[0011] Preferably, the inertial energy dissipation unit further includes a steel beam and a winch. The steel beam is located at the top of the damping counterweight chamber, and the damping counterweight is suspended from the steel beam by a steel cable. The winch is connected to the damping counterweight via the steel cable and is used to lift the damping counterweight to the design height. The damping counterweight chamber is also equipped with a maintenance ladder, which extends to the top of the dam through a maintenance well.

[0012] Preferably, when the dam unit is an overflow dam section, the downstream water-facing surface of the B dam section is provided with an erosion-resistant and wear-resistant concrete layer; when the encountered seismic action exceeds the design intensity, the A dam section and the B dam section are damaged first as sacrificial dam sections to dissipate the seismic energy.

[0013] On the other hand, the present invention also provides a construction method for the above-mentioned seismic-resistant concrete gravity dam, comprising the following steps: S1: Excavate the foundation of the dam body unit, lay the third water-stopping component horizontally on the foundation, lay the first flexible connecting layer above the third water-stopping component, pour the concrete cushion layer through the concrete pouring port reserved on the first flexible connecting layer, and make the upper surface of the concrete cushion layer form an uneven structure. After the pouring is completed, seal the concrete pouring port. S2: At the transverse joint between adjacent dam units, a first water-stopping element is vertically laid along the water-facing side of the adjacent dam section A and the adjacent dam section B, and a second flexible connecting layer and a second water-stopping element are laid along the backwater side of the adjacent dam section A and the adjacent dam section B; the bottom end of the first water-stopping element is sealed to the third water-stopping element, and the second water-stopping element is sealed to the first flexible connecting layer. S3: The A, C, and B sections of the dam unit are poured in sections; the bottom of the dam unit matches the concave-convex structure shape of the upper surface of the concrete cushion to form a concave-convex connection interface; wherein, self-compacting concrete is poured on the upstream side of the A section and the downstream side of the B section, and rockfill concrete is poured on the remaining parts of the A section, the remaining parts of the B section, and the C section. S4: Install inertial energy dissipation units inside dam section C; S5: Continue pouring the remaining concrete up to the top of the dam; S6: Repeat steps S1 to S5 above to complete the pouring construction of the remaining dam body units.

[0014] The beneficial technical effects of this invention are as follows: This invention provides a seismic-resistant concrete gravity dam that utilizes a first flexible connecting layer at the concave-convex interface, a second flexible connecting layer between adjacent dam sections within the same dam unit, and an inertial energy dissipation unit 3 located within the middle dam section to form a three-tiered seismic mitigation system of blocking, buffering, and energy dissipation. When seismic waves propagate upwards from the bedrock, the first flexible connecting layer acts as an energy-blocking barrier at the bottom of the dam, significantly weakening the peak seismic energy transmitted upwards to the dam. Even if some energy bypasses the first flexible connecting layer and enters the dam, the second flexible connecting layer further absorbs the energy of relative motion between adjacent dam sections through elastic deformation and damping, preventing localized stress concentration caused by rigid collisions. When the remaining energy drives the dam to sway as a whole, the damping counterweight of the inertial energy dissipation unit oscillates in the opposite direction to the dam's vibration, further dissipating the residual vibration energy through its own inertial reaction force. Through the synergistic effect of these three layers, seismic energy is progressively reduced along the transmission path, significantly suppressing the dam's acceleration response and crest displacement, thus mitigating the problem of drastic amplification of seismic response in traditional rigidly connected dams. Its concave-convex interface has a non-planar morphological feature, forming mechanical embedment resistance in the horizontal direction. When the first flexible connection layer undergoes vertical elastic deformation during an earthquake, the concave-convex structure of this interface can still provide anti-sliding capacity in the horizontal direction, preventing the dam body from sliding along the bedrock surface. This solves the problem that flexible seismic resistance measures cannot simultaneously ensure anti-sliding stability. Simultaneously, the first and second water-stopping components of the seepage prevention and water-stopping unit are respectively installed along the water-facing and backwater-facing sides of the transverse joint between adjacent dam units, forming two vertical seepage barriers perpendicular to the dam axis; the third water-stopping component is horizontally installed between the dam foundation and the main dam body, solving the problem of horizontal seepage at the bottom contact surface. Through the spatially staggered arrangement and sealed connection of multiple water-stopping components, the integrity and reliability of the dam seepage prevention system under seismic conditions are ensured.

[0015] In summary, the earthquake-resistant concrete gravity dam of the present invention reduces the transmission of seismic energy through a first flexible connecting layer, a second flexible connecting layer, and an inertial energy dissipation unit. At the same time, it utilizes the mechanical embedding effect of the concave-convex connection interface to ensure anti-sliding stability, and ensures seepage prevention and sealing by using two water-stopping components on the water-facing and back surfaces of the transverse joint and the bottom horizontal water-stopping component to form a ring-shaped anti-seepage system. It realizes the three major functions of shock reduction, anti-sliding and seepage prevention under strong earthquake action, and improves the seismic safety and engineering reliability of gravity dams in high-intensity areas. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the dam axis of an earthquake-resistant concrete gravity dam according to one embodiment of the present invention; Figure 2 for Figure 1 Sectional view 1-1; Figure 3 for Figure 2 Enlarged view of point B; Figure 4 for Figure 2 Sectional view 2-2; Figure 5 for Figure 2 Sectional view 3-3; Figure 6 for Figure 1 Sectional view 4-4; Figure 7 for Figure 1 Sectional view 5-5; Figure 8 This is a schematic diagram of the structure of the second flexible connection layer in one embodiment of the present invention; Figure 9 for Figure 8 AA sectional view.

[0017] Explanation of reference numerals in the attached figures: 1-Dam body unit; 01-Concave-convex connection interface; 02-Transverse joint; 11-Dam section A; 12-Dam section C; 13-Dam section B; 131-Impact and wear-resistant concrete layer; 21-First flexible connection layer; 22-Second flexible connection layer; 201-Rubber damping layer; 202-Spring; 203-Connecting steel plate; 204-Waterproof flange; 3-Inertial energy dissipation unit; 31-Damping counterweight chamber; 32-Damping counterweight block; 33-Limiter; 34-Steel beam; 35-Maintenance ladder; 41-First waterstop; 42-Second waterstop; 43-Third waterstop; 421-Rubber waterstop; 422-Spare rubber waterstop; 5-Concrete cushion layer. Detailed Implementation

[0018] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0019] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0020] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0021] It should be noted that transverse joint 02 is a vertical structural joint along the dam axis, extending from the left bank to the right bank, dividing the dam body into multiple independent dam body units 1. In engineering, it is often referred to as a temperature joint or expansion joint. Transverse joint 02 runs through the entire dam cross-section and is a natural weak channel for upstream water pressure to seep downstream. Simultaneously, adjacent dam body units 1 will inevitably experience relative displacement due to temperature changes, uneven foundation settlement, and seismic activity. If the waterproofing structure cannot adapt to these deformations, it is easily torn or sheared, forming concentrated seepage channels and threatening the long-term safe operation of the dam. Therefore, a waterproofing structure must be installed on transverse joint 02. The waterproofing structure is a continuous sealing component mounted on both sides of adjacent dam body units 1 and along transverse joint 02, covering the entire surface of transverse joint 02 to seal the seepage path.

[0022] Please see Figures 1 to 4 and Figure 6On one hand, embodiments of the present invention provide an earthquake-resistant concrete gravity dam, comprising a dam body, connecting units, inertial energy dissipation units 3, and seepage prevention and water-stopping units. The dam body includes multiple dam body units 1 arranged sequentially along the dam axis, each dam body unit 1 including multiple dam segments arranged sequentially along the upstream and downstream directions, and a concave-convex connection interface 01 is provided between the bottom of the dam body unit 1 and the dam foundation; the connecting unit includes a first flexible connecting layer 21 and a second flexible connecting layer 22, the first flexible connecting layer 21 being disposed at the concave-convex connection interface 01 for isolating the transmission of seismic energy; the second flexible connecting layer 22 being disposed between adjacent dam segments within the same dam body unit 1 for buffering the relative displacement of the dam segments and dissipating seismic energy. The vibration energy is dissipated; the inertial energy dissipation unit 3 is located inside the middle section of the dam body unit 1. The inertial energy dissipation unit 3 includes a damping counterweight 32, which is used to absorb and dissipate seismic energy; the seepage prevention and water-stopping unit includes a first water-stopping component 41, a second water-stopping component 42 and a third water-stopping component 43; the first water-stopping component 41 is located on the water-facing side of the adjacent dam body unit 1 at the transverse joint 02, the second water-stopping component 42 is located between the adjacent dam sections of the adjacent dam body unit 1 at the transverse joint 02; the third water-stopping component 43 is horizontally located between the dam foundation and the main body of the dam.

[0023] It should be noted that in this embodiment, a three-stage damping system is constructed, consisting of a first flexible connecting layer 21 located at the concave-convex connection interface 01, a second flexible connecting layer 22 located between adjacent dam sections within the same dam unit 1, and an inertial energy dissipation unit 3 located within the middle dam section. This system constitutes blocking, buffering, and energy dissipation. When seismic waves propagate upwards from the bedrock, the first flexible connecting layer 21, acting as a flexible barrier between the bottom of the dam and the bedrock, utilizes its own material damping characteristics to weaken the peak seismic energy transmitted upwards to the dam. Furthermore, the second flexible connecting layer 22, located between adjacent dam sections within the same dam unit 1, absorbs the relative motion energy between dam sections through interlayer shear deformation when an earthquake causes asynchronous relative swaying between adjacent dam sections, effectively preventing local stress concentration and structural damage caused by rigid collisions. The inertial energy dissipation unit 3, located within the middle dam section, generates a swaying motion opposite to the direction of dam movement during vibration, further dissipating residual vibration energy through inertial reaction force and reducing the overall displacement response of the dam. Through the coordinated operation of the above three layers, seismic energy is gradually reduced along the transmission path, solving the problem of drastic amplification of dynamic response caused by the lack of energy attenuation in rigidly connected dam bodies.

[0024] The concave-convex interface 01 serves as a non-planar joint surface between the bottom of dam unit 1 and the dam foundation. Its undulating shape provides a mechanical embedding effect in the horizontal direction. When the first flexible connection layer 21 undergoes vertical deformation during an earthquake, the concave-convex structure of this interface still provides horizontal anti-sliding resistance to the dam body, preventing it from sliding along the bedrock surface and compensating for the shortcomings of traditional smooth contact surfaces that rely solely on friction. Simultaneously, the first flexible connection layer 21, laid at the concave-convex interface 01, retains the energy absorption function of the flexible layer while maintaining a tight fit between the dam body and the bedrock by adhering to the concave-convex interface, effectively balancing shock absorption and anti-sliding stability.

[0025] The seepage prevention and water-stopping unit employs multi-layered protection. The first water-stopping element 41 is located on the water-facing side of the adjacent dam body unit 1 at the transverse joint 02. The second water-stopping element 42 is located between adjacent dam sections of the adjacent dam body unit 1 at the transverse joint 02. The third water-stopping element 43 is horizontally positioned between the dam foundation and the main dam body to address seepage at the bottom horizontal contact surface. The first water-stopping element 41 is positioned close to the water body to directly block water head pressure, while the second water-stopping element 42 serves as a backup seepage prevention line. Together, they form a multi-level seepage prevention zone along the longitudinal direction of the transverse joint 02. The third water-stopping element 43 is horizontally positioned at the dam foundation contact surface, with its two ends connected to the first water-stopping elements 41 on both sides. The first water-stopping elements 41 on both sides refer to the upstream and downstream water-facing sides, forming a closed annular seepage prevention ring that spatially cuts off the possible path for seepage from the transverse joint 02 to extend to the bottom contact surface. This spatially staggered seepage prevention system effectively solves the problem of rigid water-stopping elements easily failing at flexible deformation interfaces, ensuring the complete maintenance of the seepage prevention function of the structure under seismic deformation conditions.

[0026] In one embodiment of the present invention, each dam unit 1 includes dam section A 11, dam section C 12 and dam section B 13 arranged sequentially along the upstream and downstream directions, and the inertial energy dissipation unit 3 is disposed inside dam section C 12.

[0027] It should be noted that dam segment A 11 is the dam segment closer to the upstream side, dam segment B 13 is the dam segment closer to the downstream side, and dam segment C 12 is the dam segment located in the middle of dam unit 1. Self-compacting concrete is poured on the upstream faces of both dam segments A 11 and B 13. By dividing dam unit 1 into three independent dam segments and using the second flexible connection layer 22 to flexibly isolate adjacent dam segments, the dynamic response of the dam body under seismic loading is decoupled by region. In the initial stage of an earthquake, dam segments A 11 and B 13, located on the outer edge of the structure, are able to absorb and withstand some of the seismic inertial forces first. Through relative displacement with dam segment C 12 via the second flexible connection layer 22, some vibrational energy is dissipated through damping deformation, thus providing seismic isolation protection for dam segment C 12 located in the core area.

[0028] Multiple inertial energy dissipation units 3 can be installed inside dam segment 12 (C section). Dam segment 12 is located near the center of mass and geometric center of the dam body, where the seismic response displacement is typically minimal and the constraint is strongest. Placing damping counterweights 32 here can suppress the first-order bending-shear vibration mode of the dam body as a whole, making the swing of the damping counterweights 32 more precise during strong earthquakes, thereby maximizing the reduction of peak displacement at the dam crest. Furthermore, the upstream faces of dam segments 11 (A section) and 13 (B section) are the main water-retaining structures that directly bear the water pressure from the upstream and downstream sides. During strong earthquakes, they are highly susceptible to cracking due to concentrated bending and tensile stress. Self-compacting concrete is poured on the upstream faces of both dam segments 11 and 13. Utilizing the characteristics of self-compacting concrete—no vibration required, high fluidity, and high density—a dense and uniform surface structure can be formed between the complex seismic structural layers, improving the crack resistance and seepage resistance of the dam's upstream face and effectively reducing the probability of through cracks and concentrated leakage on the upstream face under seismic conditions.

[0029] Please see Figure 7 In one embodiment of the present invention, the second water-stopping element 42 includes a rubber water-stop 421 and a spare rubber water-stop 422; the rubber water-stop 421 is disposed on the backwater side of the adjacent A dam section 11 and on the backwater side of the adjacent B dam section 13; the spare rubber water-stop 422 is disposed on at least one side of the adjacent C dam section 12 (i.e., the side closer to A dam section 11 and / or the side closer to B dam section 13); the first water-stopping element 41 and the third water-stopping element 43 are both copper water-stopping elements, the third water-stopping element 43 is disposed in the concrete cushion layer 5 and close to the bedrock of the dam foundation, and both ends of the third water-stopping element 43 are respectively connected to the corresponding first water-stopping element 41 to form an annular closed seepage prevention ring.

[0030] It should be noted that the first waterstop 41, as a copper waterstop, is arranged along the water-facing side of the transverse joint 02. The water-facing side includes the upstream water-facing side and the downstream water-facing side. Utilizing the good plasticity and excellent impermeability of copper, it directly bears the upstream water head pressure, forming the first rigid barrier of the seepage prevention system. The third waterstop 43, also a copper waterstop, is horizontally placed between the bedrock and the concrete cushion layer 5 of the dam foundation. Its two ends are respectively sealed and connected to the first waterstop 41 on the upstream and downstream water-facing sides, forming a closed annular seepage prevention ring. This seepage prevention ring completely seals the seepage path between the water-facing side of the transverse joint 02 and the bottom horizontal contact surface. Even if the dam body sways laterally or shifts vertically during an earthquake, this annular copper waterstop can still maintain the overall seal integrity due to the ductility and good tensile strength of copper, cutting off the downstream seepage channel. Meanwhile, the rubber waterstop 421 is installed on the backwater side of the adjacent A dam section 11 and on the backwater side of the adjacent B dam section 13. Its function is that during an earthquake, the rubber waterstop 421 and the second flexible connection layer 22 are both located on the backwater side of the transverse joint 02. Both have elastic deformation capabilities. When the adjacent dam body units 1 experience relative horizontal displacement or vertical reciprocating displacement due to an earthquake, the rubber waterstop 421 can synchronously undergo tensile or compressive deformation with the second flexible connection layer 22, thus avoiding the problem of rigid waterstops tearing and failing at the flexible deformation interface due to their inability to adapt to displacement. The backup rubber waterstop 422 is located on at least one side of the adjacent C dam section 12 (i.e., the side closer to A dam section 11 and / or B dam section 13), serving as a seepage prevention reserve system. Its main function is that, in the event of an extreme earthquake exceeding the design fortification intensity, if the first waterstop 41 or the rubber waterstop 421 suffers local damage, the backup rubber waterstop 422 can still serve as the last line of defense to maintain seepage prevention, thereby enhancing the seepage prevention safety redundancy of the seismic gravity dam under extreme conditions. Furthermore, in this embodiment, since the third waterstop 43 is connected to the first waterstop 41 to form a closed annular seepage prevention ring, and the rubber waterstop 421 is sealed to the flexible damping material of the first flexible connecting layer 21, the seepage prevention ring of the copper waterstop and the backwater rubber waterstop form a cross-lock in space, ultimately constituting a three-dimensional seepage prevention network. This allows the structure to adapt to the dynamic deformation of the flexible damping layer during strong earthquakes and maintain reliable long-term seepage prevention performance.

[0031] Please see Figure 8 , Figure 9 and Figure 3In one embodiment of the present invention, the first flexible connecting layer 21 and the second flexible connecting layer 22 both include a rubber damping layer 201, a plurality of springs 202 and a plurality of connecting steel plates 203; each spring 202 is embedded inside the rubber damping layer 201, and both ends of the spring 202 extend out of the rubber damping layer 201 and are respectively connected to the corresponding connecting steel plates 203, and the connecting steel plates 203 extend into the corresponding concrete components to achieve anchoring; the rubber waterstop 421 of the second waterstop 42 is sealed to the rubber damping layer 201 of the first flexible connecting layer 21 by vulcanization welding.

[0032] It should be noted that when seismic waves reach the concave-convex interface 01, the rubber damping layer 201 in the first flexible connection layer 21 first bears high-frequency vibration, which can directly dissipate some mechanical energy as heat energy. At the same time, the spring 202 embedded in the rubber damping layer 201 undergoes elastic deformation under compression or shear, temporarily storing the vibration energy in the form of elastic potential energy. Subsequently, it is released at a lower frequency during the rebound process, thereby achieving peak reduction of high-frequency energy and hysteresis of low-frequency response, so that the amplitude and spectral characteristics of the energy finally transmitted to the main body of the dam are effectively optimized. The connecting steel plate 203 extends into the corresponding concrete component to achieve anchoring, so that the flexible connection layer does not slip or detach under stress. This ensures the long-term positional stability and functional reliability of the flexible connection layer, and avoids collision or shear damage to adjacent components caused by excessive displacement of the flexible connection layer.

[0033] In addition, the second flexible connection layer 22 is located between adjacent dam sections within the same dam unit 1. Its core function is that when an earthquake causes asynchronous relative displacement between adjacent dam sections, the spring 202 in the second flexible connection layer 22 absorbs the relative motion energy between the dam sections through shear deformation, while the rubber damping layer 201 dissipates this energy synchronously through internal damping. This effectively controls the relative displacement between the dam sections, thereby avoiding local stress concentration and dam cracking caused by rigid collisions, and achieving vibration decoupling between the dam sections.

[0034] Based on this, the rubber waterstop 421 of the second waterstop 42 and the rubber damping layer 201 of the first flexible connecting layer 21 are sealed together by vulcanization welding. This ensures that the rubber waterstop 421 and the rubber damping layer 201 can expand and contract synchronously and rebound synchronously during an earthquake, avoiding tearing of the sealing interface caused by the incoordination of their deformation. This solves the problem that traditional rigid waterstops of gravity dams cannot adapt to displacement at flexible deformation interfaces and thus fail. At the same time, the homogeneous sealing surface formed by vulcanization welding creates a seamless transition between the horizontal and vertical directions, enabling the vertical seepage prevention system of the transverse joint 02 and the bottom horizontal seepage prevention system to achieve physical connection at the material level, effectively eliminating weak joints and seepage blind spots between the components in the waterstop structure.

[0035] In one embodiment of the present invention, the rubber damping layer 201 of the second flexible connecting layer 22 is further provided with a waterproof flange 204, which is attached to and covers the joint between the rubber damping layer 201 and the corresponding concrete component.

[0036] It should be noted that the waterproof flange 204 further enhances the seepage prevention reliability of the second flexible connection layer 22 at the transverse joint 02. Its core function is to solve the interfacial seepage problem caused by material differences and deformation incoordination between the flexible damping layer 201 and the concrete component. Specifically, the second flexible connection layer 22 is sandwiched between adjacent dam sections within the same dam unit 1. During an earthquake, when the adjacent dam sections undergo relative displacement, the rubber damping layer 201 of the second flexible connection layer 22 mainly absorbs vibration energy through shear deformation. At this time, there will inevitably be repeated sliding and compression between the rubber damping layer 201 and the concrete components on both sides. If the rubber damping layer 201 only relies on its own surface to contact the concrete, micro-cracks or peeling are easily generated at the interface after long-term repeated deformation, forming seepage channels. The waterproof flange 204 is fitted and covered at the joint between the rubber damping layer 201 and the corresponding concrete component. Utilizing its own flexible deformation capability, it moves synchronously with the rubber damping layer 201, closely following the opening and closing changes of the interface during an earthquake, effectively sealing any dynamic gaps that may occur. Meanwhile, the waterproof flange 204, as an extension of the rubber damping layer 201, can be integrally molded with the rubber damping layer 201 using the same vulcanization process, eliminating material seams between the flange and the damping layer and removing weak points caused by differences in material interfaces. Furthermore, the coverage area of ​​the waterproof flange 204 can be appropriately extended along the joint direction, providing continuous barrier protection for the interface between the flexible layer and the concrete component throughout the entire height of the transverse joint 02. Even if the second flexible connection layer 22 experiences local tearing or damage during an earthquake, the waterproof flange 204 can still serve as an auxiliary waterproofing layer to maintain its seepage prevention function.

[0037] In one embodiment of the present invention, a first flexible connecting layer 21 is laid on the concave-convex connecting interface 01 and forms a sawtooth structure with the concave-convex connecting interface 01. The first flexible connecting layer 21 is provided with a concrete pouring reserved opening, which is sealed by a sealing component after the pouring is completed.

[0038] It should be noted that the first flexible connecting layer 21 is fitted to the sawtooth-shaped arrangement of the concave-convex connecting interface 01. This sawtooth interface has a natural mechanical embedding effect in the horizontal direction. When the dam body is subjected to horizontal seismic forces, the inclined surface of the sawtooth will convert part of the horizontal thrust into a normal pressure along the inclined surface, thereby increasing the equivalent frictional resistance between the interfaces and inhibiting the tendency of the dam body to slide along the bedrock surface. At the same time, the sawtooth structure increases the contact area between the first flexible connecting layer 21 and the concrete compared to a smooth interface, making the stress distribution of the flexible layer more uniform under stress and avoiding tearing or damage caused by local stress concentration.

[0039] The pre-reserved concrete pouring opening allows concrete to be poured from the top surface of the first flexible connecting layer 21 into the serrated groove from top to bottom. Utilizing gravity and vibration during the pouring and compaction process, air within the groove is completely expelled, ensuring the concrete fills the serrated groove densely, ultimately forming a complete, continuous, and tightly fitted concave-convex interface 01 with the first flexible connecting layer 21. After pouring and compaction are completed and the initial setting strength is reached, the pre-reserved concrete pouring opening is sealed with a plug.

[0040] In one embodiment of the present invention, the inertial energy dissipation unit 3 further includes a damping counterweight chamber 31 and a limiter 33. The damping counterweight chamber 31 is located inside the C dam section 12, and the damping counterweight block 32 is suspended on the side wall of the damping counterweight chamber 31. The limiter 33 is located on the side wall of the damping counterweight chamber 31 and is used to limit the swing amplitude of the damping counterweight block 32.

[0041] It should be noted that when a strong earthquake occurs, dam segment 12, as the main structure, experiences horizontal acceleration due to the vibration of the bedrock. The damping counterweight 32, suspended on the sidewall, lags behind the movement of dam segment 12 in the initial stage of vibration due to its own inertia. Subsequently, under the combined action of gravity and inertial force, it oscillates around the suspension point, similar to a simple pendulum. During this process, the damping counterweight 32 converts some of the seismic energy into its own kinetic energy through oscillation and dissipates it through friction and damping effects at the suspension nodes. Essentially, it forms an inertial force inside the dam body that is opposite in phase to the vibration of the main structure, thus suppressing the acceleration response of dam segment 12. The limiter 33, located on the sidewall of the damping counterweight chamber 31, mechanically blocks the oscillation of the damping counterweight 32 when its amplitude reaches a preset threshold, limiting the oscillation within the design limits and preventing a hard collision between the damping counterweight 32 and the sidewall of the damping counterweight chamber 31.

[0042] In one embodiment of the present invention, the inertial energy dissipation unit 3 further includes a steel beam 34 and a winch. The steel beam 34 is located at the top of the damping counterweight chamber 31. The damping counterweight 32 is suspended on the steel beam 34 by steel cables. The winch is connected to the damping counterweight 32 by steel cables and is used to lift the damping counterweight 32 to the design height. The damping counterweight chamber 31 is also equipped with a maintenance ladder 35, which extends to the top of the dam through a maintenance well.

[0043] It should be noted that the steel beam 34 is fixedly connected to the internal structure of dam section 12 (such as the reinforced concrete walls or roof of dam section C). The steel beam 34 is located at the top of the damping counterweight chamber 31, serving as the load-bearing framework of the entire suspension system. Its core function is to provide a stable mechanical support for the suspension and oscillation of the damping counterweight 32. Simultaneously, the damping counterweight 32 is suspended from the steel beam 34 by steel cables. This suspension method provides the damping counterweight 32 with sufficient degrees of freedom, enabling it to generate an approximate pendulum-like reciprocating oscillation under the drive of horizontal seismic forces, thereby achieving efficient inertial reaction force output and energy dissipation.

[0044] The winch configuration allows for precise adjustment of the suspension height of the damping counterweight 32 during construction and maintenance. Specifically, the natural frequency of the damping counterweight 32 is inversely proportional to the cable length: the longer the suspension length, the lower the natural frequency of the damping counterweight 32; the shorter the suspension length, the higher the natural frequency of the damping counterweight 32. The maintenance ladder 35 and maintenance well provide safe and convenient access for maintenance personnel, ensuring that the inertial energy dissipation unit 3 maintains reliable operation throughout its entire life cycle, and preventing degradation or even failure of the damping function due to a lack of post-maintenance measures.

[0045] Please see Figure 5 In one embodiment of the present invention, when the dam unit 1 is an overflow dam section, the downstream water-facing surface of dam section B 13 is provided with an anti-erosion and wear-resistant concrete layer 131; when the earthquake action encountered exceeds the design intensity, dam sections A 11 and B 13 are damaged first as sacrificial dam sections to dissipate earthquake energy.

[0046] It should be noted that the erosion-resistant and wear-resistant concrete layer 131 is a functional structural layer configured based on the unique operating conditions of the spillway section. During flood season, the high-speed water flow carrying solid particles such as sand and gravel flows downstream of the upstream side of section B 13, generating strong erosion and abrasion effects on the dam surface. The erosion-resistant and wear-resistant concrete layer 131 is cast using high-strength, high-density erosion-resistant and wear-resistant materials and is attached to the downstream upstream side of section B 13. It can effectively resist the erosion and abrasion of water flow and sediment during flood discharge, protect the surface integrity of the main concrete structure of section B 13, and prevent dam surface spalling, aggregate exposure, or even structural section weakening due to long-term erosion, thereby ensuring the structural safety of the spillway section under flood discharge operation and seismic conditions.

[0047] Sections A (11) and B (13) are designated as sacrificial dam sections, their functional positioning based on an active defense logic of damage dissipation and core protection. In the event of an extreme earthquake exceeding the design intensity, the seismic input energy far exceeds the absorption capacity of conventional damping systems. Indiscriminately transmitting this energy to all dam sections could lead to irreversible and severe damage to the core structural area, section C (12), potentially threatening the overall stability of the dam. Designing sections A (11) and B (13) as sacrificial dam sections essentially creates energy dissipation buffer zones within the structural system. In the initial stages of an earthquake, sections A (11) and B (13) act as the first line of defense, absorbing and bearing some of the seismic inertial forces and impact energy. Through self-generated, controllable damage (such as crack propagation and localized crushing), they prevent the excessive seismic energy from being directly transmitted to section C (12). Meanwhile, dam sections A (section 11) and B (section 13) are located at the edges of dam unit 1. Even if controllable damage occurs, it will not rapidly affect the core structure and critical water-retaining sections of the dam, thus saving time and space for emergency rescue and post-disaster repair. During this process, the first flexible connection layer 21 and the second flexible connection layer 22 also work in concert: when dam sections A (section 11) and B (section 13) experience significant lateral displacement due to damage, the second flexible connection layer 22 can absorb some of the displacement energy through shear deformation and control the displacement transmission within an acceptable range, preventing the damage to the sacrificial dam section from rapidly spreading to dam section C (section 12).

[0048] This invention also includes the above-mentioned construction method for earthquake-resistant concrete gravity dams, comprising the following steps: S1: Excavate the foundation of dam unit 1, lay the third water-stop 43 horizontally on the foundation, lay the first flexible connection layer 21 above the third water-stop 43, pour the concrete cushion layer 5 through the concrete pouring port reserved on the first flexible connection layer 21, and make the upper surface of the concrete cushion layer 5 form a concave-convex structure. After the pouring is completed, seal the concrete pouring port. S2: Lay a first water-stopping element 41 along the water-facing side of the adjacent A dam section 11 and the adjacent B dam section 13, and lay a second flexible connecting layer 22 and a second water-stopping element 42 along the backwater side of the adjacent A dam section 11 and the adjacent B dam section 13; seal the bottom end of the first water-stopping element 41 to the third water-stopping element 43, and seal the second water-stopping element 42 to the first flexible connecting layer 21. S3: The A section 11, C section 12 and B section 13 of the dam body unit 1 are poured in sections. The bottom of the dam body unit 1 matches the concave and convex structure shape of the upper surface of the concrete cushion layer 5 to form a concave and convex connection interface 01. Among them, self-compacting concrete is poured on the upstream side of the A section 11 and the downstream side of the B section 13, and rockfill concrete is poured on the remaining parts of the A section 11, the remaining parts of the B section 13 and the C section 12. S4: Install an inertial energy dissipation unit 3 inside section 12 of dam C; S5: Continue pouring the remaining concrete up to the top of the dam; S6: Repeat steps S1 to S5 above to complete the pouring construction of the remaining dam unit 1.

[0049] In one embodiment of the present invention, a construction method for an earthquake-resistant concrete gravity dam includes the following steps: First, the foundation excavation of dam unit 1 is carried out. Since concrete gravity dams are usually constructed starting from the lowest section of the foundation, this embodiment preferably starts construction sequentially from dam unit 1 with the lowest elevation. After the foundation excavation is accepted, a third waterstop 43 is laid horizontally on the bedrock surface of the foundation, serving as the bottom horizontal seepage prevention layer.

[0050] Subsequently, a first flexible connecting layer 21 is laid above the third water-stopping component 43. The first flexible connecting layer 21 is laid at the concave-convex connection interface 01, and a concrete pouring port is reserved on it. A concrete pad layer 5 is poured into the sawtooth groove of the concave-convex connection interface 01 through the concrete pouring port. The concrete is fully filled into the sawtooth groove by gravity and vibration. After the concrete reaches the design strength, the concrete pouring port is sealed with a rubber stopper or other sealing component to form a complete concave-convex connection interface 01.

[0051] Then, the seepage prevention and vibration reduction structure is constructed at the transverse joint 02 between adjacent dam unit 1. A first waterstop 41, made of copper, is laid vertically along the water-facing side of the transverse joint 02, forming the main seepage barrier on the water-facing side of the transverse joint 02. Simultaneously, a second flexible connecting layer 22 and a second waterstop 42 are laid on the water-repellent side of the transverse joint 02. The second waterstop 42 includes a rubber waterstop 421 and a spare rubber waterstop 422. During construction, the bottom end of the first waterstop 41 is sealed to a horizontally positioned third waterstop 43, forming a closed annular seepage prevention ring between the copper waterstop on the water-facing side of the transverse joint 02 and the bottom horizontal copper waterstop. At the same time, the rubber waterstop 421 in the second waterstop 42 is sealed to the rubber vibration reduction layer 201 of the first flexible connecting layer 21 through vulcanization welding, integrating the vertical rubber waterstop with the bottom horizontal flexible vibration reduction layer at the material level to form a closed seepage prevention structure. Special attention should be paid to layered installation in this step. The height of each layer should be slightly higher than the thickness of the riprap concrete pouring layer, leaving welding positions to facilitate on-site vulcanization welding operations.

[0052] Next, the concrete for sections A (11), C (12), and B (13) of dam unit 1 will be poured in layers. Self-compacting concrete will be poured on the upstream side of section A (11) and the downstream side of section B (13), utilizing its characteristics of requiring no vibration and high fluidity to ensure the compactness and crack resistance of the surface concrete on the water-facing side. The remaining portions of section A (11), section B (13), and section C (12) will be poured with riprap concrete to leverage its advantages of large volume and low heat of hydration. During the pouring process, the second flexible connection layer 22 and rubber waterstop 421 at the transverse joint 02 should be continuously embedded in layers, extending upwards layer by layer as the concrete pouring height increases.

[0053] When the concrete is poured to the elevation of the damping counterweight chamber 31 near section C of the dam, formwork is erected along the side wall of the damping counterweight chamber 31, and limiters 33 are installed on the side wall. The function of the limiters 33 is to limit the swing amplitude of the damping counterweight block 32 and prevent the counterweight block from directly impacting the side wall of the damping counterweight chamber 31 under extreme seismic action. Subsequently, the damping counterweight block 32 is installed. The damping counterweight block 32 can be made of steel or reinforced concrete and is suspended from the steel beam 34 by steel cables. Concrete pouring continues upward. When the concrete reaches the elevation of the steel beam 34, the steel beam 34 and the winch are installed. The winch is connected to the damping counterweight block 32 by steel cables. After the steel beam 34 is installed and fixed, the winch is started to slowly lift the damping counterweight block 32 to the design height, suspending it inside the damping counterweight chamber 31.

[0054] During the above construction process, a maintenance ladder 35 needs to be installed in the damping counterweight chamber 31. The maintenance ladder 35 extends to the top of the dam through the maintenance well, so that maintenance personnel can enter the damping counterweight chamber 31 from the top of the dam for daily inspection and maintenance during the later operation and maintenance phase.

[0055] Subsequently, the remaining concrete of the dam unit 1 was poured in layers until the dam crest elevation was reached. At the same time, the second flexible connecting layer 22 and rubber waterstop 421 were buried layer by layer at the transverse joint 02 until the dam crest was completely sealed.

[0056] Finally, following the steps described above, the remaining dam body units 1 are poured and constructed. It should be noted that whether or not an inertial energy dissipation unit 3 is installed in each dam body unit 1 needs to be determined comprehensively based on the size of the specific dam section and the seismic fortification intensity. For dam sections with smaller size or better geological conditions, the damping counterweight chamber 31 may not be installed, thereby further reducing the project cost while meeting seismic safety requirements.

[0057] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A seismic-resistant concrete gravity dam, characterized in that, include: The dam body includes multiple dam body units (1) arranged sequentially along the dam axis. Each dam body unit (1) includes multiple dam sections arranged sequentially along the upstream and downstream directions. The bottom of the dam body unit (1) is provided with a concave-convex connection interface (01) between it and the dam foundation. The connecting unit includes a first flexible connecting layer (21) and a second flexible connecting layer (22). The first flexible connecting layer (21) is located at the concave-convex connecting interface (01) and is used to isolate the transmission of seismic energy. The second flexible connecting layer (22) is located between adjacent dam sections within the same dam body unit (1) and is used to buffer the relative displacement of the dam sections and dissipate vibration energy. An inertial energy dissipation unit (3) is located inside the dam section in the middle of the dam body unit (1). The inertial energy dissipation unit (3) includes a damping counterweight (32) for absorbing and dissipating seismic energy. The seepage prevention and water-stopping unit includes a first water-stopping component (41), a second water-stopping component (42), and a third water-stopping component (43); the first water-stopping component (41) is disposed on the water-facing side of the adjacent dam body unit (1) at the transverse joint (02), the second water-stopping component (42) is disposed between the adjacent dam sections of the adjacent dam body unit (1) at the transverse joint (02), and the third water-stopping component (43) is horizontally disposed between the dam foundation and the dam body.

2. The earthquake-resistant concrete gravity dam according to claim 1, characterized in that, Each dam unit (1) includes dam section A (11), dam section C (12) and dam section B (13) arranged sequentially along the upstream and downstream directions, and the inertial energy dissipation unit (3) is located inside dam section C (12).

3. The earthquake-resistant concrete gravity dam according to claim 2, characterized in that, The second water-stopping element (42) includes a rubber water-stop (421) and a spare rubber water-stop (422); the rubber water-stop (421) is located on the backwater side of the adjacent A dam section (11) and on the backwater side of the adjacent B dam section (13); the spare rubber water-stop (422) is located on at least one side of the adjacent C dam section (12); the first water-stopping element (41) and the third water-stopping element (43) are both copper water-stopping elements. The first water-stopping element (41) is located on the water-facing side of the adjacent A dam section (11) and on the water-facing side of the adjacent B dam section (13). The third water-stopping element (43) is located in the concrete cushion layer (5) and close to the bedrock of the dam foundation. Both ends of the third water-stopping element (43) are connected to the corresponding first water-stopping element (41) to form a closed annular seepage-proof ring.

4. The earthquake-resistant concrete gravity dam according to claim 3, characterized in that, Both the first flexible connecting layer (21) and the second flexible connecting layer (22) include a rubber damping layer (201), multiple springs (202) and multiple connecting steel plates (203); each spring (202) is embedded inside the rubber damping layer (201), and both ends of the spring (202) extend out of the rubber damping layer (201) and are respectively connected to the corresponding connecting steel plate (203), and the connecting steel plate (203) extends into the corresponding concrete component to achieve anchoring; the rubber waterstop (421) of the second waterstop (42) and the rubber damping layer (201) of the first flexible connecting layer (21) are sealed together by vulcanization welding.

5. The earthquake-resistant concrete gravity dam according to claim 4, characterized in that, The rubber damping layer (201) of the second flexible connecting layer (22) is also provided with a waterproof flange (204), which is attached to and covers the joint between the rubber damping layer (201) and the corresponding concrete component.

6. The earthquake-resistant concrete gravity dam according to claim 5, characterized in that, The first flexible connecting layer (21) is laid at the concave-convex connecting interface (01) and forms a sawtooth structure with the concave-convex connecting interface (01). The first flexible connecting layer (21) is provided with a reserved concrete pouring port, which is sealed by a sealing component after the pouring is completed.

7. The earthquake-resistant concrete gravity dam according to claim 2, characterized in that, The inertial energy dissipation unit (3) also includes: Damping counterweight chamber (31), the damping counterweight chamber (31) is located inside the C dam section (12), The damping counterweight (32) is suspended on the side wall of the damping counterweight chamber (31); Limiter (33), which is located on the side wall of the damping counterweight chamber (31), is used to limit the swing amplitude of the damping counterweight block (32).

8. The earthquake-resistant concrete gravity dam according to claim 7, characterized in that, The inertial energy dissipation unit (3) also includes a steel beam (34) and a winch. The steel beam (34) is located at the top of the damping counterweight chamber (31). The damping counterweight (32) is suspended on the steel beam (34) by a steel cable. The winch is connected to the damping counterweight (32) by the steel cable and is used to lift the damping counterweight (32) to the design height. The damping counterweight chamber (31) is also equipped with a maintenance ladder (35), which extends to the top of the dam through a maintenance well.

9. The earthquake-resistant concrete gravity dam according to claim 7, characterized in that, When the dam unit (1) is an overflow dam section, the downstream water-facing surface of the B dam section (13) is provided with an anti-erosion and wear-resistant concrete layer (131); when the earthquake action encountered exceeds the design intensity, the A dam section (11) and the B dam section (13) are damaged first as sacrificial dam sections to dissipate earthquake energy.

10. A construction method for a seismic-resistant concrete gravity dam as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1: Excavate the foundation of the dam body unit (1), lay the third water-stop (43) horizontally on the foundation, lay the first flexible connecting layer (21) above the third water-stop (43), pour the concrete cushion layer (5) through the concrete pouring port reserved on the first flexible connecting layer (21), and make the upper surface of the concrete cushion layer (5) form a concave-convex structure. After the pouring is completed, seal the concrete pouring port. S2: At the transverse joint (02) between adjacent dam body units (1), a first water-stopping element (41) is laid along the water-facing side of the adjacent A dam section (11) and the adjacent B dam section (13), and a second flexible connecting layer (22) and a second water-stopping element (42) are laid along the water-repellent side of the adjacent A dam section (11) and the adjacent B dam section (13); the bottom end of the first water-stopping element (41) is sealed to the third water-stopping element (43), and the second water-stopping element (42) is sealed to the first flexible connecting layer (21); S3: The A section (11), C section (12) and B section (13) of the dam unit (1) are poured in sections. The bottom of the dam unit (1) matches the concave-convex structure shape of the upper surface of the concrete cushion layer (5) to form a concave-convex connection interface (01). Among them, self-compacting concrete is poured on the upstream side of the A section (11) and the downstream side of the B section (13), and rockfill concrete is poured on the remaining part of the A section (11), the remaining part of the B section (13) and the C section (12). S4: An inertial energy dissipation unit (3) is installed inside the C dam section (12); S5: Continue pouring the remaining concrete up to the top of the dam; S6: Repeat steps S1 to S5 above to complete the pouring construction of the remaining dam body units (1).

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