A thin-layer seismic isolation foundation for nuclear power plants in high-intensity seismic zones and its construction method

Abstract

This invention discloses a thin-layer seismic isolation foundation for nuclear power plants in high-intensity seismic zones and its construction method. The seismic isolation foundation includes the nuclear power plant building floor slab and the outer walls of the nuclear power plant building. The floor slab has multiple pre-drilled grouting holes. A foundation pit is sealed below the floor slab, and a pile foundation is installed below the foundation pit. A single-layer pebble cushion layer is laid between the floor slab and the foundation pit. A shallow diaphragm wall is installed below the ground on the outer side of the outer walls of the nuclear power plant building. A tire buffer layer is installed between the outer walls and the shallow diaphragm wall. This invention, by laying a single-layer pebble cushion layer, allows the particles to roll under strong earthquakes, thus isolating the seismic force from further upward transmission and significantly reducing the dynamic response of the nuclear power plant building and reactor building. Point grouting is performed in certain areas of the cushion layer, forming a semi-rigid connection between the floor slab and the foundation pit, allowing the seismic isolation pebble cushion layer to fully exert its seismic isolation effect, while the tire buffer layer provides displacement recovery force.

Description

Technical Field

[0001] This invention relates to a seismic isolation foundation for buildings and its construction method, and more particularly to a thin-layer seismic isolation foundation for nuclear power plants in high-intensity seismic zones and its construction method. Background Technology

[0002] In seismically active regions, conventional energy sources such as hydropower and thermal power are limited by terrain and environment, failing to meet the ever-increasing electricity demand. Nuclear power plants, due to their high efficiency, low carbon footprint, and sustainability, have become an important energy option in these areas. High-intensity seismic zones are typically located in areas of frequent seismic activity, such as near seismic fault lines. The high seismic intensity in these areas places extremely high demands on the seismic resistance of building structures, especially critical infrastructure like nuclear power plants. With the development of seismic engineering technology, it is now possible to design and construct nuclear power plants capable of withstanding extreme seismic events in high-intensity zones. For example, the use of seismic isolation technology, energy-absorbing devices, and high-performance materials can significantly improve the seismic resistance of nuclear power plants.

[0003] However, existing seismic isolation foundations, as a type of foundation for nuclear power plants in high-intensity seismic zones that requires further development, still face several challenges in terms of both seismic isolation effectiveness and recovery capability. Firstly, under strong earthquake conditions, the existing foundations' seismic isolation performance is not outstanding. Even in environments most conducive to seismic isolation, the foundation isolation rate is still less than 30%, compared to the 40%–80% isolation rate of traditional lead-core rubber bearings for superstructures, indicating significant potential for improvement. Secondly, the existing foundation pads for high-intensity seismic isolation power plants are approximately 2.0m–4.0m thick. Under dynamic loads, the pad may experience unacceptable vertical compressive deformation, or even differential settlement, leading to superstructure tilting and affecting structural safety. Finally, existing foundations for high-intensity seismic isolation power plants suffer from poor seismic toughness, high costs associated with setting up recovery facilities, and the inability to fully recover horizontal displacement after an earthquake, which is detrimental to the safe use of the structure after an earthquake. Under minor earthquake conditions, existing foundations for high-intensity seismic isolation power plants, despite their relatively good performance, exhibit excessive displacement response of the superstructure, potentially significantly impacting the normal operation of the nuclear power plant.

[0004] To address the above issues, it is necessary to design a thin-layer seismic isolation foundation for nuclear power plants with high seismic isolation rate and good seismic toughness. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a thin-layer seismic isolation foundation for nuclear power plants in high-intensity seismic zones, which has high seismic isolation rate, low cushion settlement, and good seismic toughness.

[0006] The second objective of this invention is to provide a construction method for the aforementioned thin-layer seismic isolation foundation for nuclear power plants in high-intensity seismic zones.

[0007] Technical Solution: The thin-layer seismic isolation foundation for nuclear power plants in high-intensity seismic zones described in this invention includes a nuclear power plant building floor slab and an outer wall of the nuclear power plant building fixed on the floor slab. The floor slab has multiple grouting holes. A foundation pit is sealed below the floor slab, and a pile foundation is installed below the foundation pit. A single-layer pebble cushion is provided between the floor slab and the foundation pit, and the grouting holes communicate with the pebble cushion to allow grout to enter and bind the pebble particles. A shallow diaphragm wall is provided below the ground on the outer side of the outer wall. A tire buffer layer is provided between the outer wall and the shallow diaphragm wall to restrict the horizontal displacement of the nuclear power plant.

[0008] A detachable displacement recovery device is installed between the shallow diaphragm wall and the outer wall of the nuclear power plant building.

[0009] The grouting holes are arranged symmetrically, taking into account both the center and the surrounding area of ​​the base slab, to provide sufficient torsional moment and uniform shear force. The grouting holes are located in the center and surrounding areas of the nuclear power plant building base slab. The spacing between the grouting holes in the center area is 0.05 to 0.1 times the length of the long side of the nuclear power plant building base slab, depending on the shear force requirements, while the spacing between the grouting holes in the surrounding area is 0.05 to 0.2 times the length of the long side of the nuclear power plant building base slab.

[0010] The grouting holes are arranged in a dotted pattern. The cement mortar filling the spaces between the single-layer pebble cushion layer through these holes effectively improves the horizontal bearing capacity of the pebble cushion layer and reduces the displacement response of the structure under minor earthquakes and normal service loads. The cement mortar filling the spaces between the pebble particles has two effects: first, it directly bonds the nuclear power plant building floor slab and the foundation pit bottom, making them a unified whole and preventing slippage; second, it wraps around and bonds multiple pebbles, changing their rounded geometry and making them difficult to roll. Both of these effects significantly improve the horizontal bearing capacity and stiffness of the foundation. The grouting area under each grouting hole is no less than 0.78m². 2 At least 5 bedding particles should be bonded; grouting holes can be laid in multiple batches.

[0011] The tire buffer layer is filled with cut-up waste tire blocks.

[0012] The pebble size in the single-layer pebble cushion layer is 25cm to 40cm.

[0013] The tire buffer layer is filled to a height of 1 / 4 to 1 / 2 of the depth of the nuclear power plant building floor.

[0014] The horizontal gap between the outer side of the nuclear power plant building's exterior wall and the inner side of the shallow diaphragm wall ranges from 0.5m to 3.0m.

[0015] The detachable displacement recovery device includes multiple detachable actuators and an electronic control system. The detachable actuators are arranged between the shallow diaphragm wall and the outer wall of the nuclear power plant building, and are located above the tire buffer layer. The height of the detachable actuators is the same as the height of the floor slab inside the nuclear power plant building, forming a synchronous jacking group. After the jacking is completed, the detachable displacement recovery device can be disassembled and stored.

[0016] The construction method for the thin-layer seismic isolation foundation of the nuclear power plant in the high-intensity seismic zone mentioned above includes the following steps:

[0017] (A1) Clean and level the construction site, excavate the trench, precast the shallow diaphragm wall steel cage on the ground, and then use a lifting device to put it into the trench. Pour concrete to form a shallow diaphragm wall, then excavate the soil inside the wall. After excavating to the design elevation, use a pile driver to complete the construction of the group pile foundation one by one from the inside out.

[0018] (B1) Reinforced concrete is poured at the bottom of the foundation pit to form the foundation pit bottom seal. After the bottom seal layer is leveled and has reached strength, a single layer of pebble cushion is laid on it. The nuclear power plant building floor slab is prefabricated and multiple grouting holes are reserved. The multiple grouting holes are grouted in batches. The prefabricated nuclear power plant building floor slab is placed on the pebble cushion layer using lifting equipment. The first batch of grouting holes is grouted, and the remaining batches of grouting holes are grouted as needed.

[0019] (C1) Tie the steel bars of the outer wall of the nuclear power plant, install the wall formwork, pour concrete, and build the outer wall of the nuclear power plant. Then continue the construction of other structures and equipment of the nuclear power plant.

[0020] (D1) The cut waste tire blocks are filled between the shallow diaphragm wall and the outer wall of the nuclear power plant building to form a tire buffer layer.

[0021] The construction method for the thin-layer seismic isolation foundation of the nuclear power plant in the high-intensity seismic zone mentioned above includes the following steps:

[0022] (A2) Clean and level the construction site, excavate the trench, precast the shallow diaphragm wall steel cage on the ground, and then use a lifting device to put it into the trench. Pour concrete to form a shallow diaphragm wall, then excavate the soil inside the wall. After excavating to the design elevation, use a pile driver to complete the construction of the group pile foundation one by one from the inside out.

[0023] (B2) Reinforced concrete is poured at the bottom of the foundation pit to form the foundation pit bottom seal. After the bottom seal is leveled and has reached strength, a single layer of pebble cushion is laid on it. The nuclear power plant building floor slab is prefabricated and multiple grouting holes are reserved. The multiple grouting holes are grouted in batches. The prefabricated nuclear power plant building floor slab is placed on the pebble cushion using lifting equipment. The first batch of grouting holes is grouted, and the remaining batches of grouting holes are grouted as needed.

[0024] (C2) Tie the steel bars of the outer wall of the nuclear power plant, install the wall formwork, pour concrete to build the outer wall of the nuclear power plant, and then continue the construction of other structures and equipment of the nuclear power plant;

[0025] (D2) The cut waste tire blocks are filled between the shallow diaphragm wall and the outer wall of the nuclear power plant building to form a tire buffer layer;

[0026] (E2) Install a detachable displacement recovery device on the outer wall of the nuclear power plant building outside the floor slab inside the nuclear power plant building to restore the irrecoverable horizontal displacement after the earthquake, and complete a batch of grouting holes to restore the horizontal stiffness of the foundation.

[0027] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects:

[0028] (1) This invention lays a single layer of pebble cushion between the base slab of the nuclear power plant building and the bottom of the shallow diaphragm wall foundation pit, so that the cushion particles can roll under strong earthquake action, thereby isolating the earthquake action from further upward transmission, which can significantly reduce the dynamic response of the nuclear power plant building and the reactor building. Secondly, point grouting is carried out in some areas of the cushion layer to form a semi-rigid connection between the base slab of the nuclear power plant building and the bottom of the foundation pit, so that the overall structure has greater stiffness under small earthquake action, and the point connection is sheared under large earthquake action, so that the seismic isolation pebble cushion can fully play its seismic isolation effect. At the same time, a tire buffer layer is set between the outer wall of the nuclear power plant building and the outer wall of the shallow diaphragm wall to provide horizontal displacement recovery force.

[0029] (2) When the residual displacement after the earthquake is large, a detachable displacement recovery device can be installed on the outer wall of the nuclear power plant building to quickly restore the structural deformation, so that the seismic isolation foundation has sufficient seismic toughness.

[0030] (3) Good seismic isolation effect: Under strong earthquake, the pebble particles of the cushion layer roll between the two hard layers of the nuclear power plant building floor and the foundation pit. Since there is only one layer of particles, plus the influence of the two hard layers that move against each other, the rolling resistance of the cushion layer particles is very small. Compared with the seismic isolation principle of the existing technology that mainly relies on the movement of thick cushion layer particles, the present invention can isolate most of the horizontal seismic force from propagating upward, so the seismic isolation effect is significantly improved.

[0031] (4) Small compression deformation of the cushion layer: Since the cushion layer is only arranged with one layer of particles, the thickness of the cushion layer is extremely small compared with the existing technology. Therefore, if particle breakage is not considered, the cushion layer will hardly undergo compression deformation. Even if particle breakage is considered, the vertical compression of the cushion layer is negligible and there will be no differential settlement. Therefore, it overcomes the problem of large deformation of the cushion layer in the existing technology.

[0032] (5) Convenient post-earthquake maintenance: Grouting in the reserved grouting holes can effectively improve the horizontal bearing capacity of the pebble cushion layer and reduce the displacement response of the structure to small earthquakes. At the same time, multiple batches of grouting holes are set in the foundation slab of the nuclear power plant building so that if the previous grouting area is damaged when the foundation experiences a major earthquake, the foundation structure can be repaired multiple times by grouting to restore the horizontal bearing capacity.

[0033] (6) Good seismic toughness: By cutting and processing waste tires and filling them between the outer wall of the nuclear power plant building and the shallow diaphragm wall, a tire buffer layer is set up to improve the horizontal displacement recovery ability of the structure under earthquake action and reduce the displacement response of the structure. If necessary, a detachable displacement recovery device can be set at the outer wall position of the rectangular podium floor after the earthquake to restore the residual displacement.

[0034] (7) Low cost of seismic isolation measures: Using pebbles and waste tires as the materials for the seismic isolation foundation effectively reduces the cost of seismic isolation measures compared to traditional seismic isolation bearings, and recycling waste materials is beneficial to environmental protection. Attached Figure Description

[0035] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0036] Figure 2 This is a front view of the structure of the present invention;

[0037] Figure 3 This is a three-dimensional exploded view of the present invention;

[0038] Figure 4 This is a top view schematic diagram of the pile foundation and grouting hole arrangement of the present invention;

[0039] Figure 5 This is a schematic cross-sectional view of the pebble interlayer of the present invention;

[0040] Figure 6 This is a side view of the arrangement of the detachable displacement recovery device of the present invention;

[0041] Figure 7 This is a schematic diagram of tire blocks in the tire buffer layer of the present invention. Detailed Implementation

[0042] The present invention will now be described in further detail.

[0043] Please see Figures 1-7 This invention discloses a thin-layer seismic isolation foundation for a nuclear power plant in a high-intensity seismic zone, comprising a nuclear power plant building floor slab 1, a nuclear power plant building exterior wall 2, a single-layer pebble cushion layer 3, a tire buffer layer 4, a shallow diaphragm wall 5, a foundation pit bottom sealing 6, a pile foundation 7, and a detachable displacement recovery device.

[0044] The nuclear power plant building floor slab 1 has multiple sets of point-like grouting holes 101, and the outer side of the nuclear power plant building floor slab 1 is fixedly connected to the outer wall 2 of the nuclear power plant building. A foundation pit bottom seal 6 is located below the nuclear power plant building floor slab 1, and a pile foundation 7 is installed below the foundation pit bottom seal 6. A single-layer pebble cushion layer 3 is provided between the nuclear power plant building floor slab 1 and the foundation pit bottom seal 6. The single-layer pebble cushion layer 3 is composed of a single layer of pebbles, and the grouting holes 101 communicate with the single-layer pebble cushion layer 3 to allow grout to enter the single-layer pebble cushion layer for bonding the pebble particles. A shallow diaphragm wall 5 is provided below the ground on the outer side of the nuclear power plant building outer wall 2. A tire buffer layer 4, composed of cut and processed waste tire blocks, is provided between the nuclear power plant building outer wall 2 and the shallow diaphragm wall 5 to restrict the horizontal displacement of the nuclear power plant.

[0045] The arrangement of multiple sets of point-source grouting holes 101 needs to consider both the center and peripheral areas of the foundation slab and be symmetrically distributed to provide sufficient torsional moment and uniform shear force. The grouting holes are located in the central and peripheral areas of the nuclear power plant building's foundation slab. The spacing between grouting holes in the central area is 0.05 to 0.1 times the length of the long side of the nuclear power plant building's foundation slab, depending on the shear force requirements; the spacing between grouting holes in the peripheral area is 0.05 to 0.2 times the length of the long side of the nuclear power plant building's foundation slab. The diameter of each grouting hole 101 is 3.5 cm to 5.0 cm. Grouting is carried out in batches, with at least 10 grouting holes 101 injected in each batch. Specific batch details can be found in [reference needed]. Figure 4 The diagram shows four batches of grouting holes, with A, B, C, and D each representing a batch. The structure of this invention can withstand at least four major earthquakes. PVC pipes are pre-embedded during the pouring of the nuclear power plant building's foundation slab 1. The grouting volume per hole is no less than 0.12 cubic meters, the equivalent filling diameter is no less than 1 meter, the concrete grout grade is no less than C30, the slump is 60mm~90mm, and the initial setting time is 20min~40min. The outer wall 2 of the nuclear power plant building has a rectangular frame shape, with the structural parts shallowly embedded in the soil, and is made of reinforced concrete.

[0046] A single-layer pebble cushion layer 3 is laid between the nuclear power plant building floor slab 1 and the foundation pit sealing layer 6. It consists of a uniformly distributed single layer of large-diameter pebble particles, meaning the cushion layer thickness equals the maximum particle size, and the particle size distribution is concentrated, with pebble sizes ranging from 25cm to 40cm. The pebble particles are sandwiched between two rigid layers, namely the nuclear power plant building floor slab 1 and the foundation pit sealing layer 6, resulting in low rolling resistance. Therefore, during an earthquake, the cushion layer particles can isolate the seismic forces transmitted from underground through rolling displacement, fully utilizing their seismic isolation function. Simultaneously, cement mortar filled between the single-layer pebble cushion layer 3 through point-filled grouting holes 101 effectively improves the horizontal bearing capacity of the single-layer pebble cushion layer 3, reducing the structural displacement response under minor earthquakes and normal service loads. The cement mortar filling the spaces between the foundation particles serves two purposes: first, it directly bonds the nuclear power plant building floor slab 1 and the foundation pit sealing layer 6, making them a unified whole and preventing slippage; second, it encapsulates and bonds multiple pebbles, altering their rounded geometric shape and making them difficult to roll. Both of these effects significantly improve the foundation's horizontal bearing capacity and rigidity. The grouting area under each grouting hole should be no less than 0.78 m². 2 At least 5 bedding particles should be bonded, and the grouting holes can be arranged according to... Figure 4 The deployment was carried out in multiple batches as shown.

[0047] The tire buffer layer 4 is located between the outer wall 2 of the nuclear power plant building and the shallow diaphragm wall 5, with a gap of 0.5m to 3m between the two walls. It is filled with cut and processed waste tires, and the filling is made as uniform and dense as possible. The filling height is 1 / 4 to 1 / 2 of the building's burial depth. The tire buffer layer 4 improves the structure's horizontal displacement recovery force under seismic loading and reduces the structure's displacement response.

[0048] To address the irreversible horizontal displacement after the earthquake, a detachable displacement recovery device was installed at location 2 on the exterior wall of the nuclear power plant building, at the rectangular podium floor slab, to restore horizontal displacement and allow the structure to be quickly restored to use after the major earthquake. Figure 6 As shown, the detachable displacement recovery device includes multiple detachable actuators 801 and an electronic control system 802. The detachable actuators are arranged between the shallow diaphragm wall and the outer wall of the nuclear power plant building, and are located above the tire buffer layer. The height of the detachable actuators 801 is the same as the height of the floor slab inside the nuclear power plant building, forming a synchronous jacking group. After the jacking is completed, the detachable displacement recovery device can be detached and stored.

[0049] The shallow diaphragm wall 5 is located outside the outer wall 2 of the nuclear power plant building and is a reinforced concrete structure. The bottom seal 6 of the foundation pit is not less than 1m thick, and the pile group foundation 7 is arranged in a square shape below the bottom seal 6 of the foundation pit. The pile group foundation 7 can use steel pipe piles, concrete mixing piles, precast piles or other suitable pile types.

[0050] This invention also provides a construction method for thin-layer seismic isolation foundations of nuclear power plants in high-intensity seismic zones, comprising the following steps:

[0051] A. Clean and level the construction site, excavate trenches, precast the shallow diaphragm wall 5 steel cage on the ground, and then use lifting equipment to put it into the trenches. After pouring concrete to form the shallow diaphragm wall 5, excavate the soil inside the wall. After excavating to the design elevation, use a pile driver to complete the construction of the group pile foundation 7 one by one from the inside out.

[0052] B. Pour reinforced concrete at the bottom of the foundation pit to form the foundation pit bottom seal 6. After the bottom seal is leveled and has formed strength, lay a single layer of pebble cushion 3 on it. Precast the nuclear power plant building floor slab 1 on the ground and reserve multiple batches of grouting holes 101. Use lifting equipment to place the precast floor slab on the single layer of pebble cushion 3. The first batch of grouting holes 101 is grouted.

[0053] C. Tie the steel bars of the outer wall of the nuclear power plant building, install the wall formwork, pour concrete, and build the outer wall of the nuclear power plant building. Then continue the construction of other structures and equipment of the nuclear power plant.

[0054] D. The symmetrically cut waste tire blocks are filled between the shallow diaphragm wall 5 and the outer wall 2 of the nuclear power plant building to form a tire buffer layer 4.

[0055] If there is irreversible horizontal displacement after the earthquake, a detachable displacement recovery device can be installed at position 2 on the outer wall of the nuclear power plant building outside the floor slab inside the nuclear power plant building to restore the displacement, and a batch of grouting holes 101 can be grouted to restore the horizontal stiffness of the foundation.

[0056] Working principle: The thin-layer seismic isolation foundation of nuclear power plants in high-intensity seismic zones mainly includes three functions. First, this invention meets the requirements of nuclear power plants for foundation bearing capacity and deformation stiffness under normal serviceability limits. Second, the thin-layer foundation involved in this invention only has a single layer of cushion particles, which can roll under strong earthquakes with minimal resistance, thus isolating most of the horizontal seismic forces and exhibiting good seismic isolation effect. Finally, this invention has good seismic toughness and can quickly recover the residual deformation of the structure after a major earthquake.

[0057] To fulfill the first functional requirement, a pile group foundation 7 is arranged below the foundation pit bottom seal 6. Combined with the large cross-sectional area of ​​the foundation pit bottom seal 6 itself, the foundation easily meets the usage requirements in terms of vertical bearing capacity and deformation stiffness. Horizontally, the seismic isolation foundation requires sufficient horizontal bearing capacity and stiffness under normal use and minor earthquake conditions, while under major earthquake conditions, the horizontal stiffness must be sufficiently small to fully utilize the seismic isolation effect. Therefore, a single-layer large-diameter pebble cushion layer is installed. This cushion layer has excellent horizontal stiffness and seismic isolation effect. Simultaneously, point grouting is installed on the cushion layer to bond part of it, ensuring sufficient horizontal stiffness and bearing capacity under normal use and minor earthquake conditions. Under major earthquake conditions, the grouting points are damaged by excessive seismic force and lose their horizontal restraint, thus drastically reducing the horizontal stiffness of the cushion foundation and fully utilizing its seismic isolation function. After the earthquake, the horizontal resistance of the foundation can be restored by re-bonding the cushion layer through the reserved grouting holes.

[0058] To fulfill the second function mentioned above, a single-layer pebble cushion layer is installed between the nuclear power plant building floor slab 1 and the foundation pit sealing layer 6. In a structure that is mostly rigidly connected from top to bottom, an "artificially weak surface" is actively created to allow the cushion layer to deform sufficiently under seismic loads, isolating it from the adverse effects of earthquakes and protecting all structures above it. To achieve this, the pebble particles in the single-layer pebble cushion layer 3 have a relatively large particle size, and the contact areas between the particles and the upper and lower hard layers are relatively flat, allowing the particles to roll and dissipate energy sufficiently within the gaps between these hard layers.

[0059] To fulfill the third function mentioned above, the tires in the tire buffer layer 4 are first symmetrically cut into waste tire blocks and then filled into the buffer layer. The elasticity of the buffer layer provides the displacement recovery force of the structure and inhibits the development of horizontal displacement of the structure under seismic action. When the residual displacement is large, the residual deformation can be quickly restored by setting a detachable displacement recovery device between the shallow diaphragm wall 5 and the outer wall 2 of the nuclear power plant building.

Claims

1. A thin-layer seismic isolation foundation for a nuclear power plant in a high-intensity seismic zone, characterized in that, The structure includes a nuclear power plant building base slab (1) and a nuclear power plant building exterior wall (2) fixed on the nuclear power plant building base slab (1). The nuclear power plant building base slab (1) has multiple grouting holes (101). A foundation pit bottom seal (6) is provided below the nuclear power plant building base slab (1), and a pile foundation (7) is provided below the foundation pit bottom seal (6). A single-layer pebble cushion layer (3) is provided between the nuclear power plant building base slab (1) and the foundation pit bottom seal (6). The grouting holes (101) are connected to the single-layer pebble cushion layer (3) to allow grout to enter the single-layer pebble cushion layer for bonding pebble particles. A shallow diaphragm wall (5) is provided below the ground on the outer side of the nuclear power plant building exterior wall (2). A tire buffer layer (4) is provided between the nuclear power plant building exterior wall (2) and the shallow diaphragm wall (5) to limit the horizontal displacement of the nuclear power plant.

2. The thin-layer seismic isolation foundation for nuclear power plants in high-intensity seismic zones according to claim 1, characterized in that, A detachable displacement recovery device is installed between the shallow diaphragm wall (5) and the outer wall (2) of the nuclear power plant building.

3. The thin-layer seismic isolation foundation for nuclear power plants in high-intensity seismic zones according to claim 1, characterized in that, The grouting holes are located in the central area and the surrounding area of ​​the nuclear power plant building floor slab (1). The spacing between the grouting holes in the central area is 0.05 to 0.1 times the length of the long side of the nuclear power plant building floor slab (1) according to the shear resistance requirements, and the spacing between the grouting holes in the surrounding area is 0.05 to 0.2 times the length of the long side of the nuclear power plant building floor slab (1).

4. The thin-layer seismic isolation foundation for nuclear power plants in high-intensity seismic zones according to claim 1, characterized in that, The tire buffer layer (4) is filled with cut-up waste tire blocks.

5. The thin-layer seismic isolation foundation for nuclear power plants in high-intensity seismic zones according to claim 1, characterized in that, The pebble size in the single-layer pebble cushion is 25cm~40cm.

6. The thin-layer seismic isolation foundation for nuclear power plants in high-intensity seismic zones according to claim 1, characterized in that, The filling height of the tire buffer layer (4) is 1 / 4 to 1 / 2 of the burial depth of the nuclear power plant building floor slab (1).

7. The thin-layer seismic isolation foundation for nuclear power plants in high-intensity seismic zones according to claim 1, characterized in that, The horizontal gap between the outer side of the outer wall (2) of the nuclear power plant building and the inner side of the shallow diaphragm wall (5) is 0.5m to 3.0m.

8. The thin-layer seismic isolation foundation for nuclear power plants in high-intensity seismic zones according to claim 2, characterized in that, The detachable displacement recovery device includes multiple detachable actuators (801) and an electronic control system (802). The detachable actuators (801) are arranged between the shallow diaphragm wall (5) and the outer wall (2) of the nuclear power plant building and are located above the tire buffer layer (4).

9. A construction method for a thin-layer seismic isolation foundation for a nuclear power plant in a high-intensity seismic zone as described in claim 1, characterized in that, Includes the following steps: (A1) Clean and level the construction site, excavate the trench, prefabricate the shallow diaphragm wall (5) steel cage on the ground, and then use a lifting device to put it into the trench, pour concrete to form a shallow diaphragm wall (5), then excavate the soil inside the wall, and after excavating to the design elevation, use a pile driver to complete the construction of the group pile foundation (7) from the inside out. (B1) A reinforced concrete is poured at the bottom of the foundation pit to form a foundation pit seal (6). After the seal layer is leveled and has reached strength, a single layer of pebble cushion (3) is laid on it. The prefabricated nuclear power plant building base plate (1) is constructed, and multiple grouting holes (101) are reserved. The multiple grouting holes (101) are grouted in batches. The prefabricated nuclear power plant building base plate (1) is placed on the pebble cushion using a lifting device. The first batch of grouting holes is completed, and the remaining batches of grouting holes are grouted as needed. (C1) Tie the steel bars of the outer wall (2) of the nuclear power plant building, install the wall formwork, pour concrete, and build the outer wall (2) of the nuclear power plant building. Then continue the construction of other structures and equipment of the nuclear power plant. (D1) The cut waste tire blocks are filled between the shallow diaphragm wall (5) and the outer wall (2) of the nuclear power plant building to form a tire buffer layer (4).

10. A construction method for a thin-layer seismic isolation foundation for a nuclear power plant in a high-intensity seismic zone as described in claim 2, characterized in that, Includes the following steps: (A2) Clean and level the construction site, excavate the trench, prefabricate the shallow diaphragm wall (5) steel cage on the ground, and then use a lifting device to put it into the trench, pour concrete to form a shallow diaphragm wall (5), then excavate the soil inside the wall, and after excavating to the design elevation, use a pile driver to complete the construction of the group pile foundation (7) from the inside out. (B2) Reinforced concrete is poured at the bottom of the foundation pit to form the foundation pit bottom seal (6). After the bottom seal is leveled and has formed strength, a single layer of pebble cushion (3) is laid on it. The nuclear power plant building floor slab (1) is prefabricated and multiple grouting holes (101) are reserved. The multiple grouting holes (101) are grouted in batches. The prefabricated nuclear power plant building floor slab (1) is placed on the pebble cushion using lifting equipment. The first batch of grouting holes is grouted. The remaining batches of grouting holes are grouted as needed. (C2) Tie the steel bars of the outer wall (2) of the nuclear power plant building, install the wall formwork, pour concrete, and build the outer wall (2) of the nuclear power plant building. Then continue the construction of other structures and equipment of the nuclear power plant. (D2) The cut waste tire blocks are filled between the shallow diaphragm wall (5) and the outer wall (2) of the nuclear power plant building to form a tire buffer layer (4). (E2) A detachable displacement recovery device is installed at the location of the outer wall (2) of the nuclear power plant building outside the floor slab inside the nuclear power plant building to restore the unrecoverable horizontal displacement after the earthquake, and to complete a batch of grouting holes (101) grouting to restore the horizontal stiffness of the foundation.

Images