Construction method of reinforced grid for earth-rock dam in strong earthquake area

Abstract

This invention relates to the field of geotechnical construction technology, specifically to a method for laying reinforced geogrid in earth-rock dams in strong earthquake zones. It includes an earth-rock dam body, with a geogrid layer on its upper side. Several anchor nails are uniformly fixed at the edges of the geogrid layer, and a filler layer is placed on top of the geogrid layer. This invention eliminates the stress response delay caused by geogrid relaxation in traditional processes by making pre-tensioning a mandatory independent process, ensuring the reinforced geogrid forms a stable initial tensile stress structure layer before covering with filler. Discrete anchor nodes and end tensioning work together to form a prestressed spatial transfer system, ensuring uniform distribution of prestress and avoiding stress concentration. Filler spreading and compaction are performed while maintaining tension, allowing filler particles to fully embed into the geogrid mesh, forming a uniform interlocking interface structure.

Description

Technical Field

[0001] This invention relates to the field of geotechnical construction technology, and more specifically, to a method for laying reinforced grids for earth-rock dams in strong earthquake zones. Background Technology

[0002] Earth-rock dams have become one of the most widely used dam types in water conservancy and hydropower projects due to their advantages such as strong adaptability to foundation conditions, wide availability of dam construction materials, and relatively low engineering costs. In areas prone to strong earthquakes, reinforcement techniques are often used in engineering practice to improve the seismic stability, crack resistance, and overall integrity of the dam body. This involves laying reinforcing materials such as geogrids between the dam fill layers. The reinforced geogrid, through the mechanical interlocking of its mesh and the fill material, as well as the frictional effect at the geogrid-soil interface, achieves stress dispersion, lateral deformation restriction, and overall stiffness enhancement, thereby improving the dam's performance under static and dynamic loads.

[0003] However, traditional reinforced geogrid laying methods have fundamental limitations in their technical principles, mainly in the following aspects: In traditional construction methods, after the reinforced geogrid is laid on top of the fill layer, it is fixed in a plane using only simple methods such as U-shaped nails or sandbags. The geogrid is in a relaxed state, exhibiting significant initial deflection and wrinkles. During the covering and compaction of the fill material, the geogrid does not actively participate in the stress distribution. Instead, it is only gradually tightened and begins to function after the dam body deforms under subsequent fill loads or seismic dynamics. The essence of this "passive reinforcement" mode is that the geogrid is always regarded as a passive constraint element that "can only be activated after the soil deforms," ​​rather than a structural element that actively participates in the stress distribution from the beginning of construction. The consequence is a significant response lag in the reinforcement effect. Under instantaneous dynamic loads such as earthquakes, the geogrid cannot immediately constrain soil deformation, the tensile strength of the reinforcement material cannot be effectively utilized, and the seismic safety margin of the dam body is severely limited. The underlying cause of these problems lies in the lack of a systematic design for the formation mechanism of composite structures in traditional construction methods. Specifically: First, existing technologies lack a mandatory process for applying controllable prestress to the geogrid, leaving it in a state of zero or low stress before being covered with fill material, thus failing to establish an initial tensile stress field. Second, due to the looseness of the geogrid, the interfacial interlocking between the geogrid and the soil after compaction of the fill material occurs only locally and randomly, failing to form a uniform and continuous interlocking structure. Third, the anchor points only serve a temporary fixing function and do not constitute a complete prestressed spatial transfer system with the tensioning end, making the geogrid prone to stress concentration or localized failure in the early stages of stress. In short, traditional processes only focus on the operational act of geogrid laying, without making the formation of a high-performance composite structure between the geogrid and fill material the core objective of process design, resulting in a disconnect between process and structure.

[0004] For earthquake zones with seismic fortification intensity of 8 degrees or higher, the aforementioned defects are particularly fatal. The main risks faced by earth-rock dams under strong earthquakes—including tensile cracking caused by the dam crest amplification effect, dam slope slippage, liquefaction deformation, and uneven settlement—place extremely high demands on the immediate response capability and overall synergy of the reinforced structure. Traditional passive reinforcement methods, due to their delayed stress response and poor synergy, are unable to provide effective restraint in the instantaneous dynamic response of strong earthquakes. Earthquake damage surveys and experimental studies have shown that reinforced earth-rock dams constructed using traditional methods are prone to interface separation, grid breakage, or anchorage failure under strong earthquakes, compromising the integrity of the reinforced structure. Therefore, this invention proposes a construction method for laying reinforced grids in earth-rock dams in strong earthquake zones. Summary of the Invention

[0005] The purpose of this invention is to provide a construction method for laying reinforced grids in earth-rock dams in strong earthquake zones, so as to solve the problem mentioned in the background art that the traditional passive reinforcement method is difficult to meet the seismic requirements of earth-rock dams for immediate response and overall coordination of reinforced structures in strong earthquake zones due to the lag in force and poor coordination.

[0006] To address the aforementioned problems, the present invention aims to provide a method for laying reinforced geogrid in earth-rock dams in strong earthquake zones, comprising the following steps: S1: Perform foundation treatment and acceptance on the top surface of the completed dam filling layer; After processing, a flat and compacted supporting structural surface is formed.

[0007] S2: On the accepted supporting structure surface, reinforced grids are laid according to the design requirements, and discrete anchor points are used for planar anchoring to form the boundary constraint structure of the grids. On the accepted supporting structure surface, reinforced grids are laid according to design requirements, and discrete anchor points are used for planar anchoring to form the boundary constraint structure of the grids.

[0008] S3: Apply pretension to the reinforced grid after it has been laid and anchored, so that it reaches and maintains the preset tension state, forming an initial tensile stress structural layer; This step is a mandatory independent procedure in the construction method described above.

[0009] S4: While maintaining the pretension, the first layer of filler is spread and compacted so that the filler and the tensioned grid interlock and lock together to form a prestressed reinforced composite structure layer.

[0010] The tensioning equipment must maintain pressure continuously or use a mechanical locking device to maintain tension until the first layer of filler covers the designed thickness. The paving adopts the forward unloading method, and the compaction adopts light equipment and follows the operation restrictions.

[0011] Upon completion of construction, the following structures will be included: It includes an earth-rock dam body, wherein a grid layer is provided on the upper side of the earth-rock dam body to protect the surface of the earth-rock dam body; Several anchor nails are uniformly fixed at the edge of the grid layer to fix the grid layer to the surface of the earth-rock dam. The grid layer is composed of a supporting structural surface, a stiffened grid, a discrete constraint anchoring structure, an initial tensile stress structural layer, a filler covering and protection structure, and an interface interlocking structure, forming a composite load-bearing body with initial stiffness and stress transmission path.

[0012] A filler layer is provided on the upper side of the grid layer, and the filler layer and the grid layer interlock to form a new composite structure layer.

[0013] The first layer of filler is laid using the forward unloading method, where dump trucks unload at the front end of the laid grid, and the paver spreads the filler outward from the tensioned area of ​​the grid, forming a stress protection structure in which the filler coverage takes precedence over compaction.

[0014] As a further improvement to this technical solution, the specific method for applying pretension in step S3 is as follows: using a special tensioning device, a constant pretension of 10%-25% of the ultimate tensile strength of the grid is applied to the reinforced grid through clamps set at the end or side of the grid, and the load is held for 30-60 seconds.

[0015] During the holding process, the tensioning equipment should maintain stable tension and avoid fluctuations. After the holding period ends, the grid is in a stable elastic pre-stressed state, its elongation is basically stable, and its surface is flat and wrinkle-free.

[0016] As a further improvement to this technical solution, in step S2, the planar anchoring adopts U-shaped steel bar anchors or sandbag arrays for weighting, with the anchoring point spacing not exceeding 2 meters, forming a discrete constraint node structure, which together with the end tensioning constitutes a spatial transfer system for grid prestress.

[0017] U-shaped steel anchors are made of steel bars with a diameter of 10-14mm, bent to a height of 30-50cm, driven into the base surface at least 30cm, with a spacing of no more than 2 meters, and arranged in a quincunx or rectangular array.

[0018] As a further improvement to this technical solution, in step S4, light machinery is used for spreading the first layer of filler, and no compaction equipment is allowed to walk or operate on the reinforced grid that is not covered with filler or whose cover thickness is less than the design thickness.

[0019] Lightweight equipment, such as small tracked bulldozers or light loaders, should be given priority for paving machinery. Tracked machinery exerts less contact pressure on the grating compared to wheeled machinery, and the tracks can effectively distribute the load.

[0020] As a further improvement to this technical solution, in step S4, after the rolling is completed, the filler and the tensioned grid form an interface interlocking structure through the mechanical interlocking effect of the mesh and the filler particles.

[0021] After the first layer of filler is compacted while maintaining pretension, the filler particles are forced into the mesh of the tension grid by the roller, forming a mechanical interlock.

[0022] As a further improvement to this technical solution, the reinforced geogrid is any one of bidirectional polypropylene geogrid, glass fiber geogrid, or steel-plastic composite geogrid.

[0023] Regardless of the type of grid chosen, ensure that it is compatible with the packing gradation and that the mesh size matches the maximum particle size of the packing to form a good mechanical interlock.

[0024] As a further improvement to this technical solution, the method is particularly applicable to earth-rock dam projects in strong earthquake zones with seismic fortification intensity of 8 degrees or above. The prestressed reinforced composite structural layer formed has a seismic resistance mechanism of delayed failure and stress redistribution under strong earthquake action.

[0025] In this type of project, the dam body is subjected to large seismic dynamic loads. Traditional reinforcement methods are difficult to guarantee the safety of the dam body due to response lag and poor coordination. The prestressed reinforced composite structure layer formed by the method of this invention exhibits a unique seismic resistance mechanism under strong earthquakes.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In the construction method of reinforcing grid laying for earth-rock dams in strong earthquake zones, by setting pre-tensioning as a mandatory independent process, the reinforcing grid forms a stable initial tensile stress structural layer before covering the fill material, eliminating the stress response delay caused by grid relaxation in traditional processes; discrete anchoring nodes and end tensioning work together to form a prestress spatial transfer system, ensuring uniform distribution of prestress and avoiding stress concentration; the fill material is laid and compacted while maintaining tension, so that the fill material particles are fully embedded in the grid mesh, forming a uniform interlocking structure, and the prestress is simultaneously converted into the initial normal stress and tangential resistance of the interface; finally, a prestressed reinforced composite structural layer is formed, realizing the integrated design of construction technology and engineering structure.

[0027] 2. In the construction method of reinforced grid laying for earth-rock dams in strong earthquake zones, on the basis of prestressed reinforced composite structures, the prestress is effectively maintained throughout the filling process by using the timing coupling of tensioning equipment and paving and compaction processes, the forward unloading method, and light machinery operation. The initial normal stress and tangential resistance provided by the interface interlocking structure effectively prevent interface separation and grid slippage under seismic cyclic loads. The synergistic effect of the above mechanisms gives the composite structure the characteristics of progressive failure, significantly improving the integrity and crack resistance of earth-rock dams in strong earthquake zones. Attached Figure Description

[0028] Figure 1 This is a flowchart of the present invention; Figure 2 This is a schematic diagram of the overall structure of the present invention; Figure 3 This is an exploded view of the overall structure of the present invention; Figure 4 This is a cross-sectional front view of the overall structure of the present invention.

[0029] The meanings of the labels in the diagram are as follows: 1. Earth-rock dam body; 2. Grid layer; 3. Anchor nails; 4. Filling layer. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0032] Example 1 First, please refer to Figure 1 The purpose of this embodiment is to provide a construction method for laying reinforced geogrid in earth-rock dams in strong earthquake zones, including the following steps: S1: Perform surface treatment and acceptance on the top surface of the completed dam fill layer. After treatment, a flat and compacted supporting structural surface will be formed. The specific operations for surface treatment and acceptance are as follows: A grader is used to finely level the top surface of the completed dam fill layer, removing loose material, debris, and sharp objects. Uneven areas are manually repaired. Then, a road roller is used to statically compact the surface twice to ensure that the flatness of the base surface is controlled within ±20mm and the compaction degree is not less than 98%. During acceptance, instruments such as a level and straightedge are used to check the slope and flatness, and a nuclear density meter or sand cone method is used to check the compaction degree. After passing the test, the process proceeds to the next step. The resulting supporting structure provides uniform and stable support for the subsequent grid, preventing local settlement or stress concentration during the tensioning process.

[0033] S2: On the accepted supporting structure surface, lay the reinforced grid according to the design requirements, and use discrete anchor points for planar anchoring to form the boundary constraint structure of the grid. The laying of the reinforced grid should be strictly in accordance with the specifications, main force direction and overlap length determined by the design drawings. When laying the grid, it should be flattened and straightened to avoid wrinkles. The overlap can be fixed with plastic binding tape or special connectors. The overlap width should not be less than 0.5 meters. The planar anchoring adopts discrete anchor points, that is, anchor points are set at a certain interval in the plane of the grid.

[0034] S3: Apply pretension to the reinforced grid after it has been laid and anchored to achieve and maintain the preset tension state, forming an initial tensile stress structural layer. This step is a mandatory independent procedure in the construction method. Immediately after the grid is laid and anchored, use a special tensioning device to apply controllable pretension to the grid. The magnitude of the pretension, the holding time, and other parameters should be determined according to the properties of the grid material and the tension required by the design. This step enables the grid to establish initial tensile stress in a state without filler, forming an initial tensile stress structural layer.

[0035] S4: While maintaining pretension, the first layer of fill material is laid and compacted to ensure that the fill material and the tensioned grid interlock and lock together, forming a prestressed reinforced composite structural layer. Laying and compaction must be carried out while maintaining pretension. Specifically: The tensioning equipment needs to maintain pressure continuously or use a mechanical locking device to maintain tension until the first layer of filler covers the design thickness. The paving adopts the forward unloading method, and the compaction adopts light equipment and follows the operation restrictions. After compaction, the filler and the tension grid form an interlocking structure at the interface, and the pretension is converted into the initial stress at the interface, finally forming a prestressed reinforced composite structure layer composed of multiple structural units. This composite structure has initial stiffness and a clear stress transmission path.

[0036] Please refer to Figures 2-4 Upon completion of construction, the following structures will be included: The structure includes an earth-rock dam body 1, with a grid layer 2 installed on the upper side of the earth-rock dam body 1 to protect the surface of the earth-rock dam body 1. Several anchor nails 3 are evenly fixed at the edge of the grid layer 2 to fix the grid layer 2 to the surface of the earth-rock dam body 1. The grid layer 2 is composed of a supporting structural surface, a reinforced grid, a discrete constraint anchoring structure, an initial tensile stress structural layer, a filler covering and protection structure, and an interface interlocking structure, forming a composite load-bearing body with initial stiffness and stress transmission path. A filler layer 4 is provided on the upper side of the grid layer 2. The filler layer 4 and the grid layer 2 interlock to form a new composite structure layer. The first layer of filler is laid using the forward unloading method, that is, the dump truck unloads at the front end of the laid grid, and the paver lays the filler from the tensioned area of ​​the grid outward, forming a stress protection structure in which the filler coverage takes precedence over the compaction. In order to maintain the stress state of the pre-tensioned grid, the paving adopts the forward unloading method. The specific operation is as follows: The dump truck unloads material in front of the laid and tensioned grid area. After unloading, the paver paves the grid from the tensioned area outwards. That is, the paving machinery always stands on the side covered by the fill material and moves towards the uncovered area to ensure that the tracks or tires do not directly run over the tensioned grid, thus avoiding the danger of sudden changes in pretension caused by the compaction machinery directly contacting the tensioned grid.

[0037] For further details, please refer to Figure 1 In step S3, the specific method for applying pretension is as follows: using a special tensioning device, a constant pretension of 10%-25% of the ultimate tensile strength of the grid is applied to the reinforced grid through clamps set at the end or side of the grid, and the load is held for 30-60 seconds. The purpose is to make the grid complete the initial creep deformation under constant tension and eliminate the subsequent relaxation caused by material creep. During the holding process, the tensioning equipment should maintain stable tension and avoid fluctuations. After the holding period ends, the grid is in a stable elastic pre-stressed state, its elongation is basically stable, and its surface is flat and wrinkle-free.

[0038] Secondly, the dedicated tensioning equipment is a hydraulic tensioning unit or a mechanical tensioner, whose tension force can be quantitatively controlled and recorded, and is time-coupled with the subsequent paving and compaction processes.

[0039] And please see Figure 1In step S2, the planar anchoring adopts U-shaped steel bar anchors or sandbag array ballast, with the anchoring point spacing not exceeding 2 meters, forming a discrete constraint node structure. Together with the end tensioning, it constitutes the spatial transfer system of grid prestress. The U-shaped steel bar anchors are made of steel bars with a diameter of 10-14mm bent into shape, with a height of 30-50cm. They are driven into the base surface not less than 30cm, with the anchor spacing not exceeding 2 meters, and arranged in a quincunx or rectangular array. The anchors pass through the grid mesh and are fixed tightly against the base surface to form discrete constraint nodes. The sandbag array ballast is suitable for base surfaces where nailing is not advisable. Sandbags with a weight of not less than 25kg are used and arranged at a spacing not exceeding 2 meters. The sandbags are placed on the grid, which also forms discrete constraint nodes.

[0040] For further details, please refer to Figure 1 In step S4, light machinery is used for paving the first layer of fill material, and no compaction equipment is allowed to walk or operate on the reinforced grid that is not covered with fill material or whose cover thickness is less than the design thickness. In order to minimize the disturbance to the pre-tensioned grid, light equipment such as small tracked bulldozers or light loaders should be preferred for paving. Tracked machinery has less contact pressure on the grid than wheeled machinery, and the tracks can effectively distribute the load. During paving, the machinery travels parallel to the dam axis and always stays in the area covered with fill material.

[0041] For further details, please refer to Figure 1 In step S4, after compaction, the filler and the tensioned grid form an interface interlock structure through the mechanical interlocking of the mesh and filler particles. When the first layer of filler is compacted under the pretension, the filler particles are embedded in the mesh of the tensioned grid under the forced action of the roller, forming a mechanical interlock. Since the grid is under tension, its mesh remains open, making it easier for the filler particles to embed and the embedding depth is greater, and the interlocking effect is more complete.

[0042] For further details, please refer to Figure 1 The reinforced geogrid is any one of bidirectional polypropylene geogrid, glass fiber geogrid, or steel-plastic composite geogrid. Biaxial polypropylene geogrid: It is made of polypropylene through stretching and has good flexibility and ductility. It is suitable for general rockfill dams and earth-rock dams. Its ultimate tensile strength is generally 30 to 150 kN / m, which matches the pretension parameters of this invention well. Fiberglass geogrid: Made of fiberglass as the base material, it is woven and coated. It has high elastic modulus and low creep characteristics. It is suitable for high dams or strong earthquake zones with high requirements for deformation control. Its pretension can be 15% to 20% of the ultimate tensile strength, and the holding time can be appropriately shortened. Steel-plastic composite geogrid: It is made of steel wire and plastic, and has both high strength and certain ductility. It is suitable for high stress areas or parts of dam with large deformation. Its ultimate tensile strength can reach more than 200kN / m, and the pretension can be increased accordingly.

[0043] Regardless of the type of grid chosen, ensure that it is compatible with the packing gradation and that the mesh size matches the maximum particle size of the packing to form a good mechanical interlock.

[0044] And please see Figure 1-4 The method is particularly suitable for earth-rock dam projects in strong earthquake zones with seismic fortification intensity of 8 degrees or above. The prestressed reinforced composite structure layer formed has a seismic resistance mechanism of delayed failure and stress redistribution under strong earthquake action. In this type of project, the dam body bears large seismic dynamic loads. Traditional reinforcement methods are difficult to guarantee the safety of the dam body due to response lag and poor coordination. The prestressed reinforced composite structure layer formed by the method of this invention exhibits a unique seismic resistance mechanism under strong earthquakes. Delayed failure mechanism: Due to the initial stiffness and initial interfacial stress of the composite structure, in the early stages of an earthquake, the structure can absorb seismic energy through elastic deformation. The grid and filler deform together, delaying the generation and propagation of cracks. Even if the earthquake intensity exceeds the design value, the failure of the structure is gradual rather than a sudden collapse, providing valuable time for emergency rescue. Stress redistribution mechanism: When the stress concentration in a local area exceeds the strength of the grid, the discrete constraint anchoring structure can transfer the concentrated stress to the surrounding area through the elastic deformation of the anchoring points or the fine adjustment of the sandbags, so as to prevent the grid from breaking in a single section. At the same time, the tangential resistance provided by the interface interlocking structure can limit the lateral extrusion of the filler particles and maintain the integrity of the composite structure.

[0045] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A construction method for laying reinforced geogrid in earth-rock dams in strong earthquake zones, characterized in that, Includes the following steps: S1: Perform foundation treatment and acceptance on the top surface of the completed dam filling layer; S2: On the accepted supporting structure surface, reinforced grids are laid according to the design requirements, and discrete anchor points are used for planar anchoring to form the boundary constraint structure of the grids. S3: Apply pretension to the reinforced grid after it has been laid and anchored, so that it reaches and maintains the preset tension state, forming an initial tensile stress structural layer; S4: While maintaining the pretension, the first layer of filler is spread and compacted so that the filler and the tensioned grid interlock and lock together to form a prestressed reinforced composite structure layer. Upon completion of construction, the following structures will be included: It includes an earth-rock dam body (1), and a grid layer (2) is provided on the upper side of the earth-rock dam body (1) to protect the surface of the earth-rock dam body (1); Several anchor nails (3) are uniformly fixed at the edge of the grid layer (2) to fix the grid layer (2) to the surface of the earth-rock dam body (1); A filler layer (4) is provided on the upper side of the grid layer (2), and the filler layer (4) and the grid layer (2) interlock to form a new composite structure layer.

2. The construction method for laying reinforced geogrid in earth-rock dams in strong earthquake zones according to claim 1, characterized in that: In step S3, the specific method for applying pretension is as follows: using a special tensioning device, a constant pretension of 10%-25% of the ultimate tensile strength of the grid is applied to the reinforced grid through clamps set at the end or side of the grid, and the load is held for 30-60 seconds.

3. The construction method for laying reinforced geogrid in earth-rock dams in strong earthquake zones according to claim 2, characterized in that: The dedicated tensioning equipment is a hydraulic tensioning unit or a mechanical tensioner, whose tension force can be quantitatively controlled and recorded, and is time-coupled with subsequent paving and compaction processes.

4. The method for laying reinforced grid in earth-rock dams in strong earthquake zones according to claim 1, characterized in that: In step S2, the planar anchoring adopts U-shaped steel bar anchors or sandbag arrays for weighting, with the anchoring point spacing not exceeding 2 meters, forming a discrete constraint node structure, which together with the end tensioning constitutes a spatial transfer system for grid prestress.

5. The method for laying reinforced geogrid in earth-rock dams in strong earthquake zones according to claim 1, characterized in that: In step S4, the first layer of filler is laid using the forward unloading method, that is, the dump truck unloads at the front end of the laid grid, and the paver lays the filler from the tensioned area of ​​the grid outward, forming a stress protection structure in which the filler coverage takes precedence over the compaction.

6. The construction method for laying reinforced grid in earth-rock dams in strong earthquake zones according to claim 1, characterized in that: In step S4, light machinery is used to spread the first layer of filler, and no compaction equipment is allowed to walk or work on the reinforced grid that is not covered with filler or whose cover thickness is less than the design thickness.

7. The construction method for laying reinforced geogrid in earth-rock dams in strong earthquake zones according to claim 6, characterized in that: In step S4, after compaction, the filler and the tensioned grid form an interface interlocking structure through the mechanical interlocking of the mesh and filler particles.

8. The construction method for laying reinforced geogrid in earth-rock dams in strong earthquake zones according to claim 1, characterized in that: The reinforced geogrid is any one of bidirectional polypropylene geogrid, glass fiber geogrid, or steel-plastic composite geogrid.

9. The construction method for laying reinforced grid in earth-rock dams in strong earthquake zones according to claim 1, characterized in that: The method is particularly suitable for earth-rock dam projects in strong earthquake zones with seismic fortification intensity of 8 degrees or above. The resulting prestressed reinforced composite structural layer has a seismic resistance mechanism of delayed failure and stress redistribution under strong earthquake action.

10. The method for laying reinforced geogrid in earth-rock dams in strong earthquake zones according to claim 1, characterized in that: The grid layer (2) is composed of a supporting structural surface, a reinforced grid, a discrete constraint anchoring structure, an initial tensile stress structural layer, a filler covering and protection structure, and an interface interlocking structure, forming a composite stress-bearing body with initial stiffness and stress transmission path.

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