A gravity dam arch foundation bearing plate structure suitable for wide faults

Abstract

The present application relates to the technical field of water conservancy and hydropower engineering, in particular to a gravity dam arch foundation bearing plate structure suitable for wide faults. The present application comprises a fault, a dam body arranged on the fault, a reinforced concrete bearing plate arranged at the bottom of the dam body, the bottom of the reinforced concrete bearing plate being in the fault, a dam heel reinforced concrete micro-arch replacement plug and a dam toe reinforced concrete micro-arch replacement plug being arranged on the water-facing side and the backwater side of the fault respectively, and n dam foundation middle reinforced concrete micro-arch replacement plugs being arranged between the dam heel reinforced concrete micro-arch replacement plug and the dam toe reinforced concrete micro-arch replacement plug. The present application has the advantages of greatly reducing the excavation amount, fully utilizing the arch effect of the arch beam to transfer the load to the better bedrock on both sides, improving the bearing capacity of the fault part, homogenizing the dam body load by the wide bearing plate, reducing the load required to be borne by the concrete plug, and slowing down the stress concentration phenomenon at the bottom of the concrete plug.

Description

Technical Field

[0001] This invention relates to the field of water conservancy and hydropower engineering technology, specifically a gravity dam arch foundation bearing plate structure suitable for wide faults. Background Technology

[0002] In water conservancy and hydropower projects, concrete gravity dams mainly rely on the frictional force generated by their own weight on the dam foundation surface and the cohesion between the dam body and the foundation to resist water loads and maintain stability. The lithology of the foundation rock mass has a significant impact on the deformation and stability of the dam body. Therefore, concrete gravity dams have high requirements for foundation conditions and are often built on stable bedrock. However, the site selection of gravity dams sometimes inevitably involves large or super-large faults. Wide faults have a very significant impact on rigid dam bodies like gravity dams, mainly in the following aspects: First, wide faults weaken the bearing capacity of the dam foundation. Due to insufficient bearing capacity in the fault section, stress concentration and uneven deformation of the dam body will occur, resulting in deformation and damage such as cracks. Second, the physical and mechanical properties of the fault section are poor, and the anti-sliding force of the dam foundation is difficult to meet the requirements.

[0003] To address the above issues, in existing engineering examples, trapezoidal concrete plugs are often installed in the foundation of the dam. The contact area between the two sides of the trapezoid and the hard rock increases the anti-sliding force, improves the anti-sliding stability of the dam, and transfers the load to the bedrock on both sides through the side of the rock plug, thereby increasing the bearing capacity and reducing settlement during the construction and impoundment periods. The conventional foundation treatment method has the following shortcomings: ① Improving the bearing capacity of the fault section by replacing it with concrete plugs requires extensive excavation of the dam foundation, causing significant disturbance to the fault, especially in the case of wide faults. This results in longer exposure time of the dam foundation during construction, further weakening the rock mass quality of the foundation. ② Stress concentration is significant at the heel and toe of the gravity dam foundation. Using full-section excavation during foundation treatment leads to insufficient utilization of the concrete strength in the middle of the foundation along the river direction, which is uneconomical. ③ The bottom of the concrete plug tends to bend downwards, and in the treatment of wide faults, the bottom is highly likely to crack due to insufficient tensile strength. ④ The bedrock bearing capacity is limited. When the concrete plug alone bears the dam load, the stress concentration phenomenon in the bottom part embedded in the bedrock is obvious, and the bearing capacity of the dam foundation cannot meet the requirements. ⑤ When the rock plug alone bears the self-weight of the dam section, the settlement problem of the dam section where the fault is located is significant due to the large proportion of the fault at the bottom. Therefore, a bearing plate structure for the arch foundation of gravity dams suitable for wide faults has been researched and invented. Summary of the Invention

[0004] This invention provides a bearing plate structure for the arch foundation of a gravity dam suitable for wide faults. The purpose is to better address the shortcomings of using concrete plugs for gravity dam foundations on wide faults, and to meet the requirements for bearing capacity, anti-sliding stability, etc. of gravity dam foundations.

[0005] The present invention achieves its objective by employing the following technical solution:

[0006] A gravity dam arch foundation bearing plate structure suitable for wide faults includes a fault, a dam body set on the fault, a reinforced concrete bearing plate at the bottom of the dam body, the reinforced concrete bearing plate being set on the fault, reinforced concrete micro-arch replacement fillers for the dam heel and dam toe being set on the water-facing and water-repellent sides of the fault respectively, and n reinforced concrete micro-arch replacement fillers for the dam foundation middle section being arranged between the reinforced concrete micro-arch replacement fillers for the dam heel and dam toe.

[0007] In the aforementioned gravity dam arch foundation bearing plate structure applicable to wide faults, the pouring boundary of the reinforced concrete bearing plate depends on the foundation excavation range, with a width of B1 and a length of L1 perpendicular to the dam axis. L1 is consistent with the width of the bottom of the dam body perpendicular to the axis. A layer of steel bars is arranged at the bottom of the reinforced concrete bearing plate.

[0008] In the aforementioned gravity dam arch foundation bearing plate structure applicable to wide faults, the thickness H1 of the reinforced concrete bearing plate is not less than 0.07 times the dam height.

[0009] In the aforementioned gravity dam arch foundation bearing plate structure applicable to wide faults, on both sides perpendicular to the dam axis, extending upstream and downstream relative to the upstream and downstream sides of the dam body by L2 respectively, there are reinforced concrete micro-arch replacement fillers of the same size at the dam heel and dam toe. Both components are perpendicular to the dam axis and have slopes on both sides with a slope of β=115°-120°, a thickness of H2, L2=H2×sin(β-90°), H2=0.9-1.2H1, a top length of L3, a bottom length of L4, and L3=L4+2L2. Along the dam axis, the top width is B2, the bottom width is the fault width B3, and the width penetrating into the intact rock mass is B4. Slopes are set on both sides with a slope width of B5, a slope of α, and an angle of α of 120°-145°. Reinforced piles are arranged on the slopes.

[0010] In the aforementioned gravity dam arch foundation bearing plate structure applicable to wide faults, the reinforced concrete micro-arch replacement filler at the dam heel and the reinforced concrete micro-arch replacement filler at the dam toe are made of micro-expansion concrete material.

[0011] In the aforementioned gravity dam arch foundation bearing plate structure applicable to wide faults, the reinforced concrete micro-arch replacement filler at the dam heel and the reinforced concrete micro-arch replacement filler at the dam toe are provided with a circular arc micro-arch structure at the bottom. The height of the arch top is H4, where H4 = 0.06-0.1H2. The arch span is consistent with the fault width B3, and the arch radius R = [(B3 / 2)]. 2 +H4 2 ] / 2H4, the central angle of the arch is θ=2×arctan(2(R-H4) / B3); steel bars are arranged at the bottom and sides of the reinforced concrete micro-arch replacement filler at the dam heel and the reinforced concrete micro-arch replacement filler at the dam toe.

[0012] In the aforementioned gravity dam arch foundation bearing plate structure applicable to wide faults, a 0.4-0.5m micro-arch foundation excavation protection layer is provided at the bottom of the reinforced concrete micro-arch replacement filler at the dam heel and the reinforced concrete micro-arch replacement filler at the dam toe.

[0013] In the aforementioned gravity dam arch foundation bearing plate structure applicable to wide faults, n reinforced concrete micro-arch replacement fillers are arranged in the middle of the dam foundation perpendicular to the dam foundation direction. The number of reinforced concrete micro-arch replacement fillers is determined according to the dam foundation length L1. Except for the length L5 of the top perpendicular to the dam axis and the length L6 of the bottom, all other dimensions are consistent with those of the reinforced concrete micro-arch replacement fillers at the dam heel and dam toe.

[0014] In the aforementioned gravity dam arch foundation bearing plate structure applicable to wide faults, the length of L6 is not less than 5m, the top spacing of adjacent reinforced concrete micro-arch replacement fillers is L7, and L7 is not less than 2.5m.

[0015] 1. Addressing the drawbacks of conventional dam foundation treatment, such as large excavation volumes, increased investment, stress concentration in the rock plug, and excessive settlement, this invention offers a gravity dam arch foundation bearing plate structure suitable for wide faults. It modifies the traditional foundation plus concrete plug structure. First, the fault section is excavated and cleared. An arched beam foundation surface is excavated along the dam axis. Such arched beam foundations are then installed in sections at the dam heel, toe, and middle of the foundation. A wide bearing plate is then placed on the arched beam foundation. This transforms the traditional concrete plug into an arched beam-slab foundation bearing structure, significantly reducing excavation volume and fully utilizing the arch effect to transfer the load to the better bedrock on both sides, thereby improving… The dam structure's bearing capacity is enhanced by the wide bearing plate, which also homogenizes the load on the dam body, reducing the load on the concrete plug and mitigating stress concentration at the bottom of the concrete plug. Simultaneously, it mitigates the impact of insufficient bearing capacity in the wide fault, reduces uneven deformation of the dam body, and increases the contact area with the bedrock in the segmented arch beams, improving the anti-sliding force in both the vertical and horizontal directions, thus ensuring the dam's anti-sliding stability. Furthermore, the segmented arch beams also reduce the hazards caused by the hydrothermal effect of large-volume concrete. Simultaneous construction of each arch beam shortens the time the bedrock is exposed to air and rainwater, ensuring the safety of the dam foundation and saving investment.

[0016] 2. The unique load-bearing foundation structure spanning wide faults provided by this invention changes the traditional conventional concrete plug replacement structure. A wide load-bearing plate is installed at the top of the concrete plug, and a slightly arched structure is adopted at the bottom, with segmented arrangement. The structure has the following effects:

[0017] (1) The overall load-sharing effect of the bearing plate of the present invention reduces the uneven settlement of the dam body caused by the low deformation modulus of the fault zone and insufficient bearing capacity, avoids the cracking of the anti-seepage panel and the anti-seepage curtain caused by uneven deformation, and transfers the load of the upper dam body to the good bedrock with greater stiffness through the bearing plate, redistributing the stress and reducing the stress concentration caused by uneven settlement of the rigid dam body, thus avoiding the generation of cracks in the dam foundation or dam body due to excessive stress.

[0018] (2) The micro-arch structure at the bottom of the concrete plug in this invention is determined based on the distribution range of tensile stress at the bottom. Through the arch effect, the tensile stress at the bottom of the concrete plug is reduced, avoiding tensile cracking damage caused by the low deformation modulus of the wide fault and bending in the middle. At the same time, the two ends of the arch transfer most of the load to the bedrock, further weakening the adverse effects of the fault. However, the arch height should not be too large. The higher the arch, the more load the concrete plug will bear on the bottom rock mass at both ends, which is prone to damage and deformation due to insufficient bearing capacity of the bedrock. Therefore, a micro-arch type is adopted.

[0019] (3) The concrete plug of the present invention is set in multiple sections in the direction perpendicular to the dam axis, which further expands the contact area with the bedrock. At the same time, the embedding depth in the bedrock makes the resistance along the direction of water thrust greater, which improves the anti-sliding stability of the dam body and increases the degree of bonding between the foundation and the dam body.

[0020] (4) The concrete plug of the present invention has a slope along the dam axis, which increases the contact area with the bedrock, improves the foundation resistance, reduces settlement in the vertical direction, reduces displacement in the direction of water thrust, and can transfer the upper load to the bedrock on both sides, thus improving the anti-sliding force of the foundation.

[0021] (5) The present invention provides a protective layer of 0.4-0.5m thick at the bottom of the entire concrete plug to prevent further deterioration of the fault rock mass due to weathering and rainwater soaking during the period from foundation excavation to concrete pouring.

[0022] (6) The present invention excavates and pours concrete in sections, which reduces the amount of concrete used in the middle part of the dam foundation where the stress is small, saves investment, reduces the hydrothermal effect of large volume concrete, and at the same time reduces the pouring area, improves efficiency, and covers the excavated rock mass as soon as possible, thereby reducing the degree of weathering and erosion of the foundation rock mass. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the cross-sectional structure of the present invention in the direction perpendicular to the dam axis;

[0025] Figure 2 This is a schematic diagram of the cross-sectional structure along the dam axis of the present invention;

[0026] Attached reference numerals: 1-Fault; 2-Reinforced concrete bearing plate; 3-Reinforced concrete micro-arch replacement filler at the dam heel; 4-Reinforced concrete micro-arch replacement filler at the dam toe; 5-Reinforced concrete micro-arch replacement filler in the middle of the dam foundation; 6-Protective layer for the micro-arch foundation excavation; 7-Reinforced pile; 8-Dam body. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0029] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing the invention and its embodiments, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to be constructed and operated in a specific orientation.

[0030] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain situations to indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0031] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] Example. A gravity dam arch foundation bearing slab structure suitable for wide faults, such as... Figure 1-2 As shown, this invention includes the following components: fault 1 (fault fracture zone and affected zone); reinforced concrete bearing plate 2; reinforced concrete micro-arch replacement filler at the dam heel 3; reinforced concrete micro-arch replacement filler at the dam toe 4; reinforced concrete micro-arch replacement filler in the middle of the dam foundation 5; excavation protective layer for the micro-arch foundation 6; steel piles 7; dam body 8. The specific structural relationships and arrangement are as follows:

[0034] A dam body 8 is set on fault 1. A reinforced concrete bearing plate 2 is set at the bottom of the dam body 8. The reinforced concrete bearing plate 2 is set on fault 1. Reinforced concrete micro-arch replacement plugs 3 and 4 are set on the water-facing and back-facing sides of fault 1, respectively. n reinforced concrete micro-arch replacement plugs 5 are arranged in the middle of the dam foundation between the dam heel reinforced concrete micro-arch replacement plugs 3 and the dam toe reinforced concrete micro-arch replacement plugs 4.

[0035] The pouring boundary of the reinforced concrete bearing plate 2 depends on the foundation excavation range, with a width of B1. The width can be adjusted according to the excavation of the dam shoulder. The length in the direction perpendicular to the dam axis is L1, and L1 is consistent with the width in the direction perpendicular to the dam bottom. A layer of steel bars is arranged at the bottom of the reinforced concrete bearing plate 2 to resist bending moment and shear force.

[0036] The thickness H1 of the reinforced concrete bearing plate 2 shall not be less than 0.07 times the dam height. Through finite element analysis of gravity dam profile models of different heights, when the thickness exceeds 0.06 times the dam height, the deformation feedback of the reinforced concrete plate is not obvious. Taking a safety margin of 1.2, it is recommended that the thickness not be less than 0.07 times the dam height.

[0037] Perpendicular to the dam axis, L2 extends upstream and downstream relative to the upstream and downstream sides of the dam body, respectively. Slopes are constructed on both the upstream and downstream sides to the bottom. At these two locations, after excavation of fault 1, reinforced concrete micro-arch replacement plugs 3 and 4 are constructed, with identical dimensions. Both the dam heel and toe reinforced concrete micro-arch replacement plugs 3 and 4 have slopes on both sides, with a slope of β = 115°-120° and a thickness of H2. L2 = H2 × sin(β - 90°), H2 = 0.9 - 1.2H1. The top length is L3, and the bottom length is L4, L3 = L4 + 2L2. Along the dam axis, the top width is B2, and the bottom width is the fault width B3. The width of the intact rock mass is B4, with slopes on both sides. The slope width is B5, the slope is α, and the angle of α is 120°-145°. When the specific fault deformation modulus is small, the larger value should be taken. 7 steel piles are arranged on the slope.

[0038] Among them, the reinforced concrete micro-arch replacement filler 3 at the dam heel and the reinforced concrete micro-arch replacement filler 4 at the dam toe are designed with the same dimensions, assuming that the width of the fault zone in the dam foundation remains basically unchanged. Therefore, the widths of the two components are basically the same. If the width of the fault zone varies greatly between the upstream and downstream sides, the width can be adjusted according to the actual situation of the dam foundation. The dam heel and dam toe are areas with relatively concentrated stress, so the replacement filler height and length of the foundations at the two locations are basically the same.

[0039] The slope is β=115°-120°, the thickness is H2, L2=H2×sin(β-90°), H2=0.9-1.2H1, the top length is L3, the bottom length is L4, and L3=L4+2L2. These values ​​are all obtained through parameter sensitivity calculations. By establishing a refined finite element model of the dam body and foundation and adjusting the dimensional parameters, the following pattern was observed: When the slope is β=115-120°, construction and excavation are more convenient. If the slope is too steep, there is a problem of slope instability in the foundation pit. If the slope is too gentle, in order to expand the contact area of ​​the foundation, it is necessary to increase the excavation range and the amount of excavation, which will cause excessive disturbance to the foundation. Similarly, if the thickness of the replacement fill is insufficient, the lateral anti-sliding force and the stiffness of the replacement fill will be insufficient. If it is too thick, the amount of excavation and pouring will increase, which is uneconomical. L4 is determined by dividing the foundation into n basic units based on the river-direction length of the foundation and the on-site pouring intensity.

[0040] Along the dam axis, the top width is B2, the bottom width is the fault width B3, the width extending into the intact rock mass is B4, and slopes are set on both sides with a slope width of B5 and a slope of α. The angle of α is 120°-145°. In order to facilitate construction and stress homogenization, B4 can be 2-3m. The other parameters can be determined by determining B4.

[0041] The reinforced concrete micro-arch replacement plug 3 at the dam heel and the reinforced concrete micro-arch replacement plug 4 at the dam toe are made of micro-expansion concrete. Using this material can increase its cohesion.

[0042] The reinforced concrete micro-arch replacement plug 3 at the dam heel and the reinforced concrete micro-arch replacement plug 4 at the dam toe are provided with a circular arc micro-arch structure at the bottom. The height of the top of the arch is H4, where H4 = 0.06-0.1H2. The span of the arch is consistent with the fault width B3, and the arch radius R = [(B3 / 2)]. 2 +H4 2 [ / 2H4, the central angle of the arch is θ=2×arctan(2(R-H4) / B3); Reinforcing bars are arranged at the bottom and sides of the reinforced concrete micro-arch replacement plug 3 at the dam heel and the reinforced concrete micro-arch replacement plug 4 at the dam toe. The purpose of arranging the reinforcing bars is to ensure the tensile performance of the structure. Through sensitivity analysis, the smaller the arch radius, the more concentrated the dam load will be on the foundations at both ends. If the radius is larger, the dam load will be distributed to the bottom of the entire rock plug. Since the bearing capacity of the fault zone in the middle is limited, there will be a large tensile stress in the middle of the replacement plug, which is unfavorable to the structure. Therefore, after determining the arch height, the radius and central angle can be determined. The greater the difference between the geological parameters of the dam foundation rock mass and the fault, the higher the arch should be.

[0043] The bottom of the reinforced concrete micro-arch replacement plug 3 at the dam heel and the reinforced concrete micro-arch replacement plug 4 at the dam toe are provided with a 0.4-0.5m thick micro-arch foundation excavation protective layer 6. After the foundation is excavated in stages, the 0.4-0.5m thick micro-arch foundation excavation protective layer 6 is poured immediately, which can reduce the weathering and water immersion of the fault foundation rock mass.

[0044] n reinforced concrete micro-arch replacement fillers 5 are arranged in the middle of the dam foundation perpendicular to the dam foundation direction. The number of reinforced concrete micro-arch replacement fillers 5 is determined according to the length L1 of the dam foundation. Except for the length L5 of the top perpendicular to the dam axis and the length L6 of the bottom, the other dimensions are the same as those of the reinforced concrete micro-arch replacement filler 3 at the dam heel and the reinforced concrete micro-arch replacement filler 4 at the dam toe.

[0045] The length of L6 is not less than 5m, and the top spacing between adjacent reinforced concrete micro-arch replacement fillers 5 is L7, with L7 not less than 2.5m. The purpose of this technical setting is to ensure the strength of the arch beam.

[0046] This invention changes the traditional structure of a foundation with a concrete plug. First, the fault section 1 is excavated and cleared. An arched beam foundation surface is excavated along the dam axis. Such arched beam foundations are then installed in sections at the dam heel, toe, and middle of the dam foundation. A wide load-bearing plate 2 is placed on the arched beam foundation. In this way, the traditional concrete plug is transformed into an arched beam-slab foundation load-bearing structure, significantly reducing the amount of excavation. The arch effect of the arched beam is fully utilized to transfer the load to the better bedrock on both sides, improving the bearing capacity of the fault section. The wide load-bearing plate 2 also homogenizes the dam load. This reduces the load that the concrete plug needs to bear, alleviates the stress concentration at the bottom of the concrete plug, and at the same time weakens the impact of insufficient bearing capacity of the wide fault, reduces uneven deformation of the dam body, and the segmented arch beams increase the contact area with the bedrock, improve the anti-sliding force in the vertical and horizontal directions, and ensure the anti-sliding stability of the dam body 8. At the same time, the segmented arch beams can also reduce the hazards caused by the hydrothermal effect of large-volume concrete. Each arch beam can be constructed simultaneously, shortening the time that the bedrock is exposed to air and rainwater, ensuring the safety of the dam foundation and saving investment.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A reinforced concrete bearing slab structure for a gravity dam arch foundation suitable for wide faults, comprising a fault (1) and a dam body (8) disposed on the fault (1), characterized in that: The bottom of the dam body (8) is provided with a reinforced concrete bearing plate (2), which is located on the fault (1). The water-facing and back-facing sides of the fault (1) are respectively provided with a reinforced concrete micro-arch replacement plug (3) for the dam heel and a reinforced concrete micro-arch replacement plug (4) for the dam toe. There are n reinforced concrete micro-arch replacement plugs (5) in the middle of the dam foundation between the reinforced concrete micro-arch replacement plug (3) for the dam heel and the reinforced concrete micro-arch replacement plug (4) for the dam toe.

2. The reinforced concrete bearing slab structure for gravity dam arch foundations suitable for wide faults according to claim 1, characterized in that: The pouring boundary of the reinforced concrete bearing plate (2) depends on the foundation excavation range, with a width of B1 and a length of L1 in the direction perpendicular to the dam axis. L1 is consistent with the width in the direction perpendicular to the dam bottom axis. A layer of steel bars is arranged at the bottom of the reinforced concrete bearing plate (2).

3. The reinforced concrete bearing slab structure for gravity dam arch foundations suitable for wide faults according to claim 1, characterized in that: The thickness H1 of the reinforced concrete bearing plate (2) shall not be less than 0.07 times the dam height.

4. The reinforced concrete bearing slab structure for gravity dam arch foundations suitable for wide faults according to claim 3, characterized in that: On both sides perpendicular to the dam axis, after extending L2 upstream and downstream relative to the upstream and downstream sides of the dam body, respectively, there are reinforced concrete micro-arch replacement plugs (3) and reinforced concrete micro-arch replacement plugs (4) of the same size. Both components are perpendicular to the dam axis and have slopes on both sides with a slope of β=115°-120° and a thickness of H2, L2=H2×sin(β-90°), H2=0.9-1.2H1, a top length of L3, a bottom length of L4, and L3=L4+2L2. Along the dam axis, the top width is B2, the bottom width is the fault width B3, and the width into the intact rock mass is B4. There are slopes on both sides with a slope width of B5, a slope of α, and an angle of α of 120°-145°. Reinforced piles (7) are arranged on the slopes.

5. The reinforced concrete bearing slab structure for gravity dam arch foundations suitable for wide faults according to claim 1, characterized in that: The reinforced concrete micro-arch replacement plug (3) at the dam heel and the reinforced concrete micro-arch replacement plug (4) at the dam toe are made of micro-expansion concrete.

6. The reinforced concrete bearing slab structure for gravity dam arch foundations suitable for wide faults according to claim 3, characterized in that: The reinforced concrete micro-arch replacement plugs (3) at the dam heel and (4) at the dam toe are provided with a circular arc micro-arch structure at the bottom. The height of the top of the arch is H4, where H4 = 0.06 - 0.1H2. The arch span is consistent with the fault width B3, and the arch radius R = [(B3 / 2)]. 2 +H4 2 ] / 2H4, the central angle of the arch is θ=2×arctan(2(R-H4) / B3); steel bars are arranged at the bottom and sides of the reinforced concrete micro-arch replacement plug (3) at the dam heel and the reinforced concrete micro-arch replacement plug (4) at the dam toe.

7. The reinforced concrete bearing slab structure for gravity dam arch foundations suitable for wide faults according to claim 1, characterized in that: The bottom of the reinforced concrete micro-arch replacement plug (3) at the dam heel and the reinforced concrete micro-arch replacement plug (4) at the dam toe are provided with a micro-arch foundation excavation protection layer (6) of 0.4-0.5m.

8. The reinforced concrete bearing slab structure for gravity dam arch foundations suitable for wide faults according to claim 5, characterized in that: n reinforced concrete micro-arch replacement plugs (5) are arranged in the middle of the dam foundation perpendicular to the dam foundation direction. The number of reinforced concrete micro-arch replacement plugs (5) is determined according to the length L1 of the dam foundation. Except for the length L5 of the top perpendicular to the dam axis and the length L6 of the bottom, the other dimensions are consistent with the reinforced concrete micro-arch replacement plugs (3) of the dam heel and the reinforced concrete micro-arch replacement plugs (4) of the dam toe.

9. The reinforced concrete bearing slab structure for gravity dam arch foundations suitable for wide faults according to claim 8, characterized in that: The length of L6 is not less than 5m, and the top spacing of the adjacent reinforced concrete micro-arch replacement plug (5) is L7, and L7 is not less than 2.5m.

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