Waste-material-free earth and rockfill dam construction method and structure

Abstract

The invention discloses a waste-material-free earth and rockfill dam damming method and structure, and relates to the technical field of hydraulic engineering. The waste-material-free earth and rockfill dam damming method comprises the steps that filling materials are collected and subjected to grading pretreatment; carrying out a physical and mechanical property test on the pretreated filling material; the dam shell material area is subjected to filling partition division; constructing a dam body core area and a transition area; carrying out layered filling construction on a dam shell material area; and a composite protection surface and an auxiliary structure are constructed. According to the waste-material-free earth and rockfill dam construction method and structure, the base materials of the anti-seepage core wall and the transition layer are made of clay waste materials collected by engineering and are slightly modified to form high-quality anti-seepage materials, meanwhile, the engineering waste materials with different properties are matched with all vertical and horizontal subareas of the dam shell material area in a grading mode, and the dam shell material area is made of the clay waste materials. Full-amount non-waste utilization of engineering waste materials is achieved, a large number of damming raw materials do not need to be purchased, and surrounding vegetation damage and water and soil loss are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic engineering, in particular to a dam construction method and structure for earth-rock dam without waste materials. BACKGROUND

[0002] In traditional earth-rock dam construction, natural earth-rock materials generated by engineering excavation, base cleaning waste materials of dam abutment, and construction waste sand and stone materials, etc. are often judged as waste materials due to the fact that their physical and mechanical properties do not meet the "unified filling standard", which not only causes waste of resources, but also requires additional land for storage, which is easy to cause secondary geological and ecological problems. At the same time, in order to meet the demand for dam construction materials, the construction party needs to take materials from outside the reservoir area, which destroys the surrounding vegetation and exacerbates the contradiction between engineering construction and ecological protection.

[0003] Although the existing full-material dam technology can realize dam construction without waste materials, the dam structure usually includes rigid dam sections such as concrete dam body and cemented material dam body, which has problems such as high dosage of cementing materials, complex construction process, limited adaptation scenarios, etc. Moreover, it does not form a refined material adaptation system for the stress deformation zoning characteristics of earth-rock dams, which is difficult to balance the flexible adaptation of earth-rock dams and the goal of no waste materials. SUMMARY

[0004] The purpose of the present application is to provide a dam construction method and structure for earth-rock dam without waste materials to solve the problems raised in the background.

[0005] To achieve the above purpose, the present application provides a dam construction method for earth-rock dam without waste materials, which comprises the following steps: Step S1, collecting filling materials and pre-treating the filling materials by grading; Step S2, performing physical and mechanical property test on the pre-treated filling materials; Step S3, performing filling partition division on the dam shell material area; Step S4, performing dam body core area and transition area construction; Step S5, performing layer filling construction on the dam shell material area; Step S6, performing composite protection surface and auxiliary structure construction.

[0006] Preferably, the step S1 comprises: Step S11, collecting natural earth-rock materials excavated in the reservoir area, base cleaning waste materials of dam abutment, and construction waste sand and stone materials, and simultaneously performing directional excavation on the natural earth-rock materials in the reservoir area to expand the effective reservoir capacity of the reservoir; Step S12, removing impurities and oversized particles with a particle size greater than 300mm from the collected filling materials; Step S13, sunning or watering the filling materials deviating from the optimal moisture content for adjustment; Step S14: Add 5%-6% lime to the soft soil filling material in the shallow filling layer of the slope for modification; Step S15: Gradation and screening of the stone filling material for the dam foundation bearing layer.

[0007] Preferably, step S2 includes: The pretreated filling materials were tested, including tests on strength, modulus, deformation characteristics, permeability coefficient, and compaction characteristics. Simulated tests were also conducted at different locations within the dam body, as detailed below: Step S21: For the dam foundation bearing layer filling material, a high confining pressure triaxial test is added to verify its stability under high vertical stress. Step S22: For the seepage-proof core wall filling material, conduct seepage deformation tests at different vertical depths to determine the critical hydraulic gradient; Step S23: Retest the mechanical properties of the modified soft soil filling material.

[0008] Preferably, step S3 includes: Step S31: Using three-dimensional finite element software, construct a three-dimensional finite element model of the dam body based on the dam design parameters, and simulate the actual stress state of the dam body to obtain the vertical and horizontal mechanical indices of the dam shell material area, thus forming a distribution map of the mechanical properties of the dam shell material area. Step S32: Based on the distribution map of mechanical properties of the dam shell material area, divide the dam shell material area into three regions from bottom to top along the vertical height: the dam foundation bearing layer, the middle stable layer, and the upper and shallow slope filling layer. Step S33: Based on the test results obtained in step S2, the collected fill material is divided into three categories, including primary waste material, secondary waste material and tertiary waste material; Step S34: Match different grades of waste materials with different divisions of the dam shell material area, including: Step S341: Divide the dam foundation bearing layer into a core sub-zone and a secondary core sub-zone along the horizontal direction. The core sub-zone is suitable for primary waste material, and the secondary core sub-zone is suitable for primary waste material or modified secondary waste material. Step S342: The middle stabilization layer is adapted to secondary waste materials; Step S343: For the upper part and the shallow filling layer of the slope, the upper area is suitable for secondary waste material, and the shallow filling layer area of ​​the slope is suitable for tertiary waste material. In the above steps, if the primary waste material is insufficient, a modifier is added to the secondary waste material for local modification to increase its compression modulus before it is used in the core sub-area of ​​the dam foundation bearing layer; if the shear resistance of the tertiary waste material does not meet the standard, a geogrid reinforcement layer is added to enhance the shallow slope stability.

[0009] Preferably, step S5 includes: Step S51: Following the vertical filling sequence of first the dam foundation bearing layer, then the middle stabilizing layer, and finally the upper and shallow slope filling layers, the construction within the same vertical level shall proceed in the horizontal sequence of first the core sub-area, then the core sub-area, and finally the homogeneous area / slope area. Differentiated compaction processes are adopted for different types of waste materials, as detailed below: The primary waste material in the dam foundation bearing layer is compacted using a heavy vibratory roller weighing no less than 25t, with a compaction degree of no less than 96%. The secondary waste material in the middle stabilized layer is compacted using a 20t vibratory roller, with a compaction degree of not less than 95%. Lightweight compaction equipment is used for the upper part and shallow layer of the slope to compact the Class III waste material, with a compaction degree of not less than 90%. At the same time, a geogrid reinforcement layer is added to the shallow layer of the slope, and the geogrid is anchored into the dam shell material area to a depth of not less than 0.8m. Step S52: Fill the primary waste material into the core sub-area and secondary core sub-area of ​​the dam foundation bearing layer, fill the secondary waste material into the homogeneous area of ​​the central stable layer and the upper area of ​​the dam shell material area, and fill the tertiary waste material into the shallow filling layer of the slope. All the waste materials collected from the project are put into the filling, and there is no waste excavation material left.

[0010] Preferably, step S6 includes: Step S61: Lay a composite protective layer from bottom to top along the upstream and downstream slopes of the dam body. First, lay a bottom reinforced protective layer at 1 / 2 of the vertical construction ground level and dam height, using geogrid to wrap the crushed stone. The geogrid is anchored into the dam shell material area. Then, lay a middle layer of ecological vegetation at 1 / 2-2 / 3 of the vertical dam height. Finally, lay a top layer of riprap from 2 / 3 of the vertical dam height to the dam top and upstream wave-facing area. Anchor bars are used to connect the layers to ensure the integrity of the protective layer. Step S62: Construct an auxiliary drainage structure at the downstream toe of the dam body. Under rock foundation conditions, a drainage prism is laid out using rubble masonry and is connected to the lower part of the dam shell material area. Under soft foundation conditions, a retaining structure is added simultaneously. The drainage prism and the retaining structure work together to quickly drain seepage water from the dam body and reduce the pore water pressure inside the dam body.

[0011] Preferably, step S4 includes: Step S411: First, excavate the anti-seepage groove of the dam foundation, pour concrete into the groove to form an anti-seepage base, and fill the anti-seepage section of the dam foundation with the anti-seepage core wall above the anti-seepage base. Cement-modified soil is used for layered compaction and filling. At the same time, the dam foundation section of the transition layer and the dam foundation section of the anti-seepage core wall are formed into an irregular interlocking structure with an interlocking depth of not less than 0.8m. The interlocking area adopts a cross-compaction process to ensure that there are no construction joints. Step S412: The main seepage-proof section of the seepage-proof core wall is filled from bottom to top in layers. Cement-modified soil is used for filling. A seepage-proof reinforcing grid is installed at each set vertical height of filling. The grid extends laterally to a set distance inside the transition layer. At the same time, the middle section of the transition layer is filled simultaneously. It is constructed with a double-layer structure of an inner fine-grained transition layer and an outer coarse-grained transition layer. An irregular interlocking structure is formed between the two layers and between the two layers and the seepage-proof core wall. Step S413: Fill the top seepage-proof section of the seepage-proof core wall using clay-modified soil, with the thickness gradually narrowing from the middle to the top; at the same time, fill the upper section of the transition layer simultaneously, forming an irregular interlocking structure with an interlocking depth of not less than 0.5m; finally, pour the seepage-proof cover plate on the top of the dam to achieve a seamless connection between the top of the seepage-proof core wall and the top of the dam.

[0012] Preferably, step S4 includes: Step S421: Collect weeds in the project area and mix them evenly with the clay-modified soil substrate for the seepage prevention core wall. Add water to adjust the moisture content, pour it into a mold and vibrate to compact it. After curing for 48 hours, demold it to make the soil nail finished product. Step S422: First, excavate the anti-seepage toothed groove of the dam foundation, pour concrete into the toothed groove to form an anti-seepage base, and fill the anti-seepage core wall of the dam foundation in layers above the anti-seepage base. Simultaneously, carry out the filling of the transition layer dam foundation section. During the filling process, soil nails are laid. After the soil nails are laid, cross-compaction process is used for the connection area. Step S423: The main seepage-proof section of the seepage-proof core wall is filled from bottom to top in layers. Cement-modified soil is used for filling. A seepage-proof reinforcing grid is set at a set vertical height for each filling layer. The grid extends laterally to a set distance inside the transition layer. At the same time, the middle section of the transition layer is filled synchronously. Soil nails are set after each layer is filled. The soil nails of adjacent layers are staggered. Step S424: Fill the top seepage barrier section of the seepage barrier core wall, using clay-modified soil to fill in layers, with the thickness gradually narrowing from the middle of the dam body to the top of the dam. Step S425: After each layer of clay-modified soil in the top seepage prevention section is filled and compacted, soil nails are installed, with the soil nails in adjacent layers arranged in an alternating pattern. Step S426: After the soil nails are laid, the upper section of the transition layer is filled simultaneously. The upper section of the transition layer is compacted in layers. The anti-seepage cover plate on the top of the dam is poured. The cover plate covers the top of the anti-seepage core wall and the top surface of the upper section of the transition layer, so as to achieve a seamless connection between the top of the anti-seepage core wall and the top of the dam.

[0013] A structure for a waste-free earth-rock dam construction method includes a dam body, the dam body including a seepage-proof core wall, dam shell material areas symmetrically arranged on both sides of the seepage-proof core wall, the dam shell material areas and the seepage-proof core wall being connected by a transition layer, and the connection between the transition layer and the seepage-proof core wall and the connection between the transition layer and the dam shell material area forming an irregular interlocking structure. The seepage-proof core wall includes a dam foundation seepage-proof section, a central main seepage-proof section, and a top seepage-proof section; The dam shell material zone includes a dam foundation bearing layer, a middle stabilizing layer, and an upper and shallow slope filling layer. Composite protective surfaces are provided on both sides of the dam shell material area; An auxiliary drainage structure is also provided at the downstream toe of the main dam body.

[0014] A method for constructing a waste-free earth-rock dam includes a dam body, the dam body including a seepage-proof core wall, dam shell material zones symmetrically arranged on both sides of the seepage-proof core wall, the dam shell material zones and the seepage-proof core wall being connected by a transition layer, the transition layer being connected to the seepage-proof core wall and the dam shell material zones by soil nails; The seepage-proof core wall includes a dam foundation seepage-proof section, a central main seepage-proof section, and a top seepage-proof section; The dam shell material zone includes a dam foundation bearing layer, a middle stabilizing layer, and an upper and shallow slope filling layer. Composite protective surfaces are provided on both sides of the dam shell material area; An auxiliary drainage structure is also provided at the downstream toe of the main dam body.

[0015] Therefore, the present invention adopts the above-mentioned method and structure for constructing a waste-free earth-rock dam. By using clay waste collected from engineering projects as the base material for the seepage-proof core wall and transition layer, and modifying it slightly to form high-quality seepage-proof materials, the engineering waste materials with different properties are graded and adapted to the vertical and horizontal zones of the dam shell material area. This achieves the full utilization of engineering waste materials without waste, eliminating the need to purchase large quantities of dam construction materials from outside sources, and avoiding damage to surrounding vegetation and soil erosion. In addition, the dam body adopts an irregular interlocking jointless construction structure of pure granular materials and a vertical layered and zoned design, which not only ensures the seepage prevention and structural stability of the dam body, but also adapts to various foundation conditions, taking into account engineering safety, ecological environmental protection and economy.

[0016] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating a method and structural embodiment of a waste-free earth-rock dam construction method according to the present invention; Figure 2 This is a schematic diagram of the structure of a waste-free earth-rock dam construction method and structure according to the present invention; Figure 3 This is a schematic diagram showing the distribution of the irregular sawtooth structure of the earth-rock dam construction method and structure without waste material according to the present invention. Figure 4 This is a schematic diagram showing the distribution of soil nails in the method and structure for constructing a waste-free earth-rock dam according to the present invention. Attached reference numerals: 1. Impermeable core wall; 2. Transition layer; 3. Dam shell material zone; 4. Composite protective layer; 5. Auxiliary drainage structure; 6. Irregular sawtooth structure; 7. Soil nail. Detailed Implementation

[0018] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] Example Please see Figures 1-4 Please see Figures 1-4 This invention provides a method for constructing a waste-free earth-rock dam, comprising the following steps: Step S1: Collect the filling materials and perform graded pretreatment on the filling materials. This includes: Step S11: Collect the excavated natural soil and rock materials, dam shoulder mountain clearing waste materials, and construction waste sand and gravel materials in the reservoir area. During the collection, the natural soil and rock materials in the reservoir area are excavated in a directional manner to expand the effective storage capacity of the reservoir. Step S12: Remove impurities (such as construction waste and corrosive soil) and oversized particles with a diameter greater than 300mm from the collected filling material. Step S13: Adjust the filling material by turning it over or sprinkling water if the moisture content deviates from the optimum moisture content (±3%). Step S14: Add 5%-6% lime to the soft soil filling material in the shallow filling layer of the slope for modification; Step S15: Perform gradation screening on the stone filling material for the dam foundation bearing layer to ensure that the particle size meets the design requirements.

[0021] Step S2: Conduct physical and mechanical property tests on the pretreated filling material. This includes: The pretreated filling materials were tested, including tests on strength, modulus, deformation characteristics, permeability coefficient, and compaction characteristics. Simulated tests were also conducted at different locations within the dam body, as detailed below: Step S21: For the dam foundation bearing layer filling material, a high confining pressure triaxial test is added to verify its stability under high vertical stress. Step S22: For the filling material of the seepage-proof core wall 1, additional seepage deformation tests at different vertical depths are conducted to determine the critical hydraulic gradient; Step S23: Retest the mechanical properties of the modified soft soil filling material.

[0022] Step S3: Divide the dam shell material zone 3 into filling zones. This includes: Step S31: Using three-dimensional finite element software, construct a three-dimensional finite element model of the dam body according to the dam body design parameters, and simulate the actual stress state of the dam body to obtain the vertical and horizontal mechanical indices of the dam shell material zone 3, forming a distribution map of the mechanical properties of the dam shell material zone 3. Step S32: Based on the distribution map of mechanical properties of dam shell material area 3, divide dam shell material area 3 into three regions from bottom to top along the vertical height: dam foundation bearing layer, middle stable layer, and upper and shallow slope filling layer. Step S33: Based on the test results obtained in step S2, the collected fill material is divided into three categories, including primary waste material (semi-weathered rock material, internal friction angle ≥25°, compression modulus ≥60MPa), secondary waste material (construction waste sand and gravel material, internal friction angle ≥20°, compression modulus ≥40MPa), and tertiary waste material (modified dredged soft soil material, internal friction angle ≥18°, compression modulus ≥20MPa). Step S34: Match different grades of waste materials with the different divisions of the dam shell material zone 3. This includes: Step S341: Divide the dam foundation bearing layer into a core sub-zone and a secondary core sub-zone along the horizontal direction. The core sub-zone is suitable for primary waste material, and the secondary core sub-zone is suitable for primary waste material or modified secondary waste material. Step S342: The middle stabilization layer is adapted to secondary waste materials; Step S343: For the upper part and the shallow filling layer of the slope, the upper area is suitable for secondary waste material, and the shallow filling layer area of ​​the slope is suitable for tertiary waste material. In the above steps, if the primary waste material is insufficient, a modifier is added to the secondary waste material for local modification to increase its compression modulus before it is used in the core sub-area of ​​the dam foundation bearing layer; if the shear resistance of the tertiary waste material does not meet the standard, a geogrid reinforcement layer is added to enhance the shallow slope stability.

[0023] Step S4: Construct the core area and transition zone of the dam. This includes: Step S41: First, excavate the anti-seepage groove of the dam foundation, pour concrete into the groove to form an anti-seepage base, and fill the anti-seepage section of the dam foundation of the anti-seepage core wall 1 above the anti-seepage base. Cement-modified soil is used for layered compaction and filling. At the same time, the dam foundation section of the transition layer 2 and the dam foundation section of the anti-seepage core wall 1 are formed into an irregular interlocking structure 6 with an interlocking depth of not less than 0.8m. The interlocking area adopts a cross-compaction process to ensure that there are no construction joints. Step S42: The main seepage-proof section in the middle of the seepage-proof core wall 1 is filled from bottom to top in layers. Cement-modified soil is used for filling. A seepage-proof reinforcing grid is set at each set vertical height of filling. The grid extends laterally to the interior of the transition layer 2 at a set distance. At the same time, the middle section of the transition layer 2 is filled synchronously. It is constructed according to the double-layer structure of the inner fine-grained transition layer 2 and the outer coarse-grained transition layer 2. Irregular interlocking structures 6 are formed between the two layers and between the two layers and the seepage-proof core wall 1. Step S43: Fill the top seepage-proof section of the seepage-proof core wall 1, using clay-modified soil, with the thickness gradually narrowing from the middle to the top (the thickness at the top of the dam is not less than 2m); at the same time, fill the upper section of the transition layer 2 simultaneously, forming an irregular interlocking structure 6 with an interlocking depth of not less than 0.5m; finally, pour the seepage-proof cover plate on the top of the dam to achieve a seamless connection between the top of the seepage-proof core wall 1 and the top of the dam.

[0024] The cement-modified soil and clay-modified soil in the above steps are both obtained by modifying secondary waste materials. Clay-modified soil is a performance-enhancing material with a small amount of modifier (bentonite is used in this embodiment), and cement-modified soil is a performance-strengthening material with 8%-10% cement.

[0025] In addition to using an irregular interlocking structure 6, soil nails 7 can also be used to connect the core wall, transition layer 2, and dam shell material zone 3, specifically including the following steps: Step S421: Collect weeds in the engineering area and mix them evenly with clay-modified soil substrate for the seepage prevention core wall 1. Add water to adjust the moisture content, pour it into the mold and vibrate to compact it. After curing for 48 hours, demold it to make the soil nail 7 finished product. Step S422: First, excavate the anti-seepage tooth groove of the dam foundation, pour concrete into the tooth groove to form an anti-seepage base, and fill the anti-seepage core wall 1 of the dam foundation in layers above the anti-seepage base. Simultaneously, carry out the filling of the transition layer 2 dam foundation section. During the filling process, soil nails 7 are laid. After the soil nails 7 are laid, cross-compaction process is used for the connection area. Step S423: The main seepage-proof section of the seepage-proof core wall 1 is filled from bottom to top in layers. Cement-modified soil is used for filling. A seepage-proof reinforcing grid is set at a set vertical height for each filling layer. The grid extends laterally to a set distance inside the transition layer 2. At the same time, the middle section of the transition layer 2 is filled synchronously. Soil nails 7 are set after each layer is filled. The soil nails 7 of adjacent layers are staggered. Step S424: Fill the top seepage barrier section of the seepage barrier core wall 1, using clay-modified soil to fill in layers, with the thickness gradually narrowing from the middle of the dam body to the top of the dam. Step S425: After each layer of clay-modified soil in the top seepage prevention section is filled and compacted, soil nails 7 are arranged, with the soil nails 7 in adjacent layers arranged in an alternating pattern. Step S426: After the soil nails 7 are installed, the upper section of transition layer 2 is filled simultaneously. The upper section of transition layer 2 is compacted in layers, and the dam crest anti-seepage cover is poured. The cover covers the top of the anti-seepage core wall 1 and the top surface of the upper section of transition layer 2, achieving a seamless connection between the top of the anti-seepage core wall 1 and the dam crest. Step S5: The dam shell material zone 3 is filled in layers. This includes: Step S51: Following the vertical filling sequence of first the dam foundation bearing layer, then the middle stabilizing layer, and finally the upper and shallow slope filling layers, the construction within the same vertical level shall proceed in the horizontal sequence of first the core sub-area, then the core sub-area, and finally the homogeneous area / slope area. Differentiated compaction processes are adopted for different types of waste materials, as detailed below: The primary waste material in the dam foundation bearing layer is compacted using a heavy vibratory roller weighing no less than 25t, with a compaction degree of no less than 96%. The secondary waste material in the middle stabilized layer is compacted using a 20t vibratory roller, with a compaction degree of not less than 95%. Lightweight compaction equipment is used for the upper part and shallow layer of the slope to compact the Class III waste material. The compaction degree is not less than 90%. At the same time, a geogrid reinforcement layer is added to the shallow layer of the slope, and the geogrid is anchored into the dam shell material area to a depth of not less than 0.8m. Step S52: Fill the primary waste material into the core sub-area and secondary core sub-area of ​​the dam foundation bearing layer, fill the secondary waste material into the homogeneous area of ​​the central stable layer and the upper area of ​​the dam shell material area 3, and fill the tertiary waste material into the shallow filling layer of the slope. All the waste materials collected from the project are put into the filling, and there is no waste excavation material left.

[0026] Step S6: Construct the composite protective surface and auxiliary structure. This includes: Step S61: Lay the composite protective layer 4 from bottom to top along the upstream and downstream slopes of the dam body. First, lay the bottom reinforced protective layer at the vertical construction ground level - 1 / 2 of the dam height, using geogrid to wrap the crushed stone. The geogrid is anchored into the dam shell material area 3. Then, lay the middle layer of ecological vegetation at 1 / 2-2 / 3 of the vertical dam height. Finally, lay the top layer of riprap from 2 / 3 of the vertical dam height to the dam top and the upstream wave-facing area. The layers are connected by anchor bars to ensure the integrity of the protective layer. Step S62: Construct auxiliary drainage structure 5 at the downstream toe of the dam body. Under rock foundation conditions, drainage prisms are laid out and constructed with rubble, connecting with the lower part of the dam shell material area 3. Under soft foundation conditions, retaining structures are added simultaneously. The drainage prisms and retaining structures work together to quickly drain seepage water from the dam body and reduce the pore water pressure inside the dam body.

[0027] Example 1 A small reservoir expansion and renovation project plans to construct a new waste-free earth-rock dam, 50m high, 8m wide at the crest, with an upstream-to-downstream slope ratio of 1:2.5. The dam foundation is a soft gravel foundation (6m thick overburden layer, underlying weakly weathered rock bed). The total amount of fill material collected for the project is 380,000 m³. 3 It is necessary to achieve 100% zero-waste utilization, and at the same time expand the effective storage capacity of the reservoir by 1.2 million cubic meters through directional excavation. 3 .

[0028] Step S1: Collect filling materials and perform graded pretreatment.

[0029] S11, Material Collection.

[0030] 150,000 cubic meters of natural soil and rock excavated from the reservoir area were collected. 3 (Including clay, gravel, and semi-weathered rock), 120,000 m³ of waste material from the clearing of the dam abutment hillside. 3 (Semi-weathered rock fragments, cohesive waste soil), 110,000 m³ of construction waste sand and gravel. 3 (Sand and gravel mixture, fine soil); During collection, the natural soil and rock on the north bank of the reservoir will be excavated in a directional manner to a depth of 5-8m to widen the water area of ​​the reservoir and increase the effective storage capacity of the reservoir by 1.2 million m³. 3 .

[0031] S12, removal of impurities and oversized particles.

[0032] All collected materials were screened to remove impurities such as construction waste and humus, totaling 0.5 million cubic meters. 3 0.8 million m³ of ultra-large particles with a diameter >300mm were removed. 3 (After being broken down to 50-200mm, it is reintegrated into the filling system).

[0033] S13, Moisture content adjustment.

[0034] The optimal moisture content of natural clay was found to be 18%, while the actual moisture content was 22% (too high). It was then turned over and dried over an area of ​​5000㎡, and the moisture content dropped to 18.5% after drying. The optimal moisture content of construction waste sand and gravel was 12%, while the actual moisture content was 8% (too low). Water was sprinkled to adjust the moisture content to 11.8%.

[0035] S14, Modification of soft soil materials.

[0036] 30,000 m³ of soft soil from the reservoir area was selected. 3 (For use in shallow slope filling layer), 5.5% lime is added for modification, and after mixing evenly, the mixture is left to stand for 24 hours. After modification, the moisture content of the soft soil is stabilized at 17%.

[0037] S15. Grading and screening of stone materials for the dam foundation bearing layer.

[0038] 80,000 m³ of semi-weathered rock was used for the dam foundation bearing layer. 3 Grading and screening are performed to control the particle size range of 20-150mm, with particles >100mm accounting for 30%, particles 50-100mm accounting for 40%, and particles 20-50mm accounting for 30%, forming a continuous gradation.

[0039] Step S2: Physical and mechanical property test.

[0040] The pretreated material underwent comprehensive testing, and the test data are as follows: S21. High confining pressure triaxial test of the dam foundation bearing layer stone material.

[0041] The confining pressure was set at 0.8 MPa (simulating high stress in the dam foundation). The test results showed that the internal friction angle of the semi-weathered rock was 28°, the compression modulus was 75 MPa, and the cohesion was 12 kPa, which met the requirements for vertical high stress stability of the dam foundation bearing layer.

[0042] S22, Permeability deformation test of the seepage-proof core wall material 1.

[0043] Permeability tests were conducted on cement-modified soil (based on natural clay with 9% cement content) at different vertical depths. The critical hydraulic gradient was 1.8 in the foundation section (0-10m), 1.6 in the middle section (10-35m), and 1.5 in the top section (35-50m), all of which were higher than the design requirement of 1.2, and the seepage prevention performance met the standards.

[0044] S23, Retesting of mechanical properties of modified soft soil.

[0045] The internal friction angle of the modified soft soil increased from 16° to 20°, the compression modulus increased from 18MPa to 25MPa, and the shear strength met the requirements for shallow slope filling.

[0046] Step S3: Divide the dam shell material area into three filling zones.

[0047] S31. Finite element model construction and mechanical index extraction.

[0048] A 1:1 three-dimensional model was established using MidasGTS, extending 80m laterally and covering the full width of the dam (125m) and 50m upstream and downstream. The model simulated layered filling during construction, normal water level (38m) during operation, and check flood level (42m), extracting three mechanical properties of the dam shell material area: Dam foundation bearing layer (0-12m): Vertical effective stress 0.8-1.0MPa, settlement deformation ≤5mm / m; Middle stable layer (12-35m): Vertical effective stress 0.4-0.8MPa, settlement deformation 5-10mm / m; Upper part and shallow filling layer of slope (35-50m): Vertical effective stress <0.4MPa, settlement deformation ≤20mm / m.

[0049] S32. Vertical zoning.

[0050] Based on mechanical indicators, the dam shell material zone 3 is divided into three vertical areas: the dam foundation bearing layer (0-12m), the middle stable layer (12-35m), and the upper and shallow slope filling layer (35-50m).

[0051] S33, Waste material classification.

[0052] Based on the test results, the fill material was divided into three categories: Primary waste material: semi-weathered rock (80,000 m³) 3 (Internal friction angle 28°, compression modulus 75MPa) Secondary waste materials: construction waste sand and gravel and natural sand and gravel (240,000 m³) 3 (Internal friction angle 22°, compression modulus 50MPa) Tertiary waste material: Modified dredged soft soil (30,000 m³) 3 (Internal friction angle 20°, compression modulus 25MPa).

[0053] S34, Material-Zone Matching.

[0054] The dam foundation bearing layer is horizontally divided into a core sub-zone (0-8m from the central axis) and a secondary core sub-zone (8-15m). The core sub-zone uses primary waste material (50,000 m³). 3 The secondary core sub-region uses primary waste material (30,000 m³). 3 (No gaps, no modification required) Secondary waste material (180,000 m³) for the middle stabilization layer 3 ); The upper area (35-45m) uses secondary waste material (60,000 m³). 3 ), shallow slope layer (45-50m) using grade III waste material (30,000 m³) 3 ).

[0055] Step S4: Construction of the dam core area and transition area.

[0056] S41, Construction of the seepage prevention section of the dam foundation.

[0057] Excavate a seepage-proof trench, 3m deep and 2m wide, and pour C20 concrete to form a seepage-proof base. On top of the base, fill with cement-modified soil (9% cement content) as the seepage-proof core wall 1 dam foundation seepage-proof section, with a fill layer thickness of 20cm, 8 passes of compaction, and a compaction degree of 97%. Simultaneously fill the transition layer 2 dam foundation section (graded crushed stone, particle size 5-30mm), forming an irregular interlock with the core wall, with an interlock depth of 0.8m, and use a 20t vibratory roller for cross compaction, without construction joints.

[0058] S42, Construction of the central main seepage prevention section.

[0059] The main seepage-proof section (cement-modified soil) in the middle of the seepage-proof core wall 1 is filled from bottom to top. A seepage-proof reinforcing grid (geogrid and bentonite waterproof blanket) is installed every 15m of vertical height. The grid extends to the transition layer 20.3m. The middle section of the transition layer 2 is constructed according to the "inner fine-grained layer (0.5-5mm, 0.5m wide) and the outer coarse-grained layer (5-20mm, 1.0m wide)", with an interlocking depth of 1.0m with the seepage-proof core wall 1 and an overall compaction degree of 96%.

[0060] S43, Construction of the top seepage prevention section.

[0061] The top seepage barrier section of the core wall 1 is filled with clay-modified soil, with the thickness gradually narrowing from 5m to 2m; the upper section of the transition layer 2 uses medium-coarse sand (1.0m thick), with an interlocking depth of 0.5m with the core wall; finally, a C25 dam top seepage barrier cover plate (0.3m thick) is poured to achieve a seamless connection.

[0062] Step S5: Construction of the dam shell material area in three layers.

[0063] S51. Filling sequence and compaction process.

[0064] Construction proceeds vertically in the order of "dam foundation bearing layer, middle stabilizing layer, upper and shallow slope filling layer", and horizontally in the order of "core sub-area, secondary core sub-area, and slope area" within the same layer. The primary waste material in the dam foundation bearing layer was compacted using a 26t heavy vibratory roller, with 6 passes and a compaction degree of 96.5%. The secondary waste material in the middle stabilized layer was compacted using a 20t vibratory roller, with 5 passes, achieving a compaction degree of 95.2%. The shallow layer of Class III waste material on the slope was compacted with a light roller, with 4 passes and a compaction degree of 90.5%. Geogrids were laid simultaneously (1m spacing, anchored into the dam shell material area for 30.8m).

[0065] S52, Precision filling.

[0066] 50,000 m 3 Primary waste material was filled into the core sub-area of ​​the dam foundation, 30,000 m³. 3 Primary waste material was filled into the secondary core sub-area; 180,000 m³3 Secondary waste material was filled into the middle stabilization layer, 60,000 m³ 3 Secondary waste material was filled into the upper area; 30,000 m³ 3 380,000 m³ of Class III waste material was filled into the shallow layer of the slope. 3 All collected materials are utilized, with no leftover or discarded materials.

[0067] Step S6: Construction of composite protective surface and auxiliary structure.

[0068] S61, Construction of Composite Protective Layer 4.

[0069] Lay the protective layer from bottom to top: Bottom reinforced protective layer (0-25m dam height): Geogrid wrapped with crushed stone (particle size 10-20mm), the geogrid is anchored into the dam shell material area for 30.8m, with a thickness of 0.5m; Middle layer ecological vegetation (25-35m dam height): filled with a mixture of topsoil, vegetation substrate and bermudagrass seeds, with a thickness of 0.3m; Top layer of riprap facing (35-50m dam height and upstream wave-facing area): riprap particle size ≥30cm, thickened to 0.5m in the wave-facing area, and each layer is connected by anchor bars.

[0070] S62, Construction of auxiliary drainage structure 5.

[0071] A drainage prism (30-50cm diameter boulders) is installed at the downstream dam toe. The prism is 4m wide and 3m high, and it is connected to the lower part of the dam shell material area 3. At the same time, a retaining structure (C15 concrete, 0.8m thick) is added to achieve rapid drainage of dam seepage water and control the pore water pressure within the design threshold.

[0072] After completion, monitoring showed that the maximum settlement of the dam body was 25mm (< the design value of 30mm), the permeability coefficient of the anti-seepage core wall 1 was 8×10-8cm / s (better than the design requirements), and the anti-sliding stability safety factor of the dam body was 1.52 (≥1.3). All indicators met the standards, and zero waste of project materials was achieved, saving 8.6 million yuan in external material costs. The ecological benefits and engineering benefits were synergistically achieved.

[0073] The structure of a waste-free earth-rock dam construction method, such as Figure 2 and Figure 3 As shown, the dam includes a dam body, which comprises a seepage-proof core wall 1. Symmetrically arranged on both sides of the seepage-proof core wall 1 are dam shell material zones 3. The dam shell material zones 3 are connected to the seepage-proof core wall 1 via a transition layer 2. Irregular interlocking structures 6 are formed at the connections between the transition layer 2, the seepage-proof core wall 1, and the dam shell material zones 3. The seepage-proof core wall 1 includes a foundation seepage-proof section, a central main seepage-proof section, and a top seepage-proof section. The dam shell material zones 3 include a foundation bearing layer, a central stabilizing layer, and upper and shallow slope filling layers. Composite protective surfaces are provided on both sides of the dam shell material zones 3. An auxiliary drainage structure 5 is also provided at the downstream toe of the main dam body.

[0074] Example 2 In addition to using the irregular interlocking structure 6 in Example 1, soil nails 7 can also be used to connect the core wall, transition layer 2, and dam shell material zone 3, specifically including the following steps: Step S421: Collect weeds in the project area (after removing humus and impurities, cut them into 3-5cm long pieces) and mix them evenly with the clay-modified soil substrate of the seepage-proof core wall 1 at a mass ratio of 1:8. Add an appropriate amount of water to adjust the moisture content to 20%-22%, pour it into a cylindrical mold (diameter 8-10cm, length 80-100cm), vibrate and compact it, and demold it after curing for 48 hours to make the soil nail 7 finished product. Step S422: First, excavate the anti-seepage groove of the dam foundation, pour concrete into the groove to form an anti-seepage base, and fill the anti-seepage section of the dam foundation of the anti-seepage core wall 1 in layers above the anti-seepage base (using cement-modified soil). Simultaneously, carry out the filling of the transition layer 2 dam foundation section. During the filling process, prefabricated soil nails 7 are placed. One end of the soil nail 7 is embedded into the anti-seepage section of the dam foundation of the anti-seepage core wall 1 to a depth of not less than 40cm, and the other end is embedded into the transition layer 2 dam foundation section to a depth of not less than 30cm. The spacing between the soil nails is 100cm×100cm to ensure that the two are tightly connected. After the soil nails 7 are placed, the connection area is subjected to cross-compaction technology with a compaction degree of not less than 97% to ensure that there are no construction joints. Step S423: Construct the main seepage-proof section in the middle of the seepage-proof core wall 1 from bottom to top (using cement-modified soil). Install a seepage-proof reinforcing grid every 15m of vertical height. The grid extends laterally to 0.3m inside the transition layer 2. Simultaneously, construct the middle section of the transition layer 2 (constructed as a double-layer structure of inner fine-grained transition layer 2 and outer coarse-grained transition layer 2). After each layer is completed, install prefabricated soil nails 7 (parameters same as S41). One end of the soil nail 7 is embedded in the main seepage-proof section in the middle of the seepage-proof core wall 1 to a depth of not less than 40cm, and the other end penetrates the inner fine-grained transition layer 2 and is embedded in the outer coarse-grained transition layer 2 to a depth of not less than 30cm. The soil nails 7 in adjacent layers are staggered to ensure a tight connection between the seepage-proof core wall 1 and the transition layer 2, and between the two-layer structure of the transition layer 2. Step S424: Fill the top seepage barrier section of the seepage barrier core wall 1. Use clay-modified soil to fill in layers. The filling layer is 20cm thick, and the number of compaction passes is 6. The compaction degree is not less than 96%. The thickness gradually narrows from the middle of the dam body to the top of the dam body (5m thickness in the middle of the dam body and not less than 2m thickness at the top of the dam body). Step S425: After each layer of clay-modified soil in the top seepage barrier section is filled and compacted, prefabricated soil nails 7 (parameters same as S41) are installed at a spacing of 80cm×80cm. One end of the soil nail 7 is vertically embedded into the top seepage barrier section of the seepage barrier core wall 1 to a depth of not less than 40cm, and the other end penetrates the upper section of the transition layer 2 (medium-coarse sand material, 1.0m thick) and is embedded into the upper area of ​​the dam shell material zone 3 (secondary waste material) to a depth of not less than 30cm, ensuring that the soil nail 7 is in close contact with the seepage barrier core wall 1, the transition layer 2, and the dam shell material zone 3; the soil nails 7 in adjacent layers are staggered, with a misalignment distance of not less than 40cm. After the soil nails 7 are laid in step S426, the upper section of the transition layer 2 (medium-coarse sand) is filled simultaneously. During the filling process, avoid collisions with the soil nails 7 to prevent displacement. The upper section of the transition layer 2 is compacted in layers (compaction degree not less than 95%). Finally, a C25 dam top seepage prevention cover plate (thickness 0.3m) is poured. The cover plate covers the top of the seepage prevention core wall 1 and the top surface of the upper section of the transition layer 2 to achieve a seamless connection between the top of the seepage prevention core wall 1 and the dam top.

[0075] The other steps are the same as in Example 1.

[0076] The structure of a waste-free earth-rock dam construction method, such as Figure 2 and Figure 4 As shown, the dam includes a dam body, which comprises a seepage-proof core wall 1. Symmetrically arranged on both sides of the seepage-proof core wall 1 are dam shell material zones 3. The dam shell material zones 3 are connected to the seepage-proof core wall 1 via a transition layer 2. The transition layer 2 is connected to both the seepage-proof core wall 1 and the dam shell material zones 3 via soil nails 7. The seepage-proof core wall 1 includes a foundation seepage-proof section, a central main seepage-proof section, and a top seepage-proof section. The dam shell material zones 3 include a foundation bearing layer, a central stabilizing layer, and upper and shallow slope filling layers. Composite protective surfaces are provided on both sides of the dam shell material zones 3. An auxiliary drainage structure 5 is also provided at the downstream toe of the main dam body.

[0077] Therefore, the present invention adopts the above-mentioned method and structure for constructing a waste-free earth-rock dam. By using clay waste materials collected from engineering projects as the base material for the seepage-proof core wall and transition layer, and modifying them in small amounts to form high-quality seepage-proof materials, the engineering waste materials with different properties are graded and adapted to the vertical and horizontal zones of the dam shell material area. This achieves the full utilization of engineering waste materials without waste, eliminates the need to purchase a large amount of dam construction materials, and avoids damage to surrounding vegetation and soil erosion.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for constructing a waste-free earth-rock dam, characterized in that, Includes the following steps: Step S1: Collect filling materials and perform graded pretreatment on the filling materials; Step S2: Conduct physical and mechanical property tests on the pretreated filling materials; Step S3: Divide the dam shell material area into filling zones; Step S4: Construct the core area and transition area of ​​the dam. Step S5: Carry out the dam shell material layered filling construction; Step S6: Construct the composite protective surface and auxiliary structure.

2. The method for constructing a waste-free earth-rock dam according to claim 1, characterized in that, Step S1 includes: Step S11: Collect the excavated natural soil and rock materials, dam shoulder mountain clearing waste materials, and construction waste sand and gravel materials in the reservoir area. During the collection, the natural soil and rock materials in the reservoir area are excavated in a directional manner to expand the effective storage capacity of the reservoir. Step S12: Remove impurities and oversized particles with a diameter greater than 300mm from the collected filling material; Step S13: Adjust the filling material that deviates from the optimum moisture content by turning it over in the sun or sprinkling it with water; Step S14: Add 5%-6% lime to the soft soil filling material in the shallow filling layer of the slope for modification; Step S15: Gradation and screening of the stone filling material for the dam foundation bearing layer.

3. The method for constructing a waste-free earth-rock dam according to claim 2, characterized in that, Step S2 includes: The pretreated filling materials were tested, including tests on strength, modulus, deformation characteristics, permeability coefficient, and compaction characteristics. Simulated tests were also conducted at different locations within the dam body, as detailed below: Step S21: For the dam foundation bearing layer filling material, a high confining pressure triaxial test is added to verify its stability under high vertical stress. Step S22: For the seepage-proof core wall filling material, conduct seepage deformation tests at different vertical depths to determine the critical hydraulic gradient; Step S23: Retest the mechanical properties of the modified soft soil filling material.

4. The method for constructing a waste-free earth-rock dam according to claim 3, characterized in that, Step S3 includes: Step S31: Using three-dimensional finite element software, construct a three-dimensional finite element model of the dam body based on the dam design parameters, and simulate the actual stress state of the dam body to obtain the vertical and horizontal mechanical indices of the dam shell material area, thus forming a distribution map of the mechanical properties of the dam shell material area. Step S32: Based on the distribution map of mechanical properties of the dam shell material area, divide the dam shell material area into three regions from bottom to top along the vertical height: the dam foundation bearing layer, the middle stable layer, and the upper and shallow slope filling layer. Step S33: Based on the test results obtained in step S2, the collected fill material is divided into three categories, including primary waste material, secondary waste material and tertiary waste material; Step S34: Match different grades of waste materials with different divisions of the dam shell material area, including: Step S341: Divide the dam foundation bearing layer into a core sub-zone and a secondary core sub-zone along the horizontal direction. The core sub-zone is suitable for primary waste material, and the secondary core sub-zone is suitable for primary waste material or modified secondary waste material. Step S342: The middle stabilization layer is adapted to secondary waste materials; Step S343: For the upper part and the shallow filling layer of the slope, the upper area is suitable for secondary waste material, and the shallow filling layer area of ​​the slope is suitable for tertiary waste material. In the above steps, if the primary waste material is insufficient, a modifier is added to the secondary waste material for local modification to increase its compression modulus before it is used in the core sub-area of ​​the dam foundation bearing layer; if the shear resistance of the tertiary waste material does not meet the standard, a geogrid reinforcement layer is added to enhance the shallow slope stability.

5. The method for constructing a waste-free earth-rock dam according to claim 4, characterized in that, Step S5 includes: Step S51: Following the vertical filling sequence of first the dam foundation bearing layer, then the middle stabilizing layer, and finally the upper and shallow slope filling layers, the construction within the same vertical level shall proceed in the horizontal sequence of first the core sub-area, then the core sub-area, and finally the homogeneous area / slope area. Differentiated compaction processes are adopted for different types of waste materials, as detailed below: The primary waste material in the dam foundation bearing layer is compacted using a heavy vibratory roller weighing no less than 25t, with a compaction degree of no less than 96%. The secondary waste material in the middle stabilized layer is compacted using a 20t vibratory roller, with a compaction degree of not less than 95%. Lightweight compaction equipment is used for the upper part and shallow layer of the slope to compact the Class III waste material, with a compaction degree of not less than 90%. At the same time, a geogrid reinforcement layer is added to the shallow layer of the slope, and the geogrid is anchored into the dam shell material area to a depth of not less than 0.8m. Step S52: Fill the primary waste material into the core sub-area and secondary core sub-area of ​​the dam foundation bearing layer, fill the secondary waste material into the homogeneous area of ​​the central stable layer and the upper area of ​​the dam shell material area, and fill the tertiary waste material into the shallow filling layer of the slope. All the waste materials collected from the project are put into the filling, and there is no waste excavation material left.

6. A method for constructing a waste-free earth-rock dam according to claim 5, characterized in that, Step S6 includes: Step S61: Lay a composite protective layer from bottom to top along the upstream and downstream slopes of the dam body. First, lay a bottom reinforced protective layer at 1 / 2 of the vertical construction ground level and dam height, using geogrid to wrap the crushed stone. The geogrid is anchored into the dam shell material area. Then, lay a middle layer of ecological vegetation at 1 / 2-2 / 3 of the vertical dam height. Finally, lay a top layer of riprap from 2 / 3 of the vertical dam height to the dam top and upstream wave-facing area. Anchor bars are used to connect the layers to ensure the integrity of the protective layer. Step S62: Construct an auxiliary drainage structure at the downstream toe of the dam body. Under rock foundation conditions, a drainage prism is laid out using rubble masonry and is connected to the lower part of the dam shell material area. Under soft foundation conditions, a retaining structure is added simultaneously. The drainage prism and the retaining structure work together to quickly drain seepage water from the dam body and reduce the pore water pressure inside the dam body.

7. A method for constructing a waste-free earth-rock dam according to claim 6, characterized in that, Step S4 includes: Step S411: First, excavate the anti-seepage groove of the dam foundation, pour concrete into the groove to form an anti-seepage base, and fill the anti-seepage section of the dam foundation with the anti-seepage core wall above the anti-seepage base. Cement-modified soil is used for layered compaction and filling. At the same time, the dam foundation section of the transition layer and the dam foundation section of the anti-seepage core wall are formed into an irregular interlocking structure with an interlocking depth of not less than 0.8m. The interlocking area adopts a cross-compaction process to ensure that there are no construction joints. Step S412: The main seepage-proof section of the seepage-proof core wall is filled from bottom to top in layers. Cement-modified soil is used for filling. A seepage-proof reinforcing grid is installed at each set vertical height of filling. The grid extends laterally to a set distance inside the transition layer. At the same time, the middle section of the transition layer is filled simultaneously. It is constructed with a double-layer structure of an inner fine-grained transition layer and an outer coarse-grained transition layer. An irregular interlocking structure is formed between the two layers and between the two layers and the seepage-proof core wall. Step S413: Fill the top seepage-proof section of the seepage-proof core wall using clay-modified soil, with the thickness gradually narrowing from the middle to the top; at the same time, fill the upper section of the transition layer simultaneously, forming an irregular interlocking structure with an interlocking depth of not less than 0.5m; finally, pour the seepage-proof cover plate on the top of the dam to achieve a seamless connection between the top of the seepage-proof core wall and the top of the dam.

8. A method for constructing a waste-free earth-rock dam according to claim 6, characterized in that, Step S4 includes: Step S421: Collect weeds in the project area and mix them evenly with the clay-modified soil substrate for the seepage prevention core wall. Add water to adjust the moisture content, pour it into a mold and vibrate to compact it. After curing for 48 hours, demold it to make the soil nail finished product. Step S422: First, excavate the anti-seepage toothed groove of the dam foundation, pour concrete into the toothed groove to form an anti-seepage base, and fill the anti-seepage core wall of the dam foundation in layers above the anti-seepage base. Simultaneously, carry out the filling of the transition layer dam foundation section. During the filling process, soil nails are laid. After the soil nails are laid, cross-compaction process is used for the connection area. Step S423: The main seepage-proof section of the seepage-proof core wall is filled from bottom to top in layers. Cement-modified soil is used for filling. A seepage-proof reinforcing grid is set at a set vertical height for each filling layer. The grid extends laterally to a set distance inside the transition layer. At the same time, the middle section of the transition layer is filled synchronously. Soil nails are set after each layer is filled. The soil nails of adjacent layers are staggered. Step S424: Fill the top seepage barrier section of the seepage barrier core wall, using clay-modified soil to fill in layers, with the thickness gradually narrowing from the middle of the dam body to the top of the dam. Step S425: After each layer of clay-modified soil in the top seepage prevention section is filled and compacted, soil nails are installed, with the soil nails in adjacent layers arranged in an alternating pattern. Step S426: After the soil nails are laid, the upper section of the transition layer is filled simultaneously. The upper section of the transition layer is compacted in layers. The anti-seepage cover plate on the top of the dam is poured. The cover plate covers the top of the anti-seepage core wall and the top surface of the upper section of the transition layer, so as to achieve a seamless connection between the top of the anti-seepage core wall and the top of the dam.

9. A structure applied to the waste-free earth-rock dam construction method described in claim 7 above, characterized in that: The dam body includes a seepage-proof core wall, and dam shell material areas are symmetrically arranged on both sides of the seepage-proof core wall. The dam shell material areas and the seepage-proof core wall are connected by a transition layer. The connection between the transition layer and the seepage-proof core wall, and the connection between the transition layer and the dam shell material area, all form an irregular interlocking structure. The seepage-proof core wall includes a dam foundation seepage-proof section, a central main seepage-proof section, and a top seepage-proof section; The dam shell material zone includes a dam foundation bearing layer, a middle stabilizing layer, and an upper and shallow slope filling layer. Composite protective surfaces are provided on both sides of the dam shell material area; An auxiliary drainage structure is also provided at the downstream toe of the main dam body.

10. A structure applied to the waste-free earth-rock dam construction method described in claim 8 above, characterized in that: The dam body includes a seepage-proof core wall, and dam shell material areas are symmetrically arranged on both sides of the seepage-proof core wall. The dam shell material areas are connected to the seepage-proof core wall through a transition layer, and the transition layer is connected to both the seepage-proof core wall and the dam shell material areas through soil nails. The seepage-proof core wall includes a dam foundation seepage-proof section, a central main seepage-proof section, and a top seepage-proof section; The dam shell material zone includes a dam foundation bearing layer, a middle stabilizing layer, and an upper and shallow slope filling layer. Composite protective surfaces are provided on both sides of the dam shell material area; An auxiliary drainage structure is also provided at the downstream toe of the main dam body.

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