Channel type waste dump and method of dumping waste

Abstract

This invention relates to the fields of water conservancy and hydropower construction and soil and water conservation, and discloses a ditch-type spoil heap, including a ditch, a spoil retaining dam, and an in-reservoir storage area. The spoil retaining dam is located downstream of the ditch, and the in-reservoir storage area includes a first storage area and a second storage area. The first storage area is located upstream of the spoil retaining dam and can be used for storing rocky spoil; the second storage area is located upstream of the first storage area and can be used for storing soil spoil. During spoil heaping, the upstream slope of the spoil retaining dam forms the first storage area for storing rocky spoil, and the upstream side of the first storage area forms the second storage area for storing soft clay spoil. This achieves large-capacity storage of soft clay, improves the space utilization rate of the spoil heap and the capacity for disposing of engineering spoil. By adopting a classified and zoned storage method, the risk of siltation and water environment deterioration downstream of the second storage area is reduced, thus controlling soil erosion at its source. This invention also provides a spoil heaping method.

Description

Technical Field

[0001] This invention relates to the fields of water conservancy and hydropower construction and soil and water conservation technology, and in particular to a ditch-type spoil disposal site and a spoil stacking method. Background Technology

[0002] During the construction of large and extra-large hydropower projects, the amount of excavation work is enormous, generating a large amount of waste, including general slag such as boulders and gravel, as well as soft clay with low strength and high compressibility, such as fluid plastic and soft plastic clay. In engineering practice, waste disposal sites are often set up along river valleys, ditches, or hillsides for centralized storage and disposal.

[0003] Existing slag disposal sites primarily handle general slag and stone, often resorting to nearby backfilling, simple stockpiling, or mixing with general slag and stone for the storage of weak clay. On one hand, weak clay exhibits characteristics such as low strength, low permeability, easy softening upon contact with water, and rapid shear strength decay. In steep terrain and deep gullies, large-scale stockpiling of weak clay can easily lead to insufficient slope stability, localized deformation, and landslides, posing safety hazards. On the other hand, fine particles and soluble substances in weak clay are easily carried away by runoff and seepage during the rainy season or under water storage conditions, causing soil erosion, siltation, and deterioration of downstream water environments, making it difficult to meet stringent soil and water conservation and environmental protection requirements.

[0004] While traditional spoil heaps employ measures such as drainage ditches, these are primarily designed for general stone spoil heaps or conventional dam structures, failing to adequately consider the long-term seepage, pore pressure accumulation, and overall stability issues arising from the concentrated storage of weak clay. This is particularly problematic when spoil heaps are located within large gullies or other large ravine terrains. These gullies often have steep longitudinal slopes, bank slopes, and well-developed gullies. Without systematic zoned storage, dam filtration, and bottom drainage measures, weak clay is highly susceptible to poor drainage, concentrated seepage, and excessively high slag wetting lines, further exacerbating spoil heap stability risks and soil erosion. Furthermore, traditional spoil heap layouts typically lack functional zoning for weak clay and general slag, resulting in low overall spoil heap utilization efficiency. Slag retaining dams for weak clay are often constructed using specialized filling materials, failing to fully utilize engineering waste, leading to higher investment costs, longer construction periods, and insufficient consideration for environmental friendliness and sustainable utilization.

[0005] Therefore, there is an urgent need for a new type of spoil disposal layout suitable for the conditions of giant trenches in hydropower projects, which can fully dispose of project waste while achieving safe storage of large quantities of soft clay. Summary of the Invention

[0006] The purpose of this invention is to provide a trench-type spoil disposal site and a spoil stacking method to solve the problems existing in the above-mentioned related technologies, realize the safe storage of soft clay, and improve the space utilization rate and engineering spoil disposal capacity of the spoil disposal site.

[0007] To achieve the above objectives, the present invention provides the following solution: This invention provides a trench-type spoil disposal site, comprising: The ditch has a drainage blind ditch at its bottom, which is laid along the longitudinal length of the ditch. A slag-blocking dam is located downstream of the channel, and the axial length of the slag-blocking dam is not less than the cross-sectional width of the channel. The slag-blocking dam includes a dam body and a filter structure. The dam body is constructed by filling with rocky waste slag, and the filter structure is located on the upstream slope of the dam body. The storage area within the silo includes a first storage area and a second storage area. The first storage area is located upstream of the slag-blocking dam and can be used to store rocky waste. The second storage area is located upstream of the first storage area and can be used to store excavated soil. The drainage blind ditch starts from the storage area inside the reservoir and runs through the slag retaining dam.

[0008] Preferably, the reverse filter structure is inclined from the top to the bottom of the dam towards the upstream direction.

[0009] Preferably, the reverse filter structure includes a first medium-coarse sand layer, a geotextile layer, a second medium-coarse sand layer, a first graded crushed stone layer, and a transition material layer arranged sequentially from top to bottom.

[0010] Preferably, the upstream slope of the slag-blocking dam is a stepped, straight slope.

[0011] Preferably, the bottom of the first storage area extends toward the second storage area.

[0012] Preferably, the height of the slag heap in the storage area is not higher than the height of the slag retaining dam.

[0013] Preferably, the drainage ditch is provided with a third medium-coarse sand layer, a second graded crushed stone layer and a block stone layer in sequence from top to bottom.

[0014] Preferably, the number of drainage blind ditches is multiple.

[0015] The present invention also provides a method for stockpiling slag to form the above-mentioned trench-type slag dump, comprising the following steps: The dam body is filled downstream of the ditch, and a reverse filter structure is constructed on the upstream slope of the dam body; thus, the drainage blind ditch is constructed. The first storage area is formed by piling up rocky waste on the upstream side of the slag-blocking dam. The second storage area is formed by piling up waste soil on the upstream side of the first storage area.

[0016] The present invention achieves the following technical effects compared to related technologies: The trench-type spoil heap of the present invention includes a trench, a spoil retaining dam, and an in-storage storage area. A drainage blind ditch is provided at the bottom of the trench, and the drainage blind ditch is arranged along the longitudinal length of the trench. The spoil retaining dam is located downstream of the trench, and the axial length of the spoil retaining dam is not less than the cross-sectional width of the trench. The spoil retaining dam includes a dam body and a filter structure. The dam body is constructed of rocky spoil, and the filter structure is located on the upstream slope of the dam body. The in-storage storage area includes a first storage area and a second storage area. The first storage area is located upstream of the spoil retaining dam and can be used to store rocky spoil. The second storage area is located upstream of the first storage area and can be used to store excavated soil. The drainage blind ditch extends from the in-storage storage area and passes through the spoil retaining dam.

[0017] The trench-type spoil heap of this invention features a spoil retaining dam perpendicular to the flow direction of the trench, with the axial length of the dam not less than the cross-sectional width of the trench. This allows the dam to seal the trench, defining the spoil heap boundary and forming an internal storage area. The spoil retaining dam includes a dam body and a filter structure. The filter structure ensures drainage of the internal storage area while effectively preventing landslides, piping, and soil erosion due to excessive seepage pressure, fundamentally guaranteeing the stability of the second storage area. During spoil heaping, the upstream slope of the spoil retaining dam forms the first storage area for storing rocky spoil, while the upstream side forms the second storage area for storing soft clay spoil. This achieves large-capacity storage of soft clay, improving the space utilization rate of the spoil heap and the capacity for disposing of engineering spoil. The storage area within the slag heap of this invention is divided into a first storage area and a second storage area. This classified and zoned storage method reduces the risk of siltation and water environment deterioration downstream of the slag heap, controlling soil erosion at its source and significantly improving the environmental benefits of slag heap layout. Furthermore, the construction method is simple and highly mechanized, effectively shortening the construction period and reducing the overall investment in soft clay storage and soil and water conservation projects. The trench-type slag heap of this invention has strong adaptability and can provide a replicable and scalable technical approach for slag disposal in hydropower projects and other large-scale infrastructure projects under similar terrain conditions, demonstrating broad engineering application prospects.

[0018] At the same time, the present invention also provides a slag heaping method to form the above-mentioned trench-type slag heap. Naturally, the slag heaping method of the present invention can also achieve the above-mentioned beneficial effects. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings used in the embodiments 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.

[0020] Figure 1 This is a schematic diagram of a trench-type spoil disposal site disclosed in an embodiment of the present invention.

[0021] In the diagram: 1. Ditch; 2. Debris retaining dam; 3. Dam body; 4. Reverse filter structure; 5. First storage area; 6. Second storage area; 7. Ditch bottom. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The purpose of this invention is to provide a trench-type spoil disposal site and a spoil stacking method to solve the problems existing in the above-mentioned related technologies, realize the safe storage of soft clay, and improve the space utilization rate and engineering spoil disposal capacity of the spoil disposal site.

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example 1 This embodiment provides a trench-type spoil disposal site. Please refer to [reference needed]. Figure 1 The system includes a ditch 1, a slag-blocking dam 2, and an in-storage storage area. A drainage ditch 7 is installed at the bottom of ditch 1, extending along the longitudinal length of ditch 1. The slag-blocking dam 2 is located downstream of ditch 1, and its axial length is not less than the cross-sectional width of ditch 1. The slag-blocking dam 2 includes a dam body 3 and a filter structure 4. The dam body 3 is constructed from rocky waste, and the filter structure 4 is located on the upstream slope of the dam body 3. The in-storage storage area includes a first storage area 5 and a second storage area 6. The first storage area 5 is located upstream of the slag-blocking dam 2 and can be used to store rocky waste. The second storage area 6 is located upstream of the first storage area 5 and can be used to store excavated soil. The drainage ditch extends from the in-storage storage area and runs through the slag-blocking dam 2.

[0026] The trench-type spoil heap of this invention features a spoil retaining dam 2 perpendicular to the flow direction of the trench 1, with the axial length of the dam 2 not less than the cross-sectional width of the trench 1. This allows the dam 2 to seal the trench 1, defining the spoil heap boundary and forming an internal storage area. The spoil retaining dam 2 includes a dam body 3 and a filter structure 4. The filter structure 4 ensures drainage of the internal storage area while effectively preventing landslides, piping, and soil erosion due to excessive seepage pressure, fundamentally guaranteeing the stability of the second storage area 6. During spoil heaping, the upstream slope of the spoil retaining dam 2 forms the first storage area 5, used for storing rocky spoil. The upstream side of the first storage area 5 forms the second storage area 6, used for storing soft clay spoil, thus achieving large-capacity storage of soft clay and improving the space utilization rate and engineering spoil disposal capacity of the spoil heap. The storage area within the slag heap of this invention is divided into a first storage area 5 and a second storage area 6. This classified and zoned storage method reduces the risk of siltation and water environment deterioration downstream of the slag heap, controlling soil erosion at its source and significantly improving the environmental benefits of slag heap layout. Furthermore, the construction method is simple and highly mechanized, effectively shortening the construction period and reducing the overall investment in soft clay storage and soil and water conservation projects. The trench-type slag heap of this invention has strong adaptability and can provide a replicable and scalable technical path for the disposal of slag from hydropower projects and other large-scale infrastructure projects under similar terrain conditions, demonstrating broad engineering application prospects.

[0027] Among them, the filter structure 4 is inclined from the top to the bottom of the dam body 3 towards the upstream direction, which is consistent with the shape of the upstream slope of the dam body 3. The filter structure 4 of the slag retaining dam 2 is inclined on the upstream slope of the dam body 3, forming a continuous inclined filter barrier, which is closely attached to the dam body 3, with reasonable stress distribution, stable structure, and reliable filter.

[0028] In this specific embodiment, the filter structure 4 includes a first medium-coarse sand layer, a geotextile layer, a second medium-coarse sand layer, a first graded crushed stone layer, and a transition material layer arranged sequentially from top to bottom. The double-layered medium-coarse sand layer forms a flexible, two-way wrapping around the geotextile, which not only levels the foundation and alleviates stress concentration caused by irregularities on the surface of the dam body 3, preventing the geotextile from being punctured by sharp aggregates, but also enhances the interlayer adhesion and eliminates voids. The geotextile layer effectively blocks fine-particle soil / slag, preventing clogging of subsequent permeable layers. The first-grade crushed stone layer and the transition material layer can progress according to a particle size gradient, achieving synergy between filter soil and drainage, quickly draining seepage water from the storage area within the reservoir, reducing the seepage pressure on the top of the filter structure 4 and providing rigid protection for it. The multi-layered structure has complementary functions and provides layer-by-layer protection, which not only improves the overall structural stability and damage resistance of the filter structure 4, but also effectively dissipates seepage pressure, ensuring the long-term stable operation of the filter structure 4, and adapting to the stress and seepage conditions of the slag-facing surface of the slag-blocking dam 2. In practical applications, the materials of each layer of the filter structure 4 can also be adjusted according to actual working conditions to meet different filtration requirements, ensuring the working stability and reliability of the slag-blocking dam 2.

[0029] In this specific embodiment, the upstream slope of the slag retaining dam 2 is a stepped straight slope. The stepped straight slope of the slag retaining dam 2 significantly reduces the slope height of a single slope and the lateral pressure on the slag body, avoiding stress concentration on a single long slope and improving the anti-sliding and anti-overturning stability of the dam body 3. The straight slope shape ensures close adhesion between the slag body and the dam surface, resulting in uniform stress distribution and making construction layout and the laying of the filter structure 4 more convenient and precise. The step joints can also dissipate some of the kinetic energy of the slag body sliding down, further preventing slag collapse. Overall, it takes into account the multiple requirements of dam body 3 structural stability, convenient construction and maintenance, and slag adhesion protection, further improving the slag stacking stability of the ditch-type slag yard of this invention.

[0030] More specifically, the bottom of the first storage area 5 extends toward the second storage area 6, so that some of the stony waste stored in the first storage area 5 is located at the bottom of the second storage area 6, thereby enabling this part of the stony waste to support the soft clay waste stored in the second storage area 6. During the layered slag heaping, the rocky slag filled in the first storage area 5, after being compacted, becomes the rigid bearing base of the soil piled in the second storage area 6. This effectively disperses the self-weight load of the upper soil layer, preventing the upper soil layer from directly acting on the original foundation of the ditch 1 and causing local settlement and foundation instability. At the same time, the stable slope formed by the lower rocky slag layer provides lateral restraint for the upper soil layer, offsetting some of the sliding thrust of the upper soil layer and improving the anti-sliding stability of the overall slope of the slag heap within the storage area. Furthermore, the rocky slag can be tightly embedded with the soil layer, reducing interlayer voids and lowering the risk of seepage water accumulating between slag layers and forming through-flow channels. In conjunction with the laid drainage blind ditches, it can also guide the seepage water from the upper layer into the drainage blind ditches, providing stable structural support for the slag heaping and ensuring the stability of the slag yard during the layered slag heaping process.

[0031] It should also be noted that the height of the slag pile in the storage area should not exceed the height of the slag retaining dam 2, so that the slag retaining dam 2 can fully play its role in blocking and effectively resist the lateral pressure and downward thrust of the slag body. The height of the slag pile should not exceed the height of the slag retaining dam 2 to avoid the slag body being squeezed, deformed, cracked or even overturned due to excessive stacking, so as to ensure the structural stability of the slag retaining dam 2 and the safety of the slag yard storage.

[0032] The drainage blind ditch is longitudinally set along the bottom 7 of the channel 1 and flows downstream through the slag retaining dam 2 to form a drainage channel for seepage within the reservoir and seepage at the base. In this specific embodiment, the drainage blind ditch is arranged from top to bottom with a third medium-coarse sand layer, a second graded crushed stone layer, and a block stone layer. The function of the drainage blind ditch is to quickly collect and discharge seepage water from inside the slag body and the slag retaining dam 2, effectively lowering the slag wetting line and reducing the adverse effects of seepage pressure on the slag body and the slag retaining dam 2; at the same time, it can prevent fine particles of slag / soil from entering the drainage channel with the water flow, preventing siltation and failure, avoiding problems such as slag body landslides, dam foundation softening and piping, and dam shoulder seepage damage caused by seepage water accumulation, ensuring the overall structural stability of the slag body and the slag retaining dam 2, fundamentally reducing the risk of geological disasters caused by seepage in the slag yard, taking into account the operability of later dredging and maintenance, and ensuring the long-term effective operation of the drainage system. In practical applications, drainage channels and drainage holes can also be set up during the filling process of slag heaps and slag retaining dam 2 to further enhance the drainage capacity of the slag heap. Setting up drainage channels and drainage holes are common practices of those skilled in the art, and will not be elaborated here.

[0033] In a specific embodiment of the present invention, the number of drainage blind ditches can be set to multiple, so that the spoil disposal site can meet the drainage needs of different specific working conditions, further improving the adaptability of the spoil disposal site. The layout and spacing of the drainage blind ditches can be adjusted according to the actual spoil stacking needs to meet different spoil stacking conditions.

[0034] This invention achieves the safe storage of large quantities of soft clay while fully absorbing engineering waste through reasonable zoning and storage, optimization of the slag retaining dam 2 reverse filter structure, and improvement of the bottom drainage system. This effectively prevents soil erosion, reduces engineering investment, and enhances the overall safety and environmental benefits of the slag yard.

[0035] Example 2 This embodiment provides a method for stockpiling slag to form a trench-type slag disposal site as described in Embodiment 1, comprising the following steps: Downstream of channel 1, dam body 3 is constructed, and upstream of dam body 3, reverse filter structure 4 is constructed; drainage blind ditch is constructed. The first storage area 5 is formed by piling up rocky waste on the upstream side of the slag retaining dam 2. The second storage area 6 is formed by piling up the waste soil on the upstream side of the first storage area 5.

[0036] The slag dumping method in this embodiment uses a slag-blocking dam 2 to contain the slag, and separates the rocky slag and soil slag for separate storage. This achieves large-capacity storage of soft clay, improves the space utilization rate of the slag dump and the capacity to dispose of engineering slag, reduces the risk of siltation and water environment deterioration downstream of the soft clay storage area, controls soil erosion at the source, and significantly improves the environmental benefits of slag dump layout.

[0037] Example 3 This embodiment provides a trench-type spoil disposal site, which has been successfully applied in a large-scale hydropower project. The spoil disposal site in this embodiment handles approximately 13 million cubic meters of excavated material. 3 Of which, approximately 4 million cubic meters are soft clay. 3 9 million cubic meters of general slag and stone materials 3 The maximum height of the slag heap reaches 200m, classifying it as an extra-large Class 1 slag heap. Using the slag heap layout described in this embodiment, after three years of actual operation and monitoring, the slag heap remained stable overall, no abnormalities occurred in the soft clay areas, the drainage system was unobstructed, soil erosion was controllable, and there were no signs of slope deformation, verifying its reliability.

[0038] The other structures of the trench-type spoil heap in this embodiment are the same as those in Embodiment 1, and will not be described again here.

[0039] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A trench-type spoil disposal site, characterized in that, include: The ditch has a drainage blind ditch at its bottom, which is laid along the longitudinal length of the ditch. A slag-blocking dam is located downstream of the channel, and the axial length of the slag-blocking dam is not less than the cross-sectional width of the channel. The slag-blocking dam includes a dam body and a filter structure. The dam body is constructed by filling with rocky waste slag, and the filter structure is located on the upstream slope of the dam body. The storage area within the silo includes a first storage area and a second storage area. The first storage area is located upstream of the slag-blocking dam and can be used to store rocky waste. The second storage area is located upstream of the first storage area and can be used to store excavated soil. The drainage blind ditch starts from the storage area inside the reservoir and runs through the slag retaining dam.

2. The trench-type spoil heap according to claim 1, characterized in that: The reverse filter structure is inclined from the top to the bottom of the dam towards the upstream direction.

3. The trench-type spoil heap according to claim 1, characterized in that: The filter structure includes, from top to bottom, a first medium-coarse sand layer, a geotextile layer, a second medium-coarse sand layer, a first graded crushed stone layer, and a transition material layer.

4. The trench-type spoil heap according to claim 1, characterized in that: The upstream slope of the slag-blocking dam is a stepped, straight slope.

5. The trench-type spoil heap according to claim 1, characterized in that: The bottom of the first storage area extends toward the second storage area.

6. The trench-type spoil heap according to claim 1, characterized in that: The height of the slag heap in the storage area shall not exceed the height of the slag retaining dam.

7. The trench-type spoil heap according to claim 1, characterized in that: The drainage ditch contains, from top to bottom, a third medium-coarse sand layer, a second graded crushed stone layer, and a block stone layer.

8. The trench-type spoil heap according to any one of claims 1-7, characterized in that: The number of drainage blind ditches is multiple.

9. A method for stockpiling slag to form a trench-type spoil heap as described in any one of claims 1-8, characterized in that, Includes the following steps: The dam body is filled downstream of the ditch, and a reverse filter structure is constructed on the upstream slope of the dam body; thus, the drainage blind ditch is constructed. The first storage area is formed by piling up rocky waste on the upstream side of the slag-blocking dam. The second storage area is formed by piling up waste soil on the upstream side of the first storage area.

Images