Refuse landfill flexible dam construction method based on gravel ton bag anchoring

Abstract

The invention relates to the technical field of refuse landfill flexible dam construction, and discloses a refuse landfill flexible dam construction method based on gravel ton bag anchoring. Comprising the steps of site investigation and cleaning, anti-sliding tooth construction, ton bag preassembling and transporting, ton bag stepped stacking, layered filling, drainage ditch and anti-seepage film connection, seepage guide pipe installation, gas drainage guide pipe connection and quality detection and repair. By means of the construction method, lateral thrust of garbage heaps or debris flow impact can be effectively resisted, the dam break risk is avoided, the impact resistance of the dam is improved, and the safety of the dam body is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of flexible retaining dam construction in garbage landfills, and in particular relates to a flexible retaining dam construction method in garbage landfills based on anchoring of crushed stone ton bags. Background Art

[0002] In landfill dam projects, traditional dam technologies have the following main problems: 1. Rigid dam structures: Primarily constructed of concrete or mortar-stone masonry, these structures offer high strength but lack flexibility. They are often used for debris flow prevention or landfill slope reinforcement. For example, mortar-stone dams, combined with sluice holes and reinforced mesh, can drain water through the sluice holes, but their overall rigidity makes them susceptible to structural damage from impacts such as landfills or debris flows, making repair difficult and their impact resistance limited.

[0003] Reinforced geotextile retaining dam: Geotextile is used to reinforce graded crushed stone to form a flexible structure, such as a high-steep reinforced retaining dam. It has certain deformation adaptability and anti-sliding stability, but it is sensitive to the leachate water level and has insufficient permeability, which can easily lead to leachate accumulation. When the accumulated liquid level rises, it may cause the dam body to slip. If the leachate water level is too high, the stability coefficient will be reduced.

[0004] Composite cutoff wall technology, such as the GCL composite vertical flexible cutoff wall, is primarily used for seepage prevention rather than as a retaining wall. While it can prevent the spread of pollutants, it cannot address the lateral thrust of the waste pile. Furthermore, composite cutoff walls require complex construction processes, such as the fabrication of guide walls and slurry wall protection. This leads to long construction times and high costs, making it difficult to adapt to the rapid emergency response needs of landfills.

[0005] Traditional flexible landfill renovation technology: Rigid landfill renovation uses reinforced concrete unit pools to enhance stability, but the cost is high and the construction is complex, making it difficult to adapt to the rapid renovation needs of existing flexible landfills.

[0006] Therefore, we propose a flexible retaining dam construction method based on crushed stone ton bags anchoring landfill. Summary of the Invention

[0007] The purpose of the present invention is to provide a flexible dam construction method for a landfill based on gravel ton bags anchoring in order to effectively resist the lateral thrust of a garbage pile or the impact of a debris flow, avoid the risk of dam failure, improve the impact resistance of the dam, and improve the safety of the dam body.

[0008] The technical solution adopted in the present invention is as follows: Based on the construction method of flexible retaining dam of crushed stone ton bag anchored landfill, the construction method is as follows: S1: Site survey and cleaning, clearing garbage and debris within the dam foundation, ensuring the base is flat, measuring and laying out, marking the dam axis, anti-slip tooth positions and ton bag stacking reference line; S2: Anti-slip teeth construction: excavate a trench along the dam foot with a depth of 0.5m and a width of 0.5m, lay Φ8 steel mesh, pour C30 concrete, and cure for 7 days; S3: Pre-loading and transportation of ton bags: 1 ton of gravel is pre-loaded into HDPE ton bags at the factory, sealed and transported to the site. The ton bags should be stacked ≤ 2 layers to avoid squeezing and deformation. S4: Ton bags are stacked in a stepped manner, starting from the anti-slip teeth along the dam axis, and the bags are staggered layer by layer. Positioning piles are used to fix the bags in place, ensuring that the verticality deviation is ≤2%; S5: Fill in layers, fill the inner side of the ton bag with 3~5cm graded gravel in layers, with each layer thickness ≤0.5m, compact the layers to a porosity ≤35%, and use a vibratory roller to roll 3~5 times, with a compaction degree ≥95%; S6: Connect the drainage ditch with the anti-seepage membrane. Dig a flexible drainage ditch on top of the gravel layer and lay a 1.5mm HDPE membrane, which is then hot-melt welded to the anti-seepage membrane of the garbage pile. S7: Installation of seepage pipe: pre-buried DN160 perforated HDPE pipe in the graded gravel layer with a slope of ≥3%, connected to the downstream regulating pond, and covered with geotextile on the top of the pipe to prevent clogging; S8: Gas drainage pipe connection: reserve gas drainage holes every 10m between the ton bag layers and connect them to the DN160 landfill gas collection pipe; S9: Quality inspection and repair, including water permeability inspection and stability inspection. If the ton bag is found to be damaged or the film is cracked during the inspection, hot-melt repairs can be made with patches of the same material, and the repair range shall exceed the damaged edge by ≥0.2m.

[0009] In a preferred embodiment of the invention, the size of the ton bag is 1.0 m long × 1.0 m wide × 0.8 m high, and the weight of each bag of gravel is ≤ 1 ton.

[0010] In a preferred embodiment of the invention, the graded gravel has a particle size of 3-5 cm, a mud content of ≤3%, a porosity of 30%-40%, a compressive strength of ≥20 MPa, and a crushing value of ≤15%.

[0011] In a preferred embodiment of the invention, the height of the dam is 3.5~4.0m and can be adjusted according to the height of the garbage pile. The top width is ≥3.0m, the bottom width is ≥10.0m, the slope is 1:3~1:4, and each layer of the ton bag is 0.8m high, and the staggered overlap length is ≥0.3m.

[0012] In a preferred embodiment of the invention, the lifting equipment for the ton bag is a 5-ton crane, the compacting equipment for compacting the gravel layer is a 2.5-ton vibratory roller, and the welding equipment for welding the HDPE film is a double-track hot-melt welding machine.

[0013] In a preferred embodiment of the invention, the distance between two adjacent positioning piles is 2m.

[0014] In a preferred embodiment of the invention, the flexible drainage ditch is 0.5 m wide and 0.3 m deep.

[0015] In a preferred embodiment of the invention, the water permeability test is to inject water upstream of the dam body to the designed water level and detect that the drainage rate is ≥10m³ / h to meet the leachate drainage requirements.

[0016] In a preferred embodiment of the invention, the stability detection is to use an inclinometer to monitor the displacement of the dam body, and the allowable deformation is ≤5cm / year.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. In the present invention, 1-ton HDPE woven bags are pre-filled with gravel and stacked in a stepped manner to form an impact-resistant skeleton. Each layer of ton bags is staggered to enhance integrity, and 3-5 cm graded gravel is filled inside the ton bag skeleton. The interlocking effect of the gravel is utilized to enhance the stability of the dam body, while the accumulated leachate pressure is reduced through pore water permeability. Then, trenches are excavated at the dam foot and concrete anti-slip teeth are poured to form a mechanical bite with the ton bag anchor layer to prevent the dam body from slipping. The above method can make the ton bag anchor layer withstand an impact load of 5 tons / m2, far exceeding that of traditional sandbags. Combined with the anti-slip tooth design, it can effectively resist the lateral thrust of the garbage dump or the impact of mud and rock flow, avoid the risk of dam collapse, and improve the impact resistance of the dam.

[0018] In the present invention, the gaps in the ton bags and the graded gravel layer form a natural drainage channel, which is combined with the flexible drainage ditch to achieve high drainage for high water and low drainage for low water, reducing dependence on water pumps. Moreover, the ton bag structure allows the dam body to undergo limited deformation under external loads, disperses stress concentration, and avoids fracture of the rigid structure due to local overload. Through the above method, the water permeability efficiency of the dam can be improved compared with the traditional grouted stone dam, alleviates the problem of dam body slippage caused by leachate accumulation, and improves the safety of the dam body through the synergistic effect of the ton bags and gravel.

[0019] In the present invention, prefabricated ton bags are used to reduce on-site operation time, adapt to complex terrain, and positioning piles and connectors are used to achieve rapid splicing of ton bag units. It is suitable for emergency rescue scenarios and shortens construction period. Pre-installed ton bags can reduce manpower requirements and thus improve construction efficiency.

[0020] In the present invention, the method can be adapted to multiple scenarios such as landfills, river embankments, and areas prone to mudslides, and is particularly suitable for solving water accumulation problems in reservoirs where leachate is stored, and has high applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flow chart of the construction method of the present invention. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0023] The following will be combined Figure 1 The flexible retaining dam construction method of a landfill based on anchoring ton bags of crushed stone according to an embodiment of the present invention is described in detail.

[0024] Example 1: Reference Figure 1 , based on the flexible retaining dam construction method of gravel ton bag anchoring landfill, the construction method is as follows: site investigation and cleaning, cleaning up garbage and debris within the dam foundation range, ensuring the flatness of the base, and measuring and laying out the lines, marking the dam axis, anti-skid tooth position and ton bag stacking reference line; anti-skid tooth construction, excavating a trench along the dam foot, the trench is 0.5m deep and 0.5m wide, and Φ8 steel mesh is laid, C30 concrete is poured, and cured for 7 days; ton bag preloading and transportation, 1 ton of gravel is preloaded into HDPE ton bags at the factory, sealed and transported to the site, ton bag stacking height ≤ 2 layers to avoid extrusion deformation; ton bags are stacked in a stepped manner, starting from the anti-skid teeth along the dam axis, and the ton bags are staggered layer by layer, and the ton bags are fixed with positioning piles to ensure that the verticality deviation is ≤ 2%; layered filling, 3~5cm graded gravel is filled in layers on the inside of the ton bag, The thickness of each layer is ≤0.5m, and it is compacted layer by layer to a porosity of ≤35%, and rolled 3 to 5 times with a vibratory roller to a compaction degree of ≥95%; specifically, 1-ton HDPE woven bags are pre-loaded with crushed stone and stacked in a stepped manner to form an impact-resistant skeleton. Each layer of ton bags is staggered to enhance the integrity, and 3 to 5cm graded crushed stone is filled on the inside of the ton bag skeleton. The interlocking effect of crushed stone is used to improve the stability of the dam body, while the accumulation pressure of leachate is reduced through pore water permeability; then trenches are excavated at the dam foot and concrete anti-skid teeth are poured to form a mechanical bite with the ton bag anchor layer to prevent the dam body from slipping; the above method can make the ton bag anchor layer withstand an impact load of 5 tons / m2, which far exceeds that of traditional sandbags. Combined with the anti-skid tooth design, it can effectively resist the lateral thrust of the garbage pile or the impact of mud and rock flow, avoid the risk of dam collapse, and improve the impact resistance of the dam.

[0025] Reference Figure 1The size of the ton bag is 1.0m long × 1.0m wide × 0.8m high, and the weight of each bag of gravel is ≤1 ton; the particle size of the graded gravel is: 3~5cm, the mud content is ≤3%, the porosity is 30%~40%, the compressive strength is ≥20MPa, and the crushing value is ≤15%; the height of the retaining dam is 3.5~4.0m and can be adjusted according to the height of the garbage pile, the top width is ≥3.0m, the bottom width is ≥10.0m, the slope is 1:3~1:4, and the height of each ton bag layer is 0.8m, and the staggered overlap length is ≥0.3m; the lifting equipment of the ton bag It is a 5-ton crane, the compaction equipment used for compacting the gravel layer is a 2.5-ton vibratory roller, and the welding equipment used for welding the HDPE film is a double-track hot-melt welding machine; the spacing between two adjacent positioning piles is 2m; the width of the flexible drainage ditch is 0.5m and the depth is 0.3m; specifically, prefabricated ton bags are used to reduce on-site operation time, adapt to complex terrain, and positioning piles and connectors are used to achieve rapid splicing of ton bag units, which is suitable for emergency rescue scenarios and shortens construction period. Pre-installed ton bags can reduce manpower requirements and thus improve construction efficiency.

[0026] Example 2: Reference Figure 1 , the drainage ditch is connected with the anti-seepage membrane, a flexible drainage ditch is excavated on the top of the gravel layer, and a 1.5mm HDPE membrane is laid and hot-melt welded to the anti-seepage membrane of the garbage pile; the seepage pipe is installed, and a DN160 perforated HDPE pipe is pre-buried in the graded gravel layer with a slope of ≥3%, connected to the downstream regulating tank, and the top of the pipe is covered with geotextile to prevent clogging; the gas drainage pipe is connected, and a gas drainage hole is reserved at intervals of 10m in the ton bag layer, and connected to the DN160 landfill gas collection pipe; quality inspection and repair, permeability inspection and stability inspection are carried out. If the ton bag is damaged or the membrane is cracked during the inspection, the same material patch can be used for hot-melt repair, and the repair range exceeds the damaged edge by ≥0.2m; the permeability test is to inject water to the design water level upstream of the dam body, detect the drainage rate ≥10m³ / h, and meet the seepage Filtrate drainage requirements; the stability test is to use an inclinometer to monitor the displacement of the dam body, and the allowable deformation is ≤5cm / year; specifically, the gaps in the ton bags and the graded gravel layer form a natural drainage channel, combined with the flexible drainage ditch to achieve high drainage when high water is applied and low drainage when low water is applied, reducing dependence on water pumps, and the ton bag structure allows the dam body to undergo limited deformation under external loads, disperse stress concentration, and avoid fracture of the rigid structure due to local overload; the above method can improve the permeability of the dam compared to the traditional grouted stone dam, alleviate the problem of dam body slippage caused by leachate accumulation, and improve the safety of the dam body through the synergistic effect of the ton bags and gravel. This method can be adapted to multiple scenarios such as landfills, river embankments, and areas prone to mudslides. It is especially suitable for water accumulation problems in reservoirs with accumulated leachate, and has high applicability.

[0027] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0028] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A flexible retaining dam construction method for landfills based on crushed stone ton bags anchoring, characterized in that: The construction method is: S1: Site survey and cleaning, clearing garbage and debris within the dam foundation, ensuring the base is flat, measuring and laying out, marking the dam axis, anti-slip tooth positions and ton bag stacking reference line; S2: Anti-slip teeth construction: excavate a trench along the dam foot with a depth of 0.5m and a width of 0.5m, lay Φ8 steel mesh, pour C30 concrete, and cure for 7 days; S3: Pre-loading and transportation of ton bags: 1 ton of gravel is pre-loaded into HDPE ton bags at the factory, sealed and transported to the site. The ton bags should be stacked ≤ 2 layers to avoid squeezing and deformation. S4: Ton bags are stacked in a stepped manner, starting from the anti-slip teeth along the dam axis, and the bags are staggered layer by layer. Positioning piles are used to fix the bags in place, ensuring that the verticality deviation is ≤2%; S5: Fill in layers, fill the inner side of the ton bag with 3~5cm graded gravel in layers, with each layer thickness ≤0.5m, compact the layers to a porosity ≤35%, and use a vibratory roller to roll 3~5 times, with a compaction degree ≥95%; S6: Connect the drainage ditch with the anti-seepage membrane. Dig a flexible drainage ditch on top of the gravel layer and lay a 1.5mm HDPE membrane, which is then hot-melt welded to the anti-seepage membrane of the garbage pile. S7: Installation of seepage pipe: pre-buried DN160 perforated HDPE pipe in the graded gravel layer with a slope of ≥3%, connected to the downstream regulating pond, and covered with geotextile on the top of the pipe to prevent clogging; S8: Gas drainage pipe connection, reserve gas drainage holes every 10m between the ton bag layers and connect to the DN160 landfill gas collection pipe; S9: Quality inspection and repair, including water permeability inspection and stability inspection. If the ton bag is found to be damaged or the film is cracked during the inspection, hot-melt repairs can be made with patches of the same material, and the repair range shall exceed the damaged edge by ≥0.2m.

2. The flexible retaining dam construction method based on anchoring ton bags of crushed stone in a landfill as claimed in claim 1 is characterized by: The size of the ton bag is 1.0m long × 1.0m wide × 0.8m high, and the weight of each bag of gravel is ≤1 ton.

3. The flexible retaining dam construction method based on anchoring ton bags of crushed stone in a landfill as claimed in claim 1 is characterized by: The graded gravel has a particle size of 3-5 cm, a mud content of ≤3%, a porosity of 30%-40%, a compressive strength of ≥20 MPa, and a crushing value of ≤15%.

4. The flexible retaining dam construction method based on anchoring ton bags of crushed stone in a landfill as claimed in claim 1 is characterized by: The height of the dam is 3.5~4.0m and can be adjusted according to the height of the garbage pile. The top width is ≥3.0m, the bottom width is ≥10.0m, the slope is 1:3~1:4, and each layer of ton bags is 0.8m high, with an staggered overlap length of ≥0.3m.

5. The flexible retaining dam construction method based on anchoring ton bags of crushed stone in a landfill as claimed in claim 1 is characterized by: The lifting equipment for the ton bag is a 5-ton crane, the compacting equipment for the gravel layer is a 2.5-ton vibratory roller, and the welding equipment for welding the HDPE film is a double-track hot-melt welding machine.

6. The method for constructing a flexible retaining dam in a landfill based on anchoring ton bags of crushed stone as claimed in claim 1, characterized in that: The distance between two adjacent positioning piles is 2m.

7. The method for constructing a flexible retaining dam in a landfill based on anchoring ton bags of crushed stone as claimed in claim 1, characterized in that: The flexible drainage ditch has a width of 0.5 m and a depth of 0.3 m.

8. The method for constructing a flexible retaining dam in a landfill based on anchoring ton bags of crushed stone as claimed in claim 1, characterized in that: The permeability test is to inject water upstream of the dam body to the designed water level and test the drainage rate to be ≥10m³ / h to meet the leachate drainage requirements.

9. The flexible retaining dam construction method based on anchoring ton bags of crushed stone in a landfill as claimed in claim 1 is characterized by: The stability test is to use an inclinometer to monitor the displacement of the dam body, and the allowable deformation is ≤5cm / year.

Images