A method for compaction and excavation of coastal silty soil ditch slopes

Abstract

This invention discloses a method for compacting and excavating the slope of a coastal silty sandy ditch, comprising: S1 determining the center control line of the ditch, and laying out two inner embankment toe lines and two outer embankment toe lines; S2 clearing the topsoil between the inner and outer embankment toe lines, and compacting it back and forth along the two inner embankment toe lines respectively; S3 performing layered excavation between the two inner embankment toe lines, wherein the distance between the excavation edge of the next layer and the excavation edge of the previous layer is [missing information]. m · h 挖 S4 involves leveling and compacting the soil piled between the inner and outer embankment toes; S5 involves slope trimming of the ditch slope; and S6 involves covering the inner slope and field-facing slope with an ecological blanket. This method uses partial compaction, layered excavation, and slope trimming to reinforce the ditch slope, which helps improve the density of the slope soil, enhances the stability and erosion resistance of the slope, and, after the ditch is built, lays the ecological blanket to help slow down the water flow in the ditch, prevent soil erosion, and make the ditch less prone to damage and collapse during agricultural production.

Description

Technical Field

[0001] This invention belongs to the field of farmland drainage ditch construction technology, specifically relating to a method for compacting and excavating the slope of a coastal silty sandy soil farm ditch. Background Technology

[0002] Farmland drainage facilities are the most important infrastructure in agricultural production. Drainage ditches involve issues such as farmland drainage, waterlogging control, and ecological landscape. Ditch collapse not only causes economic losses but also leads to soil erosion and serious environmental hazards to the downstream catchment area. Therefore, maintaining the stability of ditch slopes is an important part of farmland water conservancy projects.

[0003] The soil in my country's coastal tidal flats is mainly composed of silt and silty clay, characterized by high permeability, small particle size, low shear strength, and high compressibility. To prevent the collapse of agricultural ditches along these tidal flats, hardening methods are commonly used for lining. However, this method is costly, environmentally unfriendly, and affects farmland drainage. Ensuring stable, safe, and environmentally friendly excavation and construction of agricultural ditches is a crucial issue in the design and construction of farmland water conservancy projects. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problems of existing construction methods, such as affecting farmland drainage, high cost, and environmental pollution. It proposes a construction method that can be used for excavating agricultural ditches in coastal tidal flat areas, ensuring the stability of the ditch slopes, and reducing damage and subsidence during agricultural production. To achieve the above objective, the technical solution of this invention is as follows:

[0005] A method for compacting and excavating the slope of a coastal silty sandy soil ditch, the specific steps of which are as follows: Step S1, Construction Layout: First, determine the center control line of the irrigation ditch according to the planning and design requirements; second, determine the width of the ditch bottom... B trench depth H Based on the design data of the slope coefficient m within the ditch, the toe lines of the two inner embankments are laid out. These two inner embankment toe lines should be parallel to the center control line of the ditch, and the horizontal distance between the two inner embankment toe lines and the center control line of the ditch should be [missing information]. L 1 : L 1 =H ‧ m+ B / 2 meters, finally based on the height of the ditch embankment h , slope coefficient within the ditch (m), width of the embankment crest b and the slope coefficient m in the direction of the field surface 1 Based on the design data, lay out the two outer toe lines. These two outer toe lines should be parallel to the inner toe line, and the horizontal distance between the outer and inner toe lines should be... L 2 for:L 2 =h ‧ m+b+h ‧ m 1 rice; The layout work is determined by the actual working environment of the construction site and there are relevant design specifications. The layout method for farm ditches is an existing technology and will not be elaborated here.

[0006] Step S2: Compact along the two inner embankment toe lines. First, clear the topsoil between the inner and outer embankment toe lines, removing rocks, debris, and other obstacles. Then, compact along the two inner embankment toe lines back and forth. The compacted width of the inner embankment toe line should be ≥ (0.5 + ...). m · h 挖 ) meters, of which the compaction width within the trench should be ≥ m · h 挖 Meters; the width outside the ditch is ≥0.5 meters; During compaction, an 8T roller is used with a speed of 1-2. The method of staggered advance and retreat is adopted, and the front and rear wheel tracks overlap by 20-30cm. Before compaction, a field test is conducted to determine the compaction parameters, including soil moisture content, paving thickness, type of compaction machinery, and number of compaction passes, until the compaction degree is not less than 85%.

[0007] The on-site test before compaction is existing technology and will not be elaborated here.

[0008] h 挖 This application requires the excavation depth. h 挖 The depth of the trench should be less than or equal to 0.3m, with each excavation reaching the same depth. The width outside the trench should be ≥0.5m. This width is the area between the inner and outer toe lines of the embankment and forms the foundation of the trench. Compaction reinforcement at this location is to prevent erosion and damage to the embankment. The compacted width inside the trench should be ≥0.5m. m · h 挖 rice," m · h 挖 "This is the minimum compaction width required by this scheme to ensure the effectiveness of this layered compaction method."

[0009] Step S3, excavation; firstly, the first layer of excavation is carried out between the two inner embankment toe lines, with an excavation depth of [depth missing]. h 挖 The first layer of excavation boundary line is 0.5 meters away from the toe lines of the two inner dikes, and the first layer of topsoil should be piled up separately. Level the excavated surface of the first layer, and compact it along the excavation edge using a road roller. The width of each compaction layer should be ≥ 1 / 2. m · h 挖After the compaction requirements are met, the second layer of excavation is carried out. The distance between the edge of the second layer of excavation and the edge of the previous layer of excavation is... m · h 挖 This layer of soil should be piled between the inner and outer toe lines of the dike as soil for building the ditch dike; Repeat the above excavation steps and continue excavating until the designed depth of the ditch is reached. H The excavated soil is piled up outside the outer embankment toe line for centralized treatment. After excavation to the bottom of the ditch, a stepped slope is formed. When the last layer of the ditch bottom is encountered after the excavation is completed, if the distance between the two excavation edges is less than the width of the roller, a narrow roller should be used for compaction. Narrow-width roller is a narrow-drum road roller. The optimal width of the road roller in this application is set at 1.3m. When the compaction working surface is smaller than this optimal working width, a narrow-width roller is used.

[0010] The impact depth of the road roller on the soil is between 0.2 and 0.3 meters, corresponding to the excavation depth required by this plan. h 挖 With a depth of 0.3m or less, layered compaction ensures that the slopes and embankments of the irrigation ditches are all compacted by the roller.

[0011] Step S4: Construct the embankment. According to the design requirements of the embankment, level and compact the soil piled between the inner and outer toe lines. Step S5: Slope trimming. Use an excavator to trim the slope of the ditch, then manually refine it to achieve a slope coefficient of m within the ditch and a slope coefficient of m on the field surface. 1 ; Step S6: Laying the ecological blanket. After the slope is trimmed and the embankment is built, cover the slope with an ecological blanket that is resistant to rainwater erosion. The selected ecological blanket should be at least 20mm thick and weigh at least 250g / m³. 2 The ecological blanket should completely cover the top of the embankment and make full contact with the slope. The overlap width of the ecological blanket should not be less than 10cm.

[0012] The first layer of excavated soil, due to its relatively low salinity, has some utilization value and can be directly laid in nearby fields as farmland soil. The second layer of excavated soil is piled between the inner and outer toe lines of the dike as soil for dike construction. The third layer, up to the bottom of the ditch, is piled at the outer toe line as waste soil and is no longer used. Except for the first and second layers of excavated soil, which have special requirements, the disposal method for other excavated soil is determined based on the actual construction site conditions, or it can be transported off-site for backfilling or landfilling after the project is completed.

[0013] The present invention has the following technical effects:

[0014] Compared with existing hardening and embankment methods, this method uses processes such as local compaction, layered excavation, and slope trimming to reinforce the slope of the agricultural ditch. This helps to improve the density of the slope soil, enhance the stability and erosion resistance of the slope. After the agricultural ditch is built, laying an ecological blanket helps to slow down the water flow in the ditch and prevent soil erosion, making the agricultural ditch less prone to damage and collapse during agricultural production. This method also uses some of the excavated soil to make ditch embankments, which is low-cost and more environmentally friendly.

[0015] In addition to vertical movement, soil moisture also undergoes lateral seepage. When the slopes of irrigation ditches are hardened, the soil's lateral seepage capacity is greatly reduced, thus affecting the drainage effect of farmland. The compaction and covering with ecological blankets proposed in this application have little impact on the lateral movement of soil moisture and result in good drainage effect of farmland. Attached Figure Description

[0016] Figure 1 This is a schematic cross-sectional view of the agricultural ditch of the present invention.

[0017] Figure 2 This is a schematic diagram of the wire laying out in this invention.

[0018] Figure 3 This is a schematic diagram of the process of the present invention.

[0019] In the diagram: 1. Center control line of the ditch; 2. Inner embankment toe line; 3. Outer embankment toe line; 4. Field surface; 5. Ecological blanket; 6. Ditch embankment; 7. Ditch bottom line; 8. Compacted width of the inner embankment toe line; 9. Compacted width within the ditch; 10. Distance between the first excavation edge line and the two inner embankment toe lines; 11. Excavation depth; 12. Compacted width of each layer; 13. Soil used for ditch embankment construction; 14. Stepped slope; 15. Distance between the second excavation edge line and the previous excavation edge line. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings.

[0021] This embodiment provides a method for compacting and excavating the slope of a coastal silty sandy soil ditch. The specific steps are as follows: Step S1, construction layout: First, determine the center control line 1 of the ditch according to the planning and design requirements. Second, determine the width of the ditch bottom. B for 0.5 Meter, trench depth H for 2.0 With the slope coefficient m of the ditch set at 1.5, two inner embankment toe lines 2 are laid out. These two inner embankment toe lines should be parallel to the center control line 1 of the ditch. The horizontal distance between the two inner embankment toe lines 2 and the center control line of the ditch is... L 1 Both are 3.25 meters, and the final height is based on the 6th embankment. h for 0.5 Meters, slope coefficient within the ditch (m), and width of the embankment crest.b for 0.3 The slope coefficient (m) of the ditches and embankments in the four directions within the ditches. 1 For a distance of 1 meter, lay out the two outer toe lines of the dike. These two outer toe lines should be parallel to the inner toe line, and the horizontal distance between the outer and inner toe lines should be... L 2 It is 1.55 meters; if Figure 1 , 2 As shown; Step S2, compaction along the two inner embankment toe lines, in this embodiment h 挖 Take a 0.3-meter section and first clear the topsoil between the inner and outer embankment toe lines, removing boulders, debris, and other obstacles. Then, compact the soil back and forth along both inner embankment toe lines. The compaction width of the inner embankment toe line should be ≥ (0.5 + 0.3 meters). m · h 挖 The compacted width of the inner embankment toe line should be greater than or equal to 0.95 meters, of which the compacted width within the ditch should be ≥ 0.95 meters. m · h 挖 The compaction width within the trench should be greater than or equal to 0.45 meters, and the width outside the trench should be ≥0.5 meters. An 8T roller should be used for compaction at speeds 1-2, employing a staggered approach with a 20-30cm overlap between the front and rear wheel tracks. Before compaction, a field test should be conducted to determine compaction parameters, including soil moisture content, paving thickness, type of compaction machinery, and number of passes, until the compaction degree is not less than 85%. Step S3, excavation; firstly, the first layer of excavation is carried out between the two inner embankment toe lines, with an excavation depth of 11. h 挖 That is, 0.3 meters. The distance between the first layer of excavation edge and the two inner embankment toe lines is 0.45 meters respectively. The first layer of topsoil should be piled up separately. After the first layer of excavation, the excavation surface is leveled, and a road roller is used to compact it along the excavation edge. The compaction width of each layer should be ≥12 mm. m · h 挖 That is, the width of each compaction layer should be greater than or equal to 0.45 meters. After the compaction requirements are met, the second layer of excavation is carried out. The distance between the edge of the second layer of excavation and the edge of the previous layer of excavation is 15 meters. m · h 挖 0.45 meters, this layer of soil should be piled between the inner and outer toe lines of the dike as soil for building the ditch dike 13; Repeat the above excavation steps and continue excavating until the designed depth of the ditch is reached. H for 2.0The excavated soil is piled up outside the outer embankment toe line for centralized disposal. After excavation to the bottom of the ditch, two ditch bottom lines (7) and a stepped slope (14) are formed. When the last layer of excavation at the bottom of the ditch is completed, if the distance between the two excavation edges is less than the width of the roller, a narrow roller should be used for compaction. Figure 3 As shown; Step S4, construct the ditch embankment 6, and level and compact the soil piled between the inner and outer embankment toe lines according to the ditch embankment design requirements; Step S5: Slope trimming. Use an excavator to trim the slope of the ditch, and then trim it manually. Step S6: Lay the ecological blanket 5. After the slope is trimmed and the embankment is built, cover it with an ecological blanket that is resistant to rainwater erosion. The selected ecological blanket should be at least 20mm thick and weigh at least 250g / m³. 2 The ecological blanket should completely cover the top of the embankment and make full contact with the slope. The overlap width of the ecological blanket should not be less than 10cm.

[0022] The above description represents the preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any simple modifications and substitutions made to the technical processes and operations provided by the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for compacting and excavating the slope of a coastal silty sandy soil ditch, characterized in that, The specific steps are as follows: Step S1, laying out the lines; First, according to the planning and design requirements, determine the center control line of the ditch. Second, based on the design data of the ditch bottom width B, ditch depth H, and ditch slope coefficient m, lay out the two inner embankment toe lines. The two inner embankment toe lines are parallel to the center control line of the ditch, and the horizontal distance between the two inner embankment toe lines and the center control line of the ditch is L1, L1 = (H·m + B / 2) meters. Finally, based on the design data of the ditch embankment height h, ditch slope coefficient m, embankment top width b, and field surface slope coefficient m1, lay out the two outer embankment toe lines. The two outer embankment toe lines are parallel to the inner embankment toe lines, and the horizontal distance between the outer embankment toe lines and the inner embankment toe lines is L2, L2 = (h·m + b + h·m1) meters. Step S2, compaction; First, clean the topsoil between the inner and outer embankment toes, removing boulders, debris, and other obstacles. Then, compact the soil back and forth along the two inner embankment toes respectively. The compaction width of the inner embankment toe should be greater than or equal to (0.5 + m·h). 挖 (meters), of which the compaction width within the trench should be greater than or equal to m·h 挖 The width of the compacted area outside the trench should be greater than or equal to 0.5 meters, and the compaction degree should not be less than 85%. 挖 This refers to the excavation depth; Step S3, excavation; the first layer of excavation is carried out between the two inner embankment toe lines, with an excavation depth of h. 挖 Less than or equal to 0.3 meters, the distances from the first excavation edge to the toe lines of the two inner embankments are respectively (m·h). 挖 The first layer of topsoil should be piled separately. Level the excavation surface of the first layer, and compact it along the excavation edge using a road roller. The width of each compaction layer should be greater than or equal to m·h. 挖 After the compaction requirement is met, the second layer of excavation is carried out. The distance between the edge of the second layer of excavation and the edge of the previous layer of excavation is m·h. 挖 This layer of soil should be piled between the inner and outer toe lines of the dike as soil for subsequent dike construction. Repeat the above excavation steps and continue excavating until the design depth H of the ditch is reached. The excavated soil is piled up outside the outer embankment and disposed of in a centralized manner. After excavating to the bottom of the ditch, a stepped slope is formed, and the excavation of the ditch is completed. Step S4, construct the embankment; according to the design requirements of the embankment, level and compact the soil piled between the inner and outer toe lines of the embankment; Step S5, slope trimming; use an excavator to trim the slope of the ditch, and then trim it manually to make the slope coefficient inside the ditch m and the slope coefficient in the field direction m1. Step S6, Lay the ecological blanket; Cover the slopes of the ditch and the slopes facing the field with the ecological blanket. The ecological blanket should completely cover the top of the embankment and make full contact with the slope. The overlap width of the ecological blanket should not be less than 10cm. Before compaction in step S2, a field test is conducted to determine the compaction parameters, including soil moisture content, paving thickness, type of compaction machinery, and number of compaction passes, until the compaction degree is not less than 85%. In step S3, when encountering the last layer of excavation at the bottom of the trench, if the distance between the two excavation edges is less than the width of the roller, a narrow roller should be used for compaction.

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