A zoned filling dike structure

Abstract

This utility model belongs to the field of civil engineering technology, specifically a partitioned embankment structure. It includes an upper capping section and a lower base. The base includes a water-facing area in contact with the river water and a backwater area on the opposite side, adjacent to the water-facing area. From top to bottom, it includes an upper backwater area and a lower backwater area. The capping section is a cement-modified soil component, the water-facing area is a non-expanding clay component, the upper backwater area is a non-expanding weathered soil component, and the lower backwater area is an expansive clay component with an embedded geogrid. The capping section, water-facing area, upper backwater area, and lower backwater area are integrated into a single unit according to their spatial positions. This structure allows for close bonding of materials in each section, ensuring the overall seepage prevention and stability of the embankment. It solves the problem of reduced embankment bearing capacity caused by the use of expansive clay during embankment construction, achieving maximum resource utilization. It is suitable for widespread use in embankment construction in river sections in areas with scarce soil resources.

Description

Technical Field

[0001] This utility model belongs to the field of civil engineering technology, and specifically discloses a zoned filling dike structure. Background Technology

[0002] As important flood control structures, dikes must possess the fundamental characteristics of water retention and stability. They are often constructed using clay fill. However, with continuous infrastructure development and the protection of basic farmland, clay resources are becoming increasingly scarce, posing new challenges to dike flood control construction in urban areas and other regions lacking suitable clay. Weathered soil has poor seepage prevention properties, while expansive clay is detrimental to dike stability. Therefore, designing a reasonable structural form is crucial when soil conditions are limited.

[0003] Currently, when high-quality soil is scarce at the project site during dike construction, the following methods are often used: ① Obtaining soil from distant locations across regions. This method has high costs for soil extraction and transportation, and obtaining approval for soil extraction is difficult; ② Using a "gold-wrapped silver" filling method, where high-quality soil is used to wrap inferior soil, without affecting the overall seepage prevention and stability of the dike. This method has poor reliability; ③ Treating and backfilling the poor soil by mixing expansive soil with cement or other materials for chemical modification before backfilling. This method has low construction efficiency.

[0004] Therefore, for areas with scarce soil resources, how to design a structure that can ensure the structural strength of the embankment while using a large amount of expansive clay as a substitute material to fill the dam body and solve the problem of insufficient high-quality soil is an urgent problem to be solved by those skilled in the art. Utility Model Content

[0005] To address the technical problems listed in the background section, this utility model provides a zoned filling dike structure. The specific technical solution is as follows: A partitioned embankment structure has a trapezoidal cross-section, divided by a horizontal plane into an upper cap and a lower base. The height ratio of the cap to the base is 0.20 to 0.45. The base includes a water-facing area in contact with the river water and a backwater area on the opposite side, which are adjacent to each other. From top to bottom, it includes an upper backwater area and a lower backwater area. The cap is a cement-modified soil component, the water-facing area is a non-expanding clay component, the upper backwater area is a non-expanding weathered soil component, and the lower backwater area is an expansive clay component with an embedded geogrid. The cap, water-facing area, upper backwater area, and lower backwater area are fitted together as a whole according to their spatial positions.

[0006] Preferably, the interface between the water-facing area and the back water-facing area is parallel to the water-facing surface, and the interface is 0.6 to 3.0 m away from the water-facing surface.

[0007] Preferably, the spacing between adjacent geogrid layers is 0.3 to 0.5 m.

[0008] Preferably, the upper backwater area and the lower backwater area are at the same height.

[0009] Preferably, the geogrid is placed on the back side of the lower backwater zone, and the space between the geogrids is filled with expansive clay. The side adjacent to the water-facing zone has only expansive clay and no geogrid is set. The geogrid area occupies 50% of the space of the lower backwater zone.

[0010] Compared with the prior art, this utility model has the following advantages: The embankment structure of this invention effectively utilizes expansive clay and weathered soil resources, solves the problem of lack of non-expansive clay resources during embankment construction, and achieves maximum resource utilization.

[0011] The cement-modified soil capping structure at the top ensures that the materials in each block below are more compact, guaranteeing the overall seepage prevention and stability of the dike. It also enhances the integrity and stability of the dike, preventing the top of the dike from collapsing or cracking due to water flow impact or vehicle load. At the same time, it can block rainwater infiltration and prevent the softening of the soil in the lower part.

[0012] The dike structure of this utility model is designed with different structural forms to meet the different needs of the water-facing side and the back water-facing side, taking into account both the seepage prevention requirements of the water-facing side and the manufacturing process cost. Attached Figure Description

[0013] Figure 1 This is a schematic cross-sectional view of the partitioned filling dike structure in an embodiment of this utility model; Among them, 1. non-expanding clay structure; 2. cement-modified soil structure; 3. expansive clay structure without grid; 4. non-expanding weathered soil structure; 5. expansive clay-grid skeleton structure. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0015] In the example of the partitioned filling embankment structure, the ground elevation is 11.20m, the cross-section of the embankment structure is trapezoidal, the top width is 6m, and the slope ratio of the two sides is 1:3.

[0016] The levee structure includes a coping at an elevation of 16m to 18.15m. Figure 1 The cement-modified soil structure 2) and the base below the highest water level; the base includes the water-facing area in contact with the river water ( Figure 1The non-expansive clay structure 1) and the opposite backwater zone, which is adjacent to the water-facing zone, and from top to bottom includes the upper backwater zone ( Figure 1 The non-expansive weathered soil structure 4) and the lower backwater area are located in the upper backwater area and the lower backwater area. The horizontal interface elevation between the upper backwater area and the lower backwater area is 12.5m. The capping is a cement-modified soil component with a cement content of 4%. The water-facing area is a non-expansive clay structure 2. The upper backwater area is a non-expansive weathered soil structure 4. The lower backwater area is an expansive clay component with an embedded geogrid. The capping, water-facing area, upper backwater area and lower backwater area are connected to each other as a whole according to the above spatial positions.

[0017] The interface between the water-facing zone and the backwater zone is parallel to the water-facing surface, and the interface is 1.5m away from the water-facing surface. The spacing between adjacent geogrid layers is 0.5m.

[0018] The geogrid is placed on the back side of the lower backwater zone, and the spaces between the geogrids are filled with expansive clay to form an expansive clay-grid skeleton structure 5. To prevent the geogrid from penetrating the expansive clay area and forming a seepage channel, the side adjacent to the water-facing zone is an expansive clay structure 3 without a geogrid. The geogrid area is located on the back side, occupying 50% of the space of the lower backwater zone.

[0019] The specific implementation steps for completing the above-mentioned zoned filling and dike structure are as follows: (1) Before filling, the turf, tree roots, humus and other materials on the foundation of the dike shall be cleaned up and the clearing range shall be 0.5m beyond the boundary of the reinforcement. (2) According to the design section, the soil material is laid in different areas, and construction is carried out at the same time and rising synchronously. When filling, the soil material is compacted in layers. Before laying the upper layer, the surface of the lower layer is roughened and moistened with water. (3) When filling in zones, the permeability coefficient of the clay body of the embankment should not be greater than 1×10-5cm / s, and the compaction degree should meet the following requirements: not less than 0.95 for Class 1 embankments, not less than 0.93 for Class 2 and Class 3 embankments with a embankment height of not less than 6m, and not less than 0.91 for Class 3 and above embankments with a embankment height of less than 6m. The compaction degree of non-cohesive weathered soil should meet the following requirements: not less than 0.65 for Class 1, Class 2 and Class 3 embankments with a embankment height of not less than 6m, and not less than 0.6 for Class 3 and above embankments with a embankment height of less than 6m. The compaction parameters for layered filling of different soil types should be determined according to the on-site compaction test. The compaction direction should be parallel to the embankment axis. After compaction is completed according to the parameters obtained from the compaction test, samples should be taken to test the compaction degree. After passing the test, the next layer of filling can be carried out. (4) When preparing cement-modified soil, it is necessary to strictly follow the parameters provided by the compaction test for mixing. After the mixture is fully mixed and discharged, a sample is taken for uniformity testing. After passing the test, it is backfilled and compacted. (5) In areas reinforced with geogrids, a layer of geogrid is laid at the bottom of the filling surface before filling. The geogrid is fixed with nails, and the connection between the webs can be manually tied and overlapped. After the geogrid is laid, the soil is spread in time. The interlayer soil laying and rolling are carried out in 2 or more times. When filling the first layer of soil on the geogrid, light compaction machinery should be used as much as possible. When the filling thickness reaches 0.5m, heavy machinery can be used for compaction. During rolling, the roller should not come into direct contact with the reinforcement. Vehicles are generally not allowed to drive on the uncompacted reinforced body to avoid the reinforcement from being misaligned.

[0020] Points to note during implementation: (1) The overall cross-section seepage prevention meets the requirements, and the upstream water-blocking section has a safe water-blocking thickness; (2) Expansive clay should not be directly exposed. Instead, it should be wrapped with weight, modified with cement, or reinforced with geogrid to prevent expansion and deformation that could affect the stability and safety of the embankment. (3) When filling the soil in the zones, the construction should be carried out simultaneously and the soil should be raised synchronously to ensure good connection between the soil zones; (4) The design of the cross section should take into account economic benefits. Expansive clay needs to be treated before use. Among them, the treatment cost of cement-modified soil is relatively high, while the treatment cost of geogrid reinforcement is relatively low. Other soil materials should be used first when filling, or geogrid reinforcement should be used first when there is no water barrier requirement.

[0021] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A zoned filling dike structure, characterized in that, The cross-section is trapezoidal, divided by a horizontal plane into an upper cap and a lower base; the height ratio of the cap to the base is 0.20 to 0.45; the base includes a water-facing area in contact with the river water and a backwater area on the opposite side, the backwater area is adjacent to the water-facing area, and from top to bottom includes an upper backwater area and a lower backwater area, wherein the cap is a cement-modified soil component, the water-facing area is a non-expanding clay component, the upper backwater area is a non-expanding weathered soil component, and the lower backwater area is an expansive clay component with an embedded geogrid, the cap, the water-facing area, the upper backwater area, and the lower backwater area are fitted together as a whole according to the above spatial positions.

2. The partitioned filling dike structure as described in claim 1, characterized in that, The interface between the water-facing area and the backwater area is parallel to the water-facing surface, and the interface is 0.6 to 3.0 meters away from the water-facing surface.

3. The partitioned filling dike structure as described in claim 2, characterized in that, The spacing between adjacent geogrid layers is 0.3 to 0.5 m.

4. A zoned filling dike structure as described in claim 3, characterized in that, The upper backwater area and the lower backwater area are at the same height.

5. A zoned filling dike structure as described in claim 4, characterized in that, The geogrid is placed on the back side of the lower backwater zone, and the space between the geogrids is filled with expansive clay. The side adjacent to the water-facing zone only has expansive clay and no geogrid is installed. The geogrid area occupies 50% of the space of the lower backwater zone.

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