Drainage system for large-area high-fill site

Abstract

The utility model relates to the technical field of geotechnical engineering, and aims to provide a drainage system for a large-area high-fill site, a main body of the drainage system is a backfill soil body, and the backfill soil body is arranged in a step-shaped layering manner and comprises a plurality of main blind ditches which are correspondingly arranged at the bottom of each layer of backfill soil body; the open trench is formed in the slope surface of the backfill soil body; the water-resisting layers are correspondingly laid on the top sides of all the layers of backfill soil bodies, and the water-resisting layers are arranged in a manner of avoiding the open trenches; a plurality of water guide slopes are arranged on the top side of the water-resisting layer, and a plurality of water collecting depressions are defined by the water guide slopes; the plurality of vertical seepage wells are respectively buried in each layer of backfill soil body, and the vertical seepage wells are correspondingly arranged below the water collecting depression; wherein a plurality of secondary blind ditches extend on the main blind ditch, and water diversion strips are arranged in the main blind ditch and the secondary blind ditches; the drainage structure has efficient drainage capacity, and can solve the problems of water and soil loss, settlement deformation, slope instability and the like of a site.

Description

A drainage system for large-area high-fill sites Technical Field

[0001] This utility model relates to the field of geotechnical engineering technology, specifically to a drainage system for large-area high-fill sites. Background Technology

[0002] Large amounts of rainwater cannot be drained in time through surface drainage ditches and instead infiltrates into the soil. Without a dedicated underground drainage system, continuous water infiltration can trigger a series of serious engineering problems. Firstly, rainwater infiltration exacerbates soil erosion. Fine particles in the soil migrate with the water flow, causing damage to the soil structure, uneven surface settlement, and potential subsidence, cracking, and other hazards that affect the normal use of the site and the safety of buildings. Secondly, in embankment slope areas, rainwater infiltration increases soil moisture content and weight, while significantly reducing shear strength. Under the influence of water seepage, slope stability is severely threatened, making slope instability, landslides, and even collapses highly likely. This can damage surrounding buildings, roads, and pipelines, and may endanger lives and property.

[0003] Currently, while some targeted measures exist for drainage in certain localized areas or small-scale embankment projects, a systematic and effective drainage system design and construction technology is lacking for large-scale high-fill sites. Existing research mainly focuses on surface drainage and shallow groundwater diversion, with insufficient research on the movement patterns and control methods of deep groundwater. Furthermore, the design of drainage systems for high-fill sites often fails to adequately consider the unique climatic conditions, topography, and soil characteristics of Fujian province, resulting in poor drainage performance and an inability to fundamentally solve the series of problems caused by water infiltration.

[0004] With the continuous expansion of high-fill site construction, drainage has become a key factor restricting project construction and the safe use of the site. Traditional surface drainage methods can no longer meet the drainage needs of large-area high-fill sites, necessitating a novel drainage system and its application method that can effectively collect and discharge rainwater and groundwater within the site. This drainage system should be adaptable to the special environmental conditions of large-area high-fill sites, possess efficient drainage capacity, and form a complete drainage network from the surface to the ground, achieving comprehensive control of rainwater and groundwater. This will solve problems such as soil erosion, settlement deformation, and slope instability, ensuring the safety, stability, and long-term use of high-fill sites.

[0005] In conclusion, developing a new drainage system and its application method to address the drainage challenges of large-area high-fill sites is of significant practical importance and engineering application value, and plays an indispensable role in ensuring the safety and sustainable development of engineering projects. Summary of the Invention

[0006] The purpose of this invention is to provide a drainage system for large-area high-fill sites, which has efficient drainage capacity and forms a complete drainage network from the surface to the ground, realizing comprehensive control of rainwater and groundwater, thereby solving problems such as soil erosion, settlement deformation, and slope instability.

[0007] The objective of this utility model is achieved through the following technical solution:

[0008] A drainage system for large-area high-fill sites, the main body of which is backfill soil, wherein the backfill soil is arranged in stepped layers, and the height of the backfill soil decreases from front to back, comprising:

[0009] Several main blind drains are set at the bottom of each layer of backfill soil, and the main blind drains extend diagonally downward from front to back;

[0010] Open ditch is constructed on the slope of backfilled soil. The outlet of the lowest main blind ditch is connected to the external drainage ditch, while the outlets of the other main blind ditches are all connected to the open ditch.

[0011] Several waterproof layers are laid on the top side of each layer of backfill soil, and the waterproof layers are set away from open ditches; the top side of the waterproof layers has several water-guiding slopes, and the water-guiding slopes enclose several water-collecting depressions.

[0012] Several vertical seepage wells are buried in each layer of backfill soil, and the vertical seepage wells are respectively located below the water collection depression;

[0013] The main blind ditch extends into several secondary blind ditches, and water-guiding strips are installed in both the main and secondary blind ditches. The lower end of the vertical seepage well is connected to the main or secondary blind ditch, while its upper end is connected to the corresponding water collection depression.

[0014] Compared with the prior art, the advantages of this utility model are:

[0015] By setting up clay layers, vertical infiltration wells, main blind drains, secondary blind drains, and open ditches, a multi-level drainage path is formed within the backfill soil. When rainfall is low, rainwater is guided sequentially through the clay layer into the vertical infiltration wells, then into the blind drains. With the connection of the open ditches, it is discharged into the external drainage ditch through the lowest main blind drain, achieving highly efficient graded drainage and avoiding water accumulation. In addition, when rainfall intensity is high, infiltrated rainwater can seep into the next level of backfill soil layer by layer, and then be guided by the water-guiding slope to the main blind drains, secondary blind drains, and branch blind drains of their respective layers. Rainwater is dispersed and drained through multiple levels of blind drains, avoiding problems such as soil erosion, settlement deformation, and slope instability in large-area high-fill sites. Attached Figure Description

[0016] Figure 1 is a longitudinal cross-sectional schematic diagram of an embodiment of a drainage system for large-area high-fill sites according to the present invention.

[0017] Figure 2 is a partial structural cross-sectional view of an embodiment of a drainage system for large-area high-fill sites according to the present invention;

[0018] Figure 3 is a top view of an embodiment of a drainage system for large-area high-fill sites according to the present invention;

[0019] Figure 4 is a simplified schematic diagram of the highest level blind drain in Figure 1;

[0020] Figure 5 is a simplified schematic diagram of the intermediate level blind drain in Figure 1;

[0021] Figure 6 is a simplified schematic diagram of the lowest level of blind drains in Figure 1.

[0022] Labeling Explanation: 1 Backfill soil, 100 slope line, 2 Main blind drain, 3 Open ditch, 4 Waterproof layer, 41 Water guiding slope, 42 Sump, 5 Vertical seepage well, 51 Precast concrete pipe, 52 Crushed stone filter material, 53 Circular waterstop, 6 Secondary blind drain, 71 Sand and gravel filter material, 72 Geotextile, 8 Branch blind drain, 9 Dry-laid rough mortar. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0024] Figures 1-6 show schematic diagrams of an embodiment of a drainage system for large-area high-fill sites provided by this utility model:

[0025] A drainage system for large-area high-fill sites, the main body of which is backfill soil 1, wherein the backfill soil 1 is arranged in stepped layers, and the height of the backfill soil 1 decreases from front to back, including:

[0026] Several main blind drains 2 are set at the bottom of each layer of backfill soil 1, and the main blind drains 2 extend obliquely downward from front to back;

[0027] Open ditch 3 is constructed on the sloping surface of backfill soil 1. Specifically, since backfill soil 1 is in the form of a stepped structure with decreasing height from front to back, the tread surface and kick plate surface of each step can be regarded as a continuous sloping surface. In this embodiment, the backfill soil 1 is set in three layers, and the kick plate surface between each layer is sloped, as shown in Figures 3-6. That is, open ditch 3 is set on the tread surface of the middle layer, the tread surface of the lowest layer, and the kick plate surface between the middle layer and the lowest layer. The outlet of the bottom main blind ditch 2 is connected to the external drainage ditch, while the outlets of the other main blind ditches 2 are all connected to open ditch 3.

[0028] Furthermore, the sidewalls of the open ditch 3 are hardened with cement.

[0029] Several waterproof layers 4 are laid on the top side of each layer of backfill soil 1, and the waterproof layers 4 are set to avoid the open ditch 3; the top side of the waterproof layers 4 has several water-guiding slopes 41, and the water-guiding slopes 41 enclose and form several water-collecting depressions 42.

[0030] Specifically, the water-guiding slope 41 is constructed manually to ensure that rainwater can smoothly enter the water collection depression 42.

[0031] Several vertical seepage wells 5 are respectively buried in each layer of backfill soil 1, and the vertical seepage wells 5 are respectively located below the water collection depression 42;

[0032] The main blind ditch 2 extends to several secondary blind ditches 6, and water-guiding strips are installed in both the main blind ditch 2 and the secondary blind ditches 6; the lower end of the vertical seepage well 5 is connected to the main blind ditch 2 or the secondary blind ditch 6, while its upper end is connected to the corresponding water collection depression 42.

[0033] The vertical seepage well 5 includes a precast concrete pipe 51 and a crushed stone filter material 52 filled in the cavity of the precast concrete pipe 51. The upper end of the precast concrete pipe 51 is connected to the water collection depression 42, and the lower part of the precast concrete pipe 51 extends into the main blind ditch 2 or the secondary blind ditch 6.

[0034] The crushed stone filter media 52 consists of gravel with a particle size of 10mm-60mm, and the crushed stone filter media 52 is filled with particles that gradually decrease in size from top to bottom.

[0035] The lower end of the precast concrete pipe 51 is also provided with an annular water-stopping part 53, which is used to seal the gap at the junction of the lower end of the precast concrete pipe 51 with the main blind ditch 2 and the secondary blind ditch 6.

[0036] Preferably, the annular water-stopping part 53 is made of clay.

[0037] The water-diverting strip is long and includes a sand and gravel filter material 71 and a geotextile 72 wrapped around the outer periphery of the sand and gravel filter material 71. The water-diverting strip is laid along its entire length in the main blind ditch 2 and the secondary blind ditch 6.

[0038] Preferably, the waterproof layer 4 is a clay layer. Due to the agglomeration, low permeability, and porous structure of clay, the clay layer can effectively prevent water from seeping into the backfill soil 1 below when the rainfall is small or the groundwater is scarce, thus playing a role in waterproof protection. At the same time, when the rainfall intensity is large or the rain lasts for a long time, some water can seep in along the pores between the clay particles, thereby achieving flow guidance or infiltration depending on the size of the water flow.

[0039] The vertical seepage wells 5 in the two adjacent backfill soil layers are staggered.

[0040] Several branch blind ditches 8 extend from the secondary blind ditch 6, and water-guiding strips are installed throughout the branch blind ditches 8.

[0041] The side walls of the main blind drain 2, the secondary blind drain 6, and the branch blind drain 8 are all provided with dry-laid rough tiles 9.

[0042] The construction method of this utility model includes the following steps:

[0043] S1. Excavate the main blind ditch 2, secondary blind ditch 6 and branch blind ditch 8 on the original site surface that has not been backfilled, and connect the main blind ditch 2 to the external drainage ditch; then lay water-guiding strips along the extension direction of the main blind ditch 2, secondary blind ditch 6 and branch blind ditch 8.

[0044] S2. Vertical seepage wells 5 are installed at the preset points of the main blind drain 2 and the secondary blind drain 6, and the backfill soil 1 is backfilled in layers to the predetermined elevation.

[0045] S3. Lay a waterproof layer 4 on the top side of the backfill soil 1, and construct several water-guiding slopes 41 on the top side of the waterproof layer 4, so that several water-collecting depressions 42 are formed between the water-guiding slopes 41, and the water-collecting depressions 42 are connected to the corresponding vertical seepage wells 5.

[0046] S4. Carry out the backfilling construction of the next layer of soil. First, backfill part of the soil to the top elevation of the main blind ditch 2, secondary blind ditch 6 and branch blind ditch 8 of this layer. Then, excavate the main blind ditch 2, secondary blind ditch 6 and branch blind ditch 8 on the surface of the backfilled soil. Next, lay water-guiding strips along the extension direction of the main blind ditch 2, secondary blind ditch 6 and branch blind ditch 8, and set up vertical seepage wells 5 at the preset points of the main blind ditch 2 and secondary blind ditch 6. Continue to backfill the remaining soil. Then, lay a water-proof layer 4 on the top side of the backfill soil 1 of this layer, and construct several water-guiding slopes 41 on the top side of the water-proof layer 4. The water-guiding slopes 41 enclose several water-collecting depressions 42, and the water-collecting depressions 42 are connected to the corresponding vertical seepage wells 5.

[0047] S5. Repeat step S4 according to the number of backfill layers until all backfilling work and the layered layout of the drainage system are completed.

[0048] S6. After all backfilling is completed, excavate open ditches 3 along a predetermined path on the surface of the backfill soil 1, so that the open ditches 3 are connected to the main blind ditches 2 of each layer in sequence to achieve step-by-step diversion and drainage.

[0049] The drainage principle of this invention is roughly as follows:

[0050] When the rainfall is small, the rainwater falls on the clay layer on the top side of each layer of backfill soil 1 and flows along the water guide slope 41 to the water collection depression 42, thus entering the vertical infiltration well 5, and then flowing into the secondary blind ditch 6 or the main blind ditch 2, and flowing into the open ditch 3 through the outlet of each layer of main blind ditch 2, and finally being discharged into the external drainage ditch through the outlet of the lowest layer of main blind ditch 2.

[0051] When rainfall is heavy, some rainwater is still guided from the clay layer into the vertical infiltration well 5, while the rest of the rainwater infiltrates downward to the clay layer on the top side of the lower backfill soil 1. Part of the infiltrated rainwater is guided through this clay layer and enters the main blind ditch 2 or secondary blind ditch 6 of this layer. The other part of the infiltrated rainwater flows directly into the branch blind ditch 8 or continues to infiltrate downward. The rainwater flowing into the branch blind ditch 8 flows back into the main blind ditch 2 through the secondary blind ditch 6, and finally enters the open ditch 3 or is discharged into the external drainage ditch through the outlet of the main blind ditch 2 of this layer.

[0052] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A drainage system for large-area high-fill sites, the main body of which is backfill soil (1), wherein the backfill soil (1) is arranged in stepped layers, and the height of the backfill soil (1) decreases from front to back, characterized in that, include: Several main blind drains (2) are correspondingly set at the bottom of each layer of backfill soil (1), and the main blind drains (2) extend obliquely downward from front to back; open ditches (3) are opened on the slope surface of the backfill soil (1), and the outlet of the lowest layer of main blind drains (2) is connected to the external drainage ditch, while the outlets of the other main blind drains (2) are all connected to the open ditches (3); several waterproof layers (4) are correspondingly laid on the top side of each layer of backfill soil (1), and the waterproof layers (4) are set to avoid the open ditches (3); the top side of the waterproof layers (4) has several water-guiding slopes (41). The water-guiding slopes (41) enclose and form several water-collecting depressions (42); several vertical seepage wells (5) are buried in each layer of backfill soil (1), and the vertical seepage wells (5) are correspondingly set below the water-collecting depressions (42); several secondary blind ditches (6) extend from the main blind ditch (2), and water-guiding strips are set in both the main blind ditch (2) and the secondary blind ditch (6); the lower end of the vertical seepage well (5) is connected to the main blind ditch (2) or the secondary blind ditch (6), and its upper end is connected to the corresponding water-collecting depression (42).

2. The drainage system for large-area high-fill sites according to claim 1, characterized in that: The vertical seepage well (5) includes a precast concrete pipe (51) and a crushed stone filter material (52) filled in the cavity of the precast concrete pipe (51). The upper end of the precast concrete pipe (51) is connected to the water collection depression (42), and the lower part of the precast concrete pipe (51) extends into the main blind ditch (2) or the secondary blind ditch (6).

3. The drainage system for large-area high-fill sites according to claim 2, characterized in that: The crushed stone filter media (52) consists of gravel with a particle size of 10mm-60mm, and the crushed stone filter media (52) is filled with particles that gradually decrease in size from top to bottom.

4. The drainage system for large-area high-fill sites according to claim 2, characterized in that: The lower end of the precast concrete pipe (51) is also provided with an annular water-stop part (53), which is used to seal the gap at the junction of the lower end of the precast concrete pipe (51) with the main blind drain (2) and the secondary blind drain (6).

5. The drainage system for large-area high-fill sites according to claim 1, characterized in that: The water-guiding strip is long and includes sand and gravel filter material (71) and geotextile (72) wrapped around the outer periphery of the sand and gravel filter material (71). The water-guiding strip is laid along its length in the main blind ditch (2) and the secondary blind ditch (6).

6. The drainage system for large-area high-fill sites according to claim 1, characterized in that: The waterproof layer (4) is a clay layer.

7. The drainage system for large-area high-fill sites according to claim 1, characterized in that: The vertical seepage wells (5) in the two adjacent backfill soil layers are staggered.

8. The drainage system for large-area high-fill sites according to any one of claims 1 to 7, characterized in that: Several branch blind ditches (8) extend from the secondary blind ditch (6), and water-guiding strips are installed along the entire length of each branch blind ditch (8).

9. The drainage system for large-area high-fill sites according to claim 8, characterized in that: Dry-laid rough tiles (9) are provided on the side walls of the main blind drain (2), secondary blind drain (6) and branch blind drain (8).

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