Water-rich cutting slope retaining structure and construction method thereof

Abstract

The invention discloses a water-rich cutting slope supporting and retaining structure and a construction method thereof, and belongs to the technical field of cutting slope construction. The water-rich cutting slope supporting and retaining structure comprises a roadbed slope protection module, a cutting foundation bed base module and an underground water cutting treatment and ground drainage module; the slope protection assembly comprises an arch-shaped framework arranged on a roadbed slope. The cutting foundation bed base module comprises a foundation bed surface layer and a foundation bed bottom layer; the underground water cutting treatment and ground drainage module comprises an open trench, side trench platforms are arranged on the two sides of the open trench, side trenches are formed in the side trench platforms, drainage holes are formed in the two sides of the open trench, and a retaining wall used for preventing a subgrade slope shallow layer from slipping and collapsing is arranged on the outer side of the open trench. By arranging supporting and retaining structures such as the arched framework protection slope, the ecological base material spray-seeding grass planting shrub and the retaining wall containing the filtering and draining channel, the stability of the cutting slope can be guaranteed, and the slope is prevented from sliding and collapsing. Meanwhile, the invention further provides a construction method applied to the water-rich cutting slope supporting and retaining structure.

Description

Technical Field

[0001] This application relates to the technical field of cutting slope construction, and in particular, to a retaining structure for a water-rich cutting slope. In addition, this application also relates to a construction method applied to the above-mentioned retaining structure for a water-rich cutting slope. Background Art

[0002] The information provided in this part is for the purpose of generally presenting the background of this application. To the extent described in this part, the work of the currently named inventors and aspects that may not constitute the prior art description at the time of filing are neither explicitly nor implicitly considered as the prior art of this application.

[0003] With the continuous advancement of infrastructure construction, such as the construction of highways (railways) becoming a top priority. During the construction process, problems such as slope excavation and support are often encountered, especially in water-rich areas, and the stability of cutting slopes is even more important.

[0004] As railways become more and more common, in some countries and regions with large rainfall, long rainy seasons, and wide rainfall ranges, due to high slopes and high fill sections in subgrade construction, and a large amount of excavation and filling throughout the section. During the rainy season, in some water-rich cutting sections, the water level is 0.2 - 3.3 m higher than the subgrade surface. It is crucial to have various protection measures to ensure the quality of the subgrade and the stability of the slope. Through on-site investigation, it is found that under the same hydrogeological conditions, there are multiple landslides, track deformations, and even temporary rerouting after the railway is built in some areas of the existing railway cutting slopes, which affects traffic operation and causes significant economic losses. Therefore, ensuring the stability of the cutting slope and the rapid and smooth drainage of the subgrade has become an important research direction in the industry.

[0005] It should be noted that the information disclosed in the above background art part is only used to strengthen the understanding of the background of this application, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0006] In view of at least one of the above technical problems, this application provides a retaining structure for a water-rich cutting slope, which can effectively increase the anti-sliding resistance on the potential rupture surface of the slope soil body by setting retaining structures such as arch-shaped frame slope protection, ecological substrate spraying and sowing of grass and shrubs, and retaining walls with filter drainage channels, and prevent the sliding trend of the slope, thereby improving the stability of the slope.

[0007] At the same time, this application also provides a construction method applied to the above-mentioned retaining structure for a water-rich cutting slope.

[0008] According to one aspect of this application, a retaining structure for a water-rich cutting slope is provided, including a subgrade slope protection module, a cutting bed base module, and a groundwater cutting treatment and surface drainage module:

[0009] The subgrade slope protection module includes a slope protection component for protecting the subgrade slope and an inclined drainage hole for being opened on the subgrade slope. The subgrade slope is stepped. The slope protection component includes an arch-shaped framework arranged on the subgrade slope, and the arch-shaped framework is used to set sowing and planting grass and shrubs to protect the subgrade slope.

[0010] The cutting subgrade bed base module includes a subgrade bed surface layer and a subgrade bed bottom layer arranged below the subgrade bed surface layer. The subgrade bed bottom layer is stratified and paved with Group AB fillers for improving the bearing capacity of the subgrade bed bottom layer.

[0011] The groundwater cutting treatment and surface drainage module includes an open ditch. Side ditch platforms are arranged on both sides of the open ditch. Side ditches are arranged in the side ditch platforms. Drainage holes are opened on both sides of the open ditch. A retaining wall for preventing shallow landslides of the subgrade slope is arranged outside the open ditch.

[0012] According to another aspect of the present application, a construction method for a water cutting slope retaining structure is further provided. It is applied to the above-mentioned water cutting slope retaining structure. The construction method for the water cutting slope retaining structure includes the following steps:

[0013] S100: Cutting excavation. First, conduct surveying and lofting, then construct a trapezoidal gutter, and then mechanically excavate the soil to form an open ditch and a subgrade slope.

[0014] S200: Construction of the subgrade slope protection module. First, conduct surveying and lofting, then construct the foundation of the arch-shaped framework, then install the formwork of the arch-shaped framework and pour concrete, and after the concrete curing is completed, sow and plant grass and shrubs.

[0015] S300: Construct the retaining wall outside the open ditch. First, construct the foundation of the retaining wall, and then construct the wall body of the retaining wall.

[0016] S400: Construction of the cutting subgrade bed base module. After the construction of the retaining wall is completed, continue to excavate the subgrade slope to the subgrade bed bottom layer, replace and fill with Group AB fillers, and construct the side ditch and the side ditch platform.

[0017] In some embodiments of the present application, in step S100, during surveying and lofting, a total station is used to loft and drive lofting piles at intervals between the land acquisition red line of the subgrade in the cutting section and the slope excavation line. Then, a trapezoidal gutter is excavated at a predetermined position away from the land acquisition red line to form an open ditch and a stepped subgrade slope. Multiple rows of inclined drainage holes are opened at the toe of the subgrade slope. The elevation angle of the inclined drainage holes is 5 - 15°. Inclined drainage pipes are arranged in the inclined drainage holes. The inclined drainage pipes are wrapped with permeable geotextiles, and holes are opened outside the inclined drainage pipes.

[0018] In some embodiments of the present application, the open ditch is constructed with M10 mortar rubble masonry. The slope rate of the outer wall of the open ditch is 1:1, the slope rate of the inner wall of the open ditch is 1:1.5, the height of the top of the open ditch from the road shoulder is not less than 1.2 m, drain holes are provided on both sides of the open ditch, and a second filter layer is arranged under the open ditch.

[0019] In some embodiments of the present application, in step S100, during mechanical excavation construction, first, a longitudinal temporary passage is excavated along the center line of the route. The side slopes on both sides of the passage are set to 1:0.5 to 1:1 according to the soil quality to ensure the stability and safety of the side slopes. Then, the soil is excavated layer by layer longitudinally along the route. For sections where the cutting depth is less than the set value, during construction, the method of one-time excavation and forming of the full cross-section is adopted for construction; while for sections where the cutting depth is greater than the set value, the method of layered and block-by-block excavation is adopted. When excavating to the roadbed side slope, a layer of soil is reserved, and after the roadbed is formed, the method of manual excavation is adopted for construction.

[0020] In some embodiments of the present application, in step S200, the positions of the main skeletons of the arch-shaped framework are located on the slope surface of the roadbed side slope according to the designed mileage position, and then the positions of the branch skeletons are located by measurement with a ruler; the foundation of the arch-shaped framework is excavated according to the lofting dimensions of the side slope, and the excavation is carried out with a pneumatic pick in cooperation with manual labor; after the concrete curing is completed, 90 - 110 mm thick planting soil is cultivated in the arch-shaped framework, and then grass seeds are sown to plant shrubs.

[0021] In some embodiments of the present application, the main skeleton of the arch-shaped framework is trough-shaped and a water retaining edge is arranged on the main skeleton. The branch skeleton of the arch-shaped framework is arch-shaped. Drainage ditches are opened on both sides of the roadbed side slope, and drainage grooves are opened on the main skeleton to introduce the water in the main skeleton into the drainage ditches on both sides of the roadbed side slope.

[0022] In some embodiments of the present application, in step S200, a mortar rubble retaining foot is constructed below the arch-shaped framework on the roadbed side slope, a border is constructed above the arch-shaped framework, steps are constructed at intervals on the slope surface of the roadbed side slope, and expansion joints are opened at intervals longitudinally along the side slope of the roadbed, and asphalt hemp ropes are filled in the expansion joints.

[0023] In some embodiments of the present application, in step S300, a retaining wall is arranged outside the open ditch in sections where the height of the roadbed side slope is greater than the set value. A first filter layer is laid along the wall height and the wall back of the retaining wall, and drain pipes are arranged at intervals in the retaining wall.

[0024] In some embodiments of the present application, in step S400, the slope rate of the side ditch is 1:0.75, and drain pipes are arranged on both sides of the side ditch.

[0025] The present application has the following beneficial effects:

[0026] In a retaining structure for a water-rich road cutting slope of the present application, the slope protection component of the subgrade slope protection module is used to protect the subgrade slope. Specifically, it includes arranging arched skeletons on the subgrade slope, and the arched skeletons are used to set up hydroseeding of grass and shrubs to protect the subgrade slope. At the same time, the subgrade slope is designed as a stepped shape, and inclined drainage holes can be arranged in the toe of the subgrade slope for timely drainage. In addition, by setting side ditch platforms and side ditches on both sides of the open ditch in the groundwater road cutting treatment and surface drainage module, multiple drainage effects are achieved. The side ditch can be deepened according to the actual situation on site to lower the groundwater level. At the same time, drainage holes are opened on both sides of the open ditch to further increase the drainage performance, and a retaining wall is also set outside the open ditch. The retaining wall can prevent shallow landslides of the subgrade slope, thereby realizing multi-dimensional and multi-level retaining and protection, effectively increasing the anti-sliding resistance on the potential rupture surface of the slope soil body, preventing the sliding trend of the slope, and thus improving the stability of the slope. At the same time, the existence of the retaining structure also helps to protect the vegetation on the slope surface, further preventing soil erosion and being beneficial to the protection of the ecological environment.

[0027] The construction method of the retaining structure for the water-rich road cutting slope of the present application also has the above beneficial effects. It also includes designing the slope support and drainage system for the water-rich road cutting in the overall construction method. The overall construction is modular, mainly including a tight construction plan in which three major modules of road cutting excavation, arched skeleton slope protection, and high and fat retaining wall construction are connected in sequence. It can efficiently realize the rapid forming operation of retaining structures such as arched skeleton slope protection, ecological substrate hydroseeding of grass and shrubs, and retaining walls with filter drainage channels, thereby effectively increasing the anti-sliding resistance on the potential rupture surface of the slope soil body, preventing the sliding trend of the slope, and thus improving the stability of the slope. Especially in water-rich areas, the action of groundwater will reduce the strength of the soil body, while the finished product of the complete construction plan of the present application can resist this additional sliding force caused by groundwater. And by maintaining the stability of the slope, the soil erosion phenomenon caused by slope instability is reduced. In the construction of the groundwater road cutting treatment and surface drainage module of the present application, by setting inclined drainage holes, side ditch platforms, and open ditches, the groundwater in the slope can be drained in time, the groundwater level can be lowered, and the hydrostatic pressure and hydrodynamic pressure of the groundwater on the slope rock and soil body can be reduced, thereby effectively controlling the adverse impact of groundwater on the slope stability.

[0028] Of course, it is not necessary for any product implementing the present application to achieve all the above-mentioned advantages simultaneously. In addition to the purposes, features, and advantages described above, the present application has other purposes, features, and advantages. The present application will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings forming a part of the present application are used to provide a further understanding of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0030] Figure 1 It is a schematic diagram of the arch-shaped frame slope protection in the soil cutting section of the preferred embodiment of the present application;

[0031] Figure 2 It is a schematic diagram of the I-I section of the arch-shaped frame slope protection in the soil cutting section of the preferred embodiment of the present application;

[0032] Figure 3 It is a schematic diagram of the II-II section of the arch-shaped frame slope protection in the soil cutting section of the preferred embodiment of the present application;

[0033] Figure 4 It is a schematic diagram of the III-III section of the arch-shaped frame slope protection in the soil cutting section of the preferred embodiment of the present application;

[0034] Figure 5 It is a detailed schematic diagram of the drain hole of the preferred embodiment of the present application;

[0035] Figure 6 It is a schematic diagram of the position of the inclined upward drain hole of the preferred embodiment of the present application;

[0036] Figure 7 It is a schematic diagram of the section of the inclined upward drain hole of the preferred embodiment of the present application;

[0037] Figure 8 It is a large-scale drawing of the inclined upward drain hole of the preferred embodiment of the present application;

[0038] Figure 9 It is a schematic diagram of the slope protection of the ecological base material spraying and planting grass and shrubs on the soil cutting slope of the preferred embodiment of the present application;

[0039] Figure 10 It is a schematic diagram of the open ditch drainage of the groundwater cutting of the preferred embodiment of the present application;

[0040] Figure 11 It is a schematic diagram of the retaining wall structure of the preferred embodiment of the present application.

[0041] Legend: 1. Open ditch; 2. Slope protection component; 3. Spraying and planting grass and shrubs; 4. Retaining wall; 41. First filter layer; 42. Rammed clay; 43. Drain pipe; 5. Anchor rod; 6. Inclined upward drain hole; 7. Second filter layer; 8. Drain hole; 9. Subgrade surface layer; 10. Subgrade bottom layer; 11. Edging; 12. Subgrade slope; 13. Arch-shaped frame; 14. Grouted rubble foot protection; 15. Side ditch platform; 16. Drainage hole; 17. Slope line; 18. Inclined upward drain pipe; 19. Filling material; 20. Precast concrete; 21. Edging top line; 22. Expansion joint; 23. Arch-shaped frame top line; 24. Arch-shaped frame bottom line; 25. Step; 26. Water retaining edge; 27. Drainage trough; 28. Grouted rubble; 29. Foot wall. Detailed implementation manners

[0042] The embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, the present application can be implemented in many different ways defined and covered by the following.

[0043] Figure 1 It is a schematic diagram of the arch-shaped frame slope protection in the soil cutting section of the preferred embodiment of the present application; Figure 2 It is a schematic diagram of the I-I section of the arch-shaped frame slope protection in the soil cutting section of the preferred embodiment of the present application; Figure 3 It is a schematic diagram of the II-II section of the arch-shaped frame slope protection in the soil cutting section of the preferred embodiment of the present application; Figure 4 It is a schematic diagram of the III-III section of the arch-shaped frame slope protection in the soil cutting section of the preferred embodiment of the present application; Figure 5 It is a detailed schematic diagram of the drain hole of the preferred embodiment of the present application; Figure 6 It is a schematic diagram of the position of the inclined drainage hole of the preferred embodiment of the present application; Figure 7 It is a schematic diagram of the section of the inclined drainage hole of the preferred embodiment of the present application; Figure 8 It is a detailed drawing of the inclined drainage hole of the preferred embodiment of the present application; Figure 9 It is a schematic diagram of the ecological base material spraying and seeding of grass and shrubs on the soil cutting slope of the preferred embodiment of the present application; Figure 10 It is a schematic diagram of the open ditch drainage of the groundwater cutting of the preferred embodiment of the present application; Figure 11 It is a schematic diagram of the retaining wall structure of the preferred embodiment of the present application.

[0044] Please refer to Figures 1 - 11 , a retaining structure for a water-rich cutting slope, characterized in that it includes a subgrade slope protection module, a cutting bed base module, and a groundwater cutting treatment and surface drainage module:

[0045] The subgrade slope protection module includes a slope protection component 2 for protecting the subgrade slope 12 and an inclined drainage hole 6 for opening on the subgrade slope 12. The subgrade slope 12 is stepped. The slope protection component 2 includes an arch-shaped frame 13 arranged on the subgrade slope 12, and the arch-shaped frame 13 is used to set the sprayed grass and shrubs 3 to protect the subgrade slope 12;

[0046] The cutting bed base module includes a surface layer 9 of the cutting bed and a bottom layer 10 of the cutting bed arranged below the surface layer 9 of the cutting bed. The bottom layer 10 of the cutting bed is layered and paved with AB group fillers for improving the bearing capacity of the bottom layer 10 of the cutting bed;

[0047] The groundwater cutting treatment and surface drainage module includes an open ditch 1. Side ditch platforms 15 are arranged on both sides of the open ditch 1. Side ditches are arranged in the side ditch platforms 15. Drainage holes 8 are opened on both sides of the open ditch 1. A retaining wall 4 for preventing shallow landslides of the subgrade slope 12 is arranged outside the open ditch 1.

[0048] Here, the meaning of "Group A and B fillers" refers to a common ground improvement method in subgrade construction projects, mainly used to improve the bearing capacity and stability of the ground. Group A fillers are high-quality fillers, and Group B fillers are good fillers. In some embodiments, Group A fillers include at least one of hard stones, pebble soil, gravel, coarse sand, and gravelly soil, with the fine-grained soil content less than 15%; Group B fillers include at least one of poorly graded gravelly soil, gravel, and sandy soil, with the fine-grained soil content between 15% and 30%. It should be noted that in this application, the subgrade bed is divided into the surface layer 9 and the bottom layer 10 of the subgrade bed. In some embodiments, the surface layer 9 of the subgrade bed uses Group A fillers in gravel or crushed stone categories, or Group B fillers in gravel, crushed stone, and sandy soil categories. The maximum particle size of the fillers shall not be greater than 100 mm, and the compaction coefficient shall not be less than 0.95; the bottom layer 10 of the subgrade bed uses Group A and B fillers in gravel, crushed stone, and sandy soil categories. The maximum particle size of the fillers shall not be greater than 200 mm, and the compaction coefficient shall not be less than 0.93.

[0049] It should be noted that when the cut subgrade bed is soft rock prone to weathering and fine-grained soil, medium coarse sand is laid on the top surface of the bottom layer 10 of the subgrade bed, and a composite geomembrane is provided in the middle of the medium coarse sand, and the other surface layer 9 of the subgrade bed is not treated.

[0050] In some embodiments, the subgrade slope 12 adopts a stepped form. Depending on the on-site land acquisition situation, the slope can be slowed down as much as possible to enhance its stability. The grading height range is 6 m to 10 m, and a slope platform of 3 m to 5 m is set. And the first-level slope is protected by an arch-shaped skeleton 13. Dry rubble is embedded in the first row of arch-shaped skeletons 13. Two rows of inclined drainage holes 6 with a longitudinal and transverse spacing of 3 m are arranged 1 m above the toe of the subgrade slope 12 to drain groundwater; after the maintenance of the arch-shaped skeleton 13 is completed, a sowing and planting grass and shrub 3 is set in the arch-shaped skeleton 13 for ecological substrate sowing and planting grass.

[0051] It should be noted that for the stepped subgrade slope 12, except for the first-level slope, other levels of slopes are protected by spraying and planting grass and shrubs 3 with skeletons or ecological substrates as appropriate. Specifically, the soil cut slope and the rock cut slope need to be protected separately. The rock cut slope can give full play to the anchoring performance of the rock mass and is protected by the bolt 5 frame beam + ecological substrate spraying and planting grass and shrub 3; it is more appropriate for the soil cut slope to be protected by the arch-shaped skeleton 13 + spraying and planting grass and shrub 3 to achieve local construction according to local conditions, effectively control costs, and ensure the protection effect.

[0052] This application protects the roadbed slope 12 through the slope protection component 2 of the roadbed slope protection module, specifically including arranging arched skeletons 13 on the roadbed slope 12, and the arched skeletons 13 are used to set up hydroseeding grass and shrubs 3 to protect the roadbed slope 12; at the same time, the roadbed slope 12 is designed as a stepped shape, and inclined drainage holes 6 can be arranged in the toe of the roadbed slope 12 for timely drainage; in addition, by setting side ditch platforms 15 and side ditches on both sides of the open ditch 1 of the groundwater cutting treatment and surface drainage module, multiple drainage effects are achieved, and the side ditch can be deepened according to the actual situation on site to lower the groundwater level; at the same time, drainage holes 8 are opened on both sides of the open ditch 1 to further increase the drainage performance, and a retaining wall 4 is also arranged outside the open ditch 1. The retaining wall 4 can prevent shallow landslides of the roadbed slope 12, thereby realizing multi-dimensional and multi-level retaining and protection, effectively increasing the anti-sliding resistance on the potential rupture surface of the slope soil body, preventing the sliding trend of the slope, and thus improving the stability of the slope. At the same time, the existence of the retaining structure also helps to protect the vegetation on the slope surface, further preventing soil erosion and being beneficial to the protection of the ecological environment.

[0053] According to another aspect of the present application, a construction method for a retaining structure of a water cutting slope is also provided, which is applied to the above-mentioned retaining structure of the water cutting slope. Please refer to Figures 1 - 11 , and the construction method for the retaining structure of the water cutting slope includes the following steps:

[0054] S100. Cutting excavation: First, conduct survey and lofting, then construct trapezoidal catch ditches, and then mechanically excavate the soil to form the open ditch 1 and the roadbed slope 12;

[0055] S200. Construction of the roadbed slope protection module: First, conduct survey and lofting, then construct the foundation of the arched skeleton 13, then install the formwork of the arched skeleton 13 and pour concrete, and after the concrete curing is completed, plant hydroseeding grass and shrubs 3;

[0056] S300. Construct the retaining wall 4 outside the open ditch 1: First, construct the foundation of the retaining wall 4, and then construct the wall body of the retaining wall 4;

[0057] S400. Construction of the roadbed subgrade base module: After the construction of the retaining wall 4 is completed, continue to excavate the roadbed slope 12 to the bottom layer 10 of the subgrade bed, replace and fill with Group AB fillers, and construct the side ditch and the side ditch platform 15.

[0058] The construction method of the retaining structure for the water-rich road cutting slope in this application also has the above beneficial effects. It also includes the overall construction method for designing the slope support and drainage system for the water-rich road cutting. The overall construction is modular, mainly including a tight construction plan that sequentially connects three major modules: road cutting excavation, construction of arched frame slope protection, and construction of high and wide retaining walls. It can efficiently achieve the rapid forming operation of retaining structures such as arched frame slope protection, spraying and planting grass and shrubs with ecological base materials 3, and retaining wall 4 with a filter drainage channel, thereby effectively increasing the anti-sliding resistance on the potential rupture surface of the slope soil mass, preventing the sliding trend of the slope, and thus improving the stability of the slope. Especially in water-rich areas, the effect of groundwater will reduce the strength of the soil mass, while the finished product of the complete construction plan in this application can resist this additional downward sliding force caused by groundwater. And by maintaining the stability of the slope, the phenomenon of soil and water loss caused by slope instability is reduced. In the construction of the groundwater road cutting treatment and surface drainage module in this application, by setting inclined drainage holes 6, side ditch platforms 15, and open ditches 1, the groundwater in the slope can be drained in time, the groundwater level can be lowered, and the hydrostatic pressure and hydrodynamic pressure of the groundwater on the slope rock and soil mass can be reduced, thereby effectively controlling the adverse impact of groundwater on the slope stability.

[0059] Preferably, in step S100, for measurement and layout, a total station is used to layout and drive layout piles at intervals between the roadbed land acquisition red line and the slope excavation line in the road cutting section. Subsequently, a trapezoidal catch ditch is excavated at a predetermined position from the land acquisition red line to form an open ditch 1 and a stepped roadbed slope 12. Multiple rows of inclined drainage holes 6 are opened at the toe of the roadbed slope 12. The elevation angle of the inclined drainage holes 6 is 5 - 15°, and inclined drainage pipes 18 are arranged in the inclined drainage holes 6. The inclined drainage pipes 18 are wrapped with permeable geotextiles, and holes are opened on the outer side of the inclined drainage pipes 18.

[0060] It can be understood that opening multiple rows of inclined drainage holes 6 at the toe of the roadbed slope 12 can play the role of draining groundwater. The inclined drainage holes 6 adopt drainage drill holes with an elevation angle of 5 - 15°, that is, the angle with the horizontal plane is 5 - 15°, and it is an acute angle with the slope line 17 of the roadbed slope 12, which is beneficial for the water flow to drain more smoothly under the action of gravity during drainage. Additionally, inclined drainage pipes 18 are arranged in the drainage drill holes 16, the inclined drainage pipes 18 are wrapped with permeable geotextiles, and holes are opened on the outer side of the inclined drainage pipes 18. At the same time, the orifice of the drainage drill hole 16 is filled with a filler 19 for filtration, such as medium-coarse sand, etc., which can prevent sediment from entering the inclined drainage pipes 18 and effectively prevent phenomena such as easy blockage of the inclined drainage pipes 18, ensuring the drainage performance of the inclined drainage holes 6 during long-term use.

[0061] It should be noted that when excavating the trapezoidal catch ditch here, in some embodiments, it also includes excavating a catch ditch above the slope to play the role of intercepting and draining water.

[0062] Optionally, the upward-inclined drain pipe 18 is a plastic perforated pipe. The protrusions on the outer wall of the plastic perforated pipe are used to support the permeable geotextile, so that there is a certain gap between the permeable geotextile and the outer wall of the plastic perforated pipe, thereby improving the water permeability.

[0063] In some embodiments, when constructing the upward-inclined drainage holes 6, to prevent groundwater from gradually eroding the slope near the orifice after flowing out of the orifice of the upward-inclined drainage hole 6, to increase the aesthetic appearance of the slope, and to facilitate the construction of slope protection, an orifice pipe is provided in the drilled hole within a range of 500-1000 mm from the orifice of the upward-inclined drainage hole 6. A white UPVC plastic pipe with a diameter slightly larger than that of the permeable pipe is used. The orifice pipe is fixed by filling the gap between the orifice pipe and the hole wall of the drainage borehole 16 with cement mortar.

[0064] Preferably, the open ditch 1 is constructed with M10 mortar rubble masonry. The slope rate of the outer wall of the open ditch 1 is 1:1, the slope rate of the inner wall of the open ditch 1 is 1:1.5, the height of the top of the open ditch 1 from the road shoulder is not less than 1.2 m, drain holes 8 are provided on both sides of the open ditch 1, and a second filter layer 7 is arranged below the open ditch 1.

[0065] It can be understood that the open ditch 1 can be connected to the nearby urban municipal pipe network. A grit chamber is added at the water collection position of the open ditch 1 and the municipal pipe network to achieve the effect of sedimentation and filtration, reducing the impact of sediment on the municipal pipe network; the second filter layer 7 includes a thick medium and coarse sand sandwich non-woven geotextile filter layer. PVC pipes can be arranged in the drain holes 8 on both sides of the open ditch 1, and the water inlet of the PVC pipe is wrapped with geotextile to reduce the problem that the PVC pipe is prone to blockage and ensure the long-term continuous normal operation of the drainage function of the drain holes 8.

[0066] Preferably, in step S100, during mechanical excavation construction, a longitudinal temporary passage is first excavated along the route center line. The slopes on both sides of the passage are set to 1:0.5 to 1:1 according to the soil quality to ensure the stability and safety of the slopes. Then, the soil is excavated layer by layer along the route longitudinally. For sections where the cutting depth is less than the set value, during construction, the method of one-time excavation and forming of the full section is adopted for construction; for sections where the cutting depth is greater than the set value, the method of layered and block-by-block excavation is adopted. When excavating to the subgrade slope 12, a layer of soil is reserved, and after the subgrade is formed, the method of manual excavation is adopted for construction.

[0067] It should be noted that the set value of the cutting depth is determined according to the on-site conditions in combination with the design requirements. In some embodiments, the set value is 3 meters. For sections with a cutting depth less than 3 meters, during construction, the method of one-time excavation and forming of the full cross-section is adopted. For sections with a cutting depth greater than 3 meters, the method of layered and block-by-block excavation is adopted, and the thickness of each layer is controlled within 2 - 3 meters to facilitate the operation of the excavator. When excavating to the roadbed slope 12, 0.3 meters thick of soil is reserved. After the roadbed is formed, the method of manual excavation is adopted for construction, which can complete the mechanical excavation construction smoothly and efficiently, and effectively ensure the quality and safety of construction.

[0068] Preferably, in step S200, the position of the main skeleton of the arch-shaped skeleton 13 is located on the slope surface of the roadbed slope 12 according to the designed mileage position, and then the position of the branch skeleton is located by measuring with a ruler; the excavation of the arch-shaped skeleton foundation is carried out according to the slope lofting dimensions, and a pneumatic pick is used in cooperation with manual labor for excavation; after the concrete curing is completed, 90 - 110 mm thick planting soil is cultivated in the arch-shaped skeleton 13, and then grass seeds are sown to plant shrubs.

[0069] It can be understood that after the position of the main skeleton of the arch-shaped skeleton 13 is located and the position of the branch skeleton is located by measuring with a ruler, the top line 23 and the bottom line 24 of the arch-shaped skeleton can be continuously located by measuring with a ruler to control the overall dimensions, so as to facilitate the accurate construction of the arranged arch-shaped skeleton 13 within the controlled dimensions. When carrying out the excavation of the arch-shaped skeleton foundation, a pneumatic pick is used in cooperation with manual labor for excavation to prevent disturbing the cutting body.

[0070] It should be noted that the formwork of the arch-shaped skeleton 13 is a customized steel formwork. Before erecting the formwork, first check the flatness of the formwork. After passing the inspection, the formwork can be installed. After the formwork is installed, angle steel is used for reinforcement to ensure the quality and strength of the construction of the arch-shaped skeleton 13, which is beneficial to improving the service life of the result and the slope protection effect.

[0071] Preferably, the main skeleton of the arch-shaped skeleton 13 is trough-shaped and a water retaining edge 26 is provided on the main skeleton. The branch skeleton of the arch-shaped skeleton 13 is arch-shaped. Drainage ditches are opened on both sides of the roadbed slope 12, and a drainage groove 27 is opened on the main skeleton to introduce the water in the main skeleton into the drainage ditches on both sides of the roadbed slope 12.

[0072] It can be understood that the water inside the main framework of the arched framework 13 is introduced into the drainage ditches on both sides of the roadbed through the drainage trough 27 extending along the main framework, which can effectively achieve the drainage effect of the arched framework 13, reduce the impact on the hydroseeding and grass planting 3 inside the arched framework 13, and reduce phenomena such as soil erosion. It should be noted that the main framework is in a groove shape and has a certain water storage and soil erosion prevention ability. The main framework and branch frameworks of the arched framework 13 are built with mortar rubble 28, and the water retaining edge 26 is made of precast concrete 20. Specifically, the water retaining edge 26 is built on both sides of the drainage trough 27 with M10 cement mortar, which can play a stable water retaining and drainage function.

[0073] In some embodiments, a mortar rubble foot protection 14 is built under the arched framework 13 on the roadbed slope 12, a border 11 is built above the arched framework 13, steps 25 are built at intervals on the slope surface of the roadbed slope 12, and expansion joints 22 are opened at intervals along the longitudinal direction of the slope on the roadbed slope 12, and asphalt hemp ropes are filled in the expansion joints 22.

[0074] It can be understood that the expansion joints 22 can improve the overall ductility of the roadbed slope 12, can accommodate structural deformation, disperse stress, and improve the overall seismic performance. Using asphalt hemp ropes to fill the expansion joints 22 can play a good waterproofing performance and can adapt to the small deformation of the expansion joints 22. In this application, by building a mortar rubble foot protection 14 under the arched framework 13 and building a border 11 above the arched framework 13, the overall strength of the roadbed slope 12 can be enhanced. Among them, the top line 21 of the border is higher than the top line 23 of the arched framework. At the same time, steps 25 are arranged at intervals on the roadbed slope 12, which is convenient for later maintenance construction.

[0075] In some embodiments, the construction sequence of the arched framework 13 slope protection is specifically: arranging the framework position → grooving → constructing the foundation → building the joints of the main and branch frameworks → building the main framework → building the vertices of the branch frameworks → building the branch frameworks → building the border 11.

[0076] Preferably, in step S300, a retaining wall 4 is set outside the open ditch 1 in the section where the height of the roadbed slope 12 is greater than the set value. The first filter layer 41 is laid along the height and the back of the retaining wall 4, and drain pipes 43 are arranged at intervals inside the retaining wall 4.

[0077] It can be understood that the retaining wall 4 can prevent shallow landslides of the slope. The retaining wall 4 is built with M10 mortar rubble masonry or rubble concrete as appropriate. In some embodiments, for the section where the height of the roadbed slope 12 is greater than 6m, a retaining wall 4 with a height of 3 - 4m is set outside the open ditch 1 to prevent shallow landslides of the slope; a highly permeable medium - coarse sand filter layer is used as the first filter layer 41 along the wall height and the wall back. Drain pipes 43 are set every 2m along the length of the wall. The drain pipes 43 are made of PVC material with a pore diameter of 100mm. The mortar around the pores must be dense. The orifices of the drain pipes 43 are rammed with clay 42 to ensure the stability of the drain pipes 43 and extend their service life.

[0078] Preferably, in step S400, the slope ratio of the side ditch is 1:0.75, and drain pipes are arranged on both sides of the side ditch.

[0079] It can be understood that the side ditch can be deepened according to the actual site conditions to play the role of lowering the groundwater level. In some embodiments, the side ditch has a thickness of 0.4m and a slope ratio of 1:0.75. Two layers of drain pipes with a diameter of 0.1m are set on both sides of the side ditch. The two layers of drain pipes are respectively located 0.55m and 1.20m below the top surface of the ditch, which can effectively play the role of multiple drainage and ensure the drainage effect.

[0080] In summary, this application can achieve railway opening under the adverse hydro - geological environment where the water - rich cutting and the slope soil are mostly red soil mixed with large stones. Through specific processes and technical measures, the stability of the cutting slope and the roadbed is ensured, laying a solid foundation for subsequent safe construction. By optimizing the construction design, the adaptability to complex geological conditions is achieved, enhancing the feasibility and safety of the project.

[0081] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non - exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not explicitly listed, or further includes elements inherent to such a process, method, article or device.

[0082] Specific examples are used in this article to elaborate on the principle and implementation manner of this application. The description of the above examples is only used to help understand the method and its core idea of this application. The above - mentioned are only the preferred implementation manners of this application. It should be pointed out that due to the limitation of literal expression and objectively existing infinite specific structures, for those of ordinary skill in the art in this technical field, without departing from the principle of this application, several improvements, refinements or changes can be made, or the above - mentioned technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or directly applying the inventive concept and technical solution to other occasions without improvement, should all be regarded as the protection scope of this application.

Claims

1. A retaining structure for a water-rich cutting slope, characterized in that It includes a subgrade slope protection module, a cutting bed base module, a groundwater cutting treatment and surface drainage module: The subgrade slope protection module includes a slope protection component (2) for protecting the subgrade slope (12) and an inclined drainage hole (6) for being opened on the subgrade slope (12). The subgrade slope (12) is stepped. The slope protection component (2) includes an arch-shaped framework (13) arranged on the subgrade slope (12). The arch-shaped framework (13) is used for arranging sprayed grass and shrubs (3) to protect the subgrade slope (12); The cutting bed base module includes a surface layer of the bed (9) and a bottom layer of the bed (10) arranged below the surface layer of the bed (9). The bottom layer of the bed (10) is layered and paved with group AB fillers for improving the bearing capacity of the bottom layer of the bed (10); The groundwater cutting treatment and surface drainage module includes an open ditch (1). Side ditch platforms (15) are arranged on both sides of the open ditch (1). Side ditches are arranged in the side ditch platforms (15). Drainage holes (8) are opened on both sides of the open ditch (1). A retaining wall (4) for preventing shallow landslides of the subgrade slope (12) is arranged outside the open ditch (1).

2. Construction method of retaining structure for water-rich cutting slope, characterized in that, Applied to the water-rich cutting slope retaining structure as described in claim 1, the construction method of the water-rich cutting slope retaining structure includes the following steps: S100. Cutting excavation. First, conduct survey and lofting, then construct a trapezoidal gutter, and then mechanically excavate the soil to form an open ditch (1) and a subgrade slope (12); S200. Construction of the subgrade slope protection module. First, conduct survey and lofting, then construct the foundation of the arch-shaped framework (13), then install the formwork of the arch-shaped framework (13) and pour concrete, and after the concrete curing is completed, plant and spray grass and shrubs (3); S300. Construct the retaining wall (4) outside the open ditch (1). First, construct the foundation of the retaining wall (4), and then construct the wall body of the retaining wall (4); S400. Construction of the cutting bed base module. After the construction of the retaining wall (4) is completed, continue to excavate the subgrade slope (12) to the bottom layer of the bed (10), replace and fill with group AB fillers, and construct side ditches and side ditch platforms (15).

3. The construction method of a retaining structure for a water-rich cutting slope according to claim 2, characterized in that, In step S100, for survey and lofting, use a total station to loft at intervals the land acquisition red line of the subgrade in the cutting section and the slope excavation line and drive lofting piles. Then, excavate a trapezoidal gutter at a predetermined position away from the land acquisition red line to form an open ditch (1) and a stepped subgrade slope (12). Open multiple rows of inclined drainage holes (6) at the toe of the subgrade slope (12). The elevation angle of the inclined drainage holes (6) is 5-15°. Inclined drainage pipes (18) are arranged in the inclined drainage holes (6). Wrap the inclined drainage pipes (18) with permeable geotextiles and open holes on the outside of the inclined drainage pipes (18).

4. The construction method of a retaining structure for a water-rich cutting slope according to claim 3, characterized in that, The open ditch (1) is built with M10 mortar rubble masonry. The slope rate of the outer wall of the open ditch (1) is 1:

1. The slope rate of the inner wall of the open ditch (1) is 1:1.

5. The height of the top of the open ditch (1) from the road shoulder is not less than 1.2 m. A second filter layer (7) is arranged below the open ditch (1).

5. The construction method of a retaining structure for a water-rich cutting slope according to claim 2, characterized in that, In step S100, during mechanical excavation construction, first dig a longitudinal temporary passage along the route center line. The side slopes on both sides of the passage are set to 1:0.5 to 1:1 according to the soil conditions to ensure the stability and safety of the side slopes. Then, excavate the soil longitudinally in layers along the route. For sections where the cutting depth is less than the set value, during construction, the method of one-time excavation and forming of the full cross-section is adopted for construction; while for sections where the cutting depth is greater than the set value, the method of layered and block-by-block excavation is adopted. When excavating to the subgrade side slope (12), reserve a layer of soil, and after the subgrade is formed, use the method of manual excavation for construction.

6. The construction method of a retaining structure for a water-rich cutting slope according to claim 2, characterized in that, In step S200, locate the positions of the main skeletons of the arch-shaped framework (13) on the slope surface of the subgrade side slope (12) according to the designed mileage position, and then locate the positions of the branch skeletons by measuring with a ruler; excavate the foundation of the arch-shaped framework according to the slope layout dimensions, and use a pneumatic pick in cooperation with manual labor for excavation; after the concrete curing is completed, cultivate planting soil with a thickness of 90 - 110 mm in the arch-shaped framework (13), and then sow grass seeds to plant shrubs.

7. The construction method of a retaining structure for a water-rich cutting slope according to claim 6, characterized in that The main skeletons of the arch-shaped framework (13) are trough-shaped and a water retaining edge (26) is set on the main skeletons. The branch skeletons of the arch-shaped framework (13) are arch-shaped. Drainage ditches are opened on both sides of the subgrade side slope (12), and drainage grooves (27) are opened on the main skeletons to introduce the water in the main skeletons into the drainage ditches on both sides of the subgrade side slope (12).

8. The construction method of a retaining structure for a water-rich cutting slope according to claim 2, characterized in that, In step S200, a masonry retaining foot (14) is built below the arch-shaped framework (13) on the subgrade side slope (12), a border (11) is built above the arch-shaped framework (13), steps (25) are built at intervals on the slope surface of the subgrade side slope (12), and expansion joints (22) are opened at intervals along the longitudinal direction of the subgrade side slope (12). Asphalt hemp ropes are stuffed in the expansion joints (22).

9. The construction method of a retaining structure for a water-rich cutting slope according to claim 2, characterized in that, In step S300, a retaining wall (4) is set outside the open ditch (1) in sections where the height of the subgrade side slope (12) is greater than the set value. A first filter layer (41) is laid along the height and the back of the retaining wall (4), and drain pipes (43) are arranged at intervals in the retaining wall (4).

10. The construction method of a retaining structure for a water-rich cutting slope according to claim 2, characterized in that, In step S400, the slope ratio of the side ditch is 1:0.75, and drain pipes are arranged on both sides of the side ditch.

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