Ecological slope protection drainage methods

Abstract

This invention discloses an ecological slope protection drainage method, belonging to the field of ecological slope protection engineering technology. The method includes deep slope drainage and surface protection: the slope is equipped with a drainage ditch and inclined drainage channels, with double-walled corrugated drainage pipes nested within the channels. The outlets of the drainage pipes are connected to the drainage ditch, and a stilling basin is located at the end of the ditch. A three-dimensional composite drainage net is laid on the slope surface, followed by a vegetation substrate layer and a vegetation concrete layer, and then shrub seedlings are planted. This invention can be used for slope surface and deep slope drainage in ecological slope protection engineering, improving slope stability while also considering ecological vegetation.

Description

Technical Field

[0001] This invention relates to the field of ecological slope protection engineering technology. More specifically, this invention relates to an ecological slope protection drainage method. Background Technology

[0002] In ecological slope protection engineering, surface protection and deep drainage are core components for ensuring slope stability and ecological vegetation. However, existing slope protection drainage methods struggle to balance the water retention required for ecological vegetation with the drainage efficiency needed for slope stability. Regarding surface protection, existing structures often fail to balance the needs of water-retaining vegetation and drainage / flood prevention. For example, some solutions use a single vegetation layer or concrete layer. If the vegetation substrate has poor permeability, surface rainwater accumulates, leading to substrate softening and loss, and root rot in shrub seedlings. Conversely, if the permeability is too high, water seeps out rapidly, failing to meet the water retention requirements for vegetation growth. In terms of deep drainage, the pore size and distribution density of drainage pipes are arbitrarily designed. Either the pores are too small and clogged by fine particles, or uneven distribution leads to concentrated drainage pressure in certain areas, reducing the overall durability of the drainage system. This application urgently aims to solve these technical problems. Summary of the Invention

[0003] This invention provides an ecological slope protection and drainage method that can simultaneously drain the slope surface and deep layers of the slope, improving slope stability while also taking into account ecological vegetation.

[0004] To achieve these objectives and other advantages according to the present invention, an ecological slope protection drainage method is provided, comprising the following steps: (1) Deep drainage of the slope: A drainage ditch is set longitudinally along the slope. The drainage ditch has a bottom width of 300-400 mm and a depth of 500-600 mm. A layer of graded crushed stone with a thickness of 100-150 mm and a particle size of 20-40 mm is laid at the bottom of the ditch. Inclined drainage channels are opened at longitudinal intervals of 8-10 m on the slope. The drainage channels are at an angle of 40-45° to the horizontal plane, the depth of the channels extends 1.5-2 m below the potential sliding surface, and the diameter of the channels is 110-130 mm. A double-walled corrugated drain pipe is nested and installed within the drainage channel. The outer diameter of the double-walled corrugated drain pipe is 80-100 mm, and the outer wall of the double-walled corrugated drain pipe is coated with 200-300 g / m² material. 2 The needle-punched geotextile has a closed inlet end and a permeable hole with a diameter of 8-10 mm on the pipe wall. The permeable hole is spaced 150-200 mm longitudinally and arranged in 4-6 rows in a circumferential direction. The outlet end of the double-wall corrugated drainage pipe is connected to the side wall of the underground drainage ditch, and a filter bag is installed at the connection. The filter bag is filled with gravel with a particle size of 5-10 mm and wrapped with an outer layer of 400 g / m³. 2 Woven geotextiles; A stilling basin with a volume of 2-3 m³ is installed at the end of the underground drainage ditch. 3 The bottom of the pool is covered with a layer of pebbles 200-300 mm thick, with a pebble diameter of 50-80 mm; (2) Slope surface protection: A three-dimensional composite drainage net is laid on the slope. The three-dimensional composite drainage net is thermally composited with an upper biaxial geogrid, a middle water-guiding rib, and a lower non-woven geotextile. The water-guiding rib is 5-8 mm high and 20-25 mm apart. A 100-120 mm thick vegetated substrate layer is laid above the three-dimensional composite drainage network. The vegetated substrate layer is composed of expanded clay pebbles with a particle size of 2-5 mm, humus and slow-release fertilizer in a mass ratio of 5:4:1. A layer of 80-100 mm thick vegetated concrete is sprayed onto the surface of the vegetated substrate layer. The vegetated concrete has a compressive strength of 3-5 MPa and a porosity of 25-30%. Shrub seedlings with a depth of 40-50 mm are then implanted before initial setting.

[0005] Preferably, the double-walled corrugated drainage pipe has through holes arranged in 4-6 rows evenly in a circumferential direction, staggered with the permeable holes, and a tightening structure is provided between the inner wall of the drainage channel and the outer wall of the double-walled corrugated drainage pipe, which includes: The top-tightening ring includes 4-6 sets of first mounting seats, arc-shaped connecting seats, second mounting seats, and arc-shaped connecting seats that are hinged together from end to end. The first mounting seats are provided with three assembly holes, and the second mounting seats are provided with two assembly holes. 4-6 sets of first column assemblies, each set of first column assemblies is installed on a first mounting base. Each first column assembly includes a clamping column and a pair of first support columns. The clamping column is fixedly inserted through the middle assembly hole of the first mounting base and movably inserted through the through hole of the double-wall corrugated drain pipe. The pair of first support columns are movably inserted through the two side assembly holes of the first mounting base and fixed by nuts. The heads of the clamping column and the pair of first support columns are both spherical surfaces that abut against the inner wall of the drain channel. 4-6 sets of second column assemblies, each set of second column assemblies is installed on a second mounting base. The second column assembly includes a pair of second support columns. The pair of second support columns are movably inserted through two mounting holes of the second mounting base and fixed by nuts. The heads of the pair of second support columns are both spherical surfaces that abut against the outer wall of the double-wall corrugated drain pipe.

[0006] Preferably, a liquid level sensor is installed at intervals of 3-5 m along the water flow direction in the drainage ditch. The liquid level sensor has a measurement range of 0-300 mm. A first electric regulating valve is installed at the inlet of the drainage channel. Both the liquid level sensor and the first electric regulating valve are electrically connected to the drainage controller. The drainage controller is configured as follows: When the liquid level sensor detects that the average liquid level in the underground drainage ditch is ≤100 mm, it is determined to be in normal drainage state, and the first electric regulating valve is controlled to maintain an opening of 20-30%. When the level sensor detects that the average level in the drainage ditch is 100-200 mm, it determines that it is the beginning of rainfall or an increase in water inflow, and controls the opening of the first electric regulating valve to increase to 50-60%. When the level sensor detects that the average level in the underground drainage ditch is greater than 200 mm, it determines that there is heavy rainfall or concentrated water inflow, and controls the opening of the first electric regulating valve to increase to 100%.

[0007] Preferably, a first pressure sensor is installed 0.1 m after the starting end of the rear section of the drain pipe, a second pressure sensor is installed 0.1 m before the outlet of the rear section of the drain pipe, a flow rate sensor is installed at the transition cone section between the middle section and the rear section of the drain pipe, a second electric regulating valve is installed at the outlet of the rear section of the drain pipe, and a pulse flushing device is also installed at the outlet of the rear section of the drain pipe to backflush from the outlet of the rear section of the drain pipe into the pipe. The first pressure sensor, the second pressure sensor, the flow rate sensor, and the second electric regulating valve are all electrically connected to the drain controller. When the flow velocity is greater than 0.5 m / s and the inlet and outlet pressure difference ΔP is greater than 10 kPa, the opening of the second electric regulating valve is increased by 15-20% every 5 minutes until it reaches 100%. When the inlet and outlet pressure difference ΔP < 5 kPa and lasts for 30 min, control the second electric regulating valve to maintain an opening of 20-30%; When the flow rate is <0.1m / s and the inlet / outlet pressure difference is >20kPa, close the second electric regulating valve and start the pulse flushing device.

[0008] Preferably, the pulse flushing device performs pulse flushing, with the first stage flushing at 0.2 MPa for 120 s, the second stage increasing to 0.3 MPa for 80 s, and the third stage increasing to 0.4 MPa for 60 s pulse flushing, wherein there is a 10 s flushing pause and a 5 s pause, and the flushing is terminated when the inlet and outlet pressure difference ΔP drops to <8 kPa.

[0009] Preferably, the pulse flushing device includes: The backwash pump unit has its inlet connected to the clean water area of ​​the stilling tank via a filter. The high-pressure bypass pipe is connected to the drain outlet via a three-way valve.

[0010] Preferably, the drainage channel adopts a graded inclination design, with the front section of the channel, which is close to the slope for 1 / 3 of its length, having an angle of 45° with the horizontal plane; the middle section of the channel, which is 1 / 3 of its length, having an angle of 40° with the horizontal plane; and the rear section of the channel, which is 1 / 3 of its length, having an angle of 35°. The double-walled corrugated drainage pipe is coaxially arranged with the drainage channel and is synchronously divided into three sections along its length. The pipe wall of the front and middle sections of the drain pipe is evenly arranged with 4 rows of permeable holes in the circumference, with a hole diameter of 8 mm and a longitudinal spacing of 200 mm. The pipe wall of the rear section of the drain pipe is evenly arranged with 6 rows of permeable holes in the circumference of the front section, with a hole diameter of 10 mm and a longitudinal spacing of 150 mm.

[0011] Preferably, the three sections of the double-walled corrugated drain pipe are provided with a transition cone section. The length of the transition cone section is 200-300 mm. The outer wall of the transition cone section adopts a gradient corrugated structure. The corrugation depth is 5 mm for the front section of the drain pipe, 8 mm for the middle section of the drain pipe, and 10 mm for the rear section of the drain pipe. The diameter of the permeable hole of the transition cone section is set according to the pipe section upstream of it.

[0012] The present invention has at least the following beneficial effects: First, this invention achieves a balance between surface water retention and drainage by combining surface protection with deep drainage of the slope. The three-dimensional composite drainage network and vegetation matrix layer ensure the growth of shrubs. The double-walled corrugated drainage pipes and drainage ditches efficiently guide deep infiltration, reduce the risk of slope sliding, and take into account both ecological vegetation and slope stability.

[0013] Secondly, the tightening structure of the present invention stably supports the drainage pipe through the adjustable column assembly, and the arc-shaped connecting seat adapts to the circumferential gap, ensuring that the drainage pipe is coaxial and the gap is uniform, avoiding displacement and blockage of the water permeable hole, ensuring the stability of the water passage space, and improving the durability of the drainage system.

[0014] Third, this invention is based on dynamic adjustment of water inlet by liquid level to balance water retention and drainage, precise control of outlet by pressure and flow rate monitoring, and efficient unblocking of blockages by step pulse flushing, forming a dynamic control system to improve drainage efficiency and stability.

[0015] Fourth, this invention adapts to the seepage path at different depths of the slope by using graded inclination angles. The front section quickly guides shallow water, while the rear section increases the density of permeable holes to enhance deep water collection. By setting a transition cone section, the gradual structure reduces water flow resistance, improves the targeting of seepage collection, and ensures smooth drainage.

[0016] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the clamping structure of one technical solution of the present invention. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0019] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0020] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are conventional methods, and the reagents and materials mentioned are commercially available. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to fixed connection or setting, detachable connection or setting, or integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0021] To address the problems of poor coordination between surface protection and deep drainage in existing ecological slope protection methods, resulting in easy water accumulation on the surface and inadequate deep drainage, this invention provides an ecological slope protection drainage method, comprising the following steps: (1) Deep drainage of the slope: A drainage ditch is set longitudinally along the slope. First, the ditch body is excavated according to the design position. The drainage ditch has a bottom width of 300-400mm and a depth of 500-600mm. The bottom of the ditch needs to be flat and have a longitudinal slope of 5‰. A layer of graded crushed stone with a thickness of 100-150mm and a particle size of 20-40mm is laid on the bottom of the ditch. It needs to be compacted in layers to ensure uniform porosity. Inclined drainage channels 1 are opened at longitudinal intervals of 8-10 m on the slope. The channels can be drilled from the slope to the depth of the soil layer of the slope using a pneumatic drilling rig. The drainage channel 1 is at an angle of 40-45° to the horizontal plane. The hole depth penetrates 1.5-2 m below the potential sliding surface (a weak interface in the slope that may be sheared and slide relative to the slope under the action of its own weight, groundwater infiltration, etc., located below the slope). The hole diameter is 110-130 mm. After drilling is completed, the debris in the hole is cleaned. A double-wall corrugated drain pipe 2 is nested and installed inside the drainage channel 1. The outer diameter of the double-wall corrugated drain pipe 2 is 80-100 mm, and the outer wall of the double-wall corrugated drain pipe 2 is coated with 200-300 g / m. 2 The needle-punched geotextile must be wrapped to ensure complete coverage of the pipe wall and overlap of more than 10 cm at the seams. The inlet end of the double-wall corrugated drainage pipe 2 is closed, and the pipe wall is provided with permeable holes with a diameter of 8-10 mm. The longitudinal spacing of the permeable holes is 150-200 mm, and they are arranged in 4-6 rows evenly in the circumferential direction. The pipe section near the slope is preferably arranged with 4 rows of permeable holes evenly in the circumferential direction, with a diameter of 8 mm and a longitudinal spacing of 200 mm. The pipe section that goes deep into the slope is preferably arranged with 6 rows of permeable holes evenly in the circumferential direction, with a diameter of 10 mm and a longitudinal spacing of 150 mm, so as to facilitate rapid water permeability and drainage.

[0022] Connect the outlet end of the double-wall corrugated drainage pipe 2 to the side wall of the underground drainage ditch. A 10-15 cm insertion depth should be reserved at the connection point. A filter bag should be installed at the connection point, filled with gravel of 5-10 mm particle size and wrapped with 400 g / m³ of outer material. 2 Woven geotextiles must be compacted and tightly wrapped during filling; A stilling basin is installed at the end of the underground drainage ditch. The stilling basin can be constructed of masonry with mortar, and its volume is 2-3 m³. 3 The bottom of the pool is laid with a pebble layer of 200-300 mm thickness and the pebble size is 50-80 mm. The pebble layer should be evenly arranged to ensure that the water can be discharged after the energy is dissipated by the pebble layer.

[0023] (2) Slope surface protection: First, the slope surface is leveled and cleaned to remove loose soil and gravel. Then, a three-dimensional composite drainage net is laid on the slope surface. The three-dimensional composite drainage net is made of an upper layer of biaxial geogrid, a middle layer of water-guiding ribs, and a lower layer of non-woven geotextile through thermal bonding. The material of the biaxial geogrid can be polypropylene, and the material of the water-guiding ribs can be polyethylene. The water-guiding ribs face upwards, with a height of 5-8 mm and a spacing of 20-25 mm. When laying, it is necessary to ensure that the drainage net fits the slope surface and the edges are fixed to the slope base layer with fixing nails. A 100-120 mm thick vegetation substrate layer is laid on top of the three-dimensional composite drainage net. The vegetation substrate layer is composed of ceramsite with a particle size of 2-5 mm, humus and slow-release fertilizer mixed in a mass ratio of 5:4:1. When laying, it should be spread evenly and pressed lightly to ensure that it adheres to the drainage net below. A layer of 80-100 mm thick vegetated concrete is sprayed onto the surface of the vegetated substrate layer. The vegetated concrete has a compressive strength of 3-5 MPa and a porosity of 25-30%. Shrub seedlings with a depth of 40-50 mm are then implanted before initial setting.

[0024] Rainwater from the slope first infiltrates into the vegetation concrete layer, then enters the vegetation matrix layer through its pores. Some of the water is absorbed by the matrix to support seedling growth, while excess water infiltrates through the matrix layer into the three-dimensional composite drainage network. The water is then guided by the water-conducting ribs in the middle layer to the bottom of the slope or near drainage channel 1. Deep seepage water from the slope infiltrates through the walls of drainage channel 1 into the circumferential gaps. After being filtered by needle-punched geotextile, it enters the pipe through the permeable holes of the double-walled corrugated drainage pipe 2, flows along the drainage pipe to the outlet, is filtered by the reverse filter bag, and then flows into the drainage ditch. In the ditch, it is buffered by a layer of graded crushed stone and then flows to the stilling basin. Finally, it is discharged after being dissipated by a layer of pebbles.

[0025] In the above technical solution, the surface protection and deep drainage are designed in a coordinated manner to achieve a balance between water retention and drainage on the slope surface, ensuring the growth of shrub seedlings, while efficiently draining deep groundwater in the slope, reducing the risk of slope sliding. In addition, the filtration structure at each stage can reduce clogging, improve the stability and durability of the drainage system, and take into account both ecology and slope stability.

[0026] To address the problem of unstable circumferential clearance between the drain pipe and drain channel 1, which easily leads to displacement and affects drainage, such as... Figure 1 As shown, the double-walled corrugated drainage pipe 2 is provided with through holes, that is, the position of the through holes avoids the circumferential area where the water permeable holes are located, and 4-6 rows are evenly arranged circumferentially, staggered with the water permeable holes. A tightening structure is provided between the inner wall of the drainage channel 1 and the outer wall of the double-walled corrugated drainage pipe 2, which includes: The tightening ring includes 4-6 sets of first mounting seats 3, arc-shaped connecting seats 4, second mounting seats 5, and arc-shaped connecting seats 4, which are hinged together from end to end. The first mounting seats 3 and second mounting seats 5 can be made of stainless steel, and the arc-shaped connecting seats 4 can be made of elastic steel sheet. The first mounting seat 3 has three assembly holes, and the second mounting seat 5 has two assembly holes. After the tightening ring is assembled as a whole, it needs to be coaxial with the double-wall corrugated drain pipe 2 and located in the middle of the circumferential gap. 4-6 sets of first column assemblies, one set of first column assemblies is installed on one first mounting base 3. The first column assembly includes a clamping column 6 and a pair of first support columns 7. The clamping column 6 is fixedly inserted through the middle assembly hole of the first mounting base 3 and movably inserted through the through hole of the double-wall corrugated drain pipe 2. The pair of first support columns 7 are movably inserted through the two side assembly holes of the first mounting base 3 and fixed by nuts. The heads of the clamping column 6 and the pair of first support columns 7 are spherical surfaces, which can be wrapped with a rubber layer and abut against the inner wall of the drain channel 1. 4-6 sets of second column assemblies, one set of second column assemblies is installed on one second mounting base 5, the second column assembly includes a pair of second support columns 8, the pair of second support columns 8 are movably inserted through two mounting holes of the second mounting base 5 and fixed by nuts, the heads of the pair of second support columns 8 are both spherical surfaces, which can be wrapped with a rubber layer and abut against the outer wall of the double-wall corrugated drain pipe 2.

[0027] During installation, first fit the top ring onto the outer wall of the drain pipe, then install the column components in sequence. Adjust the extension length of the support column by rotating the nut until all spherical surfaces are evenly in contact (the contact pressure should be moderate to the touch and without any looseness).

[0028] In the above technical solution, the tightening ring, through the hinge structure of the first mounting base 3, the arc-shaped connecting base 4, and the second mounting base 5, adapts to the circumferential gap size between the drainage channel 1 and the drainage pipe. By adjusting the nuts of the first support column 7 and the second support column 8, the spherical surfaces of the tightening column 6 and the support column respectively abut against the inner wall of the drainage channel 1 and the outer wall of the drainage pipe. The drainage pipe is fixed in the center position of the channel by multi-directional support force. The elastic characteristics of the arc-shaped connecting base 4 can absorb slight dimensional deviations, ensuring uniform circumferential gap and preventing the drainage pipe from shifting when water flows or the slope deforms. This ensures the water passage space in the circumferential gap. At the same time, the through holes and permeable holes are staggered, which does not affect the seepage of water into the drainage pipe and improves drainage stability.

[0029] To address the issue of the inability to adjust the inflow rate of drainage channel 1 based on water volume, another technical solution involves installing level sensors at 3-5 m intervals along the water flow direction within the underground drainage ditch. These level sensors can be submersible type, with a measurement range of 0-300 mm. The sensors are fixed to the sidewall of the ditch, with the bottom 100 mm from the bottom to avoid obstruction by gravel. The sensor tip must be fully in contact with the water flow. After installation, the sensor must be calibrated to ensure the displayed level matches the actual water level. A first electric regulating valve is installed at the inlet of drainage channel 1. This valve can be an electric ball valve, positioned at the inlet end of drainage channel 1 near the slope. A 50 mm straight pipe section must be reserved at the valve's front end to ensure stable water flow while avoiding the inlet end of the double-wall corrugated drainage pipe 2. The valve and the double-wall corrugated drainage pipe 2 can be connected by a flange, with proper sealing to prevent leakage. Both the level sensor and the first electric regulating valve are electrically connected to the drainage controller. The drainage controller is configured as follows: When the liquid level sensor detects that the average liquid level in the underground drainage ditch is ≤100 mm, it is determined to be in normal drainage state, and the first electric regulating valve is controlled to maintain an opening of 20-30%. When the level sensor detects that the average level in the drainage ditch is 100-200 mm, it determines that it is the beginning of rainfall or an increase in water inflow, and controls the opening of the first electric regulating valve to increase to 50-60%. When the level sensor detects that the average level in the underground drainage ditch is greater than 200 mm, it determines that there is heavy rainfall or concentrated water inflow, and controls the opening of the first electric regulating valve to increase to 100%.

[0030] In the above technical solution, the liquid level sensor monitors the water level in the drainage ditch in real time and transmits the data to the drainage controller. The controller analyzes the liquid level data, judges the drainage status according to preset logic, and sends a command to the first electric regulating valve based on the judgment result to adjust the valve opening. Under normal conditions, the valve is opened at a small opening to retain water. When the water inflow increases, the opening is increased to accelerate drainage. During heavy rainfall, the valve is fully opened to ensure drainage efficiency, thereby achieving dynamic matching between drainage rate and water inflow. During non-rainfall periods, water loss is reduced to meet vegetation growth, and during rainfall periods, rapid drainage is achieved to avoid water accumulation, thus balancing the needs of ecological vegetation and slope drainage.

[0031] To address the difficulty in controlling the drainage efficiency at the outlet of the double-walled corrugated drainage pipe, another technical solution involves installing a first pressure sensor 0.1 m downstream of the starting point of the downstream section of the drainage pipe and a second pressure sensor 0.1 m upstream of the outlet. Both sensors have a measurement range of 0-100 kPa and an accuracy of ±0.5 kPa. The sensors must be mounted flush against the inner wall of the drainage pipe, avoiding perforations and corrugated protrusions. A flow velocity sensor with a measurement range of 0-2 m / s and an accuracy of ±0.01 m / s is installed at the transition cone section between the middle and downstream sections of the drainage pipe. The pressure is m / s. A second electric regulating valve is installed at the outlet of the downstream section of the drain pipe. The nominal diameter is adapted to the outlet size of the drain pipe. The assembly position is coaxial with the outlet end. It is connected to the drain pipe through a flange. The connection needs to be sealed. A pulse flushing device is also installed at the outlet of the downstream section of the drain pipe. It backflushes from the outlet of the downstream section of the drain pipe into the pipe. The first pressure sensor, the second pressure sensor, the flow rate sensor and the second electric regulating valve are all electrically connected to the drain controller. Each sensor monitors the pressure and flow rate in the drain pipe in real time. The data is transmitted to the drain controller. The drain controller calculates the pressure difference between the inlet and outlet and judges the drainage status in combination with the flow rate. When the flow velocity is greater than 0.5 m / s and the inlet and outlet pressure difference ΔP is greater than 10 kPa, the flow velocity is high but the pressure difference is large, resulting in local blockage. Control the opening of the second electric regulating valve to increase by 15-20% every 5 minutes until it reaches 100%, and gradually open the valve to reduce resistance. When the inlet and outlet pressure difference ΔP < 5 kPa and lasts for 30 min, the pressure difference is small and stable, drainage is smooth, and the second electric regulating valve is controlled to maintain a 20-30% opening to retain water at a small opening. When the flow rate is <0.1 m / s and the inlet / outlet pressure difference is >20 kPa, the flow rate is extremely low and the pressure difference is large, resulting in severe blockage. In this case, the second electric regulating valve is closed and the pulse flushing device is activated.

[0032] In the above technical solution, the blockage status is accurately determined by pressure and flow rate monitoring, and the outlet opening is dynamically adjusted or flushing is initiated to ensure stable drainage efficiency at the outlet of the drain pipe.

[0033] To address the issue of poor flushing performance after blockage of the permeable holes in double-wall corrugated drainage pipes, another technical solution employs a pulse flushing device. Upon triggering flushing conditions, the device activates, first gradually increasing the pressure through a stepped pressurization process, followed by intermittent high-pressure water flushing. The first stage involves flushing at 0.2 MPa for 120 seconds to soften the blockage; the second stage increases the pressure to 0.3 MPa for 80 seconds to remove the blockage; and the third stage increases the pressure to 0.4 MPa for 60 seconds, with a 10-second flush followed by a 5-second pause to expel the blockage. During flushing, the drainage controller receives real-time pressure difference data from the first and second pressure sensors. The pressure difference is used to assess the unblocking effect, and flushing stops once the target is met. When the inlet-outlet pressure difference ΔP drops below 8 kPa, flushing is terminated, and the second electric regulating valve is restored to normal operation. The stepped pressurization adapts to the degree of blockage; low pressure is sufficient for minor blockages, while high-pressure pulses enhance the effect for severe blockages, preventing continuous high pressure from damaging the pipes and reducing ineffective energy consumption while improving unblocking efficiency.

[0034] To address the water intake issue in the pulse flushing device, in another technical solution, the pulse flushing device includes: The backwash pump set can be a horizontal centrifugal pump, whose inlet is connected to the clean water area of ​​the stilling tank through a filter; The high-pressure bypass pipe is connected at one end to the outlet of the backwash pump unit, and at the other end to the outlet of the downstream section of the drain pipe through a three-way valve. The three ports of the three-way valve are respectively connected to the outlet of the drain pipe, the high-pressure bypass pipe and the downstream drain pipe (connected to the guide culvert), ensuring that the ports are sealed and the switching is smooth.

[0035] During normal drainage, the three-way valve is in the state of connection between the drain outlet and the downstream pipeline, the high-pressure bypass pipe is closed, and the water flows directly into the drainage ditch through the drain outlet. When flushing is required, the drainage controller sends a signal, the three-way valve switches to the state of connection between the high-pressure bypass pipe and the drain outlet, and the backwash pump unit is started at the same time. The clean water in the stilling tank enters the pump unit after being filtered by the filter. The pressurized water flows back into the drain pipe through the high-pressure bypass pipe and the three-way valve to flush the permeable holes. After flushing is completed, the pump unit stops working, and the three-way valve switches back to the normal drainage state.

[0036] In the above technical solution, water is drawn from the clear water area of ​​the stilling tank and filtered to reduce impurities entering the drain pipe and causing secondary blockage; a three-way valve enables convenient switching between flushing and drainage, ensuring reliable operation of the device and improving the stability of the flushing process.

[0037] To address the issue of uneven deep seepage collection caused by the uniform inclination angle of drainage channel 1 and drainage pipe, another technical solution employs a graded inclination angle design for drainage channel 1. First, a total station is used to locate the channel and determine the inlet position. Then, a down-the-hole drill is used for drilling. The first section of the channel, approximately 1 / 3 of its length from the slope, has an angle of 45° with the horizontal plane; the middle section, approximately 1 / 3 of its length, has an angle of 40° with the horizontal plane; and the final section, approximately 1 / 3 of its length into the slope, has an angle of 35°. After each section is drilled, an inclinometer is used to check the inclination angle to ensure the error does not exceed ±1°. The double-walled corrugated drainage pipe 2 is coaxially arranged with drainage channel 1 and synchronously divided into three sections along its length. During installation, the three sections are connected by hot-melt welding to ensure a tight joint. The pipe wall of the front and middle sections of the drain pipe is evenly arranged with 4 rows of permeable holes in the circumference, with a hole diameter of 8 mm and a longitudinal spacing of 200 mm. The pipe wall of the rear section of the drain pipe is evenly arranged with 6 rows of permeable holes in the circumference of the front section, with a hole diameter of 10 mm and a longitudinal spacing of 150 mm. The permeable holes of each section of the drain pipe should be staggered to avoid forming a straight water flow channel.

[0038] In the above technical solution, shallow seepage near the slope can quickly flow into the front section of the drainage pipe due to the large inclination angle of the front section of the channel (45°); mid-level seepage enters the pipe through the permeable holes of the middle section of the drainage pipe via the 40° inclination angle of the middle section; deep seepage is more easily collected into the rear section of the drainage pipe due to the small inclination angle (35°) of the rear section of the channel and the denser permeable holes (6 rows of 10mm diameter holes). The water flow in the three sections of the drainage pipe eventually converges into the drainage ditch and is discharged. Through the differentiated design of the graded inclination angle and permeable holes, the seepage path is adapted to different depths of the slope, improving the deep seepage collection capacity, making drainage more targeted, and enhancing the overall drainage efficiency.

[0039] To address the issue of high water flow resistance at the joints of different sections of the drainage pipe, another technical solution involves a transition cone section at the three joints of the double-walled corrugated drainage pipe 2. This transition cone section is made of the same high-density polyethylene material as the main drainage pipe and is integrally molded using injection molding. The large end of the transition cone section has the same outer diameter as the downstream drainage pipe section, while the small end has the same outer diameter as the upstream drainage pipe section. The taper is 1:10-15, and the length of the transition cone section is 200-300 mm. The outer wall of the transition cone section adopts a gradient corrugated structure with a corrugation depth of 5 mm at the front section, 8 mm at the middle section, and 10 mm at the rear section. The pitch of the corrugations is kept consistent with that of the main drainage pipe to ensure smooth water flow along the corrugations. Furthermore, the permeable hole diameter of the transition cone section is set according to the upstream pipe section. When water flows from the front section of the drain pipe into the transition cone section, the water flows smoothly to the middle section due to the guidance of the gradually changing corrugated structure. Similarly, when flowing from the middle section into the rear section, the gradual design of the transition cone section avoids the formation of eddies at the junction of the sections, reduces water flow resistance and impurity deposition, improves drainage smoothness, and extends the service life of the drain pipe.

[0040] The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the invention will be readily apparent to those skilled in the art.

[0041] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. An ecological slope protection drainage method, characterized in that, Includes the following steps: (1) Deep drainage of the slope: A drainage ditch is set longitudinally along the slope. The drainage ditch has a bottom width of 300-400 mm and a depth of 500-600 mm. A layer of graded crushed stone with a thickness of 100-150 mm and a particle size of 20-40 mm is laid at the bottom of the ditch. Inclined drainage channels are opened at longitudinal intervals of 8-10 m on the slope. The drainage channels are at an angle of 40-45° to the horizontal plane, the depth of the channels extends 1.5-2 m below the potential sliding surface, and the diameter of the channels is 110-130 mm. A double-walled corrugated drain pipe is nested and installed within the drainage channel. The outer diameter of the double-walled corrugated drain pipe is 80-100mm, and the outer wall of the double-walled corrugated drain pipe is coated with 200-300g / m² material. 2 The needle-punched geotextile has a closed inlet end and a permeable hole with a diameter of 8-10 mm on the pipe wall. The permeable hole is spaced 150-200 mm longitudinally and arranged in 4-6 rows in a circumferential direction. The outlet end of the double-wall corrugated drainage pipe is connected to the side wall of the underground drainage ditch, and a filter bag is installed at the connection. The filter bag is filled with gravel with a particle size of 5-10 mm and wrapped with an outer layer of 400 g / m³. 2 Woven geotextiles; A stilling basin with a volume of 2-3 m³ is installed at the end of the underground drainage ditch. 3 The bottom of the pool is covered with a layer of pebbles 200-300 mm thick, with a pebble diameter of 50-80 mm; (2) Slope surface protection: A three-dimensional composite drainage net is laid on the slope. The three-dimensional composite drainage net is thermally composited with an upper biaxial geogrid, a middle water-guiding rib, and a lower non-woven geotextile. The water-guiding rib is 5-8 mm high and 20-25 mm apart. A 100-120 mm thick vegetated substrate layer is laid above the three-dimensional composite drainage network. The vegetated substrate layer is composed of expanded clay pebbles with a particle size of 2-5 mm, humus and slow-release fertilizer in a mass ratio of 5:4:

1. A layer of 80-100 mm thick vegetated concrete is sprayed onto the surface of the vegetated substrate layer. The vegetated concrete has a compressive strength of 3-5 MPa and a porosity of 25-30%. Shrub seedlings with a depth of 40-50 mm are then planted before initial setting. The drainage channel adopts a graded inclination design. The front section of the channel, which is close to the slope for 1 / 3 of its length, has an angle of 45° with the horizontal plane. The middle section of the channel, which is 1 / 3 of its length, has an angle of 40° with the horizontal plane. The rear section of the channel, which is 1 / 3 of its length, has an angle of 35°. The double-walled corrugated drainage pipe is coaxially arranged with the drainage channel and is synchronously divided into three sections along its length. The pipe wall of the front and middle sections of the drain pipe is evenly arranged with 4 rows of permeable holes in the circumference, with a hole diameter of 8 mm and a longitudinal spacing of 200 mm. The pipe wall of the rear section of the drain pipe is evenly arranged with 6 rows of permeable holes in the circumference of the front section, with a hole diameter of 10 mm and a longitudinal spacing of 150 mm. The three sections of the double-walled corrugated drainage pipe are provided with transition cone sections. The length of the transition cone section is 200-300 mm. The outer wall of the transition cone section adopts a gradient corrugated structure. The corrugation depth is 5 mm in the front section of the drainage pipe, 8 mm in the middle section of the drainage pipe, and 10 mm in the rear section of the drainage pipe. The diameter of the permeable holes in the transition cone section is set according to the pipe section upstream.

2. The ecological slope protection drainage method as described in claim 1, characterized in that, The double-walled corrugated drainage pipe is provided with through holes, arranged in 4-6 rows evenly in a circumferential direction, interspersed with the water-permeable holes. A tightening structure is provided between the inner wall of the drainage channel and the outer wall of the double-walled corrugated drainage pipe, which includes: The top-tightening ring includes 4-6 sets of first mounting seats, arc-shaped connecting seats, second mounting seats, and arc-shaped connecting seats that are hinged together from end to end. The first mounting seats are provided with three assembly holes, and the second mounting seats are provided with two assembly holes. 4-6 sets of first column assemblies, each set of first column assemblies is installed on a first mounting base. Each first column assembly includes a clamping column and a pair of first support columns. The clamping column is fixedly inserted through the middle assembly hole of the first mounting base and movably inserted through the through hole of the double-wall corrugated drain pipe. The pair of first support columns are movably inserted through the two side assembly holes of the first mounting base and fixed by nuts. The heads of the clamping column and the pair of first support columns are both spherical surfaces that abut against the inner wall of the drain channel. 4-6 sets of second column assemblies, each set of second column assemblies is installed on a second mounting base. The second column assembly includes a pair of second support columns. The pair of second support columns are movably inserted through two mounting holes of the second mounting base and fixed by nuts. The heads of the pair of second support columns are both spherical surfaces that abut against the outer wall of the double-wall corrugated drain pipe.

3. The ecological slope protection drainage method as described in claim 2, characterized in that, Liquid level sensors are installed at intervals of 3-5 m along the water flow direction in the underground drainage ditch. The liquid level sensors have a measurement range of 0-300 mm. A first electric regulating valve is installed at the inlet of the drainage channel. Both the liquid level sensors and the first electric regulating valve are electrically connected to the drainage controller. The drainage controller is configured as follows: When the liquid level sensor detects that the average liquid level in the underground drainage ditch is ≤100 mm, it is determined to be in normal drainage state, and the first electric regulating valve is controlled to maintain an opening of 20-30%. When the level sensor detects that the average level in the drainage ditch is 100-200 mm, it determines that it is the beginning of rainfall or an increase in water inflow, and controls the opening of the first electric regulating valve to increase to 50-60%. When the level sensor detects that the average level in the underground drainage ditch is greater than 200 mm, it determines that there is heavy rainfall or concentrated water inflow, and controls the opening of the first electric regulating valve to increase to 100%.

4. The ecological slope protection drainage method as described in claim 3, characterized in that, A first pressure sensor is installed 0.1m after the starting end of the rear section of the drain pipe, a second pressure sensor is installed 0.1m before the outlet of the rear section of the drain pipe, a flow rate sensor is installed at the transition cone section between the middle section and the rear section of the drain pipe, a second electric regulating valve is installed at the outlet of the rear section of the drain pipe, and a pulse flushing device is also installed at the outlet of the rear section of the drain pipe to backflush into the pipe from the outlet of the rear section of the drain pipe. The first pressure sensor, the second pressure sensor, the flow rate sensor and the second electric regulating valve are all electrically connected to the drain controller. When the flow velocity is greater than 0.5 m / s and the inlet and outlet pressure difference ΔP is greater than 10 kPa, the opening of the second electric regulating valve is increased by 15-20% every 5 minutes until it reaches 100%. When the inlet and outlet pressure difference ΔP < 5 kPa and lasts for 30 min, control the second electric regulating valve to maintain an opening of 20-30%; When the flow rate is <0.1m / s and the inlet / outlet pressure difference is >20kPa, close the second electric regulating valve and start the pulse flushing device.

5. The ecological slope protection drainage method as described in claim 4, characterized in that, The pulse flushing device performs pulse flushing. In the first stage, it flushes at 0.2 MPa for 120 s. In the second stage, it increases to 0.3 MPa for 80 s. In the third stage, it increases to 0.4 MPa for 60 s pulse flushing. During the third stage, it flushes for 10 s and then pauses for 5 s. When the pressure difference between the inlet and outlet ΔP drops to <8 kPa, the flushing is terminated.

6. The ecological slope protection drainage method as described in claim 5, characterized in that, The pulse flushing device includes: The backwash pump unit has its inlet connected to the clean water area of ​​the stilling tank via a filter. The high-pressure bypass pipe is connected to the drain outlet via a three-way valve.

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