Method for improving stability of soft soil slope by electro-osmosis-electrophoresis-grouting synergy

Abstract

This invention belongs to the field of soft soil slope reinforcement technology. To address the problems of poor effectiveness, large workload, and high cost of current soft soil slope stability methods, it provides a method for synergistically improving soft soil slope stability through electroosmosis, electrophoresis, and grouting. Hollow anchor rods are drilled and embedded in the slope surface. An anode ring is fitted onto the anchor rod and connected by a wire. The hollow anchor rod is placed at the bottom of the drilled hole, and the wire is connected to the positive terminal of a DC power supply outside the slope. Cathode rings are installed at the pad and grout stop plug, connected to the negative terminal of the DC power supply outside the slope. Electrolyte is injected into the hollow anchor rod. A current field is formed by connecting the DC power supply, enabling electroosmosis, electrophoresis, and electrochemical processes. Grouting physically fills the cracks within the slope. Grouting is stopped when the grout flows out from the slope surface. This process is simple, low-cost, and time-efficient. It reduces moisture content, increases soil density, and improves slope resistance to sliding. Construction costs and labor requirements are lower than traditional reinforcement methods.

Description

Technical Field

[0001] This invention belongs to the field of soft soil slope reinforcement technology, specifically relating to a method for improving the stability of soft soil slopes through a synergistic effect of electroosmosis-electroporation-grouting. In particular, it is a method for reinforcing soft soil slopes by means of the synergistic effects of electroosmosis drainage, electrophoretic coalescence and grouting reinforcement, thereby improving the stability of soft soil slopes. Background Technology

[0002] With the continuous expansion of human activities and the increasing demands for resources, production, and daily transportation, numerous slope stability accidents have occurred in mining, water conservancy, and transportation sectors. Most of these accidents are caused by the continuous weakening of soft soil within the slope, resulting in slope deformation and collapse accidents every year, leading to significant property losses and casualties. To reduce the occurrence of slope engineering deformation and collapse accidents, slope safety has become an urgent problem that cannot be ignored, and research on slope stability is of paramount importance.

[0003] Currently, the main treatment measures for soft soil slopes include grouting reinforcement, cable anchoring, backfilling with rock after weak layer failure, retaining wall reinforcement, wire mesh and shotcrete reinforcement, and grid beam reinforcement. Among these, grouting reinforcement has a significant reinforcement effect on hard rock with well-developed fissures, sandy soft rock with good permeability, and rock masses with high weathering degree and rich joints. It can effectively reduce the weakening effect caused by fissures in the rock mass. However, when reinforcing soft soil containing a large amount of clay minerals, the grouting effect is usually poor due to the low permeability of soft soil. Moreover, because soft soil has low strength and high viscosity, problems such as stuck drills and collapsed holes often occur, seriously affecting the progress of grouting work. For soft soil with extremely poor permeability, which is mainly characterized by soft plastic creep deformation rather than fracture failure, effective reinforcement is difficult to achieve.

[0004] Anchor cable reinforcement can achieve good reinforcement when reinforcing high-strength rocks with unfavorable fracture conditions such as joints. However, in the reinforcement of weak rock masses, especially soft soil, there is often a problem of stress loss in the later stage, which may even lead to the gradual failure of the anchoring effect.

[0005] The reinforcement method of backfilling rock after weak layer damage involves excavating and removing the soft soil interlayer to eliminate its adverse effects. This method is costly, time-consuming, and causes significant disturbance to the overall slope during construction. It can easily lead to unfavorable conditions such as cracks in the upper rock layer of the soft soil interlayer, making it unsuitable for the overall reinforcement of soft soil slopes.

[0006] The rubble masonry walls used for retaining wall reinforcement have limited strength and insufficient resistance to geological disasters, resulting in high construction and maintenance costs. Mesh-reinforced shotcrete reinforcement is mostly used for rock slopes protected by mesh and shotcrete anchors, where the rock strata are severely weathered and fractured, joints are incomplete, and the fractured rock layers are thick, making it unsuitable for soft soils with fine and loose particles. When grid beam reinforcement is applied to soil slopes, prolonged exposure to rainwater erosion can cause the grid beams to detach, rendering the reinforcement ineffective. Therefore, it is suitable for rock slopes but ineffective for soft soil slopes. Considering these various problems with soft soil slope reinforcement, there is an urgent need to find an economical, efficient, and widely applicable method for soft soil slope reinforcement. Summary of the Invention

[0007] To address the problems of poor performance, large workload, and high cost of current methods for improving the stability of soft soil slopes, this invention provides a method for improving the stability of soft soil slopes through a synergistic approach of electroosmosis, electrophoresis, and grouting.

[0008] This invention introduces a synergistic improvement method of electroosmosis-electroporation-grouting into the reinforcement of weak slope soil. Through the action of an electric field, electroosmosis is achieved to accelerate the migration and discharge of liquids between media such as coal, rock, and soil. At the same time, electrophoresis is used to achieve the directional migration and aggregation of solid particles. Furthermore, electrochemical reactions generate new cementing minerals, and after the electrochemical reaction is completed, grouting is performed on the slope cracks to achieve synergistic physical and chemical reinforcement of the slope.

[0009] This invention is achieved by the following technical solution: a method for synergistically improving the stability of soft soil slopes through electroosmosis, electrophoresis, and grouting. Hollow anchor rods are installed by drilling holes in the slope surface and embedding a borehole pipe. Grouting holes are provided around the anchor rods. An anode ring is fitted onto the anchor rod and connected by a wire. The hollow anchor rod is then placed at the bottom of the borehole pipe. The anode ring is fixed at the interface between the potential sliding layer and the stable soil layer, and is located within the stable soil layer. The wire is connected to the positive terminal of a DC power supply outside the slope. A cathode ring is installed and fixed at the pad and grout stop plug, and connected by a wire. The cathode ring is connected to the negative terminal of a DC power supply outside the slope. Electrolytes are injected into the hollow anchor rods. Electrolyte is injected into the slope soil through the grouting holes of the hollow anchor rod. A DC power supply is connected to form a current field, which performs electroosmosis, electrophoresis, and electrochemical processes. When water seeps out from the shallow soil and the water content of the potential sliding layer reaches the pre-designed anti-sliding requirements, the power supply and electrolyte injection are stopped. Grouting is then performed into the hollow anchor rod tube to physically fill the cracks in the slope. Grouting is stopped when the grout flows out from the slope surface. A pull-out test is performed on the grouted anchor rod. If the pull-out force meets the design requirements, construction is stopped. If the pull-out force does not meet the design requirements, the operation is repeated.

[0010] The specific steps are as follows:

[0011] (1) Layout the slope surface, and arrange the drilling points according to the designed slope anti-sliding strength and relevant specifications. Clear the shrubs and weeds on the surface near the drilling points to facilitate the later construction work.

[0012] (2) Conduct geological drilling on the slope surface to identify the characteristics of the sliding soil, sliding zone soil and sliding bed, determine the thickness and layering of the sliding surface, and determine the location and relevant information of the potential sliding layer;

[0013] (3) Drill holes to the drilling points on the slope, and drill through the potential sliding layer to the stable soil layer, while laying the hole pipe at the same time.

[0014] (4) After drilling and burying the hole pipe, place the hollow anchor rod, put the anode ring on the rod body of the hollow anchor rod and connect it with the wire. After placing the hollow anchor rod at the bottom of the hole, fix the anode ring at the junction of the potential sliding layer and the stable soil layer and fix it in the stable soil layer. Connect the wire to the positive terminal of the DC power supply outside the slope.

[0015] A cathode ring is fitted and fixed near the pad and the grout stopper and connected with a wire. The cathode ring is connected to the negative terminal of a DC power supply outside the slope. The hollow anchor rod is arranged at an upward angle. After the electrode arrangement is completed, electrolyte is injected into the hollow anchor rod through a high-pressure injection hose. Then the electrolyte penetrates into the slope soil through the grouting hole of the hollow anchor rod. The DC power supply is turned on to form a current field to carry out electroosmosis, electrophoresis and electrochemical effects.

[0016] (5) When water seeps out from the shallow soil of the slope and the water content of the potential sliding layer of the slope reaches the pre-designed anti-sliding requirements, stop the power supply and stop the injection of electrolyte, and the electroosmosis, electrophoresis and electrochemical action will end.

[0017] (6) Grouting is performed into the hollow anchor pipe to physically fill the cracks in the slope. Grouting is stopped when the grout flows out from the surface of the slope.

[0018] (7) After the electroosmosis, electrophoresis, electrochemical action and physical grouting are completed, a pull-out test is conducted on the grouting anchor. If the pull-out force meets the design requirements, construction is stopped; if the pull-out force does not meet the design requirements, the operation is repeated.

[0019] The drilling spacing is 1 / 2 of the length of the hollow anchor rod; the hollow anchor rods are arranged in a quincunx pattern.

[0020] The voltage of the DC power supply is 200-800V; the electrode ring is made of any one of iron, aluminum or graphite, and the electrode ring is arranged at the junction of the potential sliding layer and the stable soil layer and fixed in the stable soil layer.

[0021] The electrolyte is either a 0.05-0.8 mol / L CaCl2 electrolyte or a 0.05-0.8 mol / L AlCl3 electrolyte.

[0022] The grouting slurry is a waterproof cement slurry in which water, ash, and organosilicon with a solid content of 30% are mixed in a weight ratio of 0.8:1:0.1, or the grouting slurry is a waterproof cement slurry in which water, ash, and organosilicon with a solid content of 45% are mixed in a weight ratio of 1.2:1:0.3; the grouting pressure is the critical pressure at which the slurry flows out from the slope surface.

[0023] The cathode ring is located at the interface between the potential sliding layer and the stable soil layer, and is situated within the stable soil layer.

[0024] The method described in this invention achieves the following: by applying an electric field to the slope soil and grouting, it drives free water in the slope soil to migrate and drain towards the cathode (electroosmotic drainage); drives soil particles in the slope to migrate and aggregate near the anode area (electrophoretic coalescence); generates new cementitious materials through redox reactions and consolidates soft soil particles together (electrochemical cementation); and physically reinforces the cracks in the soft soil slope by grouting after the electrochemical process is completed (grouting reinforcement). Thus, the stability and anti-sliding strength of the soft soil slope are improved through the integrated action of electroosmotic drainage, electrophoretic coalescence, electrochemical cementation, and grouting reinforcement.

[0025] Compared to existing methods, this invention transforms the single pull-out anchoring function of anchor bolts into a multifunctional engineering anchor bolt integrating electroosmosis, electrophoresis, electrochemical processes, and grouting. Anode and cathode electrodes are installed on the same anchor bolt. When an electric field is applied to the potential sliding layer soil, water molecules between the soil particles in the potential sliding layer seep out towards the cathode of the shallow soil layer through electroosmosis. Meanwhile, soil particles in the potential sliding layer migrate to the area near the boundary between the potential sliding layer and the stable soil layer under electrophoresis, increasing the density of the potential sliding layer soil and thus enhancing the slope strength. Physicochemical processes such as electroosmosis, electrophoresis, and electrochemistry occur near the electrodes. Near the anode, limonite or silica-containing diaspore is formed, while near the cathode, gibbsite or iron minerals are formed. These newly formed minerals often have cementing properties, further strengthening the soil density. Combined with subsequent grouting reinforcement, this further improves the slope's anti-sliding strength. This process is simple, low-cost, and time-efficient, and can be coordinated with hollow anchor bolt grouting operations, mutually promoting and complementing each other.

[0026] After reinforcing the potential sliding layer of the slope using this method, the moisture content decreased by 5-13%, the soil density of the slope increased to 90.7-95.1%, and the slope's anti-sliding strength increased by 3.4-7.8 times. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the cross-sectional layout of the present invention for improving the compaction of a soft soil slope by electroosmosis-electroporation-grouting synergistic effect;

[0028] Figure 2This is a detailed cross-sectional view of the hollow anchor rod electrode and borehole of the present invention;

[0029] Figure 3 This is a schematic diagram of the borehole layout for a method of improving the stability of soft soil slopes through a combination of electroosmosis, electrophoresis, and grouting, as described in this invention.

[0030] In the diagram: 1. DC power supply, 2. Positive electrode, 3. Negative electrode, 4. Conductor I, 5. Conductor II, 6. Cathode electrode, 7. Anode electrode, 8. Potential sliding layer, 9. Stable soil layer, 10. Hollow anchor, 11. Ammeter, 12. High-pressure injection hose, L. Vertical distance from the slope surface to the junction of the potential sliding layer and the stable soil layer, 13. Slope surface, 14. Borehole. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains, and all materials publicly cited herein and cited by them are incorporated herein by reference.

[0033] Equivalent technologies of the specific embodiments described herein that are readily apparent to those skilled in the art through routine experimentation are included in this application.

[0034] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the instruments and equipment used in the following embodiments are standard laboratory instruments and equipment.

[0035] Example 1: A method for improving the stability of soft soil slopes through a combination of electroosmosis, electrophoresis, and grouting on a circular arc slip surface. The specific steps are as follows:

[0036] a) Based on the characteristics of the potential sliding layer of the slope and its control requirements for slope stability and the existing construction technology, boreholes 14 with a diameter of 110 mm are drilled vertically to the slope surface 13 in a quincunx pattern. The drilling depth is twice the thickness of the potential sliding layer 8. After the borehole enters the potential sliding layer 8, the drilling continues to penetrate into the stable soil layer 9. The depth of the borehole in the stable soil layer 9 is approximately the same as the depth in the potential sliding layer 8.

[0037] The horizontal spacing and longitudinal spacing of the boreholes 14 are both 0.5 times the length of the borehole. Hollow anchor rods 10 with an outer diameter of 25 mm, specially made for the site, are then inserted into the boreholes 14. The anchor rod body of the hollow anchor rod 10 is fitted with a solid circular iron anode electrode 7 and a cathode electrode 6. The anode electrode 7 is located at the junction of the potential sliding layer 8 and the stable soil layer 9, but is located in the stable soil layer. The cathode electrode 6 is located in front of the grout stop plug of the anchor rod body. The anode electrode 7 is connected to the positive terminal 2 of the DC power supply 1 through wire I 4, and the cathode electrode 6 is connected to the negative terminal 3 of the DC power supply 1 through wire II 5.

[0038] The electrode thickness is 30mm, the inner diameter is slightly larger than the outer diameter of the anchor rod by 1-2mm, and the width is 1 / 100 of the vertical distance L from the slope surface 13 to the junction of the potential sliding layer 8 and the stable soil layer 9.

[0039] b) After the hollow anchor rod is placed into the borehole, wire I 4 is connected to the positive terminal 2 of DC power supply 1 through ammeter 11, and wire II 5 is connected to the negative terminal 3 of DC power supply 1. The output voltage of DC power supply 1 is 200V, the output current is 140A, and the output power is 2KW.

[0040] c) Install a high-pressure injection hose 12 with an inner diameter of 10 mm and a wall thickness of 1 mm inside each hollow anchor rod 10. The high-pressure injection hose 12 is close to the expansion shell anchor head of the hollow anchor rod 10. Then, the high-pressure injection hose 12 injects a CaCl2 or AlCl3 electrolyte with a concentration of 0.5 mol / L into the hollow anchor rod. The electrolyte permeates into the slope soil through the grouting hole of the hollow anchor rod 10. Connect the DC power supply 1. At this time, the working system performs electroosmosis, electrophoresis, electrochemical and other chemical actions on the slope soil. The slope soil begins to be modified, thereby realizing the electrochemical reinforcement of the slope. When the current drops to 10% of the initial current value, the power supply process ends and the injection of CaCl2 or AlCl3 electrolyte into the hollow anchor rod is stopped. Then, the power supply is turned off.

[0041] d) After turning off the power, remove the high-pressure injection hose 12 and inject a seepage-proof cement grout with a mass ratio of water:cement:organosilicon solid content 30% = 0.8:1:0.1 into the borehole 14 to perform physical grouting on the slope. This prevents water from re-entering the potential sliding layer after the modification and causing repeated erosion and weakening of the soft soil slope, thus maintaining the modification effect. After reinforcing the potential sliding layer of the slope using this method, the moisture content decreased by 10%, the soil density of the slope increased to 94.5%, and the slope anti-sliding strength increased by 6.2 times.

[0042] Example 2: A method for improving the stability of soft soil slopes through a combination of electroosmosis, electrophoresis, and grouting, occurring on a planar slip surface. The specific steps are as follows:

[0043] a) Based on the characteristics of the potential sliding layer of the slope and its control requirements for slope stability and the existing construction technology, boreholes 14 with a diameter of 110 mm are drilled vertically to the slope surface 13 in a quincunx pattern. The drilling depth is twice the thickness of the potential sliding layer 8. After the borehole 14 enters the potential sliding layer 8, the drilling continues to penetrate into the stable soil layer 9. The depth of the borehole 14 in the stable soil layer 9 is the same as the depth in the potential sliding layer 8.

[0044] The horizontal spacing and longitudinal spacing of the boreholes 14 are both 0.5 times the length of the borehole. Then, hollow anchor rods 10 with an outer diameter of 25 mm, specially made for the site, are inserted into the boreholes 14. The anchor rod body of the hollow anchor rod 10 is fitted with a solid circular iron anode electrode 7 and a cathode electrode 6. The anode electrode 7 is located below the junction of the potential sliding layer 8 and the stable soil layer 9, and the cathode electrode 6 is located in front of the grout stop plug of the anchor rod body. The anode electrode 7 is connected to the positive terminal 2 of the power supply through wire I 4, and the cathode electrode 6 is connected to the negative terminal 3 of the power supply through wire II 5.

[0045] The electrode thickness is 30mm, the inner diameter is slightly larger than the outer diameter of the anchor rod by 1-2mm, and the width is 1 / 100 of the vertical distance L from the slope surface 13 to the junction of the potential sliding layer 8 and the stable soil layer 9.

[0046] b) After the hollow anchor body is placed into the borehole, wire I 4 is connected to the positive terminal 2 of DC power supply 1 through ammeter 11, and wire II 5 is connected to the negative terminal 3 of DC power supply 1. The output voltage of DC power supply 1 is 700V, the output current is 500A, and the output power is 6KW.

[0047] c) Install a high-pressure injection hose 12 with an inner diameter of 1 mm and a wall thickness of 1 mm inside each hollow anchor rod 10. The high-pressure injection hose 12 is close to the expansion shell anchor head of the hollow anchor rod 10. Then, inject a CaCl2 or AlCl3 electrolyte with a concentration of 0.8 mol / L into the hollow anchor rod through the high-pressure injection hose. The electrolyte permeates into the slope soil through the grouting hole of the hollow anchor rod. Connect the DC power supply 1. At this time, the working system performs electroosmosis, electrophoresis, electrochemical and other chemical actions on the slope soil. The slope soil begins to be modified, thereby realizing the electrochemical reinforcement of the slope. When the current drops to 10% of the initial current value, the power supply process ends and the injection of CaCl2 or AlCl3 electrolyte into the hollow anchor rod is stopped. Then, the power supply is turned off.

[0048] d) After turning off the power, remove the high-pressure injection hose 12 and inject a seepage-proof cement grout with a mass ratio of water:cement:organosilicon with a solid content of 45% = 1.2:1:0.3 into the borehole 14 to perform physical grouting on the slope. This prevents water from re-entering the potential sliding layer after the modification and causing repeated erosion and weakening of the soft soil slope, thus maintaining the modification effect. After reinforcing the potential sliding layer of the slope using this method, the moisture content decreased by 8%, the soil density of the slope increased to 93.2%, and the slope's anti-sliding strength increased by 5.8 times.

[0049] Example 3: A method for synergistically improving the stability of soft soil slopes through electroosmosis, electrophoresis, and grouting. Hollow anchor rods are installed by drilling holes in the slope surface, with grouting holes around each anchor rod. An anode ring is fitted onto the anchor rod and connected by a wire. The hollow anchor rod is then placed at the bottom of the hole-drilled pipe. The anode ring is fixed at the interface between the potential sliding layer and the stable soil. The wire is connected to the positive terminal of a DC power supply outside the slope. Cathode rings are installed at the pad and grout stop plug, reinforced and connected by a wire. The cathode ring is connected to the negative terminal of a DC power supply outside the slope. Electrolyte is injected into the hollow anchor rod. The electrolyte permeates into the slope soil through the grouting holes of the hollow anchor rod. A current field is formed by connecting the DC power supply. Electroosmosis, electrophoresis, and electrochemical processes are performed. When water seeps from the shallow soil layer and the water content of the weak slope surface and the soil above it reaches the pre-designed anti-sliding requirements, the power supply and electrolyte injection are stopped. Grouting is performed into the hollow anchor pipes to physically fill the cracks in the slope. When the grout flows out from the slope surface, the grouting is stopped. A pull-out test is performed on the grouted anchor. If the pull-out force meets the design requirements, construction is stopped. If the pull-out force does not meet the design requirements, the operation is repeated. After reinforcing the potential sliding layer of the slope using this method, the water content is reduced by 7.5%, the soil density of the slope is increased to 92.8%, and the anti-sliding strength of the slope is increased by 6.3 times.

[0050] The DC power supply has a voltage of 800V; the electrolyte is either a 0.05 mol / L CaCl2 electrolyte or a 0.05 mol / L AlCl3 electrolyte. The remaining methods are the same as those described in Example 1.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for synergistically improving the stability of soft soil slopes through electroosmosis, electrophoresis, and grouting, characterized in that: A borehole (14) is drilled on the slope surface (13), a borehole pipe is installed, and a hollow anchor rod (10) is installed. Grouting holes are provided around the anchor rod. An anode ring is fitted on the anchor rod and connected with a wire. Then, the hollow anchor rod (10) is placed at the bottom of the borehole pipe. The anode ring is fixed at the junction of the potential sliding layer (8) and the stable soil layer (9) and is located in the stable soil layer (9) for fixation. The wire is connected to the positive terminal of the DC power supply outside the slope. A cathode ring is installed at the pad and the grout stop plug and fixed and connected with a wire. The cathode ring is connected to the negative terminal of the DC power supply outside the slope. Electrolyte is injected into the hollow anchor rod (10). Electrolysis The liquid permeates into the slope soil through the grouting hole of the hollow anchor rod (10), and the DC power supply (1) is connected to form a current field to carry out electroosmosis, electrophoresis and electrochemical action; water in the soft soil of the slope seeps out from the shallow soil, and when the water content of the potential sliding layer (8) of the slope reaches the pre-designed anti-sliding requirements, the power supply is stopped and the injection of electrolyte is stopped; grout is injected into the hollow anchor rod to physically fill the cracks in the slope, and the grouting is stopped when the grout flows out from the slope surface; a pull-out test is carried out on the grouting anchor rod. If the pull-out force meets the design requirements, the construction is stopped; if the pull-out force does not meet the design requirements, the operation is repeated.

2. The method for synergistically improving the stability of soft soil slopes through electroosmosis-electroporation-grouting as described in claim 1, characterized in that: The specific steps are as follows: (1) Layout the slope surface, and arrange the drilling points according to the designed slope anti-sliding strength and relevant specifications. Clear the shrubs and weeds on the surface near the drilling points to facilitate the later construction work. (2) Conduct geological drilling on the slope surface to identify the characteristics of the sliding soil, sliding zone soil and sliding bed, determine the location and layering of the sliding surface, and determine the depth and related information of the potential sliding layer; (3) Drill holes to the drilling points on the slope, and drill through the potential sliding layer to the stable soil layer, while laying the hole-forming pipe at the same time. (4) After drilling and burying the hole pipe, place the hollow anchor rod, put the anode ring on the rod body of the hollow anchor rod and connect it with the wire. After placing the hollow anchor rod at the bottom of the hole, fix the anode ring at the junction of the potential sliding layer and the stable soil layer and fix it in the stable soil layer. Connect the wire to the positive terminal of the DC power supply outside the slope. A cathode ring is fitted and fixed near the pad and the grout stopper and connected with a wire. The cathode ring is connected to the negative terminal of a DC power supply outside the slope. The hollow anchor rod is arranged at an upward angle. After the electrode arrangement is completed, electrolyte is injected into the hollow anchor rod through a high-pressure injection hose. Then the electrolyte penetrates into the slope soil through the grouting hole of the hollow anchor rod. The DC power supply is turned on to form a current field to carry out electroosmosis, electrophoresis and electrochemical effects. (5) When water seeps out from the shallow soil of the slope and the water content of the potential sliding layer of the slope reaches the pre-designed anti-sliding requirements, the power supply and the injection of electrolyte are stopped, and the electroosmosis, electrophoresis and electrochemical effects end. (6) Grouting is performed into the hollow anchor rods to physically fill the cracks in the slope. Grouting is stopped when the grout flows out from the surface of the slope. (7) After the electroosmosis, electrophoresis, electrochemical action and physical grouting are completed, a pull-out test is conducted on the grouting anchor. If the pull-out force meets the design requirements, construction is stopped; if the pull-out force does not meet the design requirements, the operation is repeated.

3. The method for synergistically improving the stability of soft soil slopes through electroosmosis, electrophoresis, and grouting as described in claim 2, characterized in that: The spacing between the drilling points in step (1) is 1 / 2 of the length of the hollow anchor rod; the hollow anchor rods are arranged in a quincunx pattern.

4. The method for synergistically improving the stability of soft soil slopes through electroosmosis-electroporation-grouting as described in claim 2, characterized in that: The voltage of the DC power supply is 200-800V; the electrode ring is made of any one of iron, aluminum or graphite. The electrolyte is either a 0.05-0.8 mol / L CaCl2 electrolyte or a 0.05-0.8 mol / L AlCl3 electrolyte.

5. The method for synergistically improving the stability of soft soil slopes through electroosmosis-electroporation-grouting as described in claim 2, characterized in that: The grout used for grouting the hollow anchor rod in step (6) is a seepage-proof cement grout made by mixing water, ash and organosilicon with a solid content of 30% in a weight ratio of 0.8:1:0.1; the pressure for grouting the hollow anchor rod in step (6) is the critical pressure when the grout flows out from the slope surface.

Images