Two-way electric silicification device and method for silt layer settlement reinforcement and lifting

Abstract

This invention discloses a bidirectional electric silicification device and method for reinforcing and lifting silt formations during subsidence. The bidirectional electric silicification device includes an electrode steel pipe, an upper injection chamber located in the upper middle part of the electrode steel pipe, a lower injection chamber located in the lower middle part of the electrode steel pipe, top and bottom outlet holes of the upper chamber, top and bottom outlet holes of the lower injection chamber, a first lower injection pipe and a first upper injection pipe connected to the upper injection chamber, and a second lower injection pipe and a second upper injection pipe connected to the lower injection chamber. This invention, through the bidirectional electric silicification device, can achieve bidirectional injection, synchronous injection, and cyclic alternating injection, demonstrating good adaptability to different working conditions. It not only increases injection efficiency but also reduces labor costs. The upper and lower injection chambers enable large-scale synchronous grouting and cyclic grouting in key areas.

Description

Technical Field

[0001] This invention relates to the field of silt formation subsidence reinforcement and lifting technology, and particularly to a bidirectional electric silicification device and construction method for silt formation subsidence reinforcement and lifting. Background Technology

[0002] The riverbanks in coastal areas are mostly composed of silty soil. This type of stratum has high natural water content, large porosity, high compressibility, and low strength, and also exhibits unique engineering geological properties such as creep and thixotropy. Buildings such as factories constructed on this type of foundation are highly susceptible to settlement under heavy loads, thus affecting their normal use. Treating silty foundations is quite challenging. Existing technologies, such as grouting reinforcement and lifting, often suffer from grout leakage and loss. This not only wastes grout but also fails to guarantee the lifting effect, ultimately adversely affecting the construction schedule. Another approach is electro-silicification reinforcement, which involves dual-solution injection, requiring separate injections and presenting technical problems such as the inability to perform simultaneous construction. Summary of the Invention

[0003] This invention provides a bidirectional electric silicification device and method for reinforcing and lifting silt formations during subsidence, which solves the technical problems of designing a bidirectional alternating grouting device, performing bidirectional alternating grouting, and convenient control when using electric silicification to treat silt formation subsidence.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A bidirectional electric silicification device for settling, consolidation, and lifting of silt strata includes an electrode steel pipe, a top vent hole at the top of the electrode steel pipe, an upper injection chamber located in the upper middle part of the electrode steel pipe, a lower injection chamber located in the lower middle part of the electrode steel pipe, a bottom vent hole, a top outlet hole, and a bottom outlet hole on the upper injection chamber, a vent pipe connecting the top vent hole and the bottom vent hole, a top outlet hole and a bottom outlet hole on the lower injection chamber, a first lower injection pipe and a first upper injection pipe connected to the upper injection chamber, and a second lower injection pipe and a second upper injection pipe connected to the lower injection chamber. The upper injection tank includes upper tank area 1 and upper tank area 2, and the lower injection tank includes lower tank area 1 and lower tank area 2. The lower chamber area is connected to the first lower pressure chamber via the first lower injection tube, and the upper chamber area is connected to the first upper pressure chamber via the first upper injection tube. The lower chamber 2 is connected to the second lower pressure chamber via the second lower injection tube, and the upper chamber 2 is connected to the second upper pressure chamber via the second upper injection tube.

[0005] Furthermore, the electrode steel pipe includes a steel pipe body and an insulating layer wrapped around the top and bottom of the steel pipe body. The height of the top insulating layer corresponds to the thickness of the backfill soil layer, and the height of the bottom insulating layer is adapted to the depth of the steel pipe body extending into the bearing layer. The inner wall of the electrode steel pipe is connected to the electrical control equipment. The steel pipe between the top and bottom insulation layers is provided with a mesh of holes, the size and density of which are adapted to the designed liquid output. The top and bottom of the steel pipe at the mesh holes are covered with caps, and the top cap is provided with a vent hole.

[0006] Furthermore, both the upper and lower injection chambers are cylindrical, and cylindrical silicone plugs are installed at the bottom of both chambers. The cylindrical silicone plugs are frictionally pressed and connected to the inner wall of the electrode steel tube. The upper injection chamber is located at the bottom of the backfill soil layer, and the lower injection chamber is located at the top of the lower bearing layer. The upper filling chamber is divided into two sections: upper chamber 1 and upper chamber 2. Upper chamber 1 has a top liquid outlet and a bottom vent. Upper chamber 2 has a bottom liquid outlet. The lower compartment of the injection tank is divided into two sections: lower compartment 1 and lower compartment 2. The lower compartment 1 has a top outlet, and the lower compartment 2 has a bottom outlet.

[0007] Furthermore, the upper injection chamber is slidably connected to the first lower injection tube and the first upper injection tube, and the lower injection chamber is slidably connected to the second lower injection tube and the second upper injection tube. The bottom openings of the first and second upper injection tubes are flush with the bottom of the top surface of the upper compartment 1 and upper compartment 2, respectively; the bottom openings of the first and second lower injection tubes are located at the bottom of the lower compartment 1 and lower compartment 2, respectively.

[0008] Furthermore, the first lower pressure chamber and the first upper pressure chamber are filled with the same solution, which is a sodium silicate solution. The second lower pressure chamber and the second upper pressure chamber are filled with the same solution, which is a calcium chloride solution.

[0009] Furthermore, the construction method of the bidirectional electric silicification device for the subsidence reinforcement and lifting of silt strata is as follows: Step 1: Install monitoring devices on the existing building. Using the settlement zone provided by the construction party, install displacement sensors and tilt sensors at each corner of the settlement zone and at the center of two adjacent corners. Install crack tape near existing cracks to prevent settlement during subsequent construction. Step 2: Determine the electrochemical reinforcement zone and the uplift zone. The electrochemical reinforcement zone is defined by extending 4m outward from the outer edge of the settlement zone as a reference. The thickness of the underlying soil layer and the thickness of the silt layer are determined according to the geological survey report, and then the location of the bearing layer under the silt layer is determined. The uplift zone is defined by using the horizontal projection size of the settlement zone as a reference. Step 3: Based on the electrochemical hardening zone, anode and cathode holes are arranged in alternating rows of anode and cathode holes. An electric field is formed by inserting electrode steel pipes into the anode and cathode holes and energizing them. The anode holes are injected with solution through a bidirectional electric silicification device, and the cathode holes are connected to drainage ditches and drainage pools for drainage. Step 4: Inject sodium silicate solution and calcium chloride solution into the anode respectively; under the combined action of electric field force and osmotic pressure, the solution directionally permeates into the cathode along the direction of the electric field, uniformly filling the gaps between soil particles; among them, sodium silicate solution and calcium chloride solution are injected in a bidirectional alternating manner; Both sodium silicate solution and calcium chloride solution include upper injection and lower injection. Through the setting of upper and lower injection chambers, bidirectional staggered injection is achieved. On one side, sodium silicate solution is injected in stages from top to middle and from middle to bottom; on the other side, calcium chloride solution is injected in stages from bottom to middle and from middle to top. Step 5: After the reinforcement is completed, using the electrochemical reinforcement zone as support, grout is injected into the lifting zone above the electrochemical reinforcement zone through the grouting holes to form a grouting lifting zone until the lifting meets the design requirements, thereby completing the reinforcement and lifting of the silt stratum settlement.

[0010] Furthermore, in step three, when arranging the anode and cathode holes, every two rows of anode and cathode holes form a group; the distance between anode holes, the distance between cathode holes, and the distance between each group are all 2m. If the control position conflicts with instruments or obstacles in the field, the insertion method should be changed to oblique insertion, and the number of holes should be increased around the instruments or obstacles in the field, with the hole spacing changed to 1m.

[0011] Furthermore, in step four, when water is discharged from the cathode hole during construction, the solution is injected. The upper injection chamber is set at the bottom of the backfill soil layer, and the lower injection chamber is set at the top of the bearing layer. During solution injection, the first upper pressure chamber begins injecting sodium silicate solution, and the second lower pressure chamber begins injecting calcium chloride solution. As the solution is injected, sodium silicate solution begins to drain from the top outlet of the upper chamber, and calcium chloride solution begins to drain from the bottom outlet of the lower chamber. Simultaneously, the vent at the bottom of the upper chamber is open to prevent blockage caused by residual air. As the solution continues to be injected, the pressure from the increased liquid volume transforms into thrust. This thrust exceeds the frictional force generated by the cylindrical silicone plug, causing the upper injection chamber to move from top to bottom and the lower injection chamber to move from bottom to top. Thus, sodium silicate solution is injected from top to middle, and calcium chloride solution is injected from bottom to middle. When the air discharge rate at the bottom vent of the upper chamber slows down significantly and almost no air is discharged, it indicates that the upper and lower injection chambers have met. Subsequently, the first lower injection chamber begins to inject sodium silicate solution, and the second upper injection chamber begins to inject calcium chloride solution. As the solution is injected, calcium chloride solution begins to be discharged from the bottom outlet of the upper chamber, and sodium silicate solution begins to be discharged from the top outlet of the lower chamber. As the solution is continuously injected, the pressure caused by the increase in liquid volume transforms into thrust. This thrust is greater than the frictional force generated by the cylindrical silicone plug, causing the upper injection chamber to move upward and the lower injection chamber to move downward. Through the movement of the upper and lower injection chambers, sodium silicate solution is injected from the middle to the bottom while calcium chloride solution is injected from the middle to the top. By repeatedly injecting the above solutions, a bidirectional, independent, alternating injection of sodium silicate solution from top to bottom and calcium chloride solution from bottom to top is achieved.

[0012] Furthermore, the types of solutions in the first lower pressure liquid tank, the first upper pressure liquid tank, the second lower pressure liquid tank, and the second upper pressure liquid tank are filled according to the solution required for the electrochemical reinforcement zone; the initial positions of the upper injection tank and the lower injection tank are set according to the reinforcement range of the designed solution; among them, the upper tank area 1, upper tank area 2, lower tank area 1, and lower tank area 2 are independently controlled by pressure liquid movement according to the type and position of the solution to be injected, and the movement range is suitable for the area of ​​the designed injection solution.

[0013] Furthermore, the feature is that the electrochemical reinforcement zone is reinforced by zonal construction, which divides the whole into areas with small settlement and progressively constructs them from areas with large settlement; the energization time for each group of construction is 24 hours, and when there is obvious secondary settlement reaction, the voltage is reduced and the solution injection pressure is increased. After the construction is completed, the electrode steel pipe is pulled out and the residual holes are filled with grout.

[0014] The beneficial effects of this invention are reflected in: This invention, through the design of a bidirectional electric siliconization device, enables bidirectional liquid injection, synchronous liquid injection, and cyclic alternating liquid injection, demonstrating excellent adaptability to different working conditions. It not only increases injection efficiency but also reduces labor costs. The upper and lower injection chambers facilitate large-scale synchronous grouting and cyclic grouting in key areas. The inclusion of vent holes at the bottom of the upper chamber, vent holes at the top of the pipe, and vent pipes allows for more comprehensive solution injection and more precise control of the chamber during application. The bidirectional electric siliconization device is easy to install and operate, enabling convenient bidirectional injection of two liquids. During grouting lifting, the electric siliconization solidified body serves as a support point, forming a unified structure from the lower bearing layer, the electric siliconization solidified body, and the grouting lifting zone, thus enhancing overall structural stability.

[0015] Therefore, this application solves the technical problems of designing a bidirectional alternating grouting device, performing bidirectional alternating grouting, and convenient control when treating silt formation settlement using the electro-silicification method. Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention; the main objects and other advantages of the invention can be realized and obtained by means of the methods particularly pointed out in the description. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a bidirectional electric silicification device used in the subsidence reinforcement and lifting of silt strata. Figure 2 This is a partial schematic diagram of a bidirectional electric silicification device used in the subsidence reinforcement and lifting of silt strata. Figure 3 It is a diagram showing the arrangement of cathode holes, anode holes, and grouting holes; Figure 4 It is a layout diagram of the monitoring points; Figure 5 This is a schematic diagram of the cross-section of the silt site after it was raised; Figure 6 This is a cross-sectional view of the electrochemically reinforced zone during construction. Figure 7 This is a cross-sectional view of the electrode steel pipe used in construction; Figure 8 This is a diagram showing the layout of the anode and cathode holes at the instruments in the field. Figure 9 This is a cross-sectional layout diagram of the electrode steel pipes at the instrument location within the field; Figure 10 This is a schematic diagram of the construction and installation of electrically driven siliconized flooring.

[0017] Reference numerals: 1-Electrode steel pipe, 101-Steel pipe body, 102-Insulation layer, 2-Top vent hole, 3-Vent pipe, 4-Upper injection chamber, 41-Upper chamber zone 1, 42-Upper chamber zone 2, 5-Lower injection chamber, 51-Lower chamber zone 1, 52-Lower chamber zone 2, 6-Top outlet hole of upper chamber, 7-Top outlet hole of lower chamber, 8-First lower pressure chamber, 9-First upper pressure chamber, 10-Second lower pressure chamber, 11-Second upper pressure chamber, 12-First lower injection tube, 13-First upper injection tube, 14- 15-Second lower injection tube, 16-Upper chamber bottom outlet, 17-Upper chamber bottom vent, 18-Lower chamber bottom outlet, 19-Settling zone, 20-Anode hole, 21-Cathode hole, 22-Grouting hole, 23-Monitoring point, 24-Bearing layer, 25-Silt layer, 26-Electrochemical reinforcement zone, 27-Grouting lifting zone, 28-Backfill layer, 29-Ground surface, 30-In-situ instruments, 31-Drainage ditch, 32-Drainage pool, 33-Electrical control equipment. Detailed Implementation

[0018] Taking a certain elevated storage area as an example, the single-layer steel frame structure contains a silt layer at its bottom, with a thickness of 8m; the bearing layer below the silt layer is a silty clay layer; local settlement occurred in the warehouse floor. The ground load is approximately 10t / ㎡. The reasons for the uneven settlement of the floor are as follows: there is backfill soil under the warehouse floor, with a thickness of 2.8m. The backfill soil softened locally due to water infiltration in the later stages, resulting in uneven stress transmitted to the silt soil; the silt soil has high compressibility and low bearing capacity. Under stress differences, the high water content area has greater compression deformation, and after being disturbed by water infiltration, the structure collapses and its strength decreases; at the same time, the silt soil consolidates slowly, and the secondary consolidation deformation accumulates over a long period of time, forming a deformation difference with the locally softened area of ​​the backfill soil, ultimately leading to uneven settlement of the floor. The solution is to reinforce and lift the silt stratum using a bidirectional electric silicification device.

[0019] like Figure 1 and Figure 2 As shown, the bidirectional electric silicification device for the subsidence reinforcement and lifting of silt strata includes an electrode steel pipe 1, a top vent 2 located at the top of the electrode steel pipe 1, an upper injection chamber 4 located in the upper middle part of the electrode steel pipe 1, a lower injection chamber 5 located in the lower middle part of the electrode steel pipe 1, a bottom vent 17, a top outlet 6, and a bottom outlet 16 located on the upper injection chamber 4, a vent pipe 3 connecting the top vent 2 and the bottom vent 17, a top outlet 7 and a bottom outlet 18 located on the lower injection chamber 5, a first lower injection pipe 12 and a first upper injection pipe 13 connected to the upper injection chamber 4, and a second lower injection pipe 14 and a second upper injection pipe 15 connected to the lower injection chamber 5.

[0020] In this embodiment, the electrode steel pipe 1 includes a steel pipe body 101 and insulating layers 102 wrapped around the top and bottom of the steel pipe body 101. The height of the top insulating layer 102 corresponds to the thickness of the backfill soil layer 28, and the height of the bottom insulating layer 102 is adapted to the depth of the steel pipe body 101 extending into the bearing layer 24. The inner wall of the electrode steel pipe 1 is connected to the electrical control equipment 33. The steel pipe body 101 between the top and bottom insulating layers 102 is provided with a mesh-like perforation, the size and density of which are adapted to the designed liquid discharge volume. The top and bottom ends of the steel pipe body 101 at the mesh-like perforation are provided with caps, and the top cap is provided with a pipe top vent 2. The vent pipe 3 between the vent 17 and the bottom vent 17 of the upper compartment is introduced to the ground 29 through a pipe, and can also be connected to an air pump for rapid extraction of air from the soil.

[0021] In this embodiment, the electrode steel pipe 1 is a stainless steel pipe with a diameter of 50mm. The length of the stainless steel pipe should be greater than the thickness of the soil covering the silt plus the entire silt layer 25. The part of the steel pipe at the top of the silt covering the soil layer and the part of the steel pipe at the bottom of the silt bearing layer 24 should be coated with insulating material as an insulating layer 102 to reduce the power consumption during construction.

[0022] In this embodiment, both the upper injection chamber 4 and the lower injection chamber 5 are cylindrical chambers. The bottom of both the upper injection chamber 4 and the lower injection chamber 5 is provided with a cylindrical silicone plug with a thickness of 50mm, and the bottom area of ​​the plug is larger than the area of ​​the electrode steel pipe 1. The cylindrical silicone plug is frictionally pressed and connected to the inner wall of the electrode steel pipe 1. The upper injection chamber 4 is located at the bottom of the backfill soil layer 28, and the lower injection chamber 5 is located at the top of the lower bearing layer 24.

[0023] In this embodiment, the upper injection chamber 4 includes an upper chamber 1 area 41 and an upper chamber 2 area 42, and the lower injection chamber 5 includes a lower chamber 1 area 51 and a lower chamber 2 area 52. The lower chamber 1 area 51 is connected to the first lower pressure chamber 8 through a first lower injection tube 12, and the upper chamber 1 area 41 is connected to the first upper pressure chamber 9 through a first upper injection tube 13. The lower chamber 2 area 52 is connected to the second lower pressure chamber 10 through a second lower injection tube 14, and the upper chamber 2 area 42 is connected to the second upper pressure chamber 11 through a second upper injection tube 15. The first lower injection tube 12, the first upper injection tube 13, the second lower injection tube 14, and the second upper injection tube 15 are rigid tubes inside the electrode steel tube 1, and the outside of the electrode steel tube 1 is a rigid tube or a flexible tube.

[0024] In this embodiment, the upper filling tank 4 is divided into two halves, with upper tank section 41 and upper tank section 42. Upper tank section 41 has a top liquid outlet 6 and a bottom vent 17. Upper tank section 42 has a bottom liquid outlet 16. The lower filling tank 5 is divided into two halves, with lower tank section 51 and lower tank section 52. Lower tank section 51 has a top liquid outlet 7. Lower tank section 52 has a bottom liquid outlet 18.

[0025] In this embodiment, the upper injection chamber 4 is slidably connected to the first lower injection tube 12 and the first upper injection tube 13, and the lower injection chamber 5 is slidably connected to the second lower injection tube 14 and the second upper injection tube 15; the bottom openings of the first upper injection tube 13 and the second upper injection tube 15 are respectively flush with the bottom of the top surface of the upper chamber 1 area 41 and the upper chamber 2 area 42; the bottom openings of the first lower injection tube 12 and the second lower injection tube 14 are respectively located at the bottom of the lower chamber 1 area 51 and the lower chamber 2 area 52.

[0026] In this embodiment, the first lower pressure chamber 8 and the first upper pressure chamber 9 are filled with the same solution, which is a sodium silicate solution; the second lower pressure chamber 10 and the second upper pressure chamber 11 are filled with the same solution, which is a calcium chloride solution. The sodium silicate solution reacts with moisture and minerals in the foundation soil, or with calcium chloride solution subsequently injected from the anode, to generate cementing substances such as silica gel (SiO2·nH2O) and calcium hydroxide (Ca(OH)2). These substances encapsulate soil particles, fill pores, and bind loose soil particles into a cohesive whole, improving the foundation strength and compressibility. The discharge of pore water and the effect of the compacting electric field on the soil also promote the migration of pore water in the soil towards the cathode and the discharge of electroosmotic effects, reducing the water content of the foundation. Simultaneously, the cementing substances generated by the chemical reaction shrink and harden, further compressing the soil particles, increasing the soil density, and ultimately achieving the reinforcement purpose of improving the foundation bearing capacity and reducing settlement. This forms an electrochemical reinforcement zone 26 between the lower bearing layer 24 and the top overburden layer.

[0027] Combination Figures 1 to 10 As shown, the construction method of the bidirectional electric silicification device in the subsidence reinforcement and lifting of silt strata is further explained. The specific steps are as follows: Step 1: Install monitoring devices on the existing building. Using the settlement zone 19 provided by the construction party, install displacement sensors and tilt sensors at each corner point and the center of two adjacent corner points in the settlement zone 19. Install crack tape near existing cracks to prevent settlement during subsequent construction.

[0028] In this embodiment, settlement monitoring points 23 are set up within the settlement zone 19, and the setup method is as follows: Figure 4 Settlement measurements were conducted, and the settlement data was analyzed. The entire settlement area 19 was divided into zones according to the magnitude of settlement, from largest to smallest. Figure 3 The data is divided into three intervals: A, B, and C. The analysis results show that the settlement is B>A>C.

[0029] Step 2: Determine the electrochemical reinforcement zone 26 and the uplift zone. The electrochemical reinforcement zone 26 is defined as a 4m extension outward from the outer edge of the settlement zone 19. Based on the geological survey report, determine the thickness of the overlying soil layer beneath the surface 29 and the thickness of the silt layer 25, thus determining the location of the bearing layer 24 beneath the silt layer 25. The uplift zone is defined as 2m to 3m below the settlement zone 19.

[0030] Step 3: Based on the electrochemical hardening zone 26, anode holes 20 and cathode holes 21 are arranged in alternating rows of anode holes 20 and cathode holes 21; an electric field is formed by inserting electrode steel pipes 1 into the anode holes 20 and cathode holes 21 and energizing them; the anode holes 20 are injected with solution by installing the above-mentioned bidirectional electric silicification device, and the cathode holes 21 are connected to the drainage ditch 31 and the drainage pool 32 for drainage.

[0031] In step three, when setting up anode holes 20 and cathode holes 21, each two rows of anode holes 20 and cathode holes 21 form a group; the distance between anode holes 20 and anode holes 20, the distance between cathode holes 21 and cathode holes 21, and the distance between each group are all 2m; if the control position conflicts with the instrument 30 or obstacles in the field, the insertion method is changed to oblique insertion, and the holes are denser around the instrument 30 or obstacles in the field, and the hole spacing is changed to 1m.

[0032] In this embodiment, each anode hole 20 and cathode hole 21 is 0.2m below the silt layer 25. The electrode steel pipe 1 is 11m long and 50mm in diameter. The upper insulating layer 102 (2.8m long) and the lower insulating layer 102 (0.2m long) are insulated. The middle steel pipe body 101 has openings for liquid injection or drainage. The horizontal and vertical spacing of the small holes in the steel pipe is 50mm. To ensure that the openings of the electrode steel pipe 1 at the cathode hole 21 are covered with filter screens to prevent silt and other impurities from entering during construction, if the hole position conflicts with the on-site instrument 30, [further details to be added]. Figure 8 and 9 The insertion method is as shown. The holes are arranged with alternating cathodes and anodes on both sides of the instrument 30 at 1m intervals. The insertion method is changed to oblique insertion into the soil.

[0033] Step 4: Inject sodium silicate solution and calcium chloride solution into the anode respectively; under the combined action of electric field force and osmotic pressure, the solution directionally permeates into the cathode along the direction of the electric field, uniformly filling the gaps between soil particles; among them, sodium silicate solution and calcium chloride solution are injected in a bidirectional alternating manner.

[0034] Both sodium silicate solution and calcium chloride solution include upper injection and lower injection. Through the setting of upper injection chamber 4 and lower injection chamber 5, bidirectional staggered injection is achieved. On one side, sodium silicate solution is injected in stages from top to middle and from middle to bottom; on the other side, calcium chloride solution is injected in stages from bottom to middle and from middle to top.

[0035] In this embodiment, the electrical control device 33 uses a constant voltage power supply with a maximum voltage of 120V and a maximum current of 500A. The initial construction voltage is 120V, which is then kept constant at 100V after the solution is injected. During construction, the solution is injected when water is discharged from the cathode hole 21. The upper injection chamber 4 is located at the bottom of the backfill soil layer 28, and the lower injection chamber 5 is located at the top of the bearing layer 24.

[0036] During solution injection, the first upper pressure chamber 9 begins to inject sodium silicate solution, and the second lower pressure chamber 10 begins to inject calcium chloride solution. As the solution is injected, the top outlet 6 of the upper chamber begins to discharge sodium silicate solution, and the bottom outlet 18 of the lower chamber begins to discharge calcium chloride solution. At the same time, the bottom vent 17 of the upper chamber is open to prevent blockage caused by residual air. As the solution is continuously injected, the pressure caused by the increase in liquid volume is converted into thrust. The thrust is greater than the friction generated by the cylindrical silicone plug, so the upper injection chamber 4 begins to move from top to bottom, and the lower injection chamber 5 begins to move from bottom to top. Thus, sodium silicate solution is injected from top to middle, and calcium chloride solution is injected from bottom to middle. When the air discharge rate at the vent 17 at the bottom of the upper chamber slows down significantly and almost no air is discharged, it indicates that the upper injection chamber 4 and the lower injection chamber 5 have met. Subsequently, the first lower pressure chamber 8 begins to inject sodium silicate solution, and the second upper pressure chamber 11 begins to inject calcium chloride solution. As the solution is injected, the upper chamber bottom outlet 16 begins to discharge calcium chloride solution, and the lower chamber top outlet 7 begins to discharge sodium silicate solution. As the solution is continuously injected, the pressure caused by the increase in liquid volume transforms into thrust. This thrust is greater than the friction generated by the cylindrical silicone plug, causing the upper injection chamber 4 to move upward and the lower injection chamber 5 to move downward. Through the movement of the solution chambers in the upper and lower injection chambers 4 and 5, sodium silicate solution is injected from the middle to the bottom while calcium chloride solution is injected from the middle to the top.

[0037] This cycle of solution injection achieves bidirectional, independent, alternating injection of sodium silicate solution from top to bottom and calcium chloride solution from bottom to top. During the electrochemical reinforcement of zone 26, a zoned construction approach is adopted, dividing the entire area into zones with less settlement and progressively moving towards areas with greater settlement. Each group of construction is energized for 24 hours. When significant secondary settlement occurs, the voltage is reduced and the solution injection pressure is increased. After construction, electrode steel pipe 1 is removed, and residual cavities are filled with grout.

[0038] In this embodiment, the types of solutions in the first lower pressure liquid tank 8, the first upper pressure liquid tank 9, the second lower pressure liquid tank 10, and the second upper pressure liquid tank 11 are filled according to the designed solutions required for the electrochemical reinforcement zone 26; the initial positions of the upper injection tank 4 and the lower injection tank 5 are set according to the designed solution reinforcement range; wherein, the upper tank zone 1 41, the upper tank zone 2 42, the lower tank zone 1 51, and the lower tank zone 2 52 are independently controlled by pressure liquid movement according to the type and position of the solution to be injected, and the movement range is suitable for the designed injection solution area.

[0039] To prevent the solution from splitting during injection and to ensure uniform penetration under electroosmosis, the injection pressure should be controlled below 0.15 MPa, and sedimentation should be monitored in real time. If sedimentation occurs, the voltage should be reduced and the injection volume of the solution increased. After stabilization, the original voltage should be restored.

[0040] Step 5: After the reinforcement is completed, using the electrochemical reinforcement zone 26 as a support, grouting is carried out in the lifting zone above the electrochemical reinforcement zone 26 through the grouting holes 22 to form the grouting lifting zone 27 until the lifting meets the design requirements, thereby completing the reinforcement and lifting of the silt stratum settlement.

[0041] During grouting in the raised zone, the electrochemically reinforced zone 26 is considered as the fulcrum, and grouting is carried out slowly through the grouting pipe. The grout slowly diffuses upward, squeezing out and replacing the residual silt, and then grouting continues to slowly raise the settlement floor. This process continues until the elevation of the settlement zone 19 meets the design requirements, thus completing the grouting reinforcement and raising of the settlement floor in the silt layer. In this embodiment, the silt soil in the silt layer 25 is highly sensitive, exhibiting a soft plastic to fluid plastic state. During grouting, low-pressure, small-diameter grouting is used, with a grouting pressure of 0.2MPa to 0.5MPa and a grouting pipe diameter of 10mm. Slow grouting minimizes disturbance to the silt soil, ensuring that the grout solidifies in the area near the grouting location and does not flow around with the silt. The grout used in the grouting process has a fast setting speed, high density, and high bearing capacity after setting. Grouting in silt is a non-drained compression process due to the poor permeability of the silty soil. Under non-drained conditions, a considerable volume of silty soil is squeezed outwards or upwards near the grouting hole. A technique of small-injection, multiple-re-injection is used, injecting a small amount of grout each time, allowing it to stabilize, and then injecting more, repeating this process continuously. This causes the grout to spread outwards in concentric circles until reinforcement and lifting are complete. During the grouting process, the displacement changes at monitoring point 23 are observed to prevent the ground from bulging.

[0042] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A bidirectional electric silicification device for the subsidence reinforcement and lifting of silt strata, characterized in that, Includes an electrode steel pipe (1), a pipe top vent (2) set at the top of the electrode steel pipe (1), an upper injection chamber (4) set in the upper middle part of the electrode steel pipe (1), a lower injection chamber (5) set in the lower middle part of the electrode steel pipe (1), an upper chamber bottom vent (17), an upper chamber top outlet (6) and an upper chamber bottom outlet (16) set on the upper injection chamber (4), a vent pipe (3) connecting the pipe top vent (2) and the upper chamber bottom vent (17), a lower chamber top outlet (7) and a lower chamber bottom outlet (18) set on the lower injection chamber (5), a first lower injection pipe (12) and a first upper injection pipe (13) connected on the upper injection chamber (4), and a second lower injection pipe (14) and a second upper injection pipe (15) connected on the lower injection chamber (5). The upper injection tank (4) includes upper tank area 1 (41) and upper tank area 2 (42), and the lower injection tank (5) includes lower tank area 1 (51) and lower tank area 2 (52). The lower chamber area (51) is connected to the first lower pressure chamber (8) through the first lower injection tube (12), and the upper chamber area (41) is connected to the first upper pressure chamber (9) through the first upper injection tube (13). The lower chamber 2 (52) is connected to the second lower pressure chamber (10) through the second lower injection tube (14), and the upper chamber 2 (42) is connected to the second upper pressure chamber (11) through the second upper injection tube (15). The electrode steel pipe (1) includes a steel pipe body (101) and an insulating layer (102) wrapped around the top and bottom of the steel pipe body (101). The height of the top insulating layer (102) corresponds to the thickness of the backfill soil layer (28), and the height of the bottom insulating layer (102) is adapted to the depth of the steel pipe body (101) extending into the bearing layer (24). The inner wall of the electrode steel pipe (1) is connected to the electrical control equipment (33). The steel pipe body (101) between the top and bottom insulation layers (102) is provided with a mesh-like hole, the size and density of which are adapted to the designed liquid output; the top and bottom of the steel pipe body (101) with the mesh-like hole are provided with a cap, and the top cap is provided with a pipe top vent hole (2). Both the upper injection chamber (4) and the lower injection chamber (5) are cylindrical chambers. Both the upper injection chamber (4) and the lower injection chamber (5) are equipped with cylindrical silicone plugs at the bottom. The cylindrical silicone plugs are frictionally pressed and connected to the inner wall of the electrode steel pipe (1). The upper injection chamber (4) is located at the bottom of the backfill soil layer (28), and the lower injection chamber (5) is located at the top of the lower bearing layer (24). The upper filling tank (4) is divided into two sections: upper tank section 1 (41) and upper tank section 2 (42). The upper tank section 1 (41) has an upper tank top outlet hole (6) and an upper tank bottom vent hole (17) at the top. The upper tank section 2 (42) has an upper tank bottom outlet hole (16). The lower compartment (5) is divided into two sections: lower compartment 1 (51) and lower compartment 2 (52). The lower compartment 1 (51) has a top outlet hole (7) and the lower compartment 2 (52) has a bottom outlet hole (18). The upper injection chamber (4) is slidably connected to the first lower injection tube (12) and the first upper injection tube (13), and the lower injection chamber (5) is slidably connected to the second lower injection tube (14) and the second upper injection tube (15). The bottom openings of the first upper injection tube (13) and the second upper injection tube (15) are respectively flush with the bottom of the top surface of the upper compartment 1 (41) and the upper compartment 2 (42); the bottom openings of the first lower injection tube (12) and the second lower injection tube (14) are respectively located at the bottom of the lower compartment 1 (51) and the lower compartment 2 (52). The first lower pressure liquid chamber (8) and the first upper pressure liquid chamber (9) are filled with the same solution, which is sodium silicate solution; The second lower pressure chamber (10) and the second upper pressure chamber (11) are filled with the same solution, which is calcium chloride solution.

2. The construction method of the bidirectional electric silicification device for the subsidence reinforcement and lifting of silt strata as described in claim 1, characterized in that, The specific steps are as follows: Step 1: Install monitoring devices on the existing building. Using the settlement area (19) provided by the construction party, install displacement sensors and tilt sensors at each corner point and the center of two adjacent corner points in the settlement area (19). Install crack tape near existing cracks to prevent settlement in subsequent construction. Step 2: Determine the electrochemical reinforcement zone (26) and the uplift zone. The electrochemical reinforcement zone (26) is defined by extending 4m outward from the outer edge of the settlement zone (19) as a reference. The thickness of the overlying soil layer under the ground surface (29) and the thickness of the silt layer (25) are determined according to the geological survey report, and the location of the bearing layer (24) under the silt layer (25) is then determined. The uplift zone is defined by using the horizontal projection size of the settlement zone (19) as a reference. Step 3: Based on the electrochemical reinforcement zone (26), anode holes (20) and cathode holes (21) are arranged in alternating rows of anode holes (20) and cathode holes (21); an electric field is formed by inserting electrode steel pipes (1) into the anode holes (20) and cathode holes (21) and energizing them; the anode holes (20) are injected with solution through a bidirectional electric silicification device, and the cathode holes (21) are connected to a drainage ditch (31) and a drainage pool (32) for drainage. Step 4: Inject sodium silicate solution and calcium chloride solution into the anode respectively; under the combined action of electric field force and osmotic pressure, the solution directionally permeates into the cathode along the direction of the electric field, uniformly filling the gaps between soil particles; among them, sodium silicate solution and calcium chloride solution are injected in a bidirectional alternating manner; Both sodium silicate solution and calcium chloride solution include upper injection and lower injection. By setting up the upper injection chamber (4) and the lower injection chamber (5), bidirectional staggered injection is achieved. On one side, sodium silicate solution is injected from top to middle and from middle to bottom in stages; on the other side, calcium chloride solution is injected from bottom to middle and from middle to top in stages. Step 5: After the reinforcement is completed, the electrochemical reinforcement zone (26) is used as a support. Grouting is carried out on the lifting zone above the electrochemical reinforcement zone (26) through the grouting hole (22) to form the grouting lifting zone (27) until the lifting meets the design requirements. In this way, the reinforcement and lifting of the silt stratum settlement is completed.

3. The construction method of the bidirectional electric silicification device for the subsidence reinforcement and lifting of silt strata as described in claim 2, characterized in that, In step three, when setting up the anode holes (20) and cathode holes (21), every two rows of anode holes (20) and cathode holes (21) form a group; the distance between anode holes (20) and anode holes (20), the distance between cathode holes (21) and cathode holes (21), and the distance between each group are all 2m; If the hole placement conflicts with the instrument (30) or obstacle in the field, the hole placement method is changed to oblique insertion and the holes are denser around the instrument (30) or obstacle in the field, and the hole spacing is changed to 1m.

4. The construction method of the bidirectional electric silicification device for the subsidence reinforcement and lifting of silt strata as described in claim 3, characterized in that, In step four, when water is discharged from the cathode hole (21) during construction, the solution is injected. The upper injection chamber (4) is set at the bottom of the backfill soil layer (28), and the lower injection chamber (5) is set at the top of the bearing layer (24). When the solution is injected, the first upper pressure chamber (9) begins to inject sodium silicate solution, and the second lower pressure chamber (10) begins to inject calcium chloride solution. As the solution is injected, the top outlet (6) of the upper chamber begins to discharge sodium silicate solution, and the bottom outlet (18) of the lower chamber begins to discharge calcium chloride solution. At the same time, the bottom vent (17) of the upper chamber is open to avoid blockage caused by residual air in the middle. As the solution is continuously injected, the pressure caused by the increase in liquid volume is transformed into thrust. The thrust is greater than the friction generated by the cylindrical silicone plug. The upper injection chamber (4) begins to move from top to bottom, and the lower injection chamber (5) begins to move from bottom to top. Thus, sodium silicate solution is injected from top to middle, and calcium chloride solution is injected from bottom to middle. When the air discharge rate is significantly reduced and almost no air is discharged when the vent hole (17) at the bottom of the upper chamber is checked, it indicates that the upper injection chamber (4) and the lower injection chamber (5) have met; then the first lower pressure chamber (8) begins to pressurize and inject sodium silicate solution, and the second upper pressure chamber (11) begins to pressurize and inject calcium chloride solution; as the solution is injected, the liquid outlet hole (16) at the bottom of the upper chamber begins to discharge calcium chloride solution, and the liquid outlet hole (7) at the top of the lower chamber begins to discharge sodium silicate solution; as the solution is continuously injected, the pressure caused by the increase in liquid volume is transformed into thrust, and the thrust is greater than the friction generated by the cylindrical silicone plug, so the upper injection chamber (4) begins to move upward and the lower injection chamber (5) begins to move downward; through the movement of the solution chambers of the upper injection chamber (4) and the lower injection chamber (5), sodium silicate solution is injected from the middle to the bottom while calcium chloride solution is injected from the middle to the top; By repeatedly injecting the above solutions, a bidirectional, independent, alternating injection of sodium silicate solution from top to bottom and calcium chloride solution from bottom to top is achieved.

5. The construction method of the bidirectional electric silicification device for the subsidence reinforcement and lifting of silt strata as described in claim 4, characterized in that, The types of solutions in the first lower pressure liquid tank (8), the first upper pressure liquid tank (9), the second lower pressure liquid tank (10), and the second upper pressure liquid tank (11) are filled according to the solution required for the electrochemical reinforcement zone (26); the initial positions of the upper injection tank (4) and the lower injection tank (5) are set according to the reinforcement range of the solution; among them, the upper tank area 1 (41), the upper tank area 2 (42), the lower tank area 1 (51), and the lower tank area 2 (52) are independently controlled by pressure movement according to the type and position of the solution to be injected, and the movement range is suitable for the area of ​​the solution to be injected.

6. The construction method of the bidirectional electric silicification device for the subsidence reinforcement and lifting of silt strata as described in claim 5, characterized in that, When reinforcing the electrochemical reinforcement zone (26), the construction is carried out in sections. The construction is divided into sections, from areas with small settlement to areas with large settlement. The power supply time for each group is 24 hours. When there is obvious secondary settlement reaction, the voltage is reduced and the solution injection pressure is increased. After the construction is completed, the electrode steel pipe (1) is pulled out and the residual holes are filled with grout.

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