Electroosmosis and electrolysis combined treatment double-layer foundation reinforcing device and reinforcing method

Abstract

The application discloses a kind of electroosmosis and electrolysis combined treatment double-layer foundation reinforcing device and reinforcing method, including several electrolytic devices inserted in foundation, the electrolytic device includes drain pipe and pile, drain pipe and pile in adjacent electrolytic device are staggered distribution, the drain pipe is connected cathode, the drain pipe is communicated with drainage passage, the pile is connected anode, when low potential is passed, electrolytic desaturation is carried out to foundation by electrolytic device, then potential is increased, electroosmosis is carried out to foundation, and electrolysis and electroosmosis are repeatedly alternated in this way.The application uses electroosmosis and electrolysis combined foundation reinforcement, can efficiently utilize electric energy, save cost, effectively reduce foundation treatment time, improve reinforcing effect, when electroosmosis plays a leading role in soft soil layer, electrolysis in sandy soil layer still continuously occurs;When electrolysis in sandy soil layer is dominant, electroosmosis in soft soil foundation still occurs, which helps continuous drainage.

Description

TECHNICAL FIELD

[0001] The present application relates to a reinforcing device and a reinforcing method, in particular to a reinforcing device and a reinforcing method for treating double-layer foundation by electro-osmosis and electrolysis. BACKGROUND

[0002] In the construction process, especially in the construction of islands, the typical foundation problem of saturated sand overlying soft clay is often encountered, and effective foundation treatment methods are of great significance to engineering practice.

[0003] Mud and mucky clay are common soft clays in engineering, which have characteristics such as large void ratio, high water content, and low bearing capacity, and generally need to be treated before engineering application. Generally, the soil is a three-phase body, and when the two ends are electrified, the hydrated cations in the soil move towards the cathode under the action of the electric field force, and at the same time, the water in the soil also moves towards the cathode with the hydrated cations, which is called electro-osmosis. Under the action of the electric field force, the electric power gradient and the hydraulic gradient are coupled with each other, and the water in the soil is continuously gathered towards the cathode under the traction of the hydrated cations, and is discharged from the cathode, and the soil will gradually consolidate. Electrolysis is a method of inserting electrodes into the soil, and under the action of a direct current electric field, stable and environmentally friendly H2 and O2 are generated by electrolysis of water, thereby effectively reducing the saturation of sand. The combination of electrolysis and electro-osmosis can take advantage of each other and maximize the use of electric potential energy, convert passive drainage into active drainage, greatly shorten the foundation treatment time, and additionally add the effects of electrochemical reinforcement and ion deposition, which can greatly strengthen the reinforcement effect.

[0004] At present, scholars have done a lot of experimental research on electro-osmosis of soft clay, and have tried the electro-osmosis treatment method in the fields of port, road, railway and other engineering. At the same time, in the research on electrolytic method for reinforcing sand foundation, experimental research and specific engineering application by Chen Yumin, He Senkai, etc. have shown that: the bubbles generated by electrolysis can stably exist in the sand foundation, which has a significant effect on the anti-liquefaction capacity of the soil. In the research on electro-osmosis method, the combination of plastic drainage plate and metal electrode can effectively realize the collection and discharge of water in soft soil, promote soil consolidation, reduce water content and pore ratio, and has significant reinforcement effect. However, the existing technology does not use electro-osmosis and electrolysis to reinforce the soil foundation. SUMMARY

[0005] The purpose of the present application is to provide a reinforcing device and a reinforcing method for treating double-layer foundation by electro-osmosis and electrolysis, which can efficiently utilize electric energy, effectively reduce foundation treatment time, improve reinforcement effect, and continuously drain water.

[0006] Technical solution: The application comprises several electrolytic devices inserted into the foundation, the electrolytic devices comprise a drain pipe and a pile, the drain pipes and piles in adjacent electrolytic devices are staggered, the drain pipe is connected with a cathode, the drain pipe is communicated with a drain channel, the pile is connected with an anode, when a low potential is input, the electrolytic devices electrolyze and desaturate the foundation, then the potential is increased, the foundation is electro-osmotic, and the electrolysis and electro-osmosis are repeatedly alternated.

[0007] The top of the foundation is provided with several drain corrugated pipes, the two ends of the drain corrugated pipes are respectively communicated with the drain channels, and the drain channels are connected with water pumps, so that water in the foundation is discharged in time.

[0008] The drain pipe is communicated with the drain channel through the drain corrugated pipe.

[0009] The pile is a steel pipe pile, and the steel pipe pile is connected with the anode.

[0010] The drain pipe and the steel pipe pile are respectively connected with a junction box through wires, and the junction box is connected with a power supply.

[0011] The foundation comprises soft soil and sand soil, and the upper part of the sand soil is covered with soft soil.

[0012] The top of the soft soil is sequentially provided with geotextile and sealing film.

[0013] A reinforcing method of a reinforcing device for a double-layer foundation treated by the above-mentioned electro-osmosis and electrolysis combination, comprising the following steps:

[0014] Step one, respectively punch the pile and the drain pipe at the predetermined position, connect the drain pipe with the drain channel, and connect the drain pipe and the pile with the negative electrode and the positive electrode respectively;

[0015] Step two, check the connectivity of the drainage system;

[0016] Step three, input a low potential, at this time, the electrolytic devices electrolyze and desaturate the foundation, then increase the potential, and the foundation is electro-osmotic, and the electrolysis and electro-osmosis are repeatedly alternated.

[0017] When the electrolytic devices electrolyze and desaturate the foundation, electrolysis occurs in the sand soil foundation, at this time, electro-osmosis still occurs in the soft soil foundation, which helps to continuously drain water.

[0018] When the electrolytic devices electro-osmosis the foundation, electro-osmosis occurs in the soft soil foundation, at this time, electrolysis still occurs in the sand soil foundation, through repeated electrolysis, the number of stable bubbles remaining in the sand soil is increased, so that the effect of the electrolytic desaturation method is significantly improved.

[0019] Advantages: The application has the following advantages:

[0020] (1) The present application adopts electro-osmosis and electrolysis combined to reinforce the foundation, which can efficiently utilize electric energy, save cost, effectively reduce the foundation treatment time, and improve the reinforcement effect. When electro-osmosis plays a leading role in the soft soil layer, electrolysis in the sand layer still occurs; when electrolysis in the sand layer plays a leading role, electro-osmosis in the soft foundation still occurs, which helps to continuously drain water;

[0021] (2) The electro-osmosis and electrolysis combined treatment method is adopted to fully utilize the site environment advantage, effectively prevent the bubble escape problem caused by electrolysis in the lower sand, and improve the number of stable bubbles remaining in the sand through repeated electrolysis, so that the effect of the electrolysis desaturation method is significantly improved.

[0022] (3) The prefabricated steel pipe pile is used as the anode electrode, which saves cost, improves efficiency, fully utilizes the electrochemical method, and forms a cemented pile through the Fe(OH)3 colloid formed by the iron electrode of the anode around the electrode during the electro-osmosis process, which fills and reinforces the pores of the nearby soil, and diffuses to the cathode direction with the progress of the electro-osmosis process, so that the bearing capacity of the soft soil foundation is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a schematic view of the overall structure of the present application;

[0024] Figure 2 is a front view of the reinforcing device of the present application;

[0025] Figure 3 is a top view of Figure 1 ;

[0026] Figure 4 is a schematic view of the connection between the drainage channel and the drainage corrugated pipe of the present application. DETAILED DESCRIPTION

[0027] The present application will be further described below in conjunction with the drawings.

[0028] As shown in Figures 1 to 4 , the foundation of the present application includes soft soil 5 and sand 13, and the upper part of the sand 13 is covered with soft soil 5. A plurality of electrolysis devices are arranged at intervals in the foundation, and the electrolysis devices are inserted through the soft soil 5 and the sand 13. The electrolysis device includes a drainage pipe 7 and a steel pipe pile 6. The drainage pipes 7 and the steel pipe piles 6 in adjacent electrolysis devices are staggered. The drainage pipes 7 and the steel pipe piles 6 are connected to the junction box 2 through wires, respectively. The drainage pipe 7 is connected to the cathode, and the steel pipe pile 6 is connected to the anode. The diameter of the steel pipe pile 6 is 200-500 mm, and the wall thickness is 20 mm. The junction box 2 is connected to the power supply 1 through the main lead 3. The power supply 1 adopts a high-power constant-current stabilized adjustable power supply, as shown in Figure 2 .

[0029] As Figure 1 shown, several drainage corrugated pipes 9 are arranged at the top of the foundation with an interval, the two ends of the drainage corrugated pipes 9 are communicated with drainage channels 12 respectively, the drainage channels 12 are connected with water pumps 15 laid on the top of the soft soil 5, the drainage corrugated pipes 9 are communicated with the drainage pipes 7, so as to drain the water in the soil in time.

[0030] The reinforcing device of the present application can simultaneously reinforce the soil in the double-layer foundation of sand soil and soft soil, adopts the steel pipe pile electro-osmosis treatment method and electrolytic desaturation technology to form a foundation drainage and reinforcement composite, through controlling the current size and the electrification time, uses the method of electro-osmotic drainage combined with electrolysis to quickly consolidate and reinforce the double-layer foundation of the sand soil layer covered by the soft soil. When starting to use, the electric potential gradient is controlled to be 1.5V / dm~5.5V / dm, at this time, the electrolytic device composed of the drainage pipe 7 and the steel pipe pile 6 carries out electrolytic desaturation on the sand soil 13, forms bubbles, at this time, the electro-osmosis in the soft soil foundation also occurs; when the electrolysis is carried out for 2~4 hours, the electric potential gradient is adjusted to 8.5V / dm~20V / dm, at this time, the electro-osmosis is carried out on the soft soil 5 foundation by the drainage pipe 7 and the steel pipe pile 6, the Fe(OH)3 colloid formed around the iron electrode of the anode in the electro-osmosis process plays a good filling and reinforcing role on the nearby soil pores, forms a cementation pile, and diffuses to the cathode direction with the proceeding of the electro-osmosis process, at the same time, the water in the soil also moves to the cathode with the hydrated cations, and is finally drained from the drainage pipe 7, at this time, the electrolysis in the sand soil layer still continuously occurs. Then, the electrolysis and the electro-osmosis are repeatedly carried out, due to the problem that the bubbles generated by the electrolysis exist upward migration, a part of the bubbles naturally escape in the interval of the electrolysis, through repeatedly electrolyzing, the number of the stable bubbles remaining in the sand soil is improved, so that the effect of the electrolytic desaturation method is significantly improved. The present application has the advantages of the electro-osmosis method and the electrolytic desaturation method, avoids the problems of long reinforcement time and complex treatment of the double-layer foundation, can effectively accelerate the drainage consolidation rate of the soft soil-sand soil double-layer foundation, and significantly improves the reinforcement effect of the deep sand soil.

[0031] The steel pipe pile 6 is punched into the planned predetermined position, the drainage corrugated pipe 9 is staggered, the drainage pipe 7 is punched into the predetermined position by using a plug board machine, the top end of the drainage pipe 7 is connected with the drainage corrugated pipe 9 through a joint, and the drainage pipe 7 and the steel pipe pile 6 are connected to the negative pole and the positive pole of a direct current power supply respectively. The drainage channel 12 is connected with the water pump 15, a layer of woven geotextile is laid on the top of the soft soil 5, a sealing film is laid, the water pump 15 is opened to carry out trial pumping, and the connectivity of the drainage system is checked. When electrolysis is carried out for the first time, the potential gradient is controlled to be 1.5V / dm~5.5V / dm, electrolysis is carried out for 2~4 hours, at this time, electrolysis plays a leading role in the sand soil 13, a large number of bubbles are formed in the sand soil foundation to fill small pores, and excess water is discharged along the drainage pipe 7; then the size of the potential gradient is adjusted to be 8.5V / dm~20V / dm, at this time, electroosmosis mainly occurs in the soft soil 5, the power is continuously turned on for 8~12 hours, the upper soft soil is fully electroosmosis, the Fe(OH)3 colloid formed around the steel pipe pile 6 by the iron electrode of the anode plays a good filling and reinforcing role on the pores of the nearby soil, a cementation pile is formed, and the cementation pile diffuses to the cathode direction along with the electroosmosis process, so that the bearing capacity of the soft soil foundation is greatly improved.

[0032] The reinforcing method of the application comprises the following steps:

[0033] Step 1: dividing the region grid in the determined reclamation range, forming the reclamation site in the region, and connecting the pre-embedded drainage channel with the end of the drainage corrugated pipe in the grid;

[0034] Step 2: punching the steel pipe pile and the drainage pipe into the predetermined position respectively, connecting the top end of the drainage pipe with the drainage corrugated pipe through a joint, and connecting the drainage pipe and the steel pipe pile to the negative pole and the positive pole of a direct current power supply respectively;

[0035] Step 3: connecting the drainage channel with the water pump, laying a layer of woven geotextile on the top of the soft soil, laying a sealing film, opening the water pump to carry out trial pumping, and checking the connectivity of the drainage system, and timely remedying if there is omission;

[0036] Step 4: connecting the power supply, when electrolysis is carried out for the first time, the potential gradient is controlled to be 1.5V / dm~5.5V / dm, electrolysis is carried out for 2~4 hours, at this time, electrolysis plays a leading role, a large number of bubbles are formed in the sand soil foundation to fill small pores, and excess water is discharged along the drainage pipe; then the size of the potential gradient is adjusted to be 8.5V / dm~20V / dm, at this time, electroosmosis mainly occurs, the power is continuously turned on for 8~12 hours, the upper soft soil is fully electroosmosis, and the chemical consolidation of the steel pipe pile electrode occurs at the same time;

[0037] Step 5: repeating step 4 until the consolidation degree of the reclamation soil reaches the design requirement.

Claims

1. A method for reinforcing a double-layered ground foundation by electro-osmosis and electrolysis, the reinforcing device comprising a plurality of electrolysis devices inserted through the ground foundation, the electrolysis devices comprising a drain pipe and a steel pipe pile, the drain pipes and the steel pipe piles in adjacent electrolysis devices being staggered, the drain pipes being connected to a negative electrode, the drain pipes being in communication with a drainage channel, the steel pipe piles being connected to a positive electrode, the ground foundation being subjected to electrolytic desaturation by the electrolysis devices when a low electric potential is applied, and then the electric potential being increased to subject the ground foundation to electro-osmosis, the process being repeated alternately, a plurality of drainage corrugated pipes being arranged at intervals on the top of the ground foundation, both ends of the drainage corrugated pipes being in communication with the drainage channel, the drainage channel being connected to a water pump, the ground foundation comprising soft soil and sand, the upper part of the sand being covered with soft soil, a geotextile and a sealing membrane being arranged in sequence on the top of the soft soil; characterized in that, The method comprises the following steps: Step 1: dividing the area grid in the determined reclamation range, forming reclamation sites in different areas; connecting the pre-embedded drainage channel with the end of the drainage bellows in the grid; Step 2: respectively driving the steel pipe pile and the drainage pipe in the predetermined position, connecting the top end of the drainage pipe with the drainage bellows through the joint; connecting the drainage pipe and the steel pipe pile to the negative pole and the positive pole of the direct current power supply respectively; Step 3: connecting the drainage channel with the water pump, laying a layer of woven geotextile on the top of the soft soil, then laying a sealing film, opening the water pump for trial pumping, checking the connectivity of the drainage system, and timely remedying if there is omission; Step 4: connecting the power supply, when electrolyzing for the first time, controlling the potential gradient to be 1.5V / dm~5.5V / dm, electrolyzing for 2~4 hours, at this time, the electrolysis plays a leading role, a large number of bubbles are formed in the sandy soil foundation to fill the small pores, and the excess water is discharged along the drainage pipe; then adjusting the size of the potential gradient to be 8.5V / dm~20V / dm, at this time, the electroosmosis mainly occurs, and the power is continuously turned on for 8~12 hours, so that the upper soft soil is fully electroosmosis, and the chemical consolidation of the steel pipe pile electrode occurs; Step 5: repeating step 4 until the consolidation degree of the reclamation soil reaches the design requirement.

2. The method according to claim 1, wherein the method is characterized by, The drainage pipe is communicated with the drainage channel through the drainage bellows.

3. The method according to claim 1, wherein the method is characterized by, The drainage pipe and the steel pipe pile are respectively connected with the wire distribution box through the wire, and the wire distribution box is connected with the power supply.

4. The method of claim 1, wherein the method is characterized by: When the electrolysis device electrolyzes the foundation to reduce saturation, the electrolysis occurs in the sandy soil foundation, at this time, the electroosmosis in the soft soil foundation still occurs.

5. The method of claim 1, wherein the method is characterized by: When the electrolysis device electroosmosis the foundation, the electroosmosis occurs in the soft soil foundation, at this time, the electrolysis in the sandy soil foundation still occurs.

Images