WO2024045494A1

WO2024045494A1 - Apparatus for solidifying soft soil in water-rich area by combining thermal evaporation with electro-osmosis

Info

Publication number: WO2024045494A1
Application number: PCT/CN2023/075091
Authority: WO
Inventors: 张雷; 金海晖; 王炳辉; 贾仲泽; 张云飞; 汤俊峰; 李贵豪; 李京洋; 许荣泽
Original assignee: 江苏科技大学
Priority date: 2022-08-30
Filing date: 2023-02-09
Publication date: 2024-03-07
Also published as: CN115262525A; CN115262525B

Abstract

Disclosed in the present invention is an apparatus for solidifying soft soil in a water-rich area by combining thermal evaporation with electro-osmosis, the apparatus comprising electrode assemblies, which are arranged within a foundation; a thermal evaporation assembly, which is set up on the electrode assemblies; and a direct-current power source, which is connected to the electrode assemblies. Pore water in a soil body is collected to anodes of the electrode assemblies, and is then transported, under the action of electro-osmosis, to cathodes which are located above the foundation; and the pore water is converted from a liquid state to a gas state under the action of the thermal evaporation assembly or is directly drained upwards in the liquid state, such that the problem of the consolidation effect of deep soil being relatively poor is effectively solved. The present invention can improve the consolidation effect of a soft soil foundation at a certain depth, thus improving the overall bearing capacity of the foundation, and meeting the specific requirements of practical engineering.

Description

A device for thermal evaporation combined with electroosmosis to solidify soft soil in water-rich areas

Technical field

The present invention relates to a device for solidifying soft soil in water-rich areas, and in particular to a device for thermal evaporation combined with electroosmosis to solidify soft soil in water-rich areas.

Background technique

The poor physical properties of natural soft soil make its deformation or settlement larger, its consolidation slower, and its compression and stabilization longer required. The resulting foundation has prominent uneven settlement problems and poor bearing capacity and stability. It is difficult to meet engineering requirements. Therefore, it must be effectively reinforced before construction.

Electroosmotic drainage consolidation is a common method for solidifying foundations in the prior art. By applying a DC electric field to soft soil foundations, the pore water and weakly bound water in the soil move from the anode to the cathode. However, in actual operation, the electroosmosis method will still cause problems such as too long reinforcement period and insufficient reinforcement depth. Moreover, the range of the rod electrode assembly is small. During the electroosmosis process, local water shortage of the anode will inevitably occur, making it impossible to quickly and efficiently Extensive removal of moisture from soft soils within coverage of the unit.

Contents of the invention

Purpose of the invention: The purpose of the invention is to provide a device for thermal evaporation combined with electroosmosis solidification of soft soil in water-rich areas that can effectively solidify soil and is widely used.

Technical solution: The device of the present invention for thermal evaporation combined with electroosmosis to solidify soft soil in water-rich areas includes multiple electrode assemblies buried in the soil, thermal evaporation assemblies erected on the electrode assemblies, and a DC power supply connected to the electrode assemblies;

Among them, the thermal evaporation component is a hollow box. The side wall of the box is a circulation layer with through holes. The bottom of the box is an adsorption layer. The adsorption layer is covered with a heating layer for photothermal conversion. The heating layer is provided with There are heating holes, the top of the box is a transparent volatile layer, and the volatile layer is equipped with volatilization holes;

The electrode assembly consists of a hollow pipe I, a cathode and an anode. The lower end of pipe I is equipped with an anode and is connected to the positive electrode of the DC power supply. The upper end of pipe I is connected to the adsorption layer of the thermal evaporation component. The outer surface of the upper end of pipe I is equipped with a cathode and is connected to The negative pole of the DC power supply.

Preferably, a pipeline II corresponding to the pipeline I of the electrode assembly is provided. One end of the pipeline II is connected to the volatile layer of the thermal evaporation component, and the other end is connected to an air extraction pump; through the air extraction effect, on the one hand, part of the pore water can be extracted, and on the other hand, part of the pore water can be extracted. Through its suction, the pore water near the anode is collected, and then migrates to the cathode under the action of the electric field.

Preferably, the volatile layer is made of heat-insulating material, and the diameter of the volatile pores is 2 to 5 cm.

Preferably, the heating layer is composed of photovoltaic materials, and the diameter of the heating channel is 1 to 3 cm.

Preferably, a fan is provided in the through hole.

Preferably, the adsorption layer is made of hydrophilic material and adheres to the ground surface to form full contact.

Preferably, the anode is a metal hollow tube with anode pores on the tube wall. The structure of the anode facilitates the extraction of air and part of the pore water in the soft soil; the outer wall of the anode is equipped with an encapsulated filter cotton to prevent soil particles from being introduced during the extraction process and clogging the pipeline. Ⅰ.

Preferably, the lower end of the anode is fixedly connected to a solid anode cone head, and the solid cone facilitates the placement of pipeline I and reduces disturbance.

Preferably, the cathode is a metal wire evenly wound around the outer wall of the top of pipe I, which effectively increases the contact area with the soil.

Preferably, multiple pipelines I are arranged in parallel and arranged at staggered intervals. Pipe II can be optionally connected to several air pumps respectively to improve its efficiency.

Preferably, the DC power supply provides an electric field to the local soil, and the voltage is adjusted according to the specific distance between the cathode and the anode. The ratio of the voltage to the distance between the cathode and the anode is the potential gradient, and the potential gradient is 0.1V/cm to ensure that the potential gradient The electroosmosis effect is good, effectively improving the efficiency of pore water migration from anode to cathode.

Principle of the invention: In the device of the present invention for thermal evaporation combined with electroosmosis to solidify soft soil in water-rich areas, the adsorption layer is made of hydrophilic material, which can promptly absorb and temporarily store supersaturated pore water that migrates from the depth of the anode to the soft soil on the surface of the cathode. ; The heating layer can absorb solar energy and provide a higher temperature to the surrounding environment, thereby evaporating the temporary pore water in the adsorption layer, transforming it from liquid to gaseous state, and migrating upward through the heating pores; the circulation layer structure is hollow , thermal insulation material, which can fully preserve the heat emitted by the heating layer and reduce overflow. Several through holes are provided on the four walls of the circulation layer, and fans are arranged at the corresponding through holes. The fans can make full use of the good conditions of sufficient wind resources in water-rich areas by collecting air. Fans are used to enhance the air circulation in the circulation layer to promote evaporation and speed up the evaporation process; the volatile layer is made of thermal insulation material, which can fully preserve the heat emitted by the heating layer and reduce spillage. There are a number of volatilization pores on the upper surface of the volatile layer to facilitate pore water After evaporating, it enters the air.

By adjusting the arrangement of the electrode components so that the anode is pre-buried inside the soil and the cathode is placed on the surface soil, water in the soil can migrate to the surface against gravity. By setting an evaporation layer on the soil surface, the soil can be evaporated. The pore water in the concrete can be discharged, which can effectively solve the engineering problems of too long reinforcement period and insufficient reinforcement depth by electroosmosis method. By applying pipe extraction, the surrounding moisture can be collected toward the anode to a certain extent, thereby effectively expanding the scope of soil reinforcement, further increasing the breadth and depth of soil reinforcement, and solving the local anode shortcomings caused by rod-type electrode assemblies. Water problem. The invention can promote the pore water in the soft soil to first overcome the gravity and migrate to the cathode under the action of electroosmosis, and then be discharged upward under the action of the thermal evaporation component, achieving the effect of solidifying the soft soil in situ, and can simultaneously compensate for the reinforcement of the soft soil by thermal evaporation. Due to the defects of limited depth and uneven reinforcement effect of electroosmosis method, the pore water in the soil is collected to the anode through air pumping, and then moves to the location under the action of electroosmosis. At the cathode on the upper part of the foundation, under the action of the thermal evaporation component, the pore water is converted from liquid to gaseous state or directly discharged upward in liquid form, effectively solving the problem of poor consolidation of deep soil.

Beneficial effects: Compared with the existing technology, the present invention has the following significant advantages: (1) The present invention makes full use of the natural conditions of sufficient solar energy and wind energy in water-rich areas, and combines thermal evaporation and electroosmosis methods to treat soft soil foundations, which can achieve soil The bottom-up discharge of gray water avoids drainage blockage near the upper cathode, and can effectively improve the solidification efficiency. Compared with the pure electroosmosis solution, it can save 40% of the time, and at the same time, the soil moisture content can be reduced to less than 30%; ( 2) The present invention can improve the consolidation effect of soft soil foundation at a certain depth. Compared with the existing technology, the reinforcement depth can be increased by more than 2 times at most, and under the action of the air pump, the scope of influence of the anode in the horizontal direction can be further expanded, thereby improving The overall bearing capacity of the foundation meets the specific requirements of the actual project.

Description of drawings

Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention;

Figure 2 is a schematic structural diagram of Embodiment 2 of the present invention;

Figure 3 is a schematic structural diagram of the thermal evaporation component;

Figure 4 is a schematic structural diagram of the electrode assembly;

Figure 5 is a schematic structural diagram of the anode;

Figure 6 is a schematic structural diagram of the cathode.

Detailed ways

The technical solution of the present invention will be further described below with reference to the accompanying drawings.

Example 1

As shown in Figure 1, a device for thermal evaporation combined with electroosmosis to solidify soft soil in water-rich areas includes a thermal evaporation component 1, an electrode component 2, and a DC power supply 3.

The thermal evaporation component 1 includes a volatile layer 101, a circulation layer 103, a heating layer 105 and an adsorption layer 107 from top to bottom. The volatile layer 101 is made of heat-insulating material, which effectively reduces the waste of heat emitted by the heating layer 105. A number of volatile pores 102 are penetrated on its surface for discharging evaporated pore water. The circulation layer 103 is provided with a through hole 104, and a fan is installed in the through hole 104. Under the action of the fan, the interior of the circulation layer 103 can fully collect wind resources around the device to increase the evaporation rate. The heating layer 105 is made of photovoltaic materials, which can fully absorb solar energy and provide continuous thermal energy to promote evaporation. A number of heating channels 106 are opened therein to facilitate the circulation of gaseous and liquid pore water. The adsorption layer 107 is made of hydrophilic material and can fully absorb the pore water collected in the upper part of the soft soil foundation to prevent excessive evaporation.

The electrode assembly 2 includes pipeline I201, cathode 202 and anode 203. The upper end of pipeline I201 is connected to the air pump 4, and the lower end is connected to the anode 203, which is fixed and bonded with waterproof glue. The middle section remains intact and continuous to prevent air leakage in parts other than the anode 203; the cathode 202 is a copper wire, evenly wound around the outer wall of the pipeline I201, effectively increasing the Got it The influence range of the cathode 202 is located at the lower part of the surface of the soft soil foundation and is connected to the negative electrode of the DC power supply 3 through a wire; the anode 203 is an iron hollow tube with good electrical conductivity. There are a number of anode holes 204 on the tube wall, and the lower end is made of solid iron. The anode cone 205 needs to be wrapped with filter cotton on the outer wall of the anode 203 before construction to fully filter the pore water in the soil and prevent soil particles from blocking the channel.

Example 2

As shown in Figure 2-6, compared with the device of Embodiment 1, pipeline II 206 and air pump 4 are further added.

The electrode assembly 2 includes pipeline I201, cathode 202 and anode 203. The upper end of pipeline I201 is connected to the air pump 4, and the lower end is connected to the anode 203, which is fixed and bonded with waterproof glue. The middle section remains intact and continuous to prevent air leakage in parts other than the anode 203; the cathode 202 is a copper wire, evenly wound around the outer wall of the pipeline I201, effectively increasing the The influence range of the cathode 202 is located at the lower part of the surface of the soft soil foundation, and is connected to the negative electrode of the DC power supply 3 through a wire; the anode 203 is an iron hollow tube with good electrical conductivity, and a number of anode holes 204 are opened in the tube wall, and the lower end is solid iron The anode cone 205 is of high quality. Before construction, filter cotton must be wrapped on the outer wall of the anode 203 to fully filter the pore water in the soil and prevent soil particles from blocking the channel.

A pipe II 206 corresponding to the pipe I 201 of the electrode assembly 2 is provided on the volatile layer 101 of the thermal evaporation assembly 1 and connected to the air extraction pump 4 .

The construction method of using the device of Example 2 to perform thermal evaporation combined with electroosmosis solidification of soft soil in water-rich areas includes the following steps:

(1) Arrange thermal evaporation components 1 of corresponding sizes on the surface of the soft soil foundation. The adsorption layer 107 of the thermal evaporation component 1 is close to the surface. Holes are opened at corresponding positions to facilitate the placement of the electrode components 2. The electrode components 2 penetrate deep into the soft soil foundation. Inside, connect the male and female electrode components with wires respectively, wrap the filter cotton on the outer wall of the anode 203, and lower the pipe I201 from the corresponding hole in the thermal evaporation component 1 to the required reinforcement depth with the anode cone 205 as the starting end;

(2) The wires are connected to the corresponding positive and negative poles of the DC power supply 3, and the pipeline I201 is connected to the air pump 4;

(3) Turn on the DC power supply 3 and adjust it to the required potential gradient, apply an electric field to the soft soil foundation, and start electroosmosis;

(4) Turn on the air pump 4 and start pumping air outward to promote the collection of pore water near the anode 203;

(5) Determine the completion time of consolidation by testing the physical and chemical properties of the surface soft soil, comparing it with the actual requirements of the project, and detecting the moisture content of the adsorption layer 107; cut off the DC power supply 3 and let it stand for a period of time, then take out the construction equipment, including thermal evaporation Component 1 and electrode component 2 should be cleaned promptly and the damage to the device should be checked for reuse.

Under the suction of the air pump, the pore water in the soft soil foundation at a certain depth collects toward the anode. Under the action of the electric field, it migrates from the deep anode to the shallow cathode against gravity, and then is adsorbed and temporarily stored in the thermal evaporation component. Finally, It continues to evaporate into the air under conditions of increased temperature and increased air circulation velocity above, thereby increasing the bearing capacity of soft soil foundations at a certain depth to meet actual engineering needs. To maintain full contact between the adsorption layer and the ground surface, the size of the thermal evaporation component can be selected according to the size of the construction site. The spacing between each pipe I can be determined based on the properties of the soft soil and the size of the site. The voltage provided can be determined based on the depth of reinforcement required. , adjust the number of air pumps used according to actual needs.

Test the soil fixation capacity of Example 1 and Example 2: measure the bearing capacity of the surface soil every 4 hours during the consolidation process, and stop construction until the foundation strength near the cathode layer meets the corresponding requirements of the "Code for Design of Building Foundation Foundations" .

Compared with the pure electroosmosis solution, Example 1 solidifies soft soil by combining thermal evaporation and electroosmosis. When the foundation strength reaches the standard, the duration of the solidification process is shortened by at least 40%.

Embodiment 2 adds an air pump on the basis of Embodiment 1. Its main function is to attract water in the soil outside the anode's influence range to the vicinity of the anode through air pumping when the water content near the anode in the subsoil is reduced to the limit, so as to achieve horizontal With the expansion of the consolidation range, part of the free water in the soil can also be extracted through the filter layer and anode pores, further improving the consolidation efficiency and reducing the soil moisture content to less than 30%.

Claims

A device for thermal evaporation combined with electroosmosis to solidify soft soil in water-rich areas, which is characterized by including multiple electrode assemblies (2) buried in the soil, a thermal evaporation assembly (1) erected on the electrode assembly (2) and DC power supply (3) connected to the electrode assembly (2);

Among them, the thermal evaporation component (1) is a hollow box, the side wall of the box is a circulation layer (103) provided with a through hole (104), the bottom of the box is an adsorption layer (107), and the adsorption layer (107) There is a heating layer (105) for photothermal conversion. The heating layer (105) is provided with a heating channel (106). The top of the box is a transparent volatile layer (101). The volatile layer (101) is provided with a volatile channel (106). 102);

The electrode assembly (2) is composed of a hollow pipe I (201), a cathode (202) and an anode (203). An anode (203) is provided at the lower end of the pipe I (201) and is connected to the positive electrode of the DC power supply (3). The pipe I ( The upper end of 201) is connected to the adsorption layer (107) of the thermal evaporation component (1), and the outer surface of the upper end of pipeline I (201) is provided with a cathode (202) and is connected to the negative electrode of the DC power supply (3).
The device for thermal evaporation combined with electroosmosis solidification of soft soil in water-rich areas according to claim 1, characterized in that a pipeline II (206) corresponding to the position of the pipeline I (201) is provided on the volatile layer (101). The upper end of II (206) is collected and connected to the air pump (4).
The device for thermal evaporation combined with electroosmosis solidification of soft soil in water-rich areas according to claim 1, characterized in that the volatile layer (101) is made of heat-insulating material.
The device for thermal evaporation combined with electroosmosis to solidify soft soil in water-rich areas according to claim 1, characterized in that the diameter of the volatilization pore (102) is 2 to 5 cm.
The device for thermal evaporation combined with electroosmosis to solidify soft soil in water-rich areas according to claim 1, characterized in that a fan is provided in the through hole (104).
The device for thermal evaporation combined with electroosmosis to solidify soft soil in water-rich areas according to claim 1, characterized in that the diameter of the heating channel (106) is 1 to 3 cm.
The device for thermal evaporation combined with electroosmosis to solidify soft soil in water-rich areas according to claim 1, characterized in that the adsorption layer (107) is made of hydrophilic material and adheres to the ground surface.
The device for thermal evaporation combined with electroosmosis to solidify soft soil in water-rich areas according to claim 1, characterized in that the anode (203) is a metal hollow tube, an anode channel (204) is provided on the tube wall, and the outer wall of the anode (203) is provided with filter sponge.
The device for thermal evaporation combined with electroosmosis solidification of soft soil in water-rich areas according to claim 1, characterized in that the lower end of the anode (203) is fixedly connected to a solid anode cone (205).
The device for thermal evaporation combined with electroosmosis solidification of soft soil in water-rich areas according to claim 1, characterized in that the cathode (202) is a metal wire evenly wound around the outer wall of the pipe I (201).