Method and device for repairing ground pile toe wind erosion sandpit

Abstract

A method and a device for repairing a wind erosion sandpit at a pile toe of a ground pile are characterized in that fibers and desert soil are mixed to form fiber reinforced soil, and then the sandpit formed by wind erosion around the pile toe of the desert ground pile is filled with the fiber reinforced soil until the fiber reinforced soil is flush with the ground; secondly, a biological curing agent treating fluid is vertically sprayed on the surface of the filled and leveled fiber reinforced soil through spraying equipment, and finally standing treatment is carried out, so that a hard shell layer is formed on the surface of the fiber reinforced soil to resist wind erosion, reduce shaking of pile toes and weaken a wind field of the pile toes. According to the technology and implementation steps for repairing the wind-eroded sand pits around the ground pile toe, the biological curing agent treating fluid with the soybean urease solution as the main component is used, the wind-eroded sand pits around the ground pile toe of a desert solar panel can be effectively repaired, and secondary occurrence of the sand pits can be effectively prevented. The technology has high economical efficiency and durability, has no pollution to the environment, and can significantly reduce the maintenance cost of the desert photovoltaic panel.

Description

Technical Field

[0001] The invention relates to the field of desert windbreak and sand control, and in particular to a method and a device for repairing wind-eroded sand pits at the toes of ground piles. Background Art

[0002] In today's world, global warming and climate change are major environmental issues facing us today. The use of fossil fuels has led to increased greenhouse gas emissions, rising global temperatures, and frequent extreme weather. Traditional fossil energy sources such as oil, coal, and natural gas are limited resources. With the increase in mining and use, these resources are gradually depleted. With the development of science and technology, the cost of new energy technologies (such as wind power, solar energy, hydrogen energy, etc.) has gradually decreased, and the efficiency has continued to increase. This has made new energy more economically feasible and promoted its widespread application. On the whole, the development of new energy is a comprehensive measure to cope with challenges in many aspects such as environment, resources, energy, and security, and it has important strategic significance.

[0003] Therefore, in order to implement the national strategic requirements of high-quality development, the country has vigorously developed new energy, and the rational and full use of solar energy has become a top priority. However, in the process of building photovoltaic panels in the desert, we found that wind erosion pits appeared at the toe of the photovoltaic panel piles due to the following reasons. First, the wind speed in desert areas is usually high, and strong winds can blow up the sand on the ground; secondly, the desert ground is usually composed of loose sand, and this geological condition is easily eroded by wind. When the wind blows over the ground, the sand will be carried away; in addition, the vegetation in the desert area is sparse or almost non-vegetation-covered, which means that there are no plant roots to fix the sand, making the sand more easily blown by the wind. Therefore, under the action of strong winds, wind erosion pits are formed near the toes of the desert photovoltaic panel piles. At present, there is no repair or prevention method for wind erosion pits in the soil at the toe of the desert piles in China. Therefore, the present invention proposes a technology and implementation steps for repairing wind erosion pits around the toes of the desert solar panel piles. Summary of the invention

[0004] In view of the defects in the prior art, the present invention provides a method and device for repairing wind-eroded sand pits at the toes of piles, which is achieved through the following technical solutions:

[0005] A method for repairing a wind-eroded sand pit at the toe of a pile comprises the following steps:

[0006] S1) mixing the fiber with desert soil to form fiber reinforced soil;

[0007] S2) filling the sand pit formed by wind erosion around the pile toes in the desert with the fiber reinforced soil until it is flush with the ground;

[0008] S3) vertically spraying the bio-curing agent treatment liquid on the surface of the fiber-reinforced soil after filling and leveling with a spraying device;

[0009] S4) static treatment so that a hard crust layer is formed on the surface of the fiber reinforced soil to resist wind erosion, reduce the shaking at the pile toe, and weaken the wind field at the pile toe;

[0010] The spraying equipment includes an automatic pit filling and spraying device, a water hose, a water storage device, and a pump;

[0011] The biocuring agent treatment liquid consists of five components: soybean urease solution, urea-calcium chloride solution, xanthan gum solution, biocementing agent solution and biopolymer solution, and the concentration range of each component is (20g / L-100g / L): (0.2mol / L-3mol / L): (0.1g / L-1g / L): (0.6g / L-1.0g / L): (1g / L-3g / L).

[0012] Preferably, the soybean urease solution is taken from soybeans and obtained by grinding, standing and centrifuging the soybeans; the urea-calcium chloride solution is obtained by mixing a urea solution obtained by dissolving urea in water and a calcium chloride solution obtained by dissolving calcium chloride in water in a ratio of 1:1; the xanthan gum solution is composed of xanthan gum dissolved in water; the biocementing agent is a gelatin solution with a content of 99%, and the solvent is water; the biopolymer is a high-molecular-chain polysaccharide, and the solvent of the biopolymer solution is water.

[0013] Preferably, the desert soil is soil taken from a desert solar panel construction area, and the soil type is aeolian sandy soil and / or gray desert soil; the fibers in the fiber reinforced soil are formed by a mixture of one or more of 0.25% carbon fiber, 0.1% glass fiber and 0.2% boron fiber by mass; the mass content is the ratio of the fiber mass to the desert soil mass.

[0014] Preferably, the automatic pit filling and spraying device consists of 12 mechanical arms, iron pipes, annular water pipes, water outlet valves, wheels, a chassis, a support, a stirring tank, a connecting pipe, a motor, a propeller, a pipeline for conveying soybean urease solution, a pipeline for conveying urea-calcium chloride solution, a pipeline for conveying xanthan gum solution, a pipeline for conveying biobinder, a pipeline for conveying biopolymer, and a water stop valve.

[0015] Preferably, the pipe diameters of the pipe for conveying the soybean urease solution, the pipe for conveying the urea-calcium chloride solution, the pipe for conveying the xanthan gum solution, the pipe for conveying the biocementing agent, and the pipe for conveying the biopolymer are designed according to the following flow control formula, and the pipe flow is controlled by changing the diameters of the five conveying pipes to achieve the mixing ratio between different solutions:

[0016]

[0017] Where: q v is the flow rate, m 3 / s; C is the discharge coefficient, dimensionless; d is the pipe diameter under working conditions, mm; ΔP x is the actual pressure difference, Pa; p is the liquid density, kg / m 3 .

[0018] Preferably, when working, the automatic pit filling and spraying device is opened in the middle and sleeved on the toe of the pile, and multiple mechanical arms drive the iron pipe to fill the soil around the pit into the pit, and the iron pipe covers the mechanical arms and the ground; after filling, the five solutions with different pipeline flow rates controlled by the flow control formula are input into the mixing tank by the pump and the water hose, and after stirring, they are transported into the annular water pipe through the connecting pipe, then enter the annular pipe, and then turn to the water outlet valve on the iron pipe located on the ground to flow out; the water outlet direction of the water outlet valve is adjustable; the connecting pipe connects the mixing tank and the annular water pipe.

[0019] Preferably, the method specifically includes the following implementation steps:

[0020] Step 1: Dry the soybeans and grind them into soybean powder in a grinder. Dissolve the soybean powder in deionized water at a solid-liquid ratio of 1:50-1:10, stir thoroughly and let stand for 1 hour, wait for the dregs to precipitate, centrifuge the soybean powder solution, take the supernatant in the centrifuge tube, and obtain the soybean urease solution; pass the obtained 20g / L-100g / L soybean urease solution into the stirring tank of the automatic pit filling and spraying device through a conveying pipe; convey 0.2mol / L-3mol / L urea-calcium chloride solution, 0.1g / L-1g / L xanthan gum solution, 0.6g / L-1.0g / L biocementing agent solution and 1g / L-3g / L biopolymer solution into the stirring tank of the device through a conveying pipe, respectively, and stir evenly to obtain the biocuring agent treatment liquid;

[0021] Step 2: before spraying the treatment liquid, add one or more of 0.25% carbon fiber, 0.1% glass fiber and 0.2% boron fiber to the same type of desert soil in the wind erosion depression area around the pile toe, and mix them evenly to obtain reinforced soil;

[0022] Step 3: Put the automatic pit filling and spraying device on the pile, place it on the ground, and use the automatic pit filling and spraying device to fill the reinforced soil into the sand pit until the sand pit is flush with the surrounding soil;

[0023] Step 4: The water hose is laid in the site, and the automatic pit filling and spraying device is connected to the water hose; the treatment liquid stirred evenly in the mixing tank is transported to the spraying site through the water outlet valve on the ground, and the automatic pit filling and spraying device is controlled by the water stop valve to automatically and vertically spray evenly around the wind erosion depression area at the toe of the pile, and the spraying time each time is 3s-10s.

[0024] The present invention has the following beneficial effects:

[0025] (1) The present invention directly configures the bio-curing agent treatment liquid on site without the need to pre-configure the bio-curing agent treatment liquid; at the same time, the pit filling spraying device adopted can realize automatic pit filling and uniform, convenient and automatic spraying, which greatly improves the construction efficiency, reduces the maintenance cost of the solar photovoltaic panel piles, and has high economic benefits.

[0026] (2) The present invention provides a bio-curing agent treatment liquid with a specific formula, and realizes the synchronous mixing of the ratios between the various solutions by a specific flow control formula, automating the liquid mixing, greatly improving the efficiency of liquid mixing and transportation, and is particularly suitable for the time constraints required for on-site work.

[0027] (3) The bio-curing agent treatment liquid of the present invention has a better reinforcement effect than the curing method of the traditional formula. The maximum penetration strength of the reinforced soil can reach 10 MPa, which has the ability to stabilize the reinforced pile foundation and improve the pile's anti-lodging ability. The change in the wind field after filling and curing has the effect of reducing the impact on the pile; at the same time, it can significantly reduce the wind erosion of the solidified soil around the pile foundation. The wind erosion in the first three hours after the curing is completed is only 0.02 kg / m 3 .

[0028] (4) The components of the bio-curing agent treatment liquid of the present invention are widely available and easy to extract. The solution formula with high reinforcement effect is selected and proportioned from green and environmentally friendly materials, which is green, environmentally friendly and pollution-free. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A flowchart of the implementation steps of the technology for repairing wind-eroded sand pits around the toes of desert solar panel piles in one embodiment (1, 2, 3) of the present invention;

[0030] Figure 2 A schematic diagram of the structure of an automated pit-filling and spraying device for repairing wind-eroded sand pits around the toes of desert solar panel piles in one embodiment (1, 2, 3) of the present invention;

[0031] Figure 3 It is a schematic diagram of the on-site structure of the technology for repairing the wind-eroded sand pits around the toes of the desert solar panel piles in one embodiment (1, 2, 3) of the present invention;

[0032] Figure 4 A schematic diagram of the pile lodging resistance index of a technology for repairing wind-eroded sand pits around the toes of a desert solar panel pile in one embodiment (1, 2, 3) of the present invention;

[0033] Figure 5 It is a schematic diagram of the specific effect of the technology for repairing wind-eroded sand pits around the toes of desert solar panel piles in one embodiment (1, 2, 3) of the present invention, wherein the higher the penetration strength, the more beneficial it is to the stable reinforcement of the piles;

[0034] In the figure: 100 automatic pit filling and spraying device, 101 mechanical arm, 102 iron pipe, 103 annular water pipe, 104 water outlet valve, 105 wheel, 106 chassis, 107 support, 108 mixing tank, 110 connecting pipe, 111 motor, 112 propeller, 109 pipeline for conveying soybean urease solution, 113 pipeline for conveying urea-calcium chloride solution, 114 pipeline for conveying xanthan gum solution, 115 pipeline for conveying bio-binder, 116 pipeline for conveying bio-polymer, 117 water stop valve, 201 water hose, 301 water storage device, 401 pump, 501 photovoltaic panel, 601 pile and 701 sand pit. DETAILED DESCRIPTION

[0035] The embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.

[0036] The particle size of desert soil used for repairing wind-eroded sand pits around the toes of desert solar panel piles is concentrated in the range of 0.075-0.25 mm. The present invention uses soybean urease solution extracted from soybeans and mixed with salt solution (calcium chloride-urea solution), xanthan gum solution, bio-binder solution and bio-polymer solution to spray the treated liquid on the soil surface for bio-solidification, so as to solve the problem of wind-eroded sand pits around the toes of desert photovoltaic panel piles.

[0037] The desert soil of the present invention is the soil from the desert solar panel construction area. The soil in the desert area is rich in composition, with many types and complex distribution. The main soil types are wind sand soil and gray desert soil.

[0038] The spraying equipment used in the present invention is composed of a water hose, an automatic pit filling and spraying device, a pump and a water storage device. The spraying device is a new type of automated and convenient device, which is composed of 12 mechanical arms, an iron pipe annular water pipe and a plurality of water outlet valves. When working, the device is combined and sleeved on the pile toe, and the 12 mechanical arms drive the iron pipes covering the mechanical arms and the ground to fill the soil around the pit into the pit. After repeated filling, the pump passes the solution through the annular pipe through the water hose and then turns it to the water outlet valve located on the ground iron pipe to flow out evenly and vertically. According to the experimental results of the present invention, the specific curing effect of spraying the soybean urease treatment solution is that the penetration strength is at least 5MPa, which has the ability to stabilize and reinforce the pile foundation and improve the pile's ability to resist lodging. The change in the desert wind field after the soybean urease treatment solution is sprayed has the ability to reduce the impact on the ground pile and the wind erosion of the ground sand.

[0039] The implementation steps of the present invention for repairing wind erosion sand pits around the toes of desert solar panel piles include:

[0040] Step 1: Dry the soybeans and grind them into soybean powder in a grinder. Dissolve the soybean powder in deionized water at a solid-liquid ratio of 1:50-1:10. Stir well and let it stand for 1 hour. After the dregs are precipitated, place the soybean powder solution in a centrifuge and centrifuge. Take the supernatant in the centrifuge tube to obtain the soybean urease solution. The obtained 20g / L-100g / L soybean urease enters the stirring tank 108 of the automatic pit filling and spraying device 100 through the delivery pipe 109; 0.2mol / L-3mol / L binder (calcium chloride and urea are mixed in a molar concentration of 1:1 as the solute, and the solvent is water), 0.1g / L-1g / L xanthan gum solution (xanthan gum is dissolved in deionized water), 0.8g / L bio-binder and 2g / L biopolymer are respectively delivered into the stirring tank 108 of the device 100 through the delivery pipe 2 113, the delivery pipe 3 114, the delivery pipe 4 115, and the delivery pipe 5 116, and the treated liquid is obtained after uniform stirring.

[0041] Step 2: Before spraying the treatment liquid, carbon fiber, glass fiber, and boron fiber are added to the same type of desert soil in the wind erosion depression area around the pile toe at the same time, and reinforced soil is obtained after mixing evenly.

[0042] Step 3: Turn on the automatic pit filling and spraying device 100 to the non-working state, put the device on the ground pile and place it on the ground, and use the device to fill the sand pit with reinforced soil until the sand pit is flush with the surrounding soil.

[0043] Step 4: The water hose 201 is laid in the field, and the automatic pit filling and spraying device 100 is connected to the water hose 201. The treatment liquid in the mixing tank 108 enters the spraying field through the water outlet valve hole 104, and the spraying device can automatically spray vertically and evenly in the wind erosion depression area of ​​the pile toe.

[0044] The details are described in the following examples.

[0045] Example 1

[0046] This embodiment provides an automatic pit filling and spraying device, the structure of which includes a mechanical arm 101, an iron pipe 102, an annular water pipe 103, a water outlet valve hole 104, a water hose 201, a water storage device 301 and a pump 401. Figure 1 As shown, the automatic pit filling and spraying device is connected to a water hose 201, and the other end of the water hose 201 is connected to a pump, wherein the pump is located in the water storage device. Figure 2 As shown, the automatic pit filling and spraying device has two annular water pipes above and below. The annular water pipes themselves can be opened into two semicircles so that they can be put on the piles. There are 12 mechanical arms evenly distributed around the device. The surfaces of the mechanical arms and the lower annular water pipes are all covered with thin iron pipes, and water outlet valves are evenly distributed on the side of the iron pipe at the bottom of the device close to the ground.

[0047] A technology and implementation steps for repairing wind-eroded sand pits around the toes of desert solar panel piles, including:

[0048] The soybeans were dried and placed in a grinder to be ground into soybean powder. The soybean powder was dissolved in deionized water at a solid-liquid ratio of 1:50, and the soybean powder was fully stirred and allowed to stand for 1 hour to allow the dregs to precipitate. The soybean powder solution was centrifuged for 15 minutes, and the centrifuge parameters were set at 4°C and 3000r / min. The supernatant in the centrifuge tube was taken to obtain the soybean urease solution. The urease activity was measured by the conductivity method (the conductivity meter was Leici DDB-303A model). It was determined that the activity of the soybean urease used in the test of the present invention in hydrolyzing urea was about 6.7mmol / (L·min) at room temperature of 25°C.

[0049] The above 20g / L soybean urease solution, 0.4mol / L salt solution (calcium chloride-urea solution), 0.2g / L xanthan gum solution, 0.6g / L biocementing agent solution, and 1g / L biopolymer solution were respectively flowed from 5 pipelines into the stirring tank in the automatic pit filling and spraying device, and stirred evenly to obtain the treated liquid. The ratios of the flow rates of the 5 pipelines were 1.3:1.4:2.1:0.2:0.3. The outflow coefficients of soybean urease solution, salt solution (calcium chloride-urea solution), xanthan gum solution, 0.8g / L biocementing agent solution, and 2g / L biopolymer solution were 0.8, 0.8, 0.8, 0.6, and 0.5, respectively; the densities of the above 5 solutions were 1.02g / cm 3 , 1.07g / cm 3 , 1.00g / cm 3 , 2.03g / cm 3 , 2.31g / cm 3 The pipe diameters of the above five solutions are 25mm, 25mm, 25mm, 10mm, and 10mm respectively.

[0050] Add 4% carbon fiber, 0.2% glass fiber and 5% boron fiber to the sandy soil in the wind-eroded depression area around the pile toe. After mixing evenly, turn on the automatic pit filling and spraying device to the non-working state, put the device on the pile, place it on the ground, and use the device to fill the sand pit until it is flush with the surrounding soil.

[0051] A water hose of sufficient length is laid in the site, and the automatic pit filling and spraying device is connected to the water hose. At the edge of the site, the above five solutions are loaded respectively with five water buckets with a volume of 1 ton, pumped to the mixing tank with a 3-inch gasoline pump for uniform mixing, and then transferred to the spraying site through the communicating vessel and the water outlet valve on the ground. The water outlet valve on the iron pipe at the bottom of the device is translated on the ground through the movement of the mechanical arm, so as to vertically and evenly spray the area within 500mm from the pile toe. Among them, the spraying range is all areas within 500mm from the outermost edge of the pile, and the spraying time of one pile toe is 12s. The spraying interval is 48 hours, and spraying is carried out once on the 1st day, the 3rd day, and the 5th day respectively. After the spraying is completed through this embodiment, the penetration strength of the soil at the pile toe reaches 7.5MPa.

[0052] Example 2

[0053] Compared with Example 1, the solid-liquid ratio of soybean powder to water in this example is different. This example adopts a solid-liquid ratio of 1:25, that is, 40 g / L soybean urease solution, 1 mol / L salt solution (calcium chloride-urea solution), 0.5 g / L xanthan gum solution, 0.8 g / L biobinder solution, and 2 g / L biopolymer solution. The soil penetration strength of this example reaches 9 MPa.

[0054] Example 3

[0055] Compared with Example 1, the solid-liquid ratio of soybean powder to water in this example is different. This example adopts a solid-liquid ratio of 1:10, that is, 100g / L soybean urease solution, 2mol / L salt solution (calcium chloride-urea solution), 1g / L xanthan gum solution, 1g / L biocementing agent solution, and 3g / L biopolymer solution. The soil penetration strength of this example reaches 10MPa.

[0056] Comparative Example 1

[0057] In this comparative example, no xanthan gum additive, no biocement solution and no biopolymer solution were added to the soybean urease binder, and the remaining components were exactly the same as those in Example 1. The soil penetration strength of this example reached 5 MPa.

[0058] Comparative Example 2

[0059] In this comparative example, no xanthan gum additive, no biocement solution and no biopolymer solution were added to the soybean urease binder, and the remaining components were exactly the same as those in Example 2. The soil penetration strength of this example reached 6 MPa.

[0060] Comparative Example 3

[0061] In this comparative example, no xanthan gum additive, no biocement solution and no biopolymer solution were added to the soybean urease binder, and the remaining components were exactly the same as those in Example 3. The soil penetration strength of this example reached 7.5 MPa.

[0062] Comparative Example 4

[0063] The difference between this comparative example and Example 3 is that the spraying times are different, the spraying interval is 48 hours, and the spraying is performed once on the 1st day and once on the 3rd day. Compared with Example 3, the penetration strength of the soil is 6Mpa, because the insufficient spraying amount leads to a decrease in the penetration strength of the soil.

[0064] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for repairing wind-eroded sand pits at the toes of piles, characterized in that: The following steps are involved: S1) mixing the fiber with desert soil to form fiber reinforced soil; S2) filling the sand pit formed by wind erosion around the pile toes in the desert with the fiber reinforced soil until it is flush with the ground; S3) vertically spraying the bio-curing agent treatment liquid on the surface of the fiber-reinforced soil after filling and leveling with a spraying device; S4) static treatment so that a hard crust layer is formed on the surface of the fiber reinforced soil to resist wind erosion, reduce the shaking at the pile toe, and weaken the wind field at the pile toe; The spraying equipment comprises an automatic pit filling and spraying device (100), a water hose (201), a water storage device (301), and a pump (401); The biocuring agent treatment liquid consists of five components: soybean urease solution, urea-calcium chloride solution, xanthan gum solution, biocementing agent solution and biopolymer solution, and the concentration range of each component is (20g / L-100g / L): (0.2mol / L-3mol / L): (0.1g / L-1g / L): (0.6g / L-1.0g / L): (1g / L-3g / L).

2. A method for repairing wind-eroded sand pits at the toes of piles according to claim 1, characterized in that: The soybean urease solution is taken from soybeans and is obtained by grinding, standing and centrifuging the soybeans; the urea-calcium chloride solution is obtained by mixing a urea solution obtained by dissolving urea in water and a calcium chloride solution obtained by dissolving calcium chloride in water in a ratio of 1:1; the xanthan gum solution is composed of xanthan gum dissolved in water; the biocementing agent is a gelatin solution with a content of 99%, and the solvent is water; the biopolymer is a polysaccharide with a high molecular chain, and the solvent of the biopolymer solution is water.

3. A method for repairing wind-eroded sand pits at the toes of piles according to claim 1, characterized in that: The desert soil is soil taken from the desert solar panel construction area, and the soil type is aeolian sandy soil and / or gray desert soil; the fiber in the fiber reinforced soil is formed by a mixture of one or more of 0.25% carbon fiber, 0.1% glass fiber and 0.2% boron fiber by mass; the mass content is the ratio of the fiber mass to the desert soil mass.

4. A method for repairing wind-eroded sand pits at the toes of piles according to claim 1, characterized in that: The automatic pit filling and spraying device (100) is composed of 12 mechanical arms (101), a sheet metal pipe (102), an annular water pipe (103), a water outlet valve (104), wheels (105), a chassis (106), a support (107), a stirring tank (108), a connecting pipe (110), a motor (111), a propeller (112), a pipeline for conveying soybean urease solution (109), a pipeline for conveying urea-calcium chloride solution (113), a pipeline for conveying xanthan gum solution (114), a pipeline for conveying bio-binder (115), a pipeline for conveying biopolymer (116), and a water stop valve (117).

5. A method for repairing wind-eroded sand pits at the toes of piles according to claim 4, characterized in that: The pipe diameters of the pipe (109) for conveying the soybean urease solution, the pipe (113) for conveying the urea-calcium chloride solution, the pipe (114) for conveying the xanthan gum solution, the pipe (115) for conveying the bio-binder, and the pipe (116) for conveying the biopolymer are designed according to the following flow control formula. The pipe flow rates are controlled by changing the diameters of the five conveying pipes to achieve the mixing ratio between the different solutions: Where: q v is the flow rate, m 3 / s; C is the discharge coefficient, dimensionless; d is the pipe diameter under working conditions, mm; ΔP x is the actual pressure difference, Pa; p is the liquid density, kg / m 3 .

6. A method for repairing wind-eroded sand pits at the toes of piles according to claim 4, characterized in that: When working, the automatic pit filling and spraying device (100) is opened in the middle and sleeved on the pile toe, and the multiple mechanical arms (101) drive the iron pipe (102) to fill the soil around the pit into the pit, and the iron pipe (102) covers the mechanical arms and the ground; after filling, the pump (401) and the water hose (201) input the five solutions with different pipeline flow rates controlled by the flow control formula into the stirring tank (108), and after stirring, they are transported into the annular water pipe (103) through the connecting pipe (110), then enter the annular pipe (103), and then turn to the water outlet valve (104) on the iron pipe (102) located on the ground to flow out; the water outlet direction of the water outlet valve (104) is adjustable; the connecting pipe (110) connects the stirring tank (108) and the annular water pipe (103).

7. A method for repairing wind-eroded sand pits at the toes of piles according to claim 6, characterized in that: The specific steps include: Step 1: drying soybeans and grinding them into soybean powder in a grinder, dissolving the soybean powder in deionized water at a solid-liquid ratio of 1:50-1:10, stirring thoroughly and standing for 1 hour, and centrifuging the soybean powder solution in a centrifuge to obtain the supernatant in the centrifuge tube to obtain a soybean urease solution; passing the obtained 20g / L-100g / L soybean urease solution into a stirring tank (108) of an automatic pit filling and spraying device (100) through a conveying pipe (109); conveying 0.2mol / L-3mol / L urea-calcium chloride solution, 0.1g / L-1g / L xanthan gum solution, 0.6g / L-1.0g / L biocementing agent solution and 1g / L-3g / L biopolymer solution into the stirring tank (108) of the device (100) through conveying pipes (113), (114), (115) and (116) respectively, and stirring evenly to obtain a biocuring agent treatment liquid; Step 2: before spraying the treatment liquid, add one or more of 0.25% carbon fiber, 0.1% glass fiber and 0.2% boron fiber to the same type of desert soil in the wind erosion depression area around the pile toe, and mix them evenly to obtain reinforced soil; Step 3: Put the automatic pit filling and spraying device (100) on the pile, place it on the ground, and use the automatic pit filling and spraying device (100) to fill the reinforced soil into the sand pit until the sand pit is flush with the surrounding soil; Step 4: The water hose (201) is laid in the site, and the automatic pit filling and spraying device (100) is connected to the water hose (201); the treatment liquid stirred evenly in the mixing tank (108) is transported to the spraying site through the water outlet valve (104) on the ground, and the automatic pit filling and spraying device (100) is controlled by the water stop valve (117) to automatically and vertically spray evenly around the wind erosion depression area at the toe of the pile, and each spraying time is 3s-10s.

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