Reinforcing device and method for granular soil body

Abstract

The invention provides a reinforcing device and method for granular soil, and relates to the technical field of grouting reinforcement, the reinforcing device is characterized in that inlet and outlet pipes are arranged at the two ends of a pipe wall structure, one end of each inlet and outlet pipe is connected with the pipe wall structure, and a water stop valve is arranged at the other end of each inlet and outlet pipe; one end of the conveying structure sequentially penetrates through the water stop valve and the inlet and outlet pipe to extend into the pipe wall structure. The multiple filtering layers are arranged at the top and the bottom of the pipe wall structure, a porous water seepage layer is arranged between the two filtering layers and arranged in the circumferential direction of the inner wall of the pipe wall structure, the interior of the porous water seepage layer is used for being filled with granular soil, and the conveying structure conveys grouting liquid into the pipe wall structure. And grouting liquid uniformly permeates into the granular soil body through the filtering layer and the porous water seepage layer and reinforces the granular soil body. The problem that in the prior art, a soil body is reinforced to a certain degree, but soil body particles are basically pulverized into a muddy state, so that the soil body reinforcing effect is poor is solved.

Description

Technical Field

[0001] The invention relates to the technical field of grouting reinforcement, and in particular to a reinforcement device and method for granular soil. Background Art

[0002] In the field of grouting reinforcement technology, large-aperture weathered soil is generally reinforced by MIC mineralization technology. In actual operation, although the calcium carbonate crystals formed by this technology are in the form of flakes, the connection between the crystals and the soil particles is not complete, resulting in a large number of pores between the soil particles, especially the distribution of long strip pores is more common. This incomplete connection and the existence of pores means that although the soil has been reinforced to a certain extent, the soil particles have been basically pulverized into mud, which affects the overall strength of the soil and leads to the problem of poor soil reinforcement effect. Therefore, there is an urgent need for a reinforcement device and method for granular soil, which solves the problem in the prior art that although the soil has been reinforced to a certain extent, the soil particles have been basically pulverized into mud, which affects the overall strength of the soil and leads to poor soil reinforcement effect. Summary of the invention

[0003] The purpose of the present invention is to provide a reinforcement device and method for granular soil to improve the above problems. In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0004] In a first aspect, the present application provides a reinforcement device for granular soil, comprising:

[0005] A pipe wall structure, both ends of the pipe wall structure are provided with inlet and outlet pipes, one end of the inlet and outlet pipes is connected to the pipe wall structure, and the other end of the inlet and outlet pipes is provided with a water stop valve;

[0006] A conveying structure, one end of which passes through the water stop valve and the inlet and outlet pipes in sequence and extends into the pipe wall structure;

[0007] A plurality of filter layers are arranged at the top and bottom of the pipe wall structure, a porous water-permeable layer is arranged between two of the filter layers, the porous water-permeable layer is arranged circumferentially along the inner wall of the pipe wall structure, the interior of the porous water-permeable layer is used to fill granular soil, the conveying structure inputs grouting liquid into the pipe wall structure, and the grouting liquid uniformly penetrates into the interior of the granular soil through the filter layer and the porous water-permeable layer and reinforces the granular soil.

[0008] In a second aspect, the present application also provides a reinforcement method for granular soil, comprising:

[0009] The calcium lignin sulfonate and deionized water are uniformly mixed to obtain a calcium lignin sulfonate solution;

[0010] Adding granular soil to be reinforced into the pipe wall structure;

[0011] Grouting in batches: starting a peristaltic pump to inject the calcium lignin sulfonate solution, bacterial liquid and cementing liquid into the pipe wall structure and letting it stand, draining the liquid after the standing is completed, the bacterial liquid and the cementing liquid are injected later than the calcium lignin sulfonate solution, the bacterial liquid and the cementing liquid are injected in equal volumes, and the injection amounts of the calcium lignin sulfonate solution, the bacterial liquid and the cementing liquid are all the volume of the pipe wall structure;

[0012] Monitor the bacteria attached to the granular soil to be reinforced, and obtain the consolidation index based on the monitoring results;

[0013] A judgment is made based on the consolidation index and the fixed critical point as to whether to restart the batch grouting.

[0014] The beneficial effects of the present invention are:

[0015] The present invention introduces a filter layer, a porous water-permeable layer and a grouting liquid. The filter layer is arranged at the top and the bottom of the pipe wall structure. The filter layer effectively prevents the granular soil from being pulverized and blocked during the grouting process. The porous water-permeable layer is circumferentially arranged along the pipe wall structure. The porous water-permeable layer increases the fluidity of the grouting liquid in the pipe wall structure, avoiding the accumulation of pulverized soil particles at a certain place to cause blockage or flow obstruction. The common arrangement of the filter layer, the porous water-permeable layer and the grouting liquid solves the problem in the prior art that although the soil has been reinforced to a certain extent, the soil particles have been basically pulverized and muddy, which affects the overall strength of the soil and leads to poor soil reinforcement effect.

[0016] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or be understood by implementing the embodiments of the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a schematic diagram of the overall device of the reinforcement device for granular soil according to an embodiment of the present invention;

[0019] Figure 2is a cross-sectional view of a reinforcement device for granular soil according to an embodiment of the present invention;

[0020] Figure 3 is a schematic diagram of a reinforcement method for granular soil according to an embodiment of the present invention;

[0021] Figure 4 The amount of calcium carbonate generated by injecting different concentrations in the reinforcement method for granular soil described in the embodiment of the present invention;

[0022] Figure 5 is the amount of calcium carbonate generated at different standing times in the reinforcement method for granular soil described in the embodiment of the present invention;

[0023] Figure 6 is the amount of calcium carbonate generated with different pH values ​​in the reinforcement method for granular soil described in the embodiment of the present invention;

[0024] Figure 7 This is a SEM image of the sample prepared in Comparative Example 1 of the present invention;

[0025] Figure 8 This is a SEM image of the sample prepared in Example 2 of the present invention;

[0026] Markings in the figure: 1. Pipe wall structure; 2. Inlet and outlet pipes; 3. Water stop valve; 4. Conveying structure; 5. Filter layer; 6. Porous water permeable layer; 21. Water inlet pipe; 22. Exhaust pipe; 23. Water outlet pipe; 41. Peristaltic pump; 42. Peristaltic pipeline; 43. Air pump; 44. Air pipeline; 51. First geotextile layer; 52. Second geotextile layer; 71. Pores; 72. Calcium carbonate crystals; 73. Lignin aggregates. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0029] Embodiment 1:

[0030] The present embodiment provides a reinforcement device for granular soil, comprising: inlet and outlet pipes 2 are provided at both ends of the pipe wall structure 1, one end of the inlet and outlet pipes 2 is connected to the pipe wall structure 1, and the other end of the inlet and outlet pipes 2 is provided with a water stop valve 3; a conveying structure 4, one end of the conveying structure 4 passes through the water stop valve 3 and the inlet and outlet pipes 2 in sequence and extends into the pipe wall structure 1; a plurality of filter layers 5, the plurality of filter layers 5 are arranged at the top and bottom of the pipe wall structure 1, a porous water-permeable layer 6 is arranged between two of the filter layers 5, the porous water-permeable layer 6 is arranged along the circumferential direction of the inner wall of the pipe wall structure 1, the interior of the porous water-permeable layer 6 is used to fill the granular soil, the conveying structure 4 inputs grouting liquid into the pipe wall structure 1, the grouting liquid evenly penetrates into the interior of the granular soil through the filter layer 5 and the porous water-permeable layer 6 and reinforces the granular soil.

[0031] The technical effect of the device is as follows: in the reinforcement process of granular soil, the granular soil is easy to pulverize, resulting in the problem that the soil is smooth in the early stage due to the large pores of the soil particles, but difficult in the later stage. The device uses the filter layer 5 to effectively prevent the granular soil from being pulverized and blocked during the grouting process. The porous water-permeable layer 6 can enhance the fluidity of the grouting liquid inside the pipe wall structure 1, so that the grouting liquid can be evenly distributed, and the powdered soil particles are prevented from gathering in a certain place to cause blockage or flow obstruction. At the same time, the porous water-permeable layer 6 can alleviate the adverse effects of particle pulverization, help the grouting liquid to penetrate evenly into the soil, and promote soil cementation and reinforcement. The conveying structure 4 injects the grouting liquid into the pipe wall structure 1, and at the same time, the waste liquid generated by the grouting liquid and the granular soil can be discharged. The common setting of the filter layer, the porous water-permeable layer and the grouting liquid solves the problem in the prior art that although the soil has been reinforced to a certain extent, the soil particles have been basically pulverized into mud, affecting the overall strength of the soil, resulting in poor soil reinforcement effect.

[0032] Preferably, the porous water-permeable layer 6 is a soft porous material, the granular soil is weathered mud soft rock soil, is brown-red or brown-red in color, is rich in thin leaf-like or flaky joints, and is granular.

[0033] The filter layer 5 includes a first geotextile layer 51, which is arranged on the top of the pipe wall structure 1, and the bottom end of the first geotextile layer 51 is connected to the top end of the porous water-permeable layer 6. Further, the filter layer 5 includes a second geotextile layer 52, which is arranged on the bottom of the pipe wall structure 1, and the top end of the second geotextile layer 52 is connected to the bottom end of the porous water-permeable layer 6. In this structure, the first geotextile layer 51 and the second geotextile layer 52 are high-density structures. During the grouting process, the first geotextile layer 51 and the second geotextile layer 52 effectively prevent the granular soil from being pulverized and blocking the inlet and outlet pipes 2 during the grouting process, solving the problem in the prior art that the pores of the filter layer are large and easily blocked by fine soil particles or calcium carbonate crystals, resulting in poor slurry flow.

[0034] To clarify the specific structure of the inlet and outlet pipes 2, the inlet and outlet pipes 2 include an inlet pipe 21, an exhaust pipe 22 and an outlet pipe 23. The inlet pipe 21 and the exhaust pipe 22 are both arranged at the top end of the pipe wall structure 1, and the outlet pipe 23 is arranged at the bottom end of the pipe wall structure 1. The inlet pipe 21 and the outlet pipe 23 are both in contact with one end of the conveying structure 4.

[0035] To clarify the effect of the conveying structure 4, the conveying structure 4 includes a peristaltic pump 41 and a peristaltic pipeline 42. One end of the peristaltic pipeline 42 is connected to the peristaltic pump 41, and the other end of the peristaltic pipeline 42 passes through the water stop valve 3 and the water inlet pipe 21 in sequence to extend to the bottom of the pipe wall structure 1. In this structure, the peristaltic pump 41 and the peristaltic pipeline 42 are used to inject grouting liquid into the pipe wall structure 1, so that the grouting liquid reinforces the granular soil.

[0036] In this structure, the conveying structure 4 includes an air pump 43 and an air pipeline 44, one end of the air pipeline 44 is connected to the air pump 43, and the other end of the air pipeline 44 passes through the water stop valve 3 and the water outlet pipe 23 in sequence to extend to the top of the pipe wall structure 1. The air pump 43 can effectively discharge the air and waste liquid caused by the pulverization of the granular soil during the grouting process. The air pump 43 reduces the formation of bubbles and reduces the increase in pressure in the pipe wall structure 1 caused by the pulverization of particles, which helps to maintain the continuous flow and uniform distribution of the grouting liquid.

[0037] Preferably, the diameter of the peristaltic line 42 is greater than 40 mm.

[0038] Embodiment 2:

[0039] This embodiment provides a reinforcement method for granular soil, comprising:

[0040] See also Figure 3and Figure 4 , the figure shows that the method includes steps S1 to S5, including:

[0041] S1: Evenly mixing calcium lignin sulfonate and deionized water to obtain a calcium lignin sulfonate solution;

[0042] In this step, the molecular weight of the calcium lignin sulfonate solution is 500.00-550.00, the purity is ≥98%, the carbon content is 30%-50%, the concentration is 0.025-0.3 mol / L, and the standing time is 5 days.

[0043] In order to clarify the specific method of obtaining the calcium lignin sulfonate solution, step S1 includes S11 to S14, which are specifically:

[0044] S11: adding 10-50 g of calcium lignin sulfonate powder and 200-240 ml of deionized water into a container, and shaking the container at 200 rpm for 30 minutes to obtain a first suspension;

[0045] In this step, 10-50 g of calcium lignin sulfonate powder and 200-240 ml of deionized water are added into a clean container, the deionized water completely soaks the calcium lignin sulfonate powder, and the container is placed on a shaker and shaken at a speed of 200 rpm for 30 minutes to ensure that the calcium lignin powder and the water are fully mixed to form a uniform first suspension.

[0046] S12: filtering the first suspension through a filter to obtain an impurity-free solution;

[0047] In this step, the first suspension is filtered through a filter to remove the foam and impurities on the surface. If there is still foam or impurities, this step is repeated 3 to 5 times until there is no more foam on the surface of the first suspension.

[0048] S13: heating and irradiating the impurity-free solution with ultraviolet light to obtain a treated solution;

[0049] In this step, the impurity-free solution is poured into a clean conical beaker and sealed with a breathable sealing film, then placed in a pressure cooker and heated at 120 degrees Celsius for 30 minutes. After the heating is completed, the conical beaker is taken out and placed in an ultraviolet irradiation device for 1 hour to obtain a treated solution.

[0050] S14: reducing the temperature of the treated solution to below 60 degrees Celsius to obtain a calcium lignin sulfonate solution.

[0051] In this step, the temperature of the treated solution is lowered to below 60 degrees Celsius and sealed for storage to obtain a calcium lignin sulfonate solution.

[0052] The calcium lignin sulfonate solution has good adhesion, so that the calcium carbonate is transformed from the original random film distribution on the surface of soil particles to the bonded distribution between soil particles. The calcium lignin sulfonate solution optimizes the pore structure of soil particles, reduces the proportion of large pores, and enhances the soil reinforcement effect.

[0053] S2: adding the granular soil to be reinforced into the pipe wall structure 1;

[0054] Preferably, the granular soil to be reinforced is weathered mud soft rock soil, which is reddish brown or brownish red, rich in thin leaf-like or flaky joints, and the soil is granular.

[0055] S3: Grouting in batches: start the peristaltic pump 41 to inject the calcium lignin sulfonate solution, bacterial liquid and cementing liquid into the pipe wall structure 1 and let it stand, drain the liquid after standing, the bacterial liquid and the cementing liquid are injected later than the calcium lignin sulfonate solution, the bacterial liquid and the cementing liquid are injected in equal volumes, and the injection amounts of the calcium lignin sulfonate solution, the bacterial liquid and the cementing liquid are all the volume of the pipe wall structure 1;

[0056] In this step, 0.025-0.3 mol / L of the calcium lignin sulfonate solution is injected into the granular soil to be reinforced at a speed of 1 ml / min by a peristaltic pump 41, and 250 ml is injected and allowed to stand for 5 days. After the standing period, the air pipeline 44 is connected to the water outlet pipe 23, and the water stop valve 3 is opened to drain the liquid for ten minutes;

[0057] The bacterial liquid and the cementing liquid are injected into the granular soil to be reinforced at a speed of 1 ml / min through the peristaltic pump 41. 250 ml is injected and left to stand for 1 day. After the standing time is over, the air pipeline 44 is connected to the water outlet pipe 23, and the water stop valve 3 is opened to drain the liquid for ten minutes, which is one round of grouting process;

[0058] In order to clarify the specific method of obtaining the bacterial solution, step S3 includes S31 to S34, which are specifically:

[0059] S31: 20 g of yeast powder, 15 g of ammonium chloride, 1 ml of nickel chloride crystals and 1 L of deionized water are mixed to obtain a first mixed solution;

[0060] S32: adjusting the pH of the first mixed solution to 9.2-9.3 by using sodium hydroxide, sterilizing at high temperature for 20 minutes, and sterilizing by ultraviolet light for 2 hours to obtain a culture medium;

[0061] S33: bacterial culture: inoculate the Bacillus pasteurianus to be activated into the culture medium, and culture the culture in an air bath oscillator at a rotation speed of 200 rpm / min and a temperature of 35° C. After culturing for 24 hours, measure the urease content in the bacterial solution, select the bacterial solution with the highest unit urease activity (7.0 U / ml±0.2), and obtain the first generation bacterial solution;

[0062] S34: Repeat the bacterial culture to obtain the third-generation bacterial liquid.

[0063] In order to clarify the specific method of obtaining the cementing fluid, step S3 includes S35, which specifically includes:

[0064] S35: The binder liquid includes calcium chloride and urea, the calcium chloride content is 0.5 mol / L, the urea content is 0.5 mol / L, and the calcium chloride and urea are mixed in a volume ratio of 1:1.

[0065] In this step, calcium chloride and urea are used to provide a calcium source for the MI CP mineralization reaction to promote the precipitation of calcium carbonate.

[0066] In the existing MI CP mineralization technology for the reinforcement of large-pore weathered soil, the calcium carbonate particles are small in size, and their distribution and bonding effects in large-pore soils are limited; the calcium lignin sulfonate solution can effectively reduce the porosity of the soil and improve the bonding strength of the soil, but the strength improvement of the soil after reinforcement is limited; in the present invention, the MI CP mineralization technology for the reinforcement of large-pore weathered soil and the calcium lignin sulfonate solution are combined to overcome their respective limitations and achieve a more efficient and uniform soil reinforcement effect.

[0067] S4: monitor the bacteria attached to the granular soil to be reinforced, and obtain the consolidation index based on the monitoring results;

[0068] In this step, the consolidation index refers to the degree of compactness achieved by the soil during the consolidation process;

[0069] In order to clarify the specific method of obtaining the consolidation index, step S4 includes S41 to S43, which are:

[0070] S41: obtaining the bacterial density of the granular soil to be reinforced before grouting in batches, and calculating the bacterial solidification rate in combination with the monitoring results;

[0071] In order to clarify the specific method of obtaining the solid bacteria rate, step S41 includes S411 to S413, which are:

[0072] S411: obtaining the bacterial density of the granular soil to be reinforced before grouting in batches;

[0073] S412: monitoring the bacterial liquid flowing out during the batch grouting process of the reinforced granular soil body to obtain the bacterial density of the bacterial liquid flowing out during the grouting process;

[0074] S413: Calculate based on the bacterial density before the batch grouting and the bacterial density of the bacterial solution flowing out during the grouting process to obtain the bacterial fixation rate during the grouting process.

[0075] In this step, the solid bacteria rate during the grouting process is:

[0076]

[0077] In the above formula (1), Y represents the bacterial solidification rate during the grouting process, x represents the bacterial density of the bacterial solution before grouting, and Z represents the bacterial density of the bacterial solution flowing out during the grouting process;

[0078] The bacterial density of the bacterial solution before grouting represents the bacterial density of the granular soil to be reinforced before grouting in batches.

[0079] S42: monitoring calcium carbonate in the granular soil to be reinforced during the batch grouting process to obtain the amount of calcium carbonate generated;

[0080] In this step, different amounts of calcium carbonate generated are obtained according to different concentrations of the injected calcium lignin sulfonate solution.

[0081] S43: constructing based on the bacteria fixation rate and the calcium carbonate generation amount to obtain a consolidation degree index.

[0082] S5: judging whether to restart batch grouting based on the consolidation index and the fixed critical point.

[0083] In this step, when the consolidation index is less than a fixed critical point, the batch grouting process is repeated until the consolidation index is greater than or equal to the fixed critical point, and the reinforcement of the granular soil is completed.

[0084] Embodiment 3:

[0085] See also Figure 5 , the same as Example 1, except that: the concentration of the calcium lignin sulfonate solution is 0.225 mol / L, the variable is the standing time of 2 days, 3 days, 4 days, 5 days, 6 days or 7 days, and the calcium carbonate production amount at different standing days is obtained, and the standing days are at a higher level when 4-6 days.

[0086] Embodiment 4:

[0087] See also Figure 6, the same as Example 1, because the wood calcium solution is weakly acidic, the bacterial growth environment will be changed to a certain extent when added, the difference is that: the concentration of the calcium lignin sulfonate solution is 0.225 mol / L, the number of days of standing is 5 days, the variable is the pH value of the calcium lignin sulfonate solution (5.0, 5.5, 6.0, 6.5, 7.0), and the calcium carbonate production amount of different acids and bases is obtained, and the pH of the calcium lignin sulfonate solution is controlled at about 6 for the best.

[0088] Comparative Example 1

[0089] A reinforcement method for granular soil, comprising:

[0090] S1: Bacillus pasteurianus ATCC11859 was cultured with Bacillus pasteurianus culture medium (15 g / L tryptone, 5 g / L soy peptone, 5 g / L sodium chloride and 20 g / L urea, pH 7.2) with stirring until OD600 reached about 1.8, and wet cells were obtained by centrifugation or filtration;

[0091] S2: preparing 1M calcium chloride and 1M calcium acetate solutions, mixing them in volume ratios of 1:1, 1:3, 1:5, 1:8, and 1:10 to obtain mixed calcium salt solutions, preparing 1M urea solutions, and then mixing the mixed calcium salt solutions and urea solutions in a volume ratio of 1:1.5 to obtain different cementing solutions;

[0092] S3: Adding the granular soil to be reinforced into the grouting mold;

[0093] S4: Grouting reinforcement: start the peristaltic pump to inject the Bacillus pasteurianus culture solution and the cementing solution into the grouting mold and let it stand;

[0094] S5: Test the reinforced granular soil. If the solidification index is not reached, repeat the grouting reinforcement process until the solidification index is reached.

[0095] The calcium carbonate precipitates prepared in Example 2 and Comparative Example 1 were subjected to SEM examination, and the results were as follows: Figure 7 and Figure 8 As shown, Figure 7 This is the SEM image of the sample prepared in Comparative Example 1. Figure 8 The SEM image of the sample prepared in Example 2; Figure 7 It can be seen that the calcium carbonate on the surface of the sample prepared in comparative example 1 is randomly distributed on the surface of the granular soil. For the granular soil, the calcium carbonate crystals 72 of comparative example 1 are in the form of flakes, and the calcium carbonate crystals 72 are not completely connected to the granular soil. There are many pores 71 between the granular soil, and most of them are distributed in the form of long strips of pores 71, such as Figure 8As shown, the calcium carbonate crystals 72 generated by the enhancement technology are well connected with the soil particles, and the lignin aggregates 73 and the calcium carbonate crystals 72 work together to effectively reduce the area of ​​the pores 71 between the soil particles.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0097] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A reinforcement device for granular soil, characterized in that: include: A pipe wall structure (1), wherein both ends of the pipe wall structure (1) are provided with inlet and outlet pipes (2), one end of the inlet and outlet pipe (2) is connected to the pipe wall structure (1), and the other end of the inlet and outlet pipe (2) is provided with a water stop valve (3); A conveying structure (4), one end of the conveying structure (4) sequentially passes through the water stop valve (3) and the inlet and outlet pipes (2) and extends into the pipe wall structure (1); A plurality of filter layers (5), wherein the plurality of filter layers (5) are arranged at the top and bottom of the pipe wall structure (1), a porous water-permeable layer (6) is arranged between two of the filter layers (5), the porous water-permeable layer (6) is arranged along the circumference of the inner wall of the pipe wall structure (1), the interior of the porous water-permeable layer (6) is used to fill granular soil, the conveying structure (4) inputs grouting liquid into the pipe wall structure (1), and the grouting liquid evenly penetrates into the interior of the granular soil through the filter layer (5) and the porous water-permeable layer (6) to reinforce the granular soil.

2. The reinforcement device for granular soil according to claim 1 is characterized in that the filter layer (5) includes a first geotextile layer (51), the first geotextile layer (51) is arranged on the top of the pipe wall structure (1), and the bottom end of the first geotextile layer (51) is connected to the top of the porous water-permeable layer (6).

3. The reinforcement device for granular soil according to claim 2 is characterized in that the filter layer (5) includes a second geotextile layer (52), the second geotextile layer (52) is arranged at the bottom of the pipe wall structure (1), and the top end of the second geotextile layer (52) is connected to the bottom end of the porous water-permeable layer (6).

4. The reinforcement device for granular soil according to claim 1 is characterized in that the inlet and outlet pipes (2) include a water inlet pipe (21), an exhaust pipe (22) and a water outlet pipe (23), the water inlet pipe (21) and the exhaust pipe (22) are both arranged at the top end of the pipe wall structure (1), the water outlet pipe (23) is arranged at the bottom end of the pipe wall structure (1), and the water inlet pipe (21) and the water outlet pipe (23) are both in contact with one end of the conveying structure (4).

5. A reinforcement method for granular soil, characterized in that: include: The calcium lignin sulfonate and deionized water are uniformly mixed to obtain a calcium lignin sulfonate solution; Adding granular soil to be reinforced into the pipe wall structure (1); Grouting in batches: starting the peristaltic pump (41) to inject the calcium lignin sulfonate solution, bacterial liquid and cementing liquid into the pipe wall structure (1) and letting it stand, draining the liquid after the standing is completed, the bacterial liquid and the cementing liquid are injected later than the calcium lignin sulfonate solution, the bacterial liquid and the cementing liquid are injected in equal volumes, and the injection amounts of the calcium lignin sulfonate solution, the bacterial liquid and the cementing liquid are all equal to the volume of the pipe wall structure (1); Monitor the bacteria attached to the granular soil to be reinforced, and obtain the consolidation index based on the monitoring results; A judgment is made based on the consolidation index and the fixed critical point as to whether to restart the batch grouting.

6. The reinforcement method for granular soil according to claim 5 is characterized in that the molecular weight of the calcium lignin sulfonate solution is 500.00-550.00, the purity is ≥98%, the carbon content is 30%-50%, the concentration is 0.025-0.3 mol / L, the pH is 5.0-7.0, and the standing time is 2-7 days.

7. The reinforcement method for granular soil according to claim 6, characterized in that the calcium lignin sulfonate and deionized water are uniformly mixed to obtain a calcium lignin sulfonate solution, comprising: Add 10-50 g of calcium lignin sulfonate powder and 200-240 ml of deionized water into a container, and shake on a shaker at 200 rpm for 30 minutes to obtain a first suspension; Filtering the first suspension through a filter to obtain an impurity-free solution; heating and irradiating the impurity-free solution with ultraviolet light to obtain a treated solution; The temperature of the treated solution is lowered to below 60 degrees Celsius to obtain a calcium lignin sulfonate solution.

8. The reinforcement method for granular soil according to claim 6 is characterized in that the bacteria attached to the granular soil to be reinforced are monitored, and a consolidation index is obtained based on the monitoring result, including: Obtaining the bacterial density of the granular soil to be reinforced before grouting in batches, and calculating the bacterial consolidation rate in combination with the monitoring results; The calcium carbonate in the granular soil to be reinforced during the batch grouting process is monitored to obtain the calcium carbonate generation amount; The consolidation degree index is obtained based on the solid bacteria rate and the calcium carbonate production amount.

9. The reinforcement method for granular soil according to claim 8, characterized in that the bacterial density of the granular soil to be reinforced before grouting in batches is obtained, and the solid bacteria rate is calculated in combination with the monitoring result, comprising: Obtaining the bacterial density of the granular soil to be reinforced before batch grouting; The bacterial liquid flowing out during the batch grouting process of the reinforced granular soil is monitored to obtain the bacterial density of the bacterial liquid flowing out during the grouting process; The bacterial solidification rate during the grouting process is obtained by calculation based on the bacterial density before the batch grouting and the bacterial density of the bacterial solution flowing out during the grouting process.

10. The reinforcement method for granular soil according to claim 5, characterized in that the bacterial solution comprises: Mix 20 g of yeast powder, 15 g of ammonium chloride, 1 ml of nickel chloride crystals and 1 L of deionized water to obtain a first mixed solution; The pH of the first mixed solution is adjusted to 9.2-9.3 by using sodium hydroxide, and the mixture is sterilized at high temperature for 20 minutes and sterilized by ultraviolet light for 2 hours to obtain a culture medium; Bacterial culture: The Bacillus pasteurianus to be activated is inoculated into the culture medium, and cultured in an air bath oscillator at a rotation speed of 200 rpm / min and a temperature of 35° C. After culturing for 24 hours, the urease content in the bacterial solution is measured, and the bacterial solution with the highest unit urease activity (7.0 U / ml±0.2) is selected to obtain the first generation bacterial solution; Repeat the bacterial culture to obtain the third generation bacterial solution.

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