Construction method of high polymer reinforced soil body

Abstract

The invention provides a construction method for reinforcing a soil body through a high polymer. The construction method comprises the following steps that the soil body is paved layer by layer; measuring the natural moisture content of the soil body, obtaining a change curve of the soil body density along with the moisture content of the soil body, and taking the moisture content of the soil body corresponding to the maximum compaction density as the optimal moisture content; acquiring a soil permeability coefficient; according to the difference value of the natural moisture content and the optimal moisture content of the soil body and the total amount of the soil body, the total amount of moisture needing to be supplemented for achieving the optimal moisture content of the soil body is calculated; determining the water required to be supplemented by averagely distributing each layer of soil body, and then determining the spraying times required by each layer of soil body; after water spraying is completed, high polymer slurry is sprayed; according to the soil permeability coefficient, the infiltration time of the high polymer slurry per unit hydraulic gradient in the soil is calculated; rolling the soil body, detecting the compaction degree of the soil body, and then carrying out an irrigation test and a cutting ring test on the soil body; after the design requirement is met, the next layer of soil body is paved; and repeating the steps until the soil body reaches the designed elevation and size.

Description

Technical Field

[0001] The invention relates to the field of backfill soil construction, in particular to a construction method for polymer reinforced soil. Background Art

[0002] Backfill refers to the process of returning the compacted soil after completing the foundation and other below-ground works during construction. Backfill refers to the construction process of taking soil and backfilling it within 5m after the completion of concealed works such as foundation and cushion.

[0003] In the existing construction process, polymer slurry is often used to reinforce the backfill soil to improve the physical and mechanical properties of the backfill soil.

[0004] However, when the existing polymer slurry is used to reinforce the backfill soil, it is difficult to accurately control the spraying of the polymer slurry on the backfill soil, resulting in excessive or insufficient spraying of the polymer slurry, which affects the reinforcement effect, construction period and engineering economy of the backfill soil. Summary of the invention

[0005] The purpose of the present invention is to provide a construction method for polymer reinforced soil that solves the above technical problems.

[0006] In order to solve the above technical problems, the present invention provides a construction method for polymer reinforced soil, comprising the following steps:

[0007] Step 1: Spread the soil layer by layer;

[0008] Step 2: Take soil samples for geotechnical testing to measure the natural moisture content of the soil, and perform compaction tests to obtain a curve of soil density versus soil moisture content, and take the soil moisture content corresponding to the maximum compaction density as the optimal moisture content;

[0009] Step 3: Obtain the soil permeability coefficient, and determine the infiltration speed and time required for water and polymer slurry in the soil through the soil permeability coefficient;

[0010] Step 4: Calculate the total amount of water required to achieve the optimal moisture content of the soil based on the difference between the natural moisture content of the soil and the optimal moisture content and the total amount of soil;

[0011] Step 5: Determine the amount of water required to evenly distribute each layer of soil according to the number of layers and area of ​​soil paving, and then determine the number of times each layer of soil needs to be sprayed according to the tonnage of the sprinkler truck;

[0012] Step 6: After the water spraying is completed, the polymer slurry is sprayed;

[0013] Step 7: Calculate the infiltration time of the polymer slurry in the soil per unit hydraulic gradient according to the soil permeability coefficient;

[0014] Step 8: After the polymer slurry is infiltrated, the soil is rolled and the soil compaction degree is tested to ensure that the soil compaction degree is greater than or equal to 94%. Then, the soil is subjected to a water filling test and a ring knife test. The soil after rolling is sampled and tested. After the test meets the design requirements, the next layer of soil is spread.

[0015] Step 9. Repeat steps 5-8 until the soil reaches the designed elevation and size.

[0016] Furthermore, in step 2, the natural moisture content of the soil Among them, m w To test the quality of water in the soil, m s To test the quality of the soil after drying.

[0017] Furthermore, in step 3, the soil permeability coefficient Where: Q Z is the injection flow of the inner ring, F is the bottom area of ​​the inner ring, H is the test water head, Ha is the capillary rise height of the test soil layer, and z is the penetration depth from the bottom of the test pit.

[0018] Furthermore, in step 4, the total amount of water required to be added to the soil Among them, m 土 The soil quality.

[0019] Further, in step 5, the number of spraying times Among them, n 土 is the number of soil paving layers, The soil spreading area is s 土 The amount of water used by a sprinkler truck to spray the soil once.

[0020] Furthermore, in step 7, the infiltration time of the polymer slurry in the soil per unit hydraulic gradient is Among them, Q s高聚物 is the polymer spraying amount, k 高聚物 is the permeability coefficient of soil to polymer slurry.

[0021] Furthermore, when the water truck is spraying the polymer slurry, the spraying speed of the water truck is calculated according to the driving speed of the water truck so that Among them, V 车 is the speed of the sprinkler truck, L is the construction length of the polymer slurry spraying, v q高聚物 The spraying speed of polymer slurry sprayed by a sprinkler truck.

[0022] Furthermore, the sprinkler truck has three levels of material areas built in, and the three levels of material areas store water, polymer slurry and catalyst respectively.

[0023] Furthermore, the three-level material areas are distributed in sequence along the height direction, and the liquid outlets of the three-level material areas are located on the same side, wherein the material area storing water is located at the highest point.

[0024] The beneficial effects of the present invention are:

[0025] 1. Due to the setting of the three-level material area and the material area for storing water is located at the highest point, when water, polymer slurry and catalyst are sprayed, the dust can be suppressed by water to avoid splashing, dust and other phenomena;

[0026] 2. By calculating the soil permeability coefficient, the total amount of water required to be supplemented in the soil, the infiltration time, etc., the amount and speed of polymer spraying can be accurately controlled;

[0027] 3. By controlling the driving speed of the sprinkler truck, the optimal spraying speed of the sprinkler truck is calculated in real time to ensure uniform spraying of the polymer slurry, thereby accurately controlling the operation time and optimizing the use of the slurry.

[0028] 4. The three-level material sprinkler truck adopts an upper, middle and lower layout. The solution in the upper, middle and lower tanks can be sprayed in any proportion to keep the center of gravity of the storage tank in the center, ensure the stability of the vehicle body, and ensure that the sprinkler truck can drive safely in the loose filler; then, the spraying speed of the solution is controlled according to the driving speed and site area to ensure that the solution is sprayed evenly and that the total amount of water finally sprayed can just humidify the filler to the optimal moisture content, thereby facilitating compaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of an experiment for obtaining soil permeability coefficient in the present invention.

[0030] Figure 2 It is a structural schematic diagram of the sprinkler truck in the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0032] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or position relationship indicated by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0033] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0034] like Figure 1-Figure 2 The present invention provides a construction method for polymer reinforced soil, comprising the following construction steps:

[0035] Step 1: Spread the soil layer by layer, with each layer being 50 to 100 cm thick;

[0036] Step 2: Take samples for indoor geotechnical tests and use the drying method to test the natural moisture content of the soil A compaction test was carried out to obtain the curve of soil density changing with water content, and the water content corresponding to the maximum compaction density was taken as the optimal water content ω2. In the formula, ω1 is the water content; m w To test the mass of water in the soil (i.e. the difference between the mass of natural soil and the mass of dry soil); m s To test the mass of soil particles after soil drying (i.e. dry soil mass, the remaining mass after natural soil is dried in an oven);

[0037] Step 3: Conduct an in-situ permeability test using the double-ring method to obtain the soil permeability coefficient:

[0038]

[0039] Where: K is the permeability coefficient of the test soil layer, cm / s; Q Z is the injection flow rate of the inner ring, L / min, and the evaporation water volume should be deducted under dry and hot conditions; F is the bottom area of ​​the inner ring, cm2; H is the test water head, cm; Ha is the capillary rise height of the test soil layer, cm, and the empirical value can be taken according to different soil bodies; z is the penetration depth from the bottom of the test pit, cm;

[0040] The permeability coefficient of the soil is used to determine the speed and time required for subsequent water and polymer slurry infiltration, providing a reference for the operation time of the sprinkler truck;

[0041] Step 4: Calculate the total amount of water required to make the soil reach the optimal moisture content based on the difference between the natural moisture content of the soil and the optimal moisture content and the total amount of soil. In the formula, m 水 The amount of water required to replenish the soil to achieve the optimal moisture content, m 土 The total amount of water at this time is the total amount of water that an ordinary sprinkler truck needs to spray. The soil is replenished with water by the sprinkler truck spraying water, so that the soil reaches the optimal moisture content, which is conducive to compaction. At the same time, it can also suppress dust and purify the construction site environment.

[0042] Step 5: According to the number of layers n of soil paving 土 and area s 土 , determine the average distribution of water required for each layer of soil, and then determine the number of times each layer of soil needs to be sprayed by an ordinary sprinkler truck based on the tonnage of the sprinkler truck In the formula, The soil area is s 土 The amount of water used by the sprinkler truck to spray the soil once. The benefits of water spraying at this time are: ① replenishing water to make the soil reach the optimal moisture content, which is conducive to compaction; ② water can facilitate the subsequent water-reactive polymer to react with water, expand and solidify, and strengthen the soil; ③ it can suppress dust and purify the construction site environment.

[0043] Step 6. After the water spraying is completed, the polymer spraying operation is carried out, and the polymer slurry is sprayed. Among them, the polymer can be selected from the Superpak super foam water reaction grouting material, and the curing agent corresponding to the polymer slurry can be used as a catalyst. After it comes into contact with water, it reacts and expands and solidifies. Compared with traditional engineering materials such as cement, it has the advantages of fast curing speed, good fluidity, strong injectability, low density, small additional load, environmental protection and safety, good corrosion resistance, excellent anti-seepage performance, long service life, fast strength improvement, fast construction, good flexibility, coordinated deformation with rock and soil, and close combination with soil particles.

[0044] Step 7: Based on the soil permeability coefficient obtained from the in-situ permeability test, estimate the infiltration time of the polymer slurry in the soil per unit hydraulic gradient. In the formula, Q s高聚物 is the polymer spraying amount, k 高聚物 It is the permeability coefficient of soil to polymer slurry. Since the soil has not been compacted yet, the permeability coefficient is relatively large, so the infiltration rate of polymer slurry is relatively fast.

[0045] Step 8: After the polymer slurry has completely penetrated, use a roller to roll the soil. According to the provisions of the Highway Roadbed Design Specification (JTG D30), the soil compaction degree (that is, the ratio of the dry density of the soil after compaction to the standard maximum dry density, expressed as a percentage) is tested. The compaction degree is greater than or equal to 94%. When using the water injection test, the soil sample is taken at the bottom of each layer. When using the ring knife test, the depth is 1 / 2 of the compacted layer thickness. The detection frequency is: every 500m of each compacted layer 2 At least 3 measuring points. At the same time, the soil after rolling is sampled and sent to the geotechnical laboratory for testing. If the compaction degree and mechanical indicators do not meet the design requirements, the next process cannot be carried out; if the requirements are met, the next layer of soil can be spread, otherwise the rolling will continue until the requirements of the specification are met. Through the vibration rolling of the soil, the polymer slurry and the soil are more fully integrated, so that the reinforcement is more uniform and the effect is more significant.

[0046] Step 9. Repeat steps 5 to 8 until the backfill soil reaches the designed elevation and size.

[0047] The present invention also includes the design of the three-level material area of ​​the sprinkler truck: the three-level material area is arranged in sequence along the height direction, water and polymer slurry can be sprayed in any proportion, and the center of gravity of the three-level material area is centered to ensure the stability of the vehicle body and ensure that the sprinkler truck can drive safely in loose soil. Then, the spraying speed of the polymer slurry is controlled according to the driving speed. v q高聚物 is the polymer spraying speed of the polymer sprinkler truck, and L is the construction length of the polymer spraying. Ensure that the polymer slurry is sprayed evenly to facilitate compaction.

[0048] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A construction method for polymer reinforcement of soil, characterized in that: The following steps are involved: Step 1: Spread the soil layer by layer; Step 2: Take soil samples for geotechnical testing to measure the natural moisture content of the soil, and perform compaction tests to obtain a curve of soil density versus soil moisture content, and take the soil moisture content corresponding to the maximum compaction density as the optimal moisture content; Step 3: Obtain the soil permeability coefficient, and determine the infiltration speed and time required for water and polymer slurry in the soil through the soil permeability coefficient; Step 4: Calculate the total amount of water required to achieve the optimal moisture content of the soil based on the difference between the natural moisture content of the soil and the optimal moisture content and the total amount of soil; Step 5: Determine the amount of water required to evenly distribute each layer of soil according to the number of layers and area of ​​soil paving, and then determine the number of times each layer of soil needs to be sprayed according to the tonnage of the sprinkler truck; Step 6: After the water spraying is completed, the polymer slurry is sprayed; Step 7: Calculate the infiltration time of the polymer slurry in the soil per unit hydraulic gradient according to the soil permeability coefficient; Step 8: After the polymer slurry is infiltrated, the soil is rolled and the soil compaction degree is tested to ensure that the soil compaction degree is greater than or equal to 94%. Then, the soil is subjected to a water filling test and a ring knife test. The soil after rolling is sampled and tested. After the test meets the design requirements, the next layer of soil is spread. Step 9. Repeat steps 5-8 until the soil reaches the designed elevation and size.

2. The construction method for polymer reinforcement of soil according to claim 1 is characterized in that: In step 2, the natural moisture content of the soil Among them, m w To test the quality of water in the soil, m s To test the quality of the soil after drying.

3. The construction method for polymer reinforcement of soil according to claim 1, characterized in that: In step 3, the soil permeability coefficient Where: Q Z is the injection flow of the inner ring, F is the bottom area of ​​the inner ring, H is the test water head, Ha is the capillary rise height of the test soil layer, and z is the penetration depth from the bottom of the test pit.

4. The construction method for polymer reinforcement of soil according to claim 1 is characterized in that: In step 4, the total amount of water that needs to be added to the soil Among them, m 土 The soil quality.

5. The construction method for polymer reinforcement of soil according to claim 1 is characterized in that: In step 5, spray the Among them, n 土 is the number of soil paving layers, The soil spreading area is s 土 The amount of water used by a sprinkler truck to spray the soil once.

6. The construction method for polymer reinforcement of soil according to claim 1, characterized in that: In step 7, the infiltration time of polymer slurry in the soil per unit hydraulic gradient is Among them, Q s高聚物 is the polymer spraying amount, k 高聚物 is the permeability coefficient of soil to polymer slurry.

7. The construction method for polymer reinforcement of soil according to claim 1, characterized in that: When the sprinkler truck is spraying polymer slurry, the spraying speed of the sprinkler truck is calculated according to the driving speed of the sprinkler truck so that Among them, V 车 is the driving speed of the sprinkler truck, L is the construction length of the polymer slurry spraying, v q高聚物 The spraying speed of polymer slurry sprayed by a sprinkler truck.

8. The construction method for polymer reinforcement of soil according to claim 1, characterized in that: The sprinkler truck has three levels of material areas built in, and the three levels of material areas store water, polymer slurry and catalyst respectively.

9. The construction method for polymer reinforcement of soil according to claim 8, characterized in that: The three-level material areas are distributed in sequence along the height direction, and the liquid outlets of the three-level material areas are located on the same side, wherein the material area storing water is located at the highest point.

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