Construction method of high polymer reinforced soil

Abstract

This invention provides a construction method for polymer-reinforced soil, comprising the following steps: spreading soil layer by layer; measuring the natural moisture content of the soil and obtaining a curve showing the change in soil density with soil moisture content, taking the soil moisture content corresponding to the maximum compaction density as the optimum moisture content; obtaining the soil permeability coefficient; calculating the total amount of water required to reach the optimum moisture content of the soil based on the difference between the natural moisture content and the optimum moisture content and the total amount of soil; determining the amount of water required to be added to each layer of soil evenly, and then determining the number of spraying passes required for each layer of soil; spraying polymer slurry after completing the water spraying; calculating the infiltration time of polymer slurry per unit hydraulic gradient in the soil based on the soil permeability coefficient; compacting the soil and testing the soil compaction degree, followed by water injection test and ring cutter test; spreading the next layer of soil after meeting the design requirements; repeating the steps until the soil reaches the design elevation and dimensions.

Description

Technical Field

[0001] This invention relates to the field of backfill construction, and in particular to a construction method for polymer-reinforced soil. Background Technology

[0002] Backfill refers to the soil that is returned and compacted after the completion of underground works such as foundations in engineering construction. Backfill specifically refers to the process of taking soil from within 5 meters and backfilling it after the completion of concealed works such as foundations and subgrades.

[0003] In current construction processes, polymer grout is often used to reinforce backfill soil in order to improve its physical and mechanical properties.

[0004] However, when using existing polymer slurries to reinforce backfill soil, it is difficult to accurately control the spraying of the polymer slurry, resulting in situations where too much or too little polymer slurry is sprayed, which affects the reinforcement effect, construction period, and project economy. Summary of the Invention

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

[0006] To solve the above-mentioned 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 tests, measure the natural moisture content of the soil, and conduct compaction tests to obtain the soil density as a function of soil moisture content. Take the soil moisture content corresponding to the maximum compaction density as the optimum moisture content.

[0009] Step 3: Obtain the soil permeability coefficient to determine the rate and time required for water and polymer slurry to infiltrate the soil.

[0010] Step 4: Based on the difference between the natural moisture content and the optimum moisture content of the soil and the total amount of soil, calculate the total amount of water required to bring the soil to the optimum moisture content.

[0011] Step 5: Based on the number of soil layers and the area of ​​the soil, determine the amount of water needed to replenish each soil layer evenly, and then determine the number of spray passes required for each soil layer based on the water tonnage of the water truck.

[0012] Step 6: After completing the water spraying, spray the polymer slurry;

[0013] Step 7: Calculate the infiltration time of the polymer grout in the soil per unit hydraulic gradient based on the soil permeability coefficient;

[0014] Step 8: After the polymer slurry has penetrated, the soil is compacted and the compaction degree is tested to ensure that the compaction degree is greater than or equal to 94%. Then, a water injection test and a ring cutter test are performed on the soil. The compacted soil is sampled and tested. After the test results meet the design requirements, the next layer of soil is laid.

[0015] Step 9: Repeat steps 5-8 until the soil reaches the design elevation and dimensions.

[0016] Furthermore, in step two, the natural moisture content of the soil... Where, m w To test the mass of water in the soil, m s To test the quality of the soil after it has been dried.

[0017] Furthermore, in step three, the soil permeability coefficient Among them: Q Z F is the injection flow rate of the inner ring, H is the test head, Ha is the capillary rise height of the test soil layer, and z is the infiltration depth measured from the bottom of the test pit.

[0018] Furthermore, in step four, the total amount of water that needs to be added to the soil. Where, m 土 For soil mass.

[0019] Furthermore, in step five, the number of spraying passes... Where, n 土 The number of layers for spreading the soil. The soil paving area is s 土 The amount of water used by a sprinkler truck to spray the soil once.

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

[0021] Furthermore, when the sprinkler truck sprays the polymer slurry, the spraying speed is calculated based on the truck's travel speed to ensure... Among them, V 车 V represents the speed of the water truck, L represents the spraying length of the polymer slurry, and v represents the speed of the water truck. q高聚物 The spraying speed for the polymer slurry sprayed by the water truck.

[0022] Furthermore, the sprinkler truck has a three-level material storage area, which stores water, polymer slurry, and catalyst respectively.

[0023] Furthermore, the three material zones are distributed sequentially along the height direction, and the liquid outlets of the three material zones are located on the same side, with the water-containing material zone located at the highest point.

[0024] The beneficial effects of this invention are as follows:

[0025] 1. Due to the three-level material area setup, and the water storage area being located at the highest point, when water, polymer slurry, and catalyst are sprayed, dust can be suppressed by water, avoiding splashing and dust.

[0026] 2. By calculating the soil permeability coefficient, the total amount of water required to replenish the soil, and the infiltration time, the amount and speed of polymer spraying can be precisely controlled.

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

[0028] 4. For the three-stage material sprinkler truck, an upper, middle, and lower arrangement is adopted. 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 middle, ensuring the stability of the vehicle and ensuring the safe driving of the sprinkler truck in loose filler. Then, the spraying speed of the solution is controlled according to the driving speed and the area of ​​the site to ensure that the solution is sprayed evenly and that the total amount of water sprayed at the end can just humidify the filler to the optimal moisture content, thereby facilitating compaction. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the test for obtaining the soil permeability coefficient in this invention.

[0030] Figure 2 This is a schematic diagram of the water sprinkler truck in this invention. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0032] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

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

[0034] like Figures 1-2 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 50-100cm thick;

[0036] Step 2: Conduct indoor geotechnical tests by sampling, and use the oven-drying method to test the natural moisture content of the soil. Compaction tests were conducted to obtain the soil density versus moisture content curve. The moisture content corresponding to the maximum compaction density was taken as the optimum moisture content ω2. Where ω1 is the moisture content; m w To test the mass of water in the soil (i.e., the difference between the mass of the natural soil and the mass of the dry soil); m s To test the mass of soil particles after drying (i.e., the dry soil mass, the remaining mass of natural soil after drying in an oven)

[0037] Step 3: Conduct in-situ permeability tests 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 1. The injection flow rate of the inner ring, L / min. Under dry and hot conditions, the evaporation water volume should be deducted; F is the bottom area of ​​the inner ring, cm2; H is the test head, cm; Ha is the capillary rise height of the test soil layer, cm, which can be taken as an empirical value according to different soil types; z is the infiltration depth from the bottom of the test pit, cm.

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

[0041] Step 4: Based on the difference between the natural moisture content and the optimum moisture content of the soil, and according to the total soil volume, calculate the total amount of water required to bring the soil to its optimum moisture content. In the formula, m 水 The amount of water required to replenish the soil to reach its optimum moisture content, m 土 This refers to the soil mass. The total moisture content at this point is the same as the total amount of water that a regular sprinkler truck would spray. By spraying water from the sprinkler truck, the soil is replenished with moisture, allowing it to reach its optimal moisture content, which is beneficial for compaction and also helps to suppress dust and purify the construction site environment.

[0042] Step 5: Based on the number of soil layers n 土 and area s 土 First, determine the amount of water needed to evenly distribute to each layer of soil. Then, based on the tonnage of the water truck, determine the number of spray passes required for each layer of soil using a regular water truck. In the formula, The area of ​​the soil to be covered is s 土 The amount of water used when a water truck sprays the soil once. The benefits of spraying water at this time are: ① Replenishing moisture so that the soil reaches its optimal moisture content, which is conducive to compaction; ② Moisture facilitates the reaction of polymers in subsequent water reactions, causing them to expand and solidify, thus reinforcing the soil; ③ It can suppress dust and purify the construction site environment.

[0043] Step Six: After completing the water spraying, perform polymer spraying, spraying polymer slurry. The polymer can be selected as Speedpack Super Foam Water Reactive Grouting Material, and a corresponding curing agent can be used as a catalyst. Upon contact with water, it reacts, expands, and solidifies. Compared to traditional engineering materials such as cement, it has advantages such as fast curing speed, good fluidity, strong injectability, low density, lower additional load, environmental safety, good corrosion resistance, excellent impermeability, long service life, rapid strength improvement, quick construction, good flexibility, ability to deform in coordination with soil and rock masses, and tight bonding with soil particles.

[0044] Step 7: Based on the soil permeability coefficient obtained from the aforementioned in-situ permeability test, estimate the infiltration time of the polymer slurry per unit hydraulic gradient in the soil. In the formula, Q s高聚物 k represents the amount of polymer sprayed. 高聚物 The value is the permeability coefficient of the soil to the polymer slurry. Since the soil has not yet been compacted, the permeability coefficient is relatively large, and therefore the polymer slurry infiltrates relatively quickly.

[0045] Step 8: After the polymer slurry has fully penetrated, compact the soil using a road roller. Test the soil compaction degree (i.e., the ratio of the compacted dry density to the standard maximum dry density, expressed as a percentage) according to the "Highway Subgrade Design Specification" (JTG D30). The compaction degree should be greater than or equal to 94%. When using a water injection test, take soil samples from the bottom of each layer; when using a ring sampler, take samples at half the thickness of the compacted layer. The testing frequency is: every 500m of each compacted layer. 2 At least three measuring points should be used. Simultaneously, samples of the compacted soil should be taken and sent to a geotechnical laboratory for testing. Construction of the next stage cannot proceed if the compaction degree and mechanical properties do not meet design requirements; if they do, the next layer of soil can be laid; otherwise, compaction continues until the specifications are met. Vibratory compaction of the soil allows the polymer slurry to integrate more fully with the soil, resulting in more uniform reinforcement and a more significant effect.

[0046] Step 9: Repeat steps 5-8 until the backfill soil reaches the design elevation and dimensions.

[0047] This invention also includes a three-level material zone design for the water truck: the three material zones are arranged sequentially along the height direction, allowing water and polymer slurry to be sprayed in any proportion, and the center of gravity of the three material zones is centered to ensure vehicle stability and safe driving of the water truck in loose soil. Then, the spraying speed of the polymer slurry is adjusted according to the vehicle speed. v q高聚物 The value of L represents the polymer spraying speed of the polymer sprinkler truck, and L represents the spraying length of the polymer. This ensures uniform spraying of the polymer slurry, which facilitates compaction.

[0048] This invention is not limited to the preferred embodiments described above. Anyone can derive other products in various forms under the guidance of this invention. However, regardless of any changes in shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A construction method for polymer-reinforced soil, characterized in that, Includes the following steps: Step 1: Spread the soil layer by layer; Step 2: Take soil samples for geotechnical tests, measure the natural moisture content of the soil, and conduct compaction tests to obtain the soil density as a function of soil moisture content. Take the soil moisture content corresponding to the maximum compaction density as the optimum moisture content. Step 3: Obtain the soil permeability coefficient to determine the rate and time required for water and polymer slurry to infiltrate the soil. Step 4: Based on the difference between the natural moisture content and the optimum moisture content of the soil and the total amount of soil, calculate the total amount of water required to bring the soil to the optimum moisture content. Step 5: Based on the number of soil layers and the area of ​​the soil, determine the amount of water needed to replenish each soil layer evenly, and then determine the number of spray passes required for each soil layer based on the water tonnage of the water truck. Step 6: After completing the water spraying, spray the polymer slurry; Step 7: Calculate the infiltration time of the polymer grout in the soil per unit hydraulic gradient based on the soil permeability coefficient; Step 8: After the polymer slurry has penetrated, the soil is compacted and the compaction degree is tested to ensure that the compaction degree is greater than or equal to 94%. Then, a water injection test and a ring cutter test are performed on the soil. The compacted soil is sampled and tested. After the test results meet the design requirements, the next layer of soil is laid. Step 9: Repeat steps 5-8 until the soil reaches the design elevation and dimensions.

2. The construction method for polymer-reinforced soil according to claim 1, characterized in that: In step two, the natural moisture content of the soil ;in, To test the quality of water in the soil, To test the quality of the soil after it has been dried.

3. The construction method for polymer-reinforced soil according to claim 1, characterized in that: In step three, the soil permeability coefficient ; where: Q Z F is the injection flow rate of the inner ring, H is the test head, Ha is the capillary rise height of the test soil layer, and z is the infiltration depth measured from the bottom of the test pit.

4. The construction method for polymer-reinforced soil according to claim 1, characterized in that: In step four, the total amount of water that needs to be added to the soil. ;in, For soil quality, This refers to the natural moisture content of the soil. This represents the optimal moisture content.

5. The construction method for polymer-reinforced soil according to claim 4, characterized in that: In step five, the number of spraying passes... ;in, The number of layers for spreading the soil. The area of ​​soil paving is The amount of water used by a sprinkler truck to spray the soil once.

6. The construction method for polymer-reinforced soil according to claim 1, characterized in that: In step seven, the infiltration time of the polymer slurry per unit hydraulic gradient in the soil is measured. ;in, This refers to the amount of polymer sprayed. It is the permeability coefficient of the soil to the polymer slurry.

7. The construction method for polymer-reinforced soil according to claim 6, characterized in that: When a water truck sprays polymer slurry, the spraying speed is calculated based on the truck's travel speed to ensure... ; Among them, V 车 The speed at which the water truck travels. The construction length for spraying polymer slurry, The spraying speed for the polymer slurry sprayed by the water truck.

8. The construction method for polymer-reinforced soil according to claim 1, characterized in that: The sprinkler truck has a three-level material storage area, which stores water, polymer slurry and catalyst respectively.

9. The construction method for polymer-reinforced soil according to claim 8, characterized in that: The three material zones are distributed sequentially along the height direction, and the liquid outlets of the three material zones are located on the same side, with the water-containing material zone located at the highest point.

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