Method for solidifying soft soil ground

Abstract

This invention discloses a method for solidifying soft soil sites. The solidification steps include: S1, conducting on-site surveys to determine the density of the soft soil site and calculating the density; S2, selecting the loosest location in the soft soil site and driving a hollow steel pipe into it; S3, preparing the following materials in parts: 200-900 parts cement, 200-500 parts silicate, 10-420 parts curing agent, 1-300 parts polyethylene, 100-600 parts gypsum, and 100-1500 parts water; S4, mixing the materials from step S3 in a mixing drum; S5, pouring the mixed material into the hollow steel pipe. This application, by driving a hollow steel pipe into the soft soil site and continuously injecting hardening material inside, compacts the material into the soft soil site through tamping, reducing uneven settlement of the soft soil foundation, avoiding cracking and damage, ensuring normal construction of the soft soil site, and bringing better application prospects.

Description

Technical Field

[0001] This invention relates to the field of soft soil site treatment technology, and in particular to a method for solidifying soft soil sites, which is especially applicable to the treatment of soft soil sites in airport runways. Background Technology

[0002] Soft soil refers to cohesive soil in a soft plastic-fluid state, characterized by high natural water content, high compressibility, low bearing capacity, and very low shear strength. Soft soil is a general term for a class of land, not a specific type of soil. In engineering, soft soil is often subdivided into soft cohesive soil, silty soil, silt, peat soil, and peat, etc. It is characterized by high natural water content, large natural void ratio, high compressibility, low shear strength, small consolidation coefficient, long consolidation time, high sensitivity, large disturbance, poor permeability, complex layered distribution, and significant differences in physical and mechanical properties between layers.

[0003] Soft soil foundations are foundations whose compressible layers are mainly composed of silt, silty soil, or other highly compressible soils. Soft soil foundations have low strength and very low bearing capacity, generally not exceeding 50 kN / m. 2 Moreover, soft soil has high compressibility and is prone to large settlement. Under external loads, soft soil foundations are prone to subsidence, collapse, instability and cracking, which seriously endanger the safety and reliability of buildings. Therefore, it is necessary to solidify soft soil sites before construction.

[0004] Currently, the treatment of soft soil foundations primarily relies on physical compaction methods, represented by tamping equipment. These methods use the energy provided by the falling hammer to compact the soft soil, offering advantages such as simplicity and convenience. However, the compaction effect is generally difficult to precisely control and guarantee. This is because, due to the complex characteristics of the strata, the hardness of soft soil is not uniformly distributed. Even if a large area is generally classified as soft soil, there may still be areas that are soft and areas that are hard, or areas that are soft and areas that are even softer. In existing projects, because the tamping equipment is operated manually by workers, the criterion for judging compaction is generally that compaction is complete when there is no significant settlement on the surface. However, when the strata contain loose soil or other layers, although a few blows may appear to have compacted the soil, the compaction energy cannot actually be transmitted to deeper parts of the site, and the interior may still require further solidification treatment. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art by providing a method for solidifying soft soil sites. This method involves dividing the soft soil site into soft soil areas and systematically reinforcing each soft soil area using hollow steel pipes, thereby achieving effective solidification of the soft soil site and significantly improving its bearing capacity.

[0006] The objective of this invention is achieved through the following technical solutions:

[0007] A method for solidifying soft soil sites, characterized by the following steps:

[0008] S1. Conduct on-site surveys to determine the compaction level of the soft soil site, and calculate the compaction level and its distribution.

[0009] S2. Select multiple loose soft soil areas within the soft soil site, and drive a hollow steel pipe into the center of one of the soft soil areas.

[0010] S3. Prepare the following materials in the following proportions: 200-900 parts cement, 200-500 parts silicate, 10-420 parts curing agent, 1-300 parts polyethylene, 100-600 parts gypsum and 100-1500 parts water, and mix them together to form a cured material.

[0011] S4. Pour the mixed material into the hollow steel pipe and use a rammer to continuously compact the material into the soft soil, so that the material is fully compacted into the soft soil and squeezes the surrounding soil.

[0012] S5. Plan the soft soil area, select the side position of the soft soil area, drive the hollow steel pipe into the side position of the soft soil area, and continue to reinforce it using step S4.

[0013] S6. Select the opposite side of the reinforcement area and drive the hollow steel pipe into it, and continue to reinforce using step S4.

[0014] S7. Repeat steps S5 to S6 until the soft soil area is reinforced;

[0015] S8. Repeat steps S2 to S7 until every soft soil area in the soft soil site is reinforced.

[0016] In step S2, the location of the loosest soft soil site is calculated through data analysis. The hollow steel pipe has several holes on its outer wall, with a diameter of 100mm. The hollow steel pipe is driven into the interior of the soft soil site at the center of the loose soft soil site and fixed firmly.

[0017] The specific proportions of the curing material in step S3 are as follows: 450 parts cement, 230 parts silicate, 120 parts curing agent, 96 parts polyethylene, 420 parts gypsum and 900 parts water.

[0018] The cement is made of aluminate cement, and the internal components of the silicate include silicon, oxygen, aluminum, iron, calcium, magnesium, potassium and sodium. The curing agent contains one or more of vinyl chloride, water-based resin and ammonium sulfate.

[0019] The compactor compacts the soil using hydraulic pressure, and the solidification material is injected into the soft soil site through the holes in the hollow steel pipe.

[0020] After reinforcing a soft soil area, the hollow steel pipe is removed and the solidification material is backfilled.

[0021] The advantages of this invention are: by driving hollow steel pipes into soft soil sites and continuously injecting hardening materials inside, the materials are compacted into the soft soil sites through tamping, reducing uneven settlement of soft soil foundations, avoiding cracking and damage, ensuring normal construction of soft soil sites, and bringing better application prospects; the structure is simple and reasonable, construction is convenient, construction time is effectively shortened, and it is suitable for promotion. Detailed Implementation

[0022] The following examples further illustrate the features and other related characteristics of the present invention in detail, to facilitate understanding by those skilled in the art:

[0023] Example: This example uses a soft soil site stabilization method, and the stabilization steps include:

[0024] S1. The soil compaction is tested using the penetration method. A drill bit is continuously driven into the soil, and the soil compaction is calculated by measuring the resistance of the drill bit. The penetration method is used to determine the distribution of actual soft soil within the soft soil site, and several soft soil areas are divided according to engineering standards. Within a 5-meter range, when the distance between two adjacent soft soil areas is within 5 meters, the two adjacent soft soil areas are classified as a single general soft soil area; conversely, when the distance between two adjacent soft soil areas is greater than 5 meters, they are still considered as two independent soft soil areas.

[0025] S2. Drive a hollow steel pipe into the center of the soft soil area. The outer wall of the hollow steel pipe has several holes with a diameter of 100mm, and fix the hollow steel pipe firmly.

[0026] S3. Prepare the following materials in the indicated proportions: 200-900 parts cement, 200-500 parts silicate, 10-420 parts curing agent, 1-300 parts polyethylene, 100-600 parts gypsum, and 100-1500 parts water. Mix these materials to form a cured material. Specifically, place the above raw materials into a mixing drum and mix for 2 hours at a mixing speed of 20 r / min to ensure thorough mixing.

[0027] In this embodiment, the preferred curing material is: 450 parts cement, 230 parts silicate, 120 parts curing agent, 96 parts polyethylene, 420 parts gypsum, and 900 parts water.

[0028] The cement used is aluminate cement, and the internal components of silicate include silicon, oxygen, aluminum, iron, calcium, magnesium, potassium, and sodium. The curing agent contains one or more of the following: vinyl chloride, water-based resin, and ammonium sulfate. Water-based resin curing agents significantly increase the Mohs hardness of surfaces treated with this concrete penetrating sealant. This water-based concrete penetrating sealant can solidify the various components of concrete into a hard entity, increasing hardness and density. After curing, the wear resistance of the surface will increase by more than eight times. Simultaneously, the solubility of gypsum in salt solutions and brine largely depends on the NaCl concentration; adding it to the material can greatly enhance the hardness of the soil.

[0029] S4. Pour the mixed solidified material into the hollow steel pipe, and use a tamper to continuously compact the material into the soft soil site using hydraulic pressure and a certain impact energy, so that the material is fully compacted into the soft soil site; that is, the mixture is injected into the soft soil site through the hole.

[0030] At this point, on the one hand, the compaction energy of the rammer is transmitted to the stratum through the hollow steel pipe, achieving a certain physical compaction effect to solidify the stratum. On the other hand, the solidifying material is squeezed into the stratum through the holes in the hollow steel pipe, carrying its own pressure, which also works in conjunction with the compaction energy to exert a certain squeezing effect. Furthermore, the solidifying material itself can increase the hardness of the stratum after solidification. Through the combination of these three aspects, the soft soil site is solidified.

[0031] S5. Plan the soft soil area, select a location on the side of the soft soil area, drive hollow steel pipes into it, and continue with step S4 for reinforcement. It should be noted that because hollow steel pipes are driven into the side and solidification material is pressed in, when the soft soil within the stratum is compressed, it tends to be compressed towards the harder side. In other words, the soft soil within the soft soil area is pushed towards the side with the harder soil mass, thus trapping the soft soil between the injected solidification material and the harder soil mass, creating compression and improving the compression effect.

[0032] In this embodiment, the 5m distance between adjacent soft soil areas is based on the aforementioned mechanism. When there is a 5m hard soil layer between them, this hard soil layer can be used as the direction of compression of the soft soil within the soft soil area, i.e., the soft soil is compressed towards the hard soil layer. If the soft soil site consists entirely of soft soil areas, the softest soft soil area is taken as the starting point, and the reinforcement treatment of each soft soil area is carried out sequentially from low to high density. To a certain extent, when the soft soil on the relatively soft side is compressed towards the soft soil on the relatively hard side, the soft soil on the harder side can still provide a certain "reaction force" for reinforcement.

[0033] S6. Select the opposite side of the reinforcement area, drive in a hollow steel pipe, and continue to reinforce using step S4.

[0034] S7. Repeat steps S5 to S6 until the soft soil area is reinforced. Since the reinforcement range is actually limited each time, this embodiment uses a symmetrical cyclic reinforcement method to reinforce the soft soil area, ensuring that every location within the soft soil area can be effectively reinforced.

[0035] S8. Repeat steps S2 to S7 until every soft soil area in the soft soil site is reinforced.

[0036] S9. After completion, remove the hollow steel pipe and backfill with solidified material.

[0037] Comparative Example 1: The curing material in this comparative example consists of 450 parts cement, 230 parts silicate, 120 parts water-based resin curing agent, 96 parts polyethylene, 420 parts gypsum and 900 parts water.

[0038] Comparative Example 2: The curing material in this comparative example consists of 750 parts cement, 320 parts silicate, 400 parts ammonium sulfate curing agent, 256 parts polyethylene, 486 parts gypsum and 1000 parts water.

[0039] Comparative Example 3: The curing material in this comparative example consists of 798 parts cement, 365 parts silicate, 90 parts vinyl chloride curing agent, 211 parts polyethylene, 136 parts gypsum and 800 parts water.

[0040] Comparative Example 4: The curing material in this comparative example consists of 600 parts cement, 256 parts silicate, 258 parts vinyl chloride curing agent, 156 parts polyethylene, 562 parts gypsum and 1500 parts water.

[0041] The above four comparative examples were subjected to solidification construction in a certain soft soil site. Specifically, the soft soil site was divided into four areas with similar soft soil distribution, area, and other relevant parameters to compare the performance of the solidification materials and their reinforcement effects. The following results were obtained:

[0042] The table below shows the compaction of soft soil sites on different days in different embodiments.

[0043]

[0044] The table above shows that the solidification method used in Comparative Example 1 is more effective in solidifying and compacting the soft soil site than Comparative Examples 2 to 4.

[0045] Although the above embodiments have described the concept and embodiments of the present invention in detail, those skilled in the art will recognize that various improvements and modifications can still be made to the present invention without departing from the scope of the claims, and therefore will not be elaborated here.

Claims

1. A method for solidifying soft soil sites, characterized in that: The method includes the following steps: S1. Conduct on-site surveys to determine the compaction level of the soft soil site, and calculate the compaction level and its distribution. S2. Select multiple loose soft soil areas within the soft soil site, and drive a hollow steel pipe into the center of one of the soft soil areas. S3. Prepare the following materials in the following proportions: 200-900 parts cement, 200-500 parts silicate, 10-420 parts curing agent, 1-300 parts polyethylene, 100-600 parts gypsum and 100-1500 parts water, and mix them together to form a cured material. S4. Pour the mixed material into the hollow steel pipe and use a rammer to continuously compact the material into the soft soil, so that the material is fully compacted into the soft soil and squeezes the surrounding soil. S5. Plan the soft soil area, select the side position of the soft soil area, drive the hollow steel pipe into the side position of the soft soil area, and continue to reinforce it using step S4. S6. Select the opposite side of the reinforcement area and drive the hollow steel pipe into it, and continue to reinforce using step S4. S7. Repeat steps S5 to S6 until the soft soil area is reinforced; S8. Repeat steps S2 to S7 until every soft soil area in the soft soil site is reinforced.

2. The method for solidifying soft soil sites according to claim 1, characterized in that: In step S2, the location of the loosest soft soil site is calculated through data analysis. The hollow steel pipe has several holes on its outer wall, with a diameter of 100mm. The hollow steel pipe is driven into the interior of the soft soil site at the center of the loose soft soil site and fixed firmly.

3. The method for solidifying soft soil sites according to claim 1, characterized in that: The specific proportions of the curing material in step S3 are as follows: 450 parts cement, 230 parts silicate, 120 parts curing agent, 96 parts polyethylene, 420 parts gypsum and 900 parts water.

4. The method for solidifying soft soil sites according to claim 3, characterized in that: The cement is made of aluminate cement, and the internal components of the silicate include silicon, oxygen, aluminum, iron, calcium, magnesium, potassium and sodium. The curing agent contains one or more of vinyl chloride, water-based resin and ammonium sulfate.

5. The method for solidifying soft soil sites according to claim 1, characterized in that: The compactor compacts the soil using hydraulic pressure, and the solidification material is injected into the soft soil site through the holes in the hollow steel pipe.

6. The method for solidifying soft soil sites according to claim 1, characterized in that: After reinforcing a soft soil area, the hollow steel pipe is removed and the solidification material is backfilled.

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