Liquid light impermeable solidified soil and preparation and construction method thereof

Abstract

The invention belongs to the technical field of fluid curing. The liquid-state light-weight anti-seepage solidified soil is characterized by comprising flow-state solidified soil slurry and light-weight foamed concrete, the volume ratio of the flow-state solidified soil slurry to the light foamed concrete is 1: 1; the flow-state solidified soil slurry comprises a soil material, a curing agent and water, and the weight ratio of the soil material to the curing agent to the water is 1150: 80: 228; the light foamed concrete comprises water, cement and a foaming agent; the weight ratio of the water to the cement to the foaming agent is 150: 250: 2.24. The technical problem that backfill soil around an existing building foundation collapses is solved. The invention further discloses a preparation method of the liquid light anti-permeability solidified soil. The invention further discloses a construction method of the liquid light anti-permeability solidified soil.

Description

Technical Field

[0001] The invention belongs to the technical field of fluidized solidification, and in particular relates to a liquid lightweight anti-seepage solidified soil and a preparation method and a construction method thereof. Background Art

[0002] A certain plot of land was originally farmland and fish ponds, and was later converted into a landfill. The foundation of the project is a raft foundation, with reinforced concrete retaining walls around the original foundation. The bottom plate of the foundation raft is mainly located in the ① layer of miscellaneous fill, and partly in the ② layer of silty clay. The project is surrounded by dense river networks, and water can be seen below 1 meter. Considering the load and groundwater floating effect, the retaining walls around the foundation were cancelled and replaced with partial earth backfill around the foundation pit. The project was completed in July 2022.

[0003] Current status: After one and a half years of use, it was found that the backfill soil around the foundation of the building had collapsed, the outdoor steps were crooked, and a foul odor wafted out when the building was below ±0.00, directly affecting its use. Summary of the invention

[0004] The first object of the present invention is to provide a liquid lightweight impermeable solidified soil to solve the technical problem of backfill soil collapse around the existing building foundation.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solution: liquid lightweight anti-seepage solidified soil, including fluidized solidified soil slurry and lightweight foamed concrete; the volume ratio of the fluidized solidified soil slurry to the lightweight foamed concrete is 1:1;

[0006] The fluidized solidified soil slurry includes soil, curing agent, and water, and the weight ratio of the soil, curing agent, and water is 1150:80:228; the lightweight foamed concrete includes water, cement, and foaming agent, and the weight ratio of water:cement:foaming agent is 150:250:2.24. The technical solution of the present invention is further improved, and the curing agent is a mineral-based cementitious material, including the following components: 10wt%-30wt% of mineral powder, 5wt%-20wt% of desulfurized ash, 0.6wt%-2.5wt% of admixture, and the balance is cement;

[0007] The admixture includes a water reducer and a retarder; the amount of the water reducer is 0.5wt%-2wt% of the curing agent; the amount of the retarder is 0.1wt%-0.5wt% of the curing agent;

[0008] The cement in the curing agent is silicate cement P.O42.5.

[0009] The technical solution of the present invention is further improved, and the foaming agent is a polymer composite cement foaming agent.

[0010] The technical solution of the present invention is further improved, in which the cement in the lightweight foamed concrete is silicate cement P.O42.5.

[0011] The technical solution of the present invention is further improved, the bulk density of the liquid lightweight impermeable solidified soil is ≤10KN / M 3 , compressive strength>0.6Mpa; the slump of the liquid lightweight anti-seepage solidified soil is 180~210mm.

[0012] The cement and the foaming agent of the present invention are first stirred and mixed to form a foam mixture and then added into the solidified soil, so as to generate liquid lightweight solidified soil with stable performance and excellent quality.

[0013] The present invention is to mix a curing agent, water and soil material in a certain proportion to form a fluidized solidified soil slurry with a certain fluidity, and then add a certain amount of lightweight foamed concrete after mechanical stirring to form a new type of filling material that can be transported by a mud pump, is self-compacting, has low bulk density, is impermeable, easy to construct, has a certain strength and is green and environmentally friendly, thereby solving the following problems:

[0014] 1. The adoption of lightweight, waterproof and solidified soil technology solves the problem of insufficient bearing capacity of the building foundation and inability to use conventional earth backfill;

[0015] 2. The adoption of lightweight, impermeable solidified soil technology solves the problem of moisture-proofing the ground and wall roots of the first-floor building due to the saturation of the soil after conventional backfilling of the underground space;

[0016] 3. The pumping technology is adopted to solve the problem of human and property losses caused by the small underground space, the inability to construct manually, and the possibility of unknown situations;

[0017] 4. Self-compacting, solidifying, environmentally friendly, made from local materials, and high economic benefits.

[0018] The second object of the present invention is to provide a method for preparing a liquid lightweight impermeable solidified soil, comprising the following steps:

[0019] (1) Preparation of fluidized solidified soil slurry and lightweight foamed concrete;

[0020] (1-1) Preparation of fluidized solidified soil slurry:

[0021] Dig the original soil on site and screen and remove impurities;

[0022] Add the formulated amount of soil and the formulated amount of water into the original soil soaking slurry pool for soaking to obtain solidified soil slurry;

[0023] The solidified soil slurry is transported to a solidified soil premixing tank, a formulated amount of curing agent is added to the solidified soil premixing tank, and the solidified soil slurry is fully stirred to obtain a fluidized solidified soil slurry;

[0024] (1-2) Preparation of lightweight foamed concrete: Add a formula amount of cement, a formula amount of foaming agent, and a formula amount of water into a lightweight concrete foaming machine, and stir them thoroughly to make lightweight foamed concrete;

[0025] (2) The fluidized solidified soil slurry and the lightweight foamed concrete are respectively transported to a mixing tank and fully stirred to obtain liquid lightweight anti-seepage solidified soil.

[0026] The technical solution of the present invention is further improved, in which the step (1) uses a sieve to screen and remove impurities from the original soil on site, and the sieve hole diameter of the sieve is 2-3 mm;

[0027] In the steps (1-1), (1-2) and (2), the stirring speed is 3000-4000 r / min and the stirring time is 5-10 min. The third object of the present invention is to provide a construction method for filling the underground core of a building with liquid lightweight impermeable solidified soil, comprising the following steps:

[0028] Every 30 meters around the single building, dig holes with a width of 1-1.2 meters in the original backfill soil in the underground core of the building. Insert the exhaust pipe into the hole and go deep into the underground core of the building. Install SFG2.5-2 duct axial flow fan outside the exhaust pipe to exhaust outwards.

[0029] Before filling, remove debris from the construction surface of the underground core of the building, use a water pump to pump water to ensure that there is no water accumulation within the filling area;

[0030] The liquid lightweight anti-seepage solidifying soil is directly pumped into the core of the underground room. Under the action of gravity, the liquid lightweight anti-seepage solidifying soil flows to every corner of the core of the underground room. The discharge of the liquid lightweight anti-seepage solidifying soil avoids impacting the outer walls and supporting structures of the basement.

[0031] The technical solution of the present invention is further improved in that the size of the exhaust pipe is Φ300mm; the material of the exhaust pipe is PVC; and the exhaust time is 30-60 minutes.

[0032] The technical solution of the present invention is further improved. When the bottom elevation of the foundation pit is inconsistent, the construction should be carried out in the order of deep first and shallow later. When the foundation filling construction of a large area is carried out, it should be carried out symmetrically in sections, and the length of each section should be ≤50m.

[0033] Liquid lightweight impermeable solidified soil should be filled in layers, with the thickness of each layer ≤2m. The template should be used to achieve staggered joints between the upper and lower filling layers, with a staggered distance of 1-2m. The height difference between adjacent areas should be ≤1m, and the time interval between the upper and lower filling layers should be ≥24h.

[0034] The curing agent is added into the premixing tank of the solidified soil until the filling of the liquid lightweight anti-seepage solidified soil is completed, with a time interval of ≤4h. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The present invention is a flow chart of the preparation method of the liquid lightweight anti-seepage solidified soil. DETAILED DESCRIPTION

[0036] 1. Preliminary preparation:

[0037] 1. Personnel, site and machinery preparation

[0038] 1. A number of qualified workers who have been trained;

[0039] 2. TH lightweight concrete contracting machine;

[0040] 3. ZJQ mining submersible slurry machine;

[0041] 4. Engineering forklifts, excavators, etc.;

[0042] 5. One cement tank;

[0043] 6. Dig one original soil soaking pool (3*3*1M) and one solidification premix pool (2*2*1M).

[0044] (II) Material preparation

[0045] 1. Bulk ordinary Portland cement P.O42.5, manufacturer: Yangzhou Xinglong Cement Co., Ltd., Yangzhou Conch Cement Co., Ltd.

[0046] 2. Curing agent: mineral-based cementitious material, main ingredients: mineral powder, desulfurized ash, cement, admixtures, a new type of mineral-based cementitious material, its proportions, main ingredients and manufacturers are as follows:

[0047] (1) Mineral powder: The amount generally accounts for 10%-30% of the total cementitious materials. The main components include various metal oxides, such as iron, calcium, magnesium, aluminum and other oxides. Common mineral powders include iron ore powder, steel slag powder, etc. Some manufacturers of mineral powders include Hebei Jingye Group, Tangshan Jianlong Industrial Co., Ltd., etc.

[0048] (2) Desulfurization ash: The content of desulfurization ash is usually 5%-20%. It is a by-product produced in the flue gas desulfurization process after coal combustion. The main components are silicon dioxide, aluminum oxide, calcium oxide, sulfur trioxide, etc. Desulfurization ash is mostly produced by the desulfurization equipment of some large thermal power plants, such as some power plants under Huaneng Group and Datang Group.

[0049] (3) Cement: ordinary Portland cement;

[0050] (4) Admixtures: generally water reducers and retarders, with the following proportions and ingredients (manufacturers: Jiangsu Subote New Materials Co., Ltd., Kezhijie New Materials Group Co., Ltd.):

[0051] Water reducing agent:

[0052] Main ingredients: usually contain high molecular weight compounds such as polycarboxylic acid series and naphthalene series, as well as some auxiliary ingredients such as retarders, air entraining agents, etc.

[0053] Function and proportion: The function of water reducer is to reduce the water consumption of concrete or solidified soil and improve its fluidity. In liquefied solidified soil, the dosage of water reducer is generally 0.5%-2% of the total mass of cementitious materials.

[0054] Retarder:

[0055] Main ingredients: Commonly used ones include lignin sulfonates, sugars, etc.

[0056] Function and proportion: The function of retarder is to delay the hydration reaction of cement, prevent the solidified soil from setting too quickly, and facilitate construction. Its dosage is generally 0.1%-0.5% of the total mass of cementitious materials;

[0057] 3. Polymer composite cement foaming agent (physical type)

[0058] The manufacturer of polymer composite cement foaming agent is Weihai Zhongsheng New Building Materials Co., Ltd., the specification model is F1, the implementation standard is Appendix A of CJJ / T 177-2012 "Technical Specifications for Bubble Mixed Lightweight Soil Filling Engineering", JC / T 2199-2013 (2017) "Foaming Agent for Foamed Concrete", the parameters of polymer composite cement foaming agent are shown in the following table:

[0059] Table 1 Parameters of polymer composite cement foaming agent

[0060] <![CDATA[Bubble group density (kg / m 3 )]]> 51 The sedimentation distance of the standard bubble column after 1 hour of static standing / mm 2 Water secretion of standard bubble column after 1 hour of standing / ml 20 Foaming multiple 20 Dilution ratio: polymer composite cement foaming agent: water 1:60

[0061] The polymer composite cement foaming agent has high foaming multiple and good foam stability.

[0062] 4. Soil source: backfill soil (local materials)

[0063] 5. Tap water

[0064] 2. Determine the mix ratio:

[0065] According to the experience of construction and trial mixing, the bulk density is ≤10KN / M 3 , compressive strength: >0.6Mpa liquid lightweight anti-seepage solidified soil, foamed concrete dry density must be no less than 400kg / m 3 , theoretical calculation is based on a bulk density of 300kg / m 3 Calculate the ratio:

[0066] (I) Lightweight foam concrete mix design:

[0067] In order to prepare liquid lightweight, waterproof and solidified soil, a bulk density of 300KG / M3 Lightweight foamed concrete, the foaming agent uses a physical foaming agent: polymer composite cement foaming agent. According to the test report, its bubble group density is 51KG / M 3 , the foaming rate is 20 times, and the dilution ratio is: polymer composite cement foaming agent: water = 1:60.

[0068] 1. Theoretical calculation:

[0069] (1) Calculate 1M 3 Dry bulk density ρ=300KG / M 3 Cement dosage:

[0070] There is a formula:

[0071] ρ=Sa(Mc+Mm)

[0072] ρ—The design dry density of foam concrete is 300kg / m 3

[0073] Sa—quality coefficient is 1.2

[0074] Mc—1m 3 Cement dosage for foamed concrete

[0075] Mm—1M 3 The amount of admixture used in foamed concrete (the present invention only has foaming agent, so it is 0)

[0076] 300 = 1.2 (Mc) Mc = 250 KG

[0077] (2) Calculation of water consumption for foam:

[0078] Mw=B(Mc+Mm)

[0079] Mm—1M 3 Water consumption in foamed concrete (Kg)

[0080] B—Water-cement ratio is 0.6

[0081] Mm=0.6*250=150Kg

[0082] (3) Total volume of each component mixture in 1M3 foam concrete V1:

[0083] V1=Mc / ρc+Mw / ρw+Mm / ρm

[0084] Ρc—density of cement: 3100 / M 3

[0085] Ρw—density of water: 1000kg / m 3

[0086] Pm - density of admixture not used

[0087] V1=250 / 3100+150 / 1000=0.231M 3

[0088] (4) In 1M3 foamed concrete, the amount of foaming agent added is V2:

[0089] V2=K(1-V1)

[0090] K---Redundancy coefficient K is 1.2

[0091] V2=1.2(1-0.231)=0.923M3

[0092] (5)1M 3 The amount of physical foaming agent Mf in foamed concrete:

[0093] Mf=V2Ρf / (β+1)

[0094] PF—Measured density of foaming agent

[0095] β—Multiple of foaming agent

[0096] Mf=0.923*51 / (20+1)=2.24Kg

[0097] 2. After multiple on-site trial mixes, the dry bulk density can be tested to be 380kg / M according to the weight ratio of water: cement: foaming agent = 150: 250: 2.24. 3 , wet bulk density 425kg / M 3 Lightweight foamed concrete.

[0098] (II) Design of liquid lightweight, impermeable and solidified soil mix ratio

[0099] 1. The strength of the solidified soil increases with the increase of the amount of the curing agent. According to the technical parameter requirements of the present invention, the present invention takes 8%; 2. The amount of curing agent added:

[0100] Mc=A*Mg / 1+Wo

[0101] Mc—curing agent quality

[0102] A—Curing agent mixing ratio

[0103] Mg—test soil quantity: 1150KG

[0104] Wo—water content of the test soil (the soil excavated on site in the present invention is tested for water content:

[0105] 16.5%, wet density: 1491KG / M 3 )

[0106] Mc=8%*1150 / (1+0.165)=79Kg, take 80Kg

[0107] 3. Take 230kg of water

[0108] 4. The proportion of liquid lightweight, impermeable and solidified soil (weight ratio):

[0109] After multiple tests, the bulk density is ≤10KN / M 3 , compressive strength>0.6Mpa, the proportion is as follows:

[0110] Water: cement: foaming agent: soil: curing agent = 378: 250: 2.24: 1150: 80

[0111] 5. The adjustment of the mix ratio usually adopts two methods: adjusting the raw material method and the volume method. The volume method is now used to verify the above mix ratio (the present invention is to add lightweight foam concrete to the flowing liquefied solidified soil, wherein the foamed concrete and the anti-seepage solidified soil are both 1M 3 Calculate, so the volume of the two mixtures should be 2):

[0112]

[0113] mg—the amount of curing agent used in each cubic meter of fluidized solidified soil (kg);

[0114] pg—density of curing agent (kg / m3), for cement, it can be 3100kg / m3;

[0115] mw—the amount of water in each cubic meter of fluidized solidified soil (kg); pw—the density of water (kg / m3), which can be taken as 1000kg / m3;

[0116] ms—the amount of raw soil in each cubic meter of fluidized solidified soil (kg); ps—the solid particle density of raw soil (kg / m3);

[0117] ma—the amount of admixture in each cubic meter of fluidized solidified soil (kg); pa—the density of admixture (kg / m3);

[0118] mc—the amount of admixture in each cubic meter of fluidized solidified soil (kg); pc—the density of admixture (kg / m3);

[0119] V—the ratio of bubbles mixed in each cubic meter of fluidized solidified soil to the total volume, calculated as 3%;

[0120] 80 / 3100+228 / 1000+1150 / 1491+3%+402.24 / 425=2

[0121] Meets the requirements.

[0122] 3. Test requirements and relevant mix ratio data:

[0123] (I) Test requirements

[0124] The trial mix should be carried out on the basis of the calculated mix. It is advisable to adjust the amount of various materials in the calculated mix through trial mix until the performance of the liquid lightweight and impermeable solidified soil meets the design and construction requirements;

[0125] 4. Preparation method of liquid lightweight anti-seepage solidified soil:

[0126] 1. The soil source is transported to the original soil soaking and slurry making pool by an excavator (forklift). The on-site soil is screened and soaked with a 2mm sieve, and the impurities and large debris in the backfill are removed. The slurry is pumped into the solidified soil premixing pool through a mining slurry machine and a flow meter (for measurement);

[0127] 2. According to the data in the mix ratio and flow table, calculate the required amount of curing agent and add it in time. After sufficient stirring for no less than 5 minutes, it is pumped to the mixing tank by the mining slurry machine, and the inspectors conduct the inspection of the cured soil;

[0128] 3. When mixing and making solidified soil, bulk cement in the cement tank is electronically metered and made into foamed concrete by a lightweight concrete foaming machine, and then pumped to the mixing tank. The two different materials are fully mixed, with the stirring speed not less than 3000r / min and the stirring time not less than 5min;

[0129] 4. The liquid lightweight, waterproof solidified soil with a slump of 180-210mm is measured by the flow meter installed on the pipeline and then directly pumped to every corner of the underground room.

[0130] 5. A construction method for filling the core of an underground house with liquid lightweight impermeable solidified soil comprises the following steps:

[0131] Every 30 meters around the single building, dig the original backfill soil to a width of 1 meter, insert a Ф300mmPVC exhaust pipe deep into the underground core of the building, and install an SFG2.5-2 duct axial flow fan to exhaust the air outwards;

[0132] Before filling, after safety is confirmed, people can enter the underground room to clear garbage, tree roots and other debris on the construction surface of the room, and use water pumps to pump water to ensure that there is no water accumulation within the filling area;

[0133] Use a delivery pump to directly pump the liquid lightweight impermeable solidifying soil to every corner of the underground room. During the pumping construction, the discharged material must not directly impact the basement outer wall and supporting structure.

[0134] When the bottom elevation of the foundation pit is inconsistent, construction should be carried out in the order of deep first and shallow later;

[0135] When constructing a large area of ​​foundation filling, it should be carried out in sections symmetrically, with the length of each section ≤ 50m;

[0136] Liquid lightweight impermeable solidified soil should be filled in layers, with the thickness of each layer ≤2m. The template should be used to achieve staggered joints between the upper and lower filling layers, with a staggered distance of 1-2m. The height difference between adjacent areas should be ≤1m, and the time interval between the upper and lower filling layers should be ≥24h.

[0137] The curing agent is added into the premixing tank of the solidified soil until the filling of the liquid lightweight anti-seepage solidified soil is completed, with a time interval of ≤4h.

[0138] 6. Quality inspection and acceptance:

[0139] 6.1 The curing agent is inspected as one batch of 500t. If the quantity is less than 500t, it shall be inspected as one batch.

[0140] 6.2 Mixing performance tests shall be carried out at the mixing point and filling point respectively. If mixing is done on site, it only needs to be done once: slump and expansion tests shall be carried out every 200m 3 Sampling should be taken at least once, and mixing should be less than 200m3 per work shift. 3 , sampling shall not be less than 1 batch, and sampling shall not be less than 1 batch for each section and each layer; one inspection batch consists of 3 groups of test pieces;

[0141] 6.3 Retention of solidified soil cube compressive strength test specimens:

[0142] 6.3.1 Continuous filling of the same mix ratio is less than or equal to 400m 3 , every 200m 3 Take a group of test pieces; more than 400m 3 Every 400m 3 Take a set of test pieces.

[0143] 6.3.2 The test mold for the specimen is: 7.07*7.07*7.07cm.

[0144] 6.4 Comparison between test results and design requirements:

[0145] (1) Test results: 7-day measured compressive strength: 0.56 MPa; 28-day measured compressive strength: 0.98 MPa

[0146] Measured bulk density: 8.6KN / M 3

[0147] (2) Design requirements for liquid lightweight impermeable solidified soil: Bulk density: ≤10KN / M 3 , compressive strength:>0.6Mpa

[0148] (3) Comparing the above data, all the design requirements are met!

[0149] (4) Therefore, the optimal mix ratio of this liquid lightweight and impermeable solidified soil is:

[0150] Water: cement: foaming agent: soil: curing agent = 378: 250: 2.24: 1150: 80

[0151] 6.5. Slump: The actual measured value on site is 190mm

[0152] 6.6. Possess anti-seepage ability:

[0153] (1) Unique structure: Foam concrete contains a large number of evenly distributed closed pores, which can effectively block the channels for water penetration and reduce the possibility of water seepage.

[0154] (2) Low porosity: Compared with ordinary concrete, the porosity of foamed concrete is relatively low, and the pores are relatively small and closed, making it difficult for water to pass through.

[0155] (3) Good integrity: Foam concrete can be poured as a whole during the construction process, without weak links such as construction joints, thus improving the overall anti-seepage performance.

[0156] (4) Good filling properties: It can fully fill the construction space, tightly integrate with the surrounding structure, and reduce gaps for water seepage.

[0157] (5) Sufficient cement hydration: During the preparation process, cement can be fully hydrated, and the formed hydration products fill the pores, enhancing the density of the structure and thus improving the anti-seepage ability.

Claims

1. Liquid lightweight anti-seepage solidified soil, characterized by: It comprises fluidized solidified soil slurry and lightweight foamed concrete; the volume ratio of the fluidized solidified soil slurry to the lightweight foamed concrete is 1:1; The fluidized solidified soil slurry comprises soil material, a solidifying agent, and water, and the weight ratio of the soil material, the solidifying agent, and the water is 1150:80:228; The lightweight foamed concrete comprises water, cement and foaming agent; the weight ratio of water:cement:foaming agent is 150:250:2.

24.

2. The liquid lightweight impermeable solidified soil according to claim 1 is characterized in that: The curing agent is a mineral-based cementitious material, comprising the following components: 10wt%-30wt% of mineral powder, 5wt%-20wt% of desulfurized ash, 0.6wt%-2.5wt% of admixture, and the balance is cement; The admixture includes a water reducer and a retarder; the amount of the water reducer is 0.5wt%-2wt% of the curing agent; the amount of the retarder is 0.1wt%-0.5wt% of the curing agent; The cement in the curing agent is silicate cement P.O42.

5.

3. The liquid lightweight anti-seepage solidified soil according to claim 1 is characterized in that: The foaming agent is a polymer composite cement foaming agent.

4. The liquid lightweight anti-seepage solidified soil according to claim 1 is characterized in that: In the lightweight foamed concrete, cement is silicate cement P.O42.

5.

5. The liquid lightweight anti-seepage solidified soil according to claim 1 is characterized in that: The bulk density of the liquid lightweight impermeable solidified soil is ≤10KN / M 3 , compressive strength>0.6Mpa; the slump of the liquid lightweight anti-seepage solidified soil is 180~210mm.

6. The method for preparing the liquid lightweight impermeable solidified soil according to claim 1, characterized in that: The following steps are involved: (1) Preparation of fluidized solidified soil slurry and lightweight foamed concrete; (1-1) Preparation of fluidized solidified soil slurry: Excavate the original soil at the construction site and screen and remove impurities; Add the formulated amount of soil and the formulated amount of water into the original soil soaking slurry pool for soaking to obtain solidified soil slurry; The solidified soil slurry is transported to a solidified soil premixing tank, a formulated amount of curing agent is added to the solidified soil premixing tank, and the solidified soil slurry is fully stirred to obtain a fluidized solidified soil slurry; (1-2) Preparation of lightweight foamed concrete: Add a formula amount of cement, a formula amount of foaming agent, and a formula amount of water into a lightweight concrete foaming machine, stir them thoroughly, and make lightweight foamed concrete; (2) The fluidized solidified soil slurry and the lightweight foamed concrete are transported to a mixing tank respectively and stirred sufficiently to obtain liquid lightweight anti-seepage solidified soil.

7. The method for preparing the liquid lightweight impermeable solidified soil according to claim 1, characterized in that: In step (1), the on-site soil is screened and impurities are removed using a sieve, wherein the sieve hole diameter of the sieve is 2-3 mm; In the steps (1-1), (1-2) and (2), the stirring speed is 3000-4000 r / min and the stirring time is 5-10 min; The preparation method further comprises: step (3) detecting the fluidity of the liquid lightweight impermeable solidified soil.

8. The construction method for filling the underground core of a building with liquid lightweight impermeable solidified soil according to claim 6, characterized in that: The following steps are involved: Every 30 meters around the single building, the original backfill soil in the underground core of the building is dug to make a hole with a width of 1-1.2 meters. The exhaust pipe is inserted into the hole and penetrates into the underground core of the building. The exhaust pipe is equipped with a pipeline axial flow fan to exhaust air outwards. Before filling, remove debris from the underground core construction surface to ensure that there is no water accumulation within the filling area; The liquid lightweight anti-seepage solidifying soil is directly pumped into the core of the underground room. Under the action of gravity, the liquid lightweight anti-seepage solidifying soil flows to every corner of the core of the underground room. The discharge of the liquid lightweight anti-seepage solidifying soil avoids impacting the outer walls and supporting structures of the basement.

9. The construction method for filling the underground core of a building with liquid lightweight impermeable solidified soil according to claim 8, characterized in that: The size of the exhaust pipe is Ф300mm; the material of the exhaust pipe is PVC; the exhaust time is 30-60 minutes.

10. The construction method for filling the underground core of a building with liquid lightweight impermeable solidified soil according to claim 8, characterized in that: When the bottom elevation of the foundation pit is inconsistent, construction should be carried out in the order of deep first and shallow later; When constructing a large area of ​​foundation, it should be carried out in sections symmetrically, with the length of each section ≤ 50m; Liquid lightweight impermeable solidified soil should be filled in layers, with the thickness of each layer ≤2m. The template should be used to achieve staggered joints between the upper and lower filling layers, with a staggered distance of 1-2m. The height difference between adjacent areas should be ≤1m, and the time interval between the upper and lower filling layers should be ≥24h. The curing agent is added into the premixing tank of the solidified soil until the filling of the liquid lightweight anti-seepage solidified soil is completed, with a time interval of ≤4h.

Images