Preparation and application of a compact fine-grained till solidification material

Abstract

The application discloses a kind of preparation and application of dense fine particle moraine solidified material, belong to the field of glacial geological disaster prevention and control.The material is composed of A component, B component and active agent, A component includes water glass solution, sodium tetraborate;B component includes copper sulfate, phosphoric acid, silver chloride, hydrochloric acid;Active agent includes calcium hydroxide, potassium carbonate.Grasping when, A, B component is mixed before adding active agent to make solidified material, solidified material can be injected better, can be injected into weakly permeable stratum with permeability coefficient 10 ‑5 cm / s, its gel time can be adjusted, moraine grouting solidified body strength can reach 3-4MPa after, solve the technical problems that traditional cement solidified material cannot penetrate diffusion in moraine, poor curing effect and existing chemical solidified material is expensive, has toxicity, grouting solidification management of glacial debris flow, ice lake breach and other geological disasters has great engineering significance.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of preparation and application of dense fine particle moraine solidified material, belong to glacial geological disaster prevention field. BACKGROUND

[0002] Glacial movement has the function of transport and accumulation, and glacial movement is accompanied by energy dissipation. With the gradual loss of energy during the movement process, the transport capacity of the glacier gradually weakens, causing a large amount of rock and soil to separate from the ice body and deposit, forming different forms of accumulation bodies. Therefore, moraine is a deposit formed by the accumulation of different transport forms after the ablation of glacier, mainly composed of boulders, gravel, pebbles, sand, silt and clay, etc. It has poor sorting and no bedding, and the particle size is extremely uneven. Due to global warming, the huge glacial structure is in an accelerated ablation state, not only showing rapid recession and thinning, but also increasing the instability of the glacier itself, leading to frequent geological disasters such as glacial debris flow and ice lake outburst, causing great threat and loss to the life and property safety of local residents. Taking the Pulang copper mine in Yunnan as an example, the Pulang copper mine is an underground mine using natural caving method. Since the extraction of underground ore body will inevitably form a goaf, it will cause surface movement, subsidence, collapse and other geological disasters. The overburden strata of Pulang copper mine have a complete Quaternary glacial relic, and the moraine reserves are huge. With the increase of mining depth, the surface subsidence area is expanding. Once the flood season comes, rainfall, surface runoff and snowmelt water in the upper reaches will all drive the tens of meters of moraine overburden into the collapse area, causing underground debris flow accidents. The main source of debris flow is fine-grained moraine. Under the action of rainfall and snowmelt water, the water content of fine-grained moraine soil is easily saturated, which destroys the original soil stability structure and causes rapid collapse to form debris flow. Moraine debris flow has the characteristics of long movement distance, fast movement speed and large scale of outflow. In order to effectively prevent and control moraine debris flow disaster, grouting solidification is used to solidify the moraine stratum, which solidifies the independent fine-grained moraine into a whole, reduces the material source of debris flow and reduces the harm of debris flow.

[0003] Moraine is mainly composed of fine-grained clay wrapped around random distribution of stone blocks. After several centuries of extrusion and accumulation, its permeability is extremely poor, and its permeability coefficient is as low as 10 -5cm / s, moraine stratum becomes a great technical problem in the field of grouting due to its characteristics of high density, extremely low permeability coefficient and complex structure composition. When using traditional granular grouting materials such as ordinary Portland cement, ultra-fine cement, cement-clay and the like, there is a significant filtration effect, and the cement particles are retained on the surface of the moraine and cannot penetrate into the moraine soil, so the diffusion mode of the slurry is only splitting, and the splitting grouting has a very limited reinforcement effect on the soil. Therefore, a chemical slurry with better injectability needs to be selected to realize the penetration grouting. Common chemical solidification materials include polyurethane, acrylic, lignin, resin, water glass and the like. The strength of the polyurethane and resin grouting materials after solidification is relatively high, but the price is several hundred times that of the cement-based solidification material, so it cannot be widely used due to the high cost. The acrylic and lignin materials have certain toxicity, which not only pollutes and destroys the ecological environment, but also causes great harm to the life safety and health of local residents. As a mineral binder, the main component of water glass is sodium silicate, which is widely used due to its low price, safety and non-toxicity, but it has low strength. In view of the above shortcomings of the solidification materials, it is urgent to develop a solidification material suitable for dense fine-grained moraine stratum grouting, which has strong injectability, low cost, non-toxicity, safety, green environmental protection, controllable gel time and high strength. SUMMARY

[0004] To solve the problems in the prior art, one of the purposes of the present application is to provide a chemical solidification material with low cost, strong injectability and high strength, which has a wide range of adjustable gel time and high gel strength. When a 70.7x70.7x70.7mm mold is used to prepare a test piece, the strength under different curing ages is 3d(1.45MPa), 7d(2.63MPa) and 14d(3.61MPa) respectively.

[0005] To achieve the above-mentioned purposes, the present application discloses a dense fine-grained moraine solidification material, which is composed of A component, B component and active agent. The A component includes water glass stock solution 56%-66.5%, sodium tetraborate 0.09%-0.18% and water 33.41%-43.82% by mass percentage, wherein the total mass percentage of the water glass stock solution, sodium tetraborate and water is 100%. The B component includes copper sulfate 26.25%-28%, phosphoric acid 10%-12.5%, silver chloride 0.1%, hydrochloric acid 4.9% and water 54.5-58.75% by mass percentage, wherein the total mass percentage of the copper sulfate, phosphoric acid, silver chloride, hydrochloric acid and water is 100%. The active agent includes calcium hydroxide 0.5-1%, potassium carbonate 38.9%-40% and water 59%-60.6% by mass percentage, wherein the total mass percentage of the calcium hydroxide, potassium carbonate and water is 100%.

[0006] A preparation of a compact fine-grained till solidification material, the specific preparation method comprising the following steps:

[0007] (1) Preparation of water glass diluent

[0008] The Baume degree of the water glass stock solution is measured by a Baume meter, and the amount of water to be added is calculated according to the actual required Baume degree and the formula The Baume degree of the water glass stock solution is measured by a Baume meter, and the amount of water to be added is calculated according to the actual required Baume degree and the formula

[0009] In the formula: G a is the mass of the water glass stock solution, kg; G b is the mass of the water to be added, kg; A is the Baume degree of the water glass stock solution, °Be'; and B is the required Baume degree, °Be'.

[0010] (2) Preparation of the required solution

[0011] Sodium tetraborate solution: sodium tetraborate powder is dissolved in water to obtain a sodium tetraborate solution;

[0012] Copper sulfate solution: copper sulfate powder is dissolved in water, and stirring is performed until the solution is colorless and free of suspended precipitates to obtain a copper sulfate solution;

[0013] Phosphoric acid solution: the original phosphoric acid solution is diluted with water to obtain a phosphoric acid solution;

[0014] Saturated silver chloride solution: silver chloride crystals are added to water until complete dissolution to obtain a silver chloride solution, and hydrochloric acid solution is added to the silver chloride solution and stirred to obtain a saturated silver chloride solution;

[0015] Potassium carbonate solution: potassium carbonate powder is weighed and dissolved in water to obtain a potassium carbonate solution;

[0016] Calcium hydroxide solution: calcium hydroxide powder is weighed and dissolved in water to obtain a calcium hydroxide solution.

[0017] (3) Preparation of component A

[0018] The sodium tetraborate solution obtained in step (2) is added to the water glass diluent obtained in step (1) to obtain component A

[0019] (4) Preparation of component B

[0020] The copper sulfate solution and the saturated silver chloride solution prepared in step (2) are mixed, and the phosphoric acid solution prepared in step (2) is added to obtain component B;

[0021] (5) Preparation of the solidification material

[0022] Mixing the A component obtained in step (3) with the B component obtained in step (4) to obtain an AB mixed solution, then adding the potassium carbonate solution prepared in step (2), and then adding the calcium hydroxide solution prepared in step (2) to obtain a solidified material.

[0023] Preferably, the prepared solidified material can control the initial setting time of the slurry by adjusting the content of copper sulfate powder and phosphoric acid in the B component.

[0024] Preferably, the water glass stock solution in step (1) is a common sodium silicate solid water solution on the market, and the Béme degree of the water glass solution is required to be greater than 35°Be', and the modulus is between 3.0-3.2.

[0025] Preferably, in step (2), the mass ratio of sodium tetraborate powder to water is 9:91; the water temperature is 20-30℃; the mass ratio of copper sulfate powder to water is 3:1-4:1; the concentration of phosphoric acid solution is greater than 85%; the mass ratio of phosphoric acid stock solution to water is 1:4-1:3; the mass ratio of silver chloride crystal to water is 1:100, the water temperature is 10-15℃, the mass ratio of hydrochloric acid solution to saturated silver chloride solution is 49:101; the mass ratio of potassium carbonate powder to water is 7:5-3:2; the mass ratio of calcium hydroxide powder to water is 3:97-3:197, and the water temperature is 0℃.

[0026] Preferably, in step (3), the mass of the sodium tetraborate solution is 1%-2% of the total mass of the A component.

[0027] Preferably, in step (4), the mass ratio of copper sulfate solution, phosphoric acid solution, and saturated silver chloride solution is 7:10:3.

[0028] Preferably, in step (5), the mass ratio of the A component to the B component is 1:1; the mass ratio of the AB mixed solution, the potassium carbonate solution, and the calcium hydroxide solution is 100:6:3.

[0029] Preferably, all the reagents used are conventional commercially available reagents.

[0030] Another object of the present application is to provide a solidification process for dense moraine strata, which has the following steps:

[0031] (1) Drilling: drilling is performed by using a vertical directional drilling process;

[0032] (2) Hole washing: clay slurry with a soil slurry ratio of 0.5:1 is used for hole washing;

[0033] (3) Segmented sealing: Each segment is 5m long. When injecting the next segment, the previous segment must be sealed. A water pressure grouting column with a diameter of 70mm and an expansion diameter of 110mm is selected. When injecting the next segment, the water pressure grouting column must be placed at a position more than 1m above the segment to be injected and pressurized. After the water pressure column is pressed, its volume expands until it completely fits the hole wall.

[0034] (4) High and low pressure composite grouting: High and low pressure composite grouting is selected for grouting. After low pressure grouting, the grouting is stopped for 1-2 hours before high pressure grouting. The grout with a gel time of 45-60 minutes is selected for low pressure grouting, and the grout with a gel time of 60-96 minutes is selected for high pressure grouting. When grouting, the grouting pressure of 1-3 MPa is selected for low pressure grouting first. After low pressure grouting, the grouting is stopped for 1-2 hours to ensure uniform penetration of the grout. Then the grouting pressure of 3-6 MPa is selected for high pressure grouting.

[0035] (5) Secondary grouting: After the chemical grouting in step (4) is completed, a cement grout with a water-cement mass ratio of 1:1 is injected again;

[0036] (6) Curing: After grouting, the chemical grout and cement grout have been cured for 3 days. The soil has been initially solidified and the soil has a certain strength. Drilling can be carried out at the original hole position. A new section is formed by vertically drilling 5m below this section. The water pressure grouting column of the new section is placed 4m below the bottom of the previous section.

[0037] (7) Repeat steps (1) to (6) to carry out grouting for the next segment.

[0038] Preferably, in step (1), an XY150 drilling machine is used for drilling, and the drill rod diameter is 91mm.

[0039] Beneficial effects of the present invention

[0040] (1) The curing material of the present invention can control the initial setting time of the slurry by adjusting the content of copper sulfate powder and phosphoric acid in component B. Its gel time is adjustable and has a wide range of adjustment, which can meet the requirements of different gel times under different grouting conditions. The initial setting time of the slurry can be freely adjusted within the range of 45-96 min.

[0041] (2) Compared with granular grouts such as cement slurry and ultrafine cement, the curing material of this invention has strong injectability and a permeability coefficient of 10. -5 In dense glacial till formations with a density of cm / s, under the same grouting conditions, even ultrafine cement grout cannot penetrate into the glacial till soil, and cement particles are retained on the surface of the glacial till. However, when grouting with the solidification material of this invention, the diffusion mode of the grout in the glacial till is mainly penetration and supplemented by splitting. A huge grout-soil composite is formed on both sides and at the end of the splitting channel, which has excellent grouting effect.

[0042] (3) The present application fully stimulates the silicate ions in the water glass solution to carry out hydrolytic condensation reaction by adding various chemical reagents, and the silicate ions polymerize from disilicate, trisilicate, polysilicate to form silica sol, and SiO2 particles are continuously generated and coagulate into a continuous network structure, and intermittent condensation forms Si-O-Si bond, and finally forms silica gel with rigidity, which overcomes the technical problem of low strength of traditional water glass, and the strength of the solidified body is 3d (1.45MPa), 7d (2.63MPa), 14d (3.61MPa);

[0043] (4) The largest amount of the solidified material in the present application is water glass and water, which has a wide source of materials and low cost, and the cost of the same quality of chemical solidified material is only 1.5-2 times that of ordinary Portland cement material, which greatly reduces the grouting cost of chemical materials and is easy to be popularized and applied on a large scale;

[0044] (5) The solidified material of the present application does not contain toxic and harmful elements such as cadmium, chromium and arsenic, and is safe and non-toxic and non-polluting to the human body, soil and environment, and fully meets the requirements of green chemical industry and sustainable development;

[0045] (6) The grouting pressure in the traditional solidification process is single, the grout diffusion radius is small under low pressure grouting, but the grout diffusion range is relatively uniform, the grout diffusion radius is large under high pressure, but the grout diffusion range is relatively single, and the present solidification process combines the diffusion law of grout to select high and low pressure composite grouting, the grout penetrates uniformly around the drill hole to form a penetration circle under low pressure, and a cylindrical stone body is formed by low pressure grouting reinforcement, the grout splits a farther distance on the basis of the penetration column under high pressure, the grout diffuses uniformly along the two sides of the split channel and forms a larger grout-soil composite at the end of the split, and a tree crown-shaped stone body is formed by high pressure grouting reinforcement, which greatly improves the solidification rate of the grout and the solidification effect of the soil compared with the traditional solidification process;

[0046] (7) The solidification process of the present application re-injects cement grout after the chemical grouting is completed, which can effectively fill the split channel formed by the split and diffusion of the chemical grout, form a grout vein skeleton, and have a certain supporting and deformation limiting effect on the soil, and the cement grout can further compact the soil on both sides of the split channel under the action of split and diffusion, which has a secondary reinforcing effect on the soil. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 The flow chart for preparing the solidified material;

[0048] Figure 2 The stress-strain curve of the solidified body of moraine under uniaxial compression;

[0049] Figure 3 The schematic diagram of water pressure stop grouting column;

[0050] Figure 4 Fig. 1 is a low-pressure grouting solidification effect schematic diagram;

[0051] Figure 5 Fig. 2 is a high-low pressure composite grouting solidification effect schematic diagram;

[0052] In the figure: 1 - water inlet hole, 2 - grouting inlet, 3 - inflatable rubber ring, 4 - grouting outlet, 5 - injected section, 6 - permeation ring, 7 - permeation diffusion direction, 8 - permeation column, 9 - permeation ball, 10 - tree-shaped grouting vein, 11 - splitting channel. DETAILED DESCRIPTION

[0053] The application will be further described in detail below in combination with specific embodiments.

[0054] The example takes Pulong in Yunnan as the engineering background. Pulong copper mine is located in the southeast margin of Qinghai-Tibet Plateau, which belongs to the Himalaya-Qinghai-Tibet orogenic belt. The Himalaya-Qinghai-Tibet orogenic belt is the highest glacierized mountain outside the polar region. Therefore, the overburden stratum of Pulong copper mine has a huge glacial deposit reserve, with a distribution area of about 0.65 km 2 , a thickness of more than 80 m, and a total amount of more than 30 million tons. Pulong copper mine is an underground mine using natural caving method. Since the underground ore body must be mined out, a goaf will be formed. With the increase of mining depth and the continuous expansion of surface subsidence range, once the flood season comes, the rainfall, surface runoff of upstream, and snowmelt water of high mountains will all drive the tens of meters of glacial deposit overburden into the collapse area, causing underground debris flow accidents. In order to effectively prevent and control the glacial deposit debris flow disaster, the grouting solidification method is used to solidify the glacial deposit stratum, changing the glacial deposit from "powder" to "block", thereby reducing the material source of the starting of debris flow and reducing the harm of debris flow. However, the glacial deposit stratum is formed by the double extrusion of natural accumulation and geological movement for hundreds of centuries, which forms a soil-rock mixture with large density and extremely poor permeability. The wet density of the glacial deposit stratum is 2.5 g / cm 3 , the dry density is 2.2 g / cm 3 , and the permeability coefficient of the soil is 6.75 x 10 -5 cm / s, which is a weak permeable order. When the traditional cement-based grout is used for grouting, the cement particles are retained on the surface of the glacial deposit and cannot penetrate into the soil. When the solidification material of the application is used for grouting solidification of the dense glacial deposit stratum, the diffusion mode of the grout in the glacial deposit is mainly permeation and auxiliary splitting. The grout penetrates along both sides of the splitting channel and the end of the splitting channel to form a huge grout-soil composite.

[0055] Example 1

[0056] In this embodiment, the water glass stock solution has a Baume degree of 40°Be' and a modulus of 3.0. The actual required Baume degree is 26°Be'. The modulus of the water glass stock solution has reached the actual requirement, so there is no need to adjust the modulus of the water glass stock solution. In this embodiment, the total mass of the A component is 200 g, and the total mass of the B component is 200 g.

[0057] It is calculated that if the total mass of the A component is 200 g, 4 g of sodium tetraborate solution and 196 g of water glass diluent are required.

[0058] (1) Preparation of water glass diluent

[0059] According to the formula It is calculated that 112 g of water glass stock solution and 84 g of water are required in 196 g of water glass diluent, and the water glass diluent is obtained after mixing;

[0060] (2) Preparation of required solutions

[0061] Sodium tetraborate solution: 0.36 g of sodium tetraborate powder is dissolved in 3.64 g of water to obtain 4 g of sodium tetraborate solution;

[0062] Copper sulfate solution: 52.5 g of copper sulfate powder is dissolved in 17.5 g of water to obtain 70 g of copper sulfate solution;

[0063] Phosphoric acid solution: 20 g of phosphoric acid solution is weighed and diluted with 80 g of water to obtain 100 g of phosphoric acid solution;

[0064] Saturated silver chloride solution: 0.2 g of silver chloride crystals is dissolved in 20 g of water with a temperature of 10-15°C to obtain a silver chloride solution, and then 9.8 g of hydrochloric acid solution is added to the silver chloride solution and stirred to obtain 30 g of saturated silver chloride solution;

[0065] Potassium carbonate solution: 14 g of potassium carbonate powder is dissolved in 10 g of water to obtain 24 g of potassium carbonate solution;

[0066] Calcium hydroxide solution: 0.18 g of calcium hydroxide powder is dissolved in 11.82 g of water to obtain 12 g of calcium hydroxide;

[0067] (3) Preparation of A component

[0068] All of the water glass diluent obtained in step (1) is mixed with all of the sodium tetraborate solution obtained in step (2) to obtain 200 g of the A component;

[0069] (4) Preparation of B component

[0070] Add all the saturated silver chloride solution obtained in step (2) to all the copper sulfate solution obtained in step (2), and finally add all the phosphoric acid solution obtained in step (2) to obtain 200g of component B.

[0071] (5) Preparation of curing materials

[0072] Quickly pour all of component A obtained in step (3) into component B obtained in step (7) and mix them evenly to obtain a mixed solution of components A and B. Add all of the potassium carbonate solution prepared in step (2) into the mixed solution of components A and B, and then add all of the calcium hydroxide solution prepared in step (2) to obtain the cured material.

[0073] The cured material obtained in this embodiment has an initial setting time of 45 min, a viscosity of 40 mPa·s, and a density of 1.1 × 10⁻⁶. 3 kg / m 3 The solidified material has low viscosity, resulting in less viscous force between glacial till particles and good fluidity. Experiments show that the optimal soil-to-slurry ratio is 16.83% of the solidified material mass. Using the solidified material from this embodiment, cubic specimens of 70.1×70.1×70.1 mm were prepared. The stress-strain curves of the solidified glacial till under uniaxial compression at different curing ages are shown below. Figure 2 As shown, the peak load at failure of the specimen cured for 3 days was 1.45 MPa, the peak load at failure of the specimen cured for 7 days was 2.63 MPa, and the peak load at failure of the specimen cured for 14 days was 3.61 MPa. The properties and strength of the cured material are shown in Table 1.

[0074] Table 1. Properties of materials cured at 26° Be' Baume in Example 1

[0075]

[0076] Example 2

[0077] In this embodiment, a water glass stock solution with a Baumé degree of 38°Be' and a modulus of 3.2 is used. The actual required Baumé degree is 28°Be', and the modulus of the water glass stock solution already meets the actual requirement, so there is no need to adjust the modulus of the water glass stock solution. In this embodiment, the total mass of component A is 200g, and the total mass of component B is 200g.

[0078] Calculations show that if the total mass of component A is 200g, then 198g of water glass diluent and 2g of sodium tetraborate solution are required.

[0079] (1) Preparation of water glass diluent

[0080] According to the formula The water glass diluent solution of 198 g is prepared by mixing 133 g of water glass stock solution and 65 g of water.

[0081] (2) Preparation of the required solution

[0082] Sodium tetraborate solution: 0.18 g of sodium tetraborate powder is dissolved in 1.82 g of water to obtain 2 g of sodium tetraborate solution.

[0083] Copper sulfate solution: 56 g of copper sulfate powder is dissolved in 14 g of water to obtain 70 g of copper sulfate solution.

[0084] Phosphoric acid solution: 25 g of phosphoric acid solution is weighed and diluted with 75 g of water to obtain 100 g of phosphoric acid solution.

[0085] Saturated silver chloride solution: 0.2 g of silver chloride crystal is dissolved in 20 g of water with a temperature of 10-15 °C in a weak light environment to obtain a silver chloride solution, and then 9.8 g of hydrochloric acid solution is added to the silver chloride solution and stirred to obtain 30 g of saturated silver chloride solution.

[0086] Potassium carbonate solution: 14.4 g of potassium carbonate powder is dissolved in 9.6 g of water to obtain 24 g of potassium carbonate solution.

[0087] Calcium hydroxide solution: 0.36 g of calcium hydroxide powder is dissolved in 11.64 g of water to obtain 12 g of calcium hydroxide.

[0088] (3) Preparation of component A

[0089] All of the water glass diluent solution obtained in step (1) is mixed with all of the sodium tetraborate solution obtained in step (2) to obtain 200 g of component A.

[0090] (4) Preparation of component B

[0091] All of the saturated silver chloride solution obtained in step (2) is added to all of the copper sulfate solution obtained in step (2), and finally all of the phosphoric acid solution obtained in step (2) is added, to finally obtain 200 g of component B.

[0092] (5) Preparation of the solidified material

[0093] All of the component A obtained in step (3) is quickly poured into the component B obtained in step (7) and mixed uniformly to obtain an AB component mixed solution, all of the potassium carbonate solution prepared in step (2) is added to the AB mixed solution, and then all of the calcium hydroxide solution prepared in step (2) is added, to obtain the solidified material.

[0094] The obtained solidified material of the embodiment is grouted, the initial setting time of the solidified material is 96 min, the viscosity of the solidified material is 39 mPa·s, and the density is 1.07*10 3 kg / m 3 The viscosity of the solidified material is small, the viscous force between the particles of the moraine soil is small, and the fluidity is good.

[0095] Example 3

[0096] The gel time of the solidified material is mainly realized by changing the adding amount of copper sulfate powder and phosphoric acid in the B component, that is, the mass percentage of the copper sulfate powder and the phosphoric acid original solution in the total mass of the B component, and meanwhile the Baume degree of the water glass stock solution has a certain influence on the gel time of the slurry. The solidified material prepared in the application can control the initial setting time of the solidified material to be 1-1440 min by adjusting the proportion of the copper sulfate powder and the phosphoric acid original solution in the B component. However, if the gel time of the solidified material is too short, the grouting pipeline is easy to be blocked, which affects the normal development of grouting operation. If the gel time of the solidified material is too long, a large amount of slurry is continuously injected, which causes slurry loss. Therefore, in the actual grouting engineering, the suitable gel time of the solidified material should be controlled to be about 30-90 min. The A component with different Baume degrees shown in Table 2 is prepared according to the method in Example 1, and the B component is prepared according to the method in Example 1. The relationship between the adding amount of the copper sulfate powder and the phosphoric acid original solution in the B component and the initial setting time of the solidified material is shown in Table 2.

[0097] Table 2 Initial setting time of different slurry ratios

[0098]

[0099] The addition amount indicates the percentage of the total mass of the B component, and the total addition amount of the copper sulfate powder and the phosphoric acid stock solution accounts for 26.25%-28% of the total mass of the B component, and the mass percentage of the phosphoric acid accounts for 10%-12.5% of the B component. The gel time of the solidified material of the present application can be accurately controlled by changing the percentage of the addition amount of the copper sulfate powder and the phosphoric acid stock solution in the B component. When the Baumé degree is 26°Be', the percentage of the total addition amount of the copper sulfate powder and the phosphoric acid stock solution in the total mass of the B component required for any initial setting time of 45 min-60 min can be calculated according to the formula t=3.5x-81.75; when the Baumé degree is 28°Be', the percentage of the total addition amount of the copper sulfate powder and the phosphoric acid stock solution in the total mass of the B component required for any initial setting time of 63 min-96 min can be calculated according to the formula t=7.8x-220, wherein t is the initial setting time of the solidified material, and x is the percentage of the total addition amount of the copper sulfate powder and the phosphoric acid stock solution in the total mass of the B component. Therefore, the percentage of the total addition amount of the copper sulfate powder and the phosphoric acid stock solution in the total mass of the B component required for different initial setting times can be inversely calculated by using the linear formula. When the initial setting time exceeds 96 min, the change rule of the addition amount and the initial setting time does not follow the linear change rule, and the gel time of the slurry will suddenly increase to 1440 min.

[0100] Example 4

[0101] The present embodiment is the application of the solidified material described in the present application in practice. The preparation method of the solidified material used in the present embodiment is described in Example 1 and Example 2.

[0102] During grouting, the overall glacial deposit is relatively dense, and is a complex soil-rock mixture composed of fine clay wrapped around stone blocks, and the stone content is as high as 45-55%. The grouting is carried out according to the following steps for the dense glacial deposit.

[0103] (1) Drilling, washing and protecting the hole: XY150 drilling machine is selected for drilling, and the drill rod diameter is 91 mm. In order to avoid drilling inclination, vertical directional drilling process is adopted to ensure that the drilling is vertical. The grouting hole spacing is selected to be 2x2 m, and the hole is formed at one time. The clay slurry with a soil slurry ratio of 0.5:1 is used for washing the hole, which can effectively flush out the debris in the hole wall. After washing the hole, the clay is cemented on the hole wall to form a protective layer, which has a certain hole protection effect on the hole wall.

[0104] (2) Section sealing: each section 5 m, the need to seal the previous section when the next section is injected, select the diameter of 70 mm water pressure stop paste column its expansion diameter is 110 mm, the need to inject the next section when the water pressure stop paste column is placed in the position of the injected section 1 m or more to pressurize, water pressure column pressure water volume expansion increases until the hole wall completely, such as Figure 3 shown.

[0105] (3) high and low pressure composite grouting: select high and low pressure composite grouting method for grouting, first low pressure grouting and then stop 1.5 h before high pressure grouting, because the curing material gel time can be adjusted and the adjustable range is 45-96 min, low pressure grouting selects the slurry with gel time of 45-60 min, high pressure grouting selects the curing material with gel time of 60-96 min. When grouting, first select 1.5 MPa grouting pressure for low pressure grouting, the diffusion mode of slurry under lower grouting pressure is penetration diffusion, the curing material fully diffuses in the soil-rock mixture to form a 0.5-1 m penetration ring due to the capillary pressure between the soil, the curing material forms a cylindrical stone body along the grouting hole as the center axis, its grouting effect is shown in Figure 4 , low pressure grouting and then stop 1 h to ensure uniform penetration of slurry, then select 4.5 MPa grouting pressure for high pressure grouting, under higher grouting pressure, the diffusion mode of slurry is mainly penetration and auxiliary splitting, the curing material uniformly penetrates along both sides of the splitting channel and forms a larger slurry-soil composite at the end of the splitting channel, and under higher grouting pressure, the curing material can diffuse further along the splitting channel to form a tree crown-shaped slurry-soil composite, its grouting effect is shown in Figure 5 .

[0106] (4) secondary grouting: when using curing material for grouting, the diffusion mode of curing material is a combination of penetration and splitting, the inside of the splitting channel is hollow after the slurry penetrates and diffuses along the soil, it is necessary to re-inject cement slurry with water-cement ratio of 1:1 after chemical slurry grouting is completed, which can effectively fill the splitting channel formed by the splitting and diffusion of chemical slurry, and re-densify the soil on both sides of the splitting channel, forming a slurry vein skeleton under the action of splitting and densification, and secondary reinforcing the soil.

[0107] (5) maintenance: after grouting is completed, maintain for 3 d, the curing material and cement slurry have preliminarily solidified the soil, the soil has certain strength after which drilling can be carried out at the original hole position, vertical drilling 5 m below the section as a new section, the water pressure stop paste column of the new section is placed at the position 4 m below the bottom of the previous section, the soil around the hole wall of the previous section has been grouted and reinforced, which has certain constraint on the expansion of the water pressure column, which not only ensures that the hole wall will not be easily damaged, but also ensures the sealing effect of the curing material.

[0108] (6) repeat the above steps to carry out grouting of the next section.

[0109] The application is described above in combination with the embodiments, but the application is not limited to the above-described embodiments, and within the knowledge of those skilled in the art, various equivalent replacements or changes can be made without departing from the technical solutions and inventive concepts of the application, and all should be covered within the protection scope of the application.

Claims

1. A dense, fine-particle glacial till solidified material, characterized in that: The curing material comprises component A, component B, potassium carbonate solution, and calcium hydroxide solution. Component A, by mass percentage, comprises 56%-66.5% water glass stock solution, 0.09%-0.18% sodium tetraborate, and 33.41%-43.82% water, wherein the total mass percentage of water glass stock solution, sodium tetraborate, and water is 100%. Component B, by mass percentage, comprises 26.25%-28% copper sulfate, 10%-12.5% ​​phosphoric acid, 0.1% silver chloride, 4.9% hydrochloric acid, and 54.5%-58.75% water, wherein the total mass percentage of copper sulfate, phosphoric acid, silver chloride, hydrochloric acid, and water is 100%. The application of the dense, fine-particle glacial till solidification material in the solidification process of dense glacial till formations involves the following steps: (a) Drilling: Drilling is carried out using vertical directional drilling technology; (b) Hole washing: Clay slurry with a soil-to-slurry ratio of 0.5:1 is used for hole washing; (c) Segmented sealing: Each segment is 5m long. When injecting the next segment, the previous segment must be sealed. A water pressure grouting column with a diameter of 70mm and an expansion diameter of 110mm is selected. When injecting the next segment, the water pressure grouting column must be placed at a position more than 1m above the segment to be injected and pressurized. After the water pressure column is pressed, its volume expands until it completely adheres to the hole wall. (d) High and low pressure composite grouting: High and low pressure composite grouting is used for grouting. After low pressure grouting, the grouting is stopped for 1-2 hours before high pressure grouting. For low pressure grouting, a curing material with a gel time of 45-60 minutes is used, and for high pressure grouting, a curing material with a gel time of 60-96 minutes is used. When grouting, a grouting pressure of 1-3 MPa is used for low pressure grouting first. After low pressure grouting, the grouting is stopped for 1-2 hours to ensure uniform penetration of the curing material. Then, a grouting pressure of 3-6 MPa is used for high pressure grouting. (e) Secondary grouting: After the curing material grouting in step (d) is completed, a cement grout with a water-cement mass ratio of 1:1 is injected again; (f) Curing: After grouting, the curing material and cement grout have been cured for 3 days. The soil has been initially cured and the soil has a certain strength. Drilling can be carried out at the original hole position. A new section is formed by vertically drilling 5m below this section. The water pressure grouting column of the new section is placed 4m below the bottom of the previous section. (g) Repeat steps (a) to (f) to carry out grouting for the next segment.

2. The dense, fine-particle glacial till solidified material according to claim 1, characterized in that: In step (a) of the application process, an XY150 drilling machine is selected for drilling, and the drill rod diameter is 91mm.

3. The method for preparing the dense, fine-particle glacial till solidified material according to claim 1, characterized in that: The specific preparation method includes the following steps: (1) Preparation of water glass diluent The Baumé degree of the raw water glass solution is measured using a Baumé meter. Based on the required Baumé degree, the appropriate formula is used. Calculate the amount of water to add, and adjust the Baume degree of the water glass to the required Baume degree of 26 by adding water. ~28 After stirring the water glass solution with the adjusted Baume degree evenly with a glass rod, let it stand to obtain a diluted water glass solution. In the formula: The mass of the water glass stock solution is expressed in kg. The required mass of water to be added, in kg; A The Baumé degree of the water glass stock solution. ; B To the required Baumé degree for the experiment, ; (2) Preparation of the required solution Sodium tetraborate solution: Dissolve sodium tetraborate powder in water to obtain a sodium tetraborate solution; Copper sulfate solution: Dissolve copper sulfate powder in water and stir until the solution is colorless and there is no suspended precipitate. Phosphoric acid solution: A phosphoric acid solution is obtained by diluting the original phosphate solution with water. Saturated silver chloride solution: Add silver chloride crystals to water until they are completely dissolved to obtain a silver chloride solution. Add hydrochloric acid solution to the silver chloride solution and stir to obtain a saturated silver chloride solution. Potassium carbonate solution: Weigh out potassium carbonate powder and dissolve it in water to obtain a potassium carbonate solution; Calcium hydroxide solution: Weigh out calcium hydroxide powder and dissolve it in water to obtain a calcium hydroxide solution; (3) Preparation of component A Add the sodium tetraborate solution obtained in step (2) to the water glass diluent obtained in step (1) to obtain component A; (4) Preparation of component B Mix the copper sulfate solution and saturated silver chloride prepared in step (2), and then add the phosphoric acid solution prepared in step (2) to obtain component B; (5) Preparation of curing materials Mix component A obtained in step (3) with component B obtained in step (4) to obtain AB mixture. Then add potassium carbonate solution prepared in step (2) and calcium hydroxide solution prepared in step (2) to obtain curing material.

4. The method for preparing a dense, fine-particle glacial till solidified material according to claim 3, characterized in that: The initial setting time of the prepared curing material can be controlled between 45-60 min and 63-96 min by adjusting the content of copper sulfate powder and phosphoric acid in component B.

5. The method for preparing the dense, fine-particle glacial till solidified material according to claim 3, characterized in that: The water glass stock solution mentioned in step (1) is an aqueous solution of sodium silicate solid commonly available on the market, and the water glass solution is required to have a Baumé degree greater than 35. The modulus is between 3.0 and 3.

2.

6. The method for preparing the dense, fine-particle glacial till solidified material according to claim 3, characterized in that: In step (2), the mass ratio of sodium tetraborate powder to water is 9:91; the water temperature is 20-30℃; the mass ratio of copper sulfate powder to water is 3:1-4:1; the concentration of phosphoric acid solution is greater than 85%; the mass ratio of phosphate stock solution to water is 1:4-1:3; the mass ratio of silver chloride crystals to water is 1:100; the water temperature is 10-15℃; the mass ratio of hydrochloric acid solution to saturated silver chloride solution is 49:101; the mass ratio of potassium carbonate powder to water is 7:5~3:2; the mass ratio of calcium hydroxide powder to water is 3:97-3:197; and the water temperature is 0℃.

7. The method for preparing the dense, fine-particle glacial till solidified material according to claim 3, characterized in that: In step (3), the mass of sodium tetraborate solution is 1%-2% of the total mass of component A.

8. The method for preparing the dense, fine-particle glacial till solidified material according to claim 3, characterized in that: In step (4), the mass ratio of copper sulfate solution, phosphoric acid solution, and saturated silver chloride solution is 7:10:

3.

9. The method for preparing the dense, fine-particle glacial till solidified material according to claim 3, characterized in that: In step (5), the mass ratio of component A to component B is 1:1; the mass ratio of the AB mixture, potassium carbonate solution, and calcium hydroxide solution is 100:6:3.

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