Grouting stopping liquid for pouring of goaf orifice pipe

Abstract

The invention discloses a grout stopping liquid for pouring a goaf orifice pipe, water glass is doped in the grout stopping liquid, the water-solid ratio of the grout stopping liquid is 1: 1.1-1: 1.3, the water glass accounts for 2%-4% of the cement content, the grout stopping liquid is high in solidification speed, and the early strength of the grout can be improved; the fluidity and the permeability of the modified grout are remarkably improved, the grout can pass through fine pores and cracks more easily, the grout can be diffused and uniformly distributed in a soil body or a rock body more easily due to the low-viscosity characteristic of the grout, and therefore the grouting effect can be well improved; when being used for treating the double-layer goaf, the grout stopping liquid has more advantages, the possibility of hole collapse of upper loose bed rock during grouting is reduced, grout permeation in the grouting process can be effectively reduced, the influence on the ground surface and the underground water environment is prevented, and the damage to environmental water and soil resources is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, in particular to a grouting liquid used for pouring a hole pipe in a goaf area. Background Art

[0002] With the mining of coal mines, the surrounding geological environment conditions have been destroyed, and the serious geological disaster problem brought about is the mining collapse and its associated ground fissures; the second is the collapse causing slope instability, and the rainy season often induces the occurrence of slope disasters such as collapse and landslides. The formation of the mining area will change the underground geological structure, leading to changes in the flow path of groundwater and a decrease in the groundwater level. If the foundation of the road is located near the mining area, the formation of the mining area may cause the foundation to be unstable, affecting the construction of the structure above it and the roadbed filling. In view of the series of uncertainties and risks that the mining area brings to road construction, governance measures need to be taken to ensure the quality and safety of road construction.

[0003] The commonly used method for treating goaf is grouting, which injects grouting materials into underground structures or strata through pipes to enhance their bearing capacity and stability. The slurry of the traditional grouting method is a mixture of water, cement and fly ash or lime, which has the following shortcomings: 1) Low initial strength. When the fly ash content is high, the early strength of the slurry is low, which may not meet the requirements of some projects that require rapid consolidation and high early strength. This may have an adverse effect on projects that need to be quickly restored or reinforced; 2) Insufficient fluidity and stability. Although fly ash can improve the fluidity of the slurry, excessive fly ash content may lead to a decrease in the stability of the slurry, resulting in segregation, water seepage and other problems, affecting the grouting effect and the uniformity of the consolidation body; 3) Long-term durability issues. The chemical composition and activity of fly ash may affect long-term durability, especially in some chemical corrosion environments. Cement fly ash consolidation may show poor durability in corrosive media such as acid and sulfate. The above are the limitations of the grouting liquid used for goaf hole pipe casting in the prior art during construction. Summary of the invention

[0004] The invention discloses a grouting liquid used for casting a hole pipe in a goaf area, aiming to solve the limitations of the grouting liquid used for casting a hole pipe in a goaf area in the prior art during construction.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A grouting liquid for pouring a hole pipe in a goaf area, comprising: water, cement, fly ash and water glass;

[0007] The water-to-solid ratio of the grouting liquid is 1:1.1-1:1.3, and the water glass accounts for 2%-4% of the cement content.

[0008] In some of the embodiments, the water-to-solid ratio of the slurry is 1:1.2.

[0009] In some of the embodiments, the grouting liquid includes 1000 parts of water, 360 parts of cement, 824-840 parts of fly ash, and 8-14 parts of water glass.

[0010] In some of the embodiments, the solid phase ratio of cement to fly ash is 3:6 to 3:8.

[0011] In some of the embodiments, the solid phase ratio of cement to fly ash is 3:7.

[0012] In some of the embodiments, the water glass accounts for 3% of the cement content.

[0013] Compared with the prior art, the present invention has at least one of the following advantages or beneficial effects:

[0014] The invention discloses a grouting liquid for orifice pipe pouring in goaf area, wherein water glass is added into the grouting liquid, and the water-solid ratio of the grouting liquid is 1:1.1-1:1.3, and the water glass accounts for 2%-4% of the cement content. The grouting liquid has a fast solidification speed and can improve the early strength of the grouting liquid; and the fluidity and permeability of the modified grouting liquid are significantly improved, and it is easier to pass through small pores and cracks. Its low viscosity characteristic makes the grouting liquid easier to diffuse and evenly distribute in the soil or rock mass, so as to well improve the grouting effect; the grouting liquid has many advantages when used to treat double-layer goaf area, reduces the possibility of collapse of the upper loose bedrock during grouting, and can effectively reduce the penetration of the grouting liquid during the grouting process, prevent the impact on the surface and groundwater environment, and reduce the damage to the environmental water and soil resources. And the most suitable construction mix ratio can be obtained in combination with local geological conditions and test results, reduce the waste of materials, and use technical means to save engineering costs; it can improve the stability of the foundation, reduce the occurrence of geological disasters, and protect the water and soil resources environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The innovations, construction techniques and advantages of the present invention can be more intuitively understood by reading the accompanying drawings. The same reference numerals in all the accompanying drawings refer to the same things, and the drawings are not drawn according to the true scale, and are intended to illustrate and help understand the innovations of the present invention.

[0016] Figure 1 A comparison table of the mixing ratios of the stop grouting liquid used for casting the orifice pipe in the goaf in the embodiment of the present invention;

[0017] Figure 2 This is a graph showing the relationship between the age and strength of the specimens according to the present invention corresponding to different amounts of water glass. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0019] As a liquid material, water glass can significantly improve the fluidity and permeability of the grouting liquid, making it easier for the grouting liquid to pass through small pores and cracks. Its low viscosity makes it easier for the grouting liquid to diffuse and evenly distribute in the soil or rock mass, thereby improving the grouting effect. After the water glass in the grouting liquid penetrates into the rock formation in the goaf area, it can react chemically with the mineral components in the soil (such as calcium chloride, aluminum sulfate, etc.) to form a silicate gel, which can fill the pores in the soil and increase the density and strength of the soil. After rapid solidification under the above conditions, water glass can provide early strength, which can effectively enhance the foundation bearing capacity of the grouting orifice in the goaf area and prevent collapse before the grouting strength is formed. The impermeable solid body formed after solidification can also effectively prevent water penetration, playing a waterproof and anti-seepage role. This feature is widely used in anti-seepage treatment of underground projects, tunnels and dams. In addition, water glass is a non-toxic and harmless chemical material, and its raw material cost is low. Using water glass as an external admixture for slurry can reduce the use of fly ash, achieve energy conservation and environmental protection, and save construction costs.

[0020] The invention discloses a grouting liquid for casting a borehole pipe in a goaf area, comprising: water, cement, fly ash and water glass; the water-to-solid ratio of the grouting liquid is 1:1.1-1:1.3, and the water glass accounts for 2%-4% of the cement content; specifically, the water-to-solid ratio of the slurry is controlled according to an equal mass substitution method, and a too high or too low water-to-solid ratio will affect the strength, durability, workability and other construction parameters of cement materials. Considering the economy, construction effect and design specifications, the water-to-solid ratio of the grouting liquid is 1:1.1-1:1.3, preferably 1:1.2.

[0021] In an embodiment of the present invention, the above-mentioned slurry stop liquid includes 1000 parts of water, 360 parts of cement, 824-840 parts of fly ash, and 8-14 parts of water glass; this material ratio is only used as a control for the total material quantity and does not represent the actual preparation method. The actual preparation should first prepare solid materials such as cement, fly ash, and water glass into a diluted solution of a certain concentration, and then deduct the corresponding number of water parts according to calculation.

[0022] The present invention discloses a grouting liquid for casting a hole pipe in a goaf area. Through a mix ratio design, different dosages of water glass are added without changing the designed water-cement ratio to increase the viscosity of the grouting liquid and reduce the flow range, thereby avoiding unnecessary grout waste and environmental pollution and ensuring the construction quality. After a lot of research and continuous experiments, the technicians obtained a mix ratio of 2% to 4% of the cement content of water glass.

[0023] Specifically, the mix design should first determine the target according to actual needs, and then select the raw materials. The raw materials used in the present invention are 42.5 ordinary Portland cement, fly ash that meets the national or industry standard "Technical Specifications for the Application of Fly Ash Concrete" (GB / T 1596), and water glass with a concentration of 30%. The water should be a clean water source to avoid impurities. According to the design requirements of the specifications, the water-to-solid ratio of the slurry should be between 0.4-1.0. The water-to-solid ratio selected in this embodiment is 1:1.2, among which; the solid ratio of the cement to the fly ash is 3:7. Due to the addition of water glass, in order to ensure that the total solid phase ratio remains unchanged, the mass of the corresponding fly ash is deducted. The final result of the mix design is as follows: Figure 1 As shown; the amount of water glass is selected from 2% to 4% at intervals of 0.5% as a test group; the amount of water glass in the experiment is 0, 2%, 2.5%, 3%, 3.5%, 4%. After each group of slurry is prepared, it is mixed evenly and cast into a cylindrical concrete test mold with a size of φ50*100. After demoulding, standard curing (temperature 20±2℃, relative humidity ≥95%) is adopted. For test blocks of different ages and different proportions, compression testing machines are used to test the compressive strength or flexural strength. The loading speed is controlled at 0.5MPa / s, and the maximum load when the test pieces are destroyed is recorded one by one.

[0024] The grouting liquid was prepared according to the construction mix ratio, and the first construction of the goaf area management was carried out. The orifice pipe forming speed was significantly improved. The design strength could be reached by 70% three days after grouting, and the early strength was relatively high.

[0025] The slurry of each test group and control group was prepared and loaded into a φ50*100 cylindrical test mold. Six test blocks were prepared in each group. After demoulding, they were placed in a steam curing room for 3d and 7d of standard curing under the same conditions. After reaching the age, the compressive strength of each test block was measured using the universal pressure testing machine in the laboratory. The data was summarized and plotted as follows Figure 2 The relationship between the compressive strength of the grouting fluid at 3 days and 7 days and the sodium silicate content is shown. Figure 2 The middle X-axis represents the percentage (%) of sodium silicate in the cement mixture, the left Y-axis represents the 3d compressive strength, and the right Y-axis represents the 7d compressive strength. It can be seen from the figure that both the 3d compressive strength and the 7d compressive strength increase with the increase of the water glass content. The 3d compressive strength increases faster when the sodium silicate content reaches about 3%, and then tends to be flat, while the 7-day compressive strength increases steadily when the water glass content is below 2%, and the increase is not obvious when the water glass content is above 2%. The chart shows that adding sodium silicate to cement has a positive effect on its early and later compressive strength. Taking all factors into consideration, the 3d strength improvement effect of the grouting liquid is best when the water glass content is 3%, which not only ensures that the early strength can be quickly improved, but also ensures that the strength of the grouting hole after forming is improved, improves the stability of the foundation during grouting and reduces material consumption.

[0026] In summary, the use of grouting liquid mixed with water glass has many advantages in treating double-layer goaf areas. It can be combined with local geological conditions and test results to obtain the most suitable construction mix ratio, reduce material waste, and use technical means to save engineering costs; it can improve the stability of the foundation, reduce the occurrence of geological disasters, protect water and soil resources and the environment, and at the same time achieve green and environmentally friendly construction.

[0027] Those skilled in the art can implement variations by combining the prior art with the above embodiments, which will not be described in detail here. Such variations do not affect the essential content of the present invention, and will not be described in detail here.

[0028] The above is a description of the embodiments of the present invention. It should be clear that the present invention is not limited to the above-mentioned specific implementation methods. Equipment and structures not described in detail should be implemented in a common manner in the art. Any technician familiar with the art can make various possible changes and modifications according to the methods and technical contents disclosed above, or modify them into equivalent embodiments without departing from the technical solution of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments, as long as they do not deviate from the core of the technical solution of the present invention, still belong to the protection scope of the technical solution of the present invention.

Claims

1. A grouting liquid for pouring orifice pipes in goaf areas, characterized in that: include: water, cement, fly ash and water glass; The water-to-solid ratio of the grouting liquid is 1:1.1-1:1.3, and the water glass accounts for 2%-4% of the cement content.

2. The grouting liquid for goaf hole pipe pouring according to claim 1, characterized in that: The water-to-solid ratio of the slurry is 1:1.

2.

3. The grouting liquid for goaf hole pipe pouring according to claim 1, characterized in that: The grouting liquid comprises 1000 parts of water, 360 parts of cement, 824-840 parts of fly ash and 8-14 parts of water glass.

4. The grouting liquid for goaf hole pipe pouring according to claim 1, characterized in that: The solid ratio of the cement to the fly ash is 3:6 to 3:

8.

5. The grouting liquid for goaf hole pipe pouring as claimed in claim 4, characterized in that: The solid phase ratio of the cement to fly ash is 3:

7.

6. The grouting liquid for goaf hole pipe pouring according to claim 1, characterized in that: The water glass accounts for 3% of the cement content.

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