Diversion tunnel bottom plate pavement material based on expansive mudstone and preparation method of diversion tunnel bottom plate pavement material

Abstract

The invention discloses a diversion tunnel bottom plate pavement material based on expansive mudstone. The diversion tunnel bottom plate pavement material comprises mudstone, a solid admixture, a modifier solution, basalt chopped fibers and a fiber net body. The invention further discloses a preparation method of the diversion tunnel bottom plate pavement material based on the expansive mudstone. The red layer mudstone is modified, so that the compressive strength, the water resistance, the erosion resistance and the compactness of the red layer mudstone are remarkably improved, the requirements of a diversion tunnel bottom plate pavement material for high strength and water resistance can be met, meanwhile, the red layer mudstone has the advantages of being low in cost, high in environmental protection property, convenient to construct and the like, and an innovative solution is provided for tunnel engineering in a red layer area.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of environmental remediation, and in particular to a diversion tunnel floor pavement material based on swelling mudstone and a preparation method thereof. BACKGROUND

[0002] In recent years, major engineering construction in red-bed mudstone areas has shown a high growth trend. Statistics show that the proportion of new high-speed rail lines in the southwest of China has reached 21.94% of the total new mileage, and more than half of the planned lines need to pass through this special geological belt. In addition, the density of highway networks, deep-buried tunnels, and reservoir hubs in the red-bed area of Sichuan continues to increase, and the complex hydrogeological characteristics make this region a key area for infrastructure construction in southern China. Diversion tunnel floor pavement materials need to have high strength, water resistance, erosion resistance, and long-term stability to cope with water seepage, chemical erosion, and mechanical load under complex geological environments.

[0003] Currently, the existing diversion tunnel floor material still uses traditional roadbed fillers, but the high mountains and winding roads in the central region of Sichuan result in high transportation costs. Therefore, the present application uses a large amount of mudstone produced by tunnel excavation as raw material, which can significantly reduce costs. However, red-bed mudstone has poor water stability and swells and disintegrates when it comes into contact with water, and it also has the disadvantage of unstable engineering properties, which can directly lead to a lack of stability in later-stage engineering.

[0004] Therefore, the present application modifies a large amount of mudstone produced by tunnel excavation and directly applies it to diversion tunnel floor filler engineering, which is of great significance for protecting the environment and improving economic efficiency. SUMMARY

[0005] Therefore, the present application modifies a large amount of mudstone produced by tunnel excavation and directly applies it to diversion tunnel floor filler engineering, which is of great significance for protecting the environment and improving economic efficiency.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] A diversion tunnel floor pavement material based on swelling mudstone, by mass fraction, includes 50-70 parts of mudstone, 8-25 parts of solid admixture, 10-15 parts of modifier solution, basalt chopped fibers, and fiber network; the basalt chopped fibers are 0.15% of the total amount of mudstone and solid admixture, and the fiber network is 0.06% of the total amount of mudstone and solid admixture.

[0008] Preferably, the solid admixture is one or more of mineral powder, cement, bagasse ash or fly ash.

[0009] Preferably, the length of the chopped fiber is 2mm.

[0010] A preparation method of a water diversion tunnel floor pavement material based on swelling mudstone, comprising the following steps:

[0011] S1, mixing mudstone, solid admixture and chopped fiber according to the proportion until the color is uniform to obtain a mixture;

[0012] S2, pouring the modifier solution into the mixture and mixing uniformly to obtain a modified material;

[0013] S3, placing the fiber mesh in the mixed solution for impregnation treatment and drying to make the surface of the fiber mesh covered with the slurry; the mixed solution is a mixed solution of phenolic resin and silane coupling agent;

[0014] S4, laying a layer of modified material on the grinding tool, vibrating, leveling, then laying a layer of impregnated fiber mesh, and then laying a layer of modified material, vertically up and down tamping with a metal rod, and finally compacting by the method of first compacting and then tamping to obtain a pavement material blank;

[0015] S5, coating curing the pavement material blank for 3-28 days.

[0016] Preferably, the height of the pavement material blank in step S4 is 0.2m.

[0017] Preferably, the pavement material comprises a base layer and a surface layer above the base layer; the thicknesses of the base layer and the surface layer are 0.1m respectively; the preparation methods of the base layer and the surface layer are consistent.

[0018] Preferably, the solid admixture used in the base layer is mineral powder and cement; the mass ratio of the mineral powder to the cement is 1:1.

[0019] Preferably, the solid admixture used in the surface layer is mineral powder and fly ash; the mass ratio of the mineral powder to the fly ash is 2:1.

[0020] Preferably, the solid admixture used in the surface layer is bagasse ash, mineral powder and fly ash; the mass ratio of the bagasse ash, the mineral powder and the fly ash is 1:1:1.

[0021] The beneficial effects of the present application are:

[0022] The application can significantly improve the compressive strength, water resistance, erosion resistance and compactness of the red-bed mudstone by incorporating solid waste such as sugarcane bagasse ash, mineral powder, fly ash and cement, and under the action of the modifier, the modified mudstone material not only meets the requirements of high strength, low expansion and water resistance of the water diversion tunnel bottom plate pavement material, but also has the advantages of low cost, high environmental protection and convenient construction, thereby providing an innovative solution for tunnel engineering in red-bed areas.

[0023] Meanwhile, the addition of the chopped fibers and the fiber web can significantly improve the strength and durability of the material; vertical impact can increase the early strength of the material in the vertical direction, and can reduce the occurrence of road surface depression.

[0024] Compared with the modification of the mudstone by the traditional single solid waste and the modifier, the application can directly modify the interior of the mixed soil, ion exchange between the internal components of the mudstone and the mineral powder cement, increase the overall hardness of the cementation, and meet the requirements of high strength of the filler surface layer. In addition, due to the addition of fly ash and sugarcane bagasse ash, a large number of voids in the mudstone are filled, the porosity of the material after compaction is reduced, and the water erosion resistance of the modified material is greatly improved, thereby meeting the performance of the base material in resisting dry-wet cycles. Therefore, the application has great significance for improving the construction and operation and maintenance level of the tunnel drainage bottom plate, protecting the environment and recycling mudstone solid waste.

[0025] After the red-bed mudstone slag is modified, the application directly uses the modified mudstone slag as the bottom filler, which not only reduces the cost, but also has great significance for protecting the environment by recycling the mudstone slag.

[0026] The application modifies the mudstone slag by using solid waste and a modifier, the pores are filled with a large amount of hydration products, the particle structure is more stable, and the structural compactness and water erosion resistance are improved. In addition, the solid waste such as mineral slag and fly ash transported from the local thermal power plant is used to modify the mudstone, which not only realizes local material utilization, but also realizes rational utilization of resources and reduces environmental pollution. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The figure is a schematic diagram of the strength test results of the surface layer and the base layer in Example 2.

[0028] Figure 2 The figure is a schematic diagram of the strength test results of the surface layer and the base layer in Example 3.

[0029] Figure 3 The figure is a schematic diagram of the strength test results of the pavement layering and non-layering.

[0030] Figure 4 The figure is a schematic diagram of the strength test results of the modified material and the unmodified material after soaking in water. DETAILED DESCRIPTION

[0031] The application will be further described in connection with specific embodiments.

[0032] Embodiment 1

[0033] An expansive mudstone-based water diversion tunnel bottom plate pavement material, by mass fraction, comprises mudstone 50-70 parts, solid admixture 8-25 parts, modifier solution 10-15 parts, basalt chopped fiber and fiber web.

[0034] The basalt chopped fiber has a length of 2mm, and the addition amount is 0.15% of the total amount of mudstone and solid admixture, and the fiber web is 0.06% of the total amount of mudstone and solid admixture.

[0035] The solid admixture is one or more of mineral powder, cement, sugarcane residue ash or fly ash.

[0036] The fiber web is a material with a two-dimensional hole structure woven by basalt fiber; the hole is a square with a side length of 60mm.

[0037] Embodiment 2

[0038] A preparation method of an expansive mudstone-based water diversion tunnel bottom plate pavement material, wherein the pavement is provided in layers of a base layer and a surface layer.

[0039] Specifically comprising the following steps:

[0040] Preparation of the base layer:

[0041] S1, first mix 21840kg of mudstone, 3360kg of mineral powder, 3360kg of cement and 42.84kg of basalt chopped fiber until the color is uniform to obtain a mixture;

[0042] S2, pour 1008kg of water into 4032kg of water glass and stir to obtain a modifier solution; then pour the modifier solution into the mixture and mix evenly to obtain a base layer modified material;

[0043] S3, immerse 17.136kg of fiber web in a mixed solution of phenolic resin and silane coupling agent for dipping treatment and drying, so that the surface is covered with slurry;

[0044] S4, pour a layer of modified material on the grinding tool, shake and flatten, then lay a layer of dipped fiber web, and then lay another layer of modified material, vertically up and down with a metal rod, and finally compact the material by first compacting and then tamping to obtain a base layer material blank;

[0045] Preparation of the surface layer:

[0046] S1, 18480 kg of mudstone, 6720 kg of mineral powder, 3360 kg of cement and 42.84 kg of basalt short fiber are mixed to be uniform in color to obtain a mixture;

[0047] S2, 1008 kg of water is poured into 4032 kg of water glass and stirred to obtain a modifier solution; the modifier solution is poured into the mixture and mixed uniformly to obtain a surface layer modifier material;

[0048] S3, 17.136 kg of fiber web is immersed in a mixed solution of phenolic resin and silane coupling agent, and dried to make the surface covered with slurry;

[0049] S4, a layer of modified material is poured on the mold, vibrated and flattened,

[0050] The base material is roughened, and half of the surface layer modifier material prepared in step S2 is poured on the base material and flattened, then a layer of impregnated fiber web is laid, and then a layer of surface layer modifier material is laid, and a metal rod is used for vertical up and down tamping, and finally a pre-compaction and post-compaction method is used for compaction to obtain a base material blank;

[0051] S4, the pavement material blank is covered and maintained for 3-28 days to obtain a pavement material.

[0052] The thickness of the base layer and the surface layer is 0.1 m respectively.

[0053] Example 3

[0054] A preparation method of a water diversion tunnel bottom plate pavement material based on swelling mudstone, wherein the pavement also adopts a base layer and a surface layer.

[0055] The specific preparation steps are the same as those of Example 2, and the difference is that the type of solid admixture used in the preparation of the surface layer is mudstone, mineral powder and fly ash. Among them, the mudstone is 18480 kg, the mineral powder is 3360 kg and the fly ash is 6720 kg.

[0056] Example 4

[0057] A preparation method of a water diversion tunnel bottom plate pavement material based on swelling mudstone, comprising the following steps:

[0058] S1, 18480 kg of mudstone, 6720 kg of mineral powder, 3360 kg of fly ash and 42.84 kg of basalt short fiber are mixed to be uniform in color to obtain a mixture;

[0059] S2, pour 1008 kg of water into 5040 kg of water glass to stir and obtain a modifier solution; pour the modifier solution into the mixture to mix uniformly, and obtain a modified material;

[0060] S3, place 17.136 kg of the fiber web body in the mixed solution to perform impregnation treatment and drying, so that the surface is covered with the slurry; the mixed solution is a mixed solution of phenolic resin and silane coupling agent;

[0061] S4, pour a layer of modified material on the grinding tool, vibrate, spread, then lay a layer of the impregnated fiber web body, and then lay a layer of modified material, vertically up and down with a metal rod, and finally compacted by the method of first compacting and then tamping, to obtain a pavement material blank. The obtained pavement material blank has a height of 0.2 m and a density of 2.1 g / cm 3 ;

[0062] S4, after the pavement material blank is covered and maintained for 3-28 days, the pavement material is obtained.

[0063] Example 5

[0064] A preparation method of a diversion tunnel bottom pavement material based on swelling mudstone, the specific preparation steps are the same as those of example 4, and the difference lies in the type of solid admixture, here, sugarcane ash residue, mineral powder and fly ash are used. Among them, the sugarcane ash residue is 3360 kg, the mineral powder is 1680 kg, and the fly ash is 5040 kg.

[0065] The pavement materials obtained in examples 2-4 are respectively subjected to block experiments according to their proportions, as shown in Figures 1-4 From the figure, it can be seen that the strength of the surface layer is higher than that of the base layer; after maintenance for 28 days, the strength of the layered pavement can reach 43Mpa, and the strength of the pavement without layering can reach 57Mpa. The strength of the pavement in example 5 can reach 65Mpa. Generally, 25Mpa is required outside the tunnel, and 50Mpa is required inside the tunnel. Therefore, the pavement without layering can be used for laying the bottom plate inside the tunnel, and the layered pavement can be used for laying the bottom plate outside the tunnel. Since the amount of mineral powder is small in Sichuan area, and the cost is also high, therefore, by using different laying forms inside and outside the tunnel, the use amount of mineral powder can be reduced, thereby reducing the cost.

[0066] The present application has been used in Yibin mudstone modification test. According to the relevant specifications, the diversion tunnel bottom pavement material is laid, uniformly laid and tamped, and can be put into use after film maintenance for 28 days.

[0067] The invention adopts Sichuan mudstone, which contains quartz (SiO2), feldspar, calcite (CaCO3) and hematite (Fe2O3), and the particle size of the mudstone is not greater than 3 mm. The fly ash is grade I fly ash, the mineral powder is S95, and the cement is portland cement.

[0068] Finally, it should be pointed out that the above examples are only used to illustrate the technical solutions of the present application and not to limit it, and other modifications or equivalent replacements made by those skilled in the art to the technical solutions of the present application should be covered in the scope of the claims of the present application as long as they do not deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A pavement material for the floor slab of a water diversion tunnel based on expansive mudstone, characterized in that, By weight, it comprises 50-70 parts mudstone, 8-25 parts solid admixture, 10-15 parts modifier solution, basalt chopped fibers, and fiber web; the basalt chopped fibers constitute 0.15% of the total amount of mudstone and solid admixture, and the fiber web constitutes 0.06% of the total amount of mudstone and solid admixture.

2. The pavement material for the bottom slab of a water diversion tunnel based on expansive mudstone according to claim 1, characterized in that, The solid admixture is one or more of mineral powder, cement, bagasse ash, or fly ash.

3. The pavement material for the bottom slab of a water diversion tunnel based on expansive mudstone according to claim 1, characterized in that, The fiber mesh is a material with a two-dimensional porous structure woven from basalt fibers; Its hole is a square with a side length of 60mm.

4. The pavement material for the bottom slab of a water diversion tunnel based on expansive mudstone according to claim 1, characterized in that, The length of the chopped fiber is 2 mm.

5. A method for preparing the pavement material for the floor slab of a water diversion tunnel based on expansive mudstone as described in any of claims 1-4, characterized in that, Includes the following steps: S1. Mix mudstone, solid admixtures and chopped fibers according to the specified ratio until the color is uniform to obtain a mixture; S2. Then pour the modifier solution into the mixture and mix evenly to obtain the modified material; S3. The fiber web is immersed in the mixed solution and dried so that its surface is covered with slurry; the mixed solution is a mixture of phenolic resin and silane coupling agent. S4. First, lay a layer of modified material on the mold, vibrate and flatten it, then lay a layer of impregnated fiber mesh, then lay another layer of modified material, and use a metal rod to tamp it vertically up and down. Finally, compact it by first compacting and then tamping to obtain the road material blank. S5. Cover the rough road surface material with a film for 3-28 days for curing.

6. The method for preparing the pavement material for the bottom slab of a water diversion tunnel based on expansive mudstone according to claim 5, characterized in that, In step S4, the height of the road material blank is 0.2m.

7. The method for preparing the pavement material for the bottom slab of a water diversion tunnel based on expansive mudstone according to claim 5, characterized in that, The road surface material includes a base course and a surface course located above the base course; the thickness of the base course and the surface course are both 0.1m; the preparation methods of the base course and the surface course are the same.

8. The method for preparing the pavement material for the bottom slab of a water diversion tunnel based on expansive mudstone according to claim 7, characterized in that, The solid admixture used in the base layer is mineral powder and cement; the mass ratio of mineral powder to cement is 1:

1.

9. The method for preparing the pavement material for the bottom slab of a water diversion tunnel based on expansive mudstone according to claim 7, characterized in that, The surface layer uses solid admixtures of mineral powder and fly ash; the mass ratio of mineral powder to fly ash is 2:

1.

10. The method for preparing the pavement material for the bottom slab of a water diversion tunnel based on expansive mudstone according to claim 7, characterized in that, The solid admixture used in the surface layer is sugarcane bagasse ash, mineral powder and fly ash; The mass ratio of bagasse ash, mineral powder and fly ash is 2:1:3.

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