Soil surrounding rock similar characteristic material for simulation experiment and preparation method
By using dimensional analysis and multi-parameter matching, soil-like surrounding rock similarity materials were prepared using specific raw materials, solving the similarity and cost problems of surrounding rock simulation materials in existing technologies, and realizing efficient and low-cost tunnel model testing.
Patent Information
- Application Number
- CN202511279086.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-09
- Publication Date
- 2025-12-02
AI Technical Summary
In existing technologies, similar materials used to simulate surrounding rocks exhibit significant deviations in physical and mechanical parameters from actual surrounding rocks when simulating active faults, making it difficult to meet multi-parameter similarity requirements. Furthermore, their preparation methods are complex and costly, limiting their application in experiments.
The similarity ratio was designed using dimensional analysis and combined with multi-parameter matching. Sand, gypsum, fly ash, pumice, expanded perlite, glass short fiber and polycarboxylate superplasticizer were used as raw materials to prepare similar soil-surrounding rock materials by stirring and settling, which met the requirements of similarity in physical and mechanical parameters and cost-effectiveness.
It achieves high similarity and low-cost preparation of similar materials for soil surrounding rock, and is suitable for tunnel simulation experiments under different geological conditions, with good operability and applicability.
Smart Images
Figure CN121044879A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of tunnel model testing technology, and in particular to a soil-surrounding rock similarity characteristic material and its preparation method for simulation experiments. Background Technology
[0002] In tunnel engineering across active faults, the stability of the surrounding rock directly affects the safety of the tunnel structure and construction efficiency. As active zones of crustal movement, active faults exhibit highly complex and dynamically changing fault characteristics, stress states, and physical and mechanical properties of the surrounding rock and soil, potentially leading to serious engineering accidents such as tunnel deformation, cracking, or even collapse. Since the geological conditions of active faults in actual engineering projects cannot be replicated, and conducting large-scale field tests faces challenges such as high costs, lengthy cycles, extremely high safety risks, and potential damage to existing engineering structures, indoor model tests simulating the mechanical behavior, deformation patterns, and failure mechanisms of tunnel surrounding rock under the influence of fault activity have become an indispensable and crucial method in the research of tunnel engineering across active faults.
[0003] In existing technologies, similar materials for simulating surrounding rock often use single raw materials or simple proportions, resulting in significant deviations in physical and mechanical parameters from actual surrounding rock. Furthermore, it is difficult to simultaneously meet the similarity requirements for multiple parameters such as unit weight and elastic modulus. This is particularly problematic when simulating soil-like surrounding rock under complex geological conditions such as those spanning active faults, where material stability and similarity are difficult to guarantee. Simultaneously, some preparation methods are complex, costly, or require demanding experimental conditions, limiting their widespread application in experiments. Summary of the Invention
[0004] The purpose of this application is to provide a soil-like surrounding rock similarity material and its preparation method for simulation experiments, aiming to solve the problems in the prior art.
[0005] This application provides a soil-like rock-like material for simulation experiments. The raw materials of the similar material are proportioned by weight as follows: sand 20-25, gypsum 5-10, fly ash 10-15, pumice 2-4, expanded perlite 1-3, glass short fiber 0.5-2, water-reducing agent 0.5-2, and water 4-6.
[0006] A method for preparing soil-like surrounding rock similar characteristic materials for simulation experiments, comprising the following steps: S1. Using dimensional analysis, a similarity ratio design is carried out between actual engineering and tunnel experiments to determine the range of physical and mechanical parameters of the surrounding rock material; S2. Based on the range of physical and mechanical parameters of the simulated surrounding rock material in S1, determine the raw material composition and proportion for preparing the similar material; S3. Add the various similar material raw materials, including sand, gypsum, fly ash, pumice, expanded perlite, glass short fiber, water reducing agent and water, into a mixing tank in a certain order, mix and stir evenly, and pour into a mold to obtain similar surrounding rock material in a wet state. S4. Pour the wet, similar surrounding rock material into the mold to make it fully compacted, let it stand until it is initially set, then demold it and let it air dry naturally to obtain the similar surrounding rock material.
[0007] Further, the specific operation steps of S3 are as follows: first, mix sand, gypsum, fly ash, pumice and expanded perlite in the specified amounts, stir slowly for 2-3 minutes using a mixer, then slowly add water to initially moisten the dry material, then slowly add water-reducing agent, and finally add glass short fibers and stir at a constant speed for 5-10 minutes to fully mix the raw materials and obtain similar surrounding rock material in a wet state.
[0008] Furthermore, the range of physical and mechanical parameters of the simulated similar surrounding rock material is determined by the actual physical and mechanical parameters of the soil surrounding rock of the tunnel across the active fault to be simulated, combined with the unit weight similarity ratio, geometric similarity ratio, and elastic modulus similarity ratio.
[0009] Furthermore, the physical and mechanical parameters of the simulated similar surrounding rock material include: density, elastic modulus, Poisson's ratio, and compressive strength.
[0010] Furthermore, the sand used for construction has a particle size of 0.35–0.5 mm, the pumice has a particle size of 6–12 mm, and the expanded perlite has a particle size of 3–5 mm.
[0011] Furthermore, the gypsum is building gypsum, and the fly ash is secondary ash.
[0012] Furthermore, the glass short fiber has a length of 8 mm, and the water-reducing agent is a polycarboxylate-based water-reducing agent.
[0013] The beneficial effects of this invention are as follows: This invention designs a similarity ratio using dimensional analysis and combines it with multi-parameter matching, resulting in physical and mechanical properties (such as density, elastic modulus, compressive strength, etc.) that are highly similar to actual surrounding rock, meeting the accuracy requirements of model tests. It uses sand, gypsum, fly ash, pumice, expanded perlite, glass short fibers, polycarboxylate superplasticizer, and water as raw materials, making it low-cost and readily available, suitable for large-scale preparation. The preparation process requires no special equipment; the stirring, molding, and curing steps are simple and highly operable. Furthermore, by adjusting the raw material ratio, material parameters can be flexibly adjusted, making it suitable for simulating the surrounding rock of fault tunnels under different geological conditions, thus having wide applicability. Attached Figure Description
[0014] Figure 1 This is a flowchart illustrating the preparation process of the soil-like surrounding rock material of the present invention.
[0015] Figure 2 This is the stress-strain curve of the best sample of the soil-surrounding rock similar material of the present invention.
[0016] Figure 3 This is the calculated result of the elastic modulus of the optimal sample of the soil-surrounding rock similar material of the present invention. Detailed Implementation
[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0018] A soil-like surrounding rock similarity material for simulation experiments, wherein the raw materials of the similar material are in the following weight proportions: sand 20-25, gypsum 5-10, fly ash 10-15, pumice 2-4, expanded perlite 1-3, glass short fiber 0.5-2, water-reducing agent 0.5-2, and water 4-6.
[0019] like Figure 1 The method shown is for preparing similar characteristic materials of soil surrounding rock used in simulation experiments. The preparation method includes: S1: Using dimensional analysis, similarity ratio design is carried out for actual engineering and tunnel experiments, thereby determining the range of physical and mechanical parameters of similar surrounding rock materials; S2: Based on the range of physical and mechanical parameters of the simulated surrounding rock similar material, determine the raw material composition and proportion for preparing the similar material; the raw material composition and proportion for preparing the similar surrounding rock material are by weight, and the weight proportion of sand, gypsum, fly ash, pumice, expanded perlite, glass short fiber, polycarboxylate superplasticizer and water is 20~25:5~10:10~15:2~4:1~3:0.5~2:0.5~2:4~6; S3. Add the determined raw materials such as sand, gypsum, fly ash, pumice, expanded perlite, glass short fiber, polycarboxylate superplasticizer and water to a mixing tank in a certain order, mix and stir evenly, and pour into a mold to obtain similar surrounding rock material in a wet state. S4: Pour the wet similar surrounding rock material into the mold to make it fully compacted, let it stand until it is initially set, then demold it, and let it stand and air dry naturally to obtain the similar surrounding rock material. The similarity ratio of the similar surrounding rock materials is determined by dimensional analysis, and its physical and mechanical parameters are determined by the similarity ratio between the actual engineering and the similar surrounding rock materials. The physical and mechanical parameters of the similar surrounding rock materials include: density, elastic modulus, Poisson's ratio, and compressive strength.
[0020] The sand used as the skeleton material is selected as medium sand for construction, with a particle size of 0.35-0.5 mm; The gypsum mentioned is building gypsum; it serves as a core binding material to reinforce the strength of the material.
[0021] The fly ash is a secondary ash; it serves as an active filler to reduce the porosity between the skeletons.
[0022] The pumice has a particle size of 6–12 mm; the expanded perlite has a particle size of 3–5 mm; this can further reduce the density and better reflect actual conditions.
[0023] The glass short fibers are 8mm in length; with their high strength and stability, they can enhance the crack resistance and integrity of the material, and maintain the integrity of the surrounding rock.
[0024] The water-reducing agent is a polycarboxylate-based water-reducing agent, which can reduce the generation of bubbles and adjust the fluidity of the material through water reduction.
[0025] The following are specific embodiments. Example
[0026] First, mix 700g of sand, 175g of gypsum, 350g of fly ash, 70g of pumice and 35g of expanded perlite according to the specified amount. Stir slowly in a mixer for 2-3 minutes, then slowly add water to initially moisten the dry material. Next, slowly add 35g of polycarboxylate superplasticizer, and finally add 35g of glass short fiber and stir at a constant speed for 5-10 minutes. During this process, a total of 140g of water is added to ensure that the raw materials are fully mixed and homogeneous, thus obtaining a similar surrounding rock material in a wet state. Pour the wet mixture into a precast mold, place it on a vibrating table (or tap it manually) to vibrate until it is fully compacted, place the mold in a cool place, cover it with plastic wrap and seal it for 24 hours before demolding, and let it air dry naturally for more than 3 days to obtain a similar material. Example
[0027] First, mix 660g of sand, 210g of gypsum, 360g of fly ash, 90g of pumice and 60g of expanded perlite according to the specified amount. Stir slowly in a mixer for 2-3 minutes, then slowly add water to initially moisten the dry material. Next, slowly add 45g of polycarboxylate superplasticizer, and finally add 45g of glass short fiber and stir at a constant speed for 5-10 minutes. During this process, a total of 150g of water is added to ensure that the raw materials are fully mixed and homogeneous, thus obtaining a similar surrounding rock material in a wet state. Pour the wet mixture into a precast mold, place it on a vibrating table (or tap it manually) to vibrate until it is fully compacted, place the mold in a cool place, cover it with plastic wrap and seal it for 24 hours before demolding, and let it air dry naturally for more than 3 days to obtain a similar material. Example
[0028] First, mix 675g of sand, 255g of gypsum, 395g of fly ash, 100g of pumice and 70g of expanded perlite according to the specified amount. Stir slowly in a mixer for 2-3 minutes, then slowly add water to initially moisten the dry material. Next, slowly add 50g of polycarboxylate superplasticizer, and finally add 50g of glass short fiber and stir at a constant speed for 5-10 minutes. During this process, a total of 155g of water is added to ensure that the raw materials are fully mixed and homogeneous, thus obtaining a similar surrounding rock material in a wet state. Pour the wet mixture into a precast mold, place it on a vibrating table (or tap it manually) to vibrate until it is fully compacted, place the mold in a cool place, cover it with plastic wrap and seal it for 24 hours before demolding, and let it air dry naturally for more than 3 days to obtain a similar material. Example
[0029] First, mix 665g of sand, 265g of gypsum, 400g of fly ash, 105g of pumice and 80g of expanded perlite according to the specified amount. Stir slowly in a mixer for 2-3 minutes, then slowly add water to initially moisten the dry material. Next, slowly add 52g of polycarboxylate superplasticizer, and finally add 52g of glass short fiber. Stir at a constant speed for 5-10 minutes. During this process, a total of 160g of water is added to ensure that the raw materials are fully mixed and homogeneous, thus obtaining a similar surrounding rock material in a wet state. Pour the wet mixture into a precast mold, place it on a vibrating table (or tap it manually) to vibrate until it is fully compacted, place the mold in a cool place, cover it with plastic wrap and seal it for 24 hours before demolding, and let it air dry naturally for more than 3 days to obtain a similar material.
[0030] Table 1 compares the properties of similar materials for simulated tunnels across active faults prepared in Examples 1-4: The density was measured using an electronic balance. The elastic modulus and Poisson's ratio were measured in the elastic phase of the uniaxial compression test of the rock. The compressive strength was measured in the uniaxial compressive strength test of the rock. The test results are shown in Table 1.
[0031] Based on Table 1 obtained from the four examples, the optimal mass ratio of sand, gypsum, fly ash, pumice, expanded perlite, glass short fibers, polycarboxylate superplasticizer, and water was determined to be 20:5:10:2:1:1:1:4, i.e., Example 1. The calculated stress-strain curves of the optimal specimen are shown in [Table 1]. Figure 2 The calculation results of the elastic modulus of the optimal specimen are shown in [reference needed]. Figure 3 .
[0032] The above embodiments are not intended to limit the present invention. Unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. The present invention is not limited to the above examples. Changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the technical solutions of the present invention are also within the protection scope of the present invention. Furthermore, the technical features involved in the different embodiments of the present application described above can be combined with each other as long as they do not conflict with each other.
[0033] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
Claims
1. A soil-rock similarity characteristic material for simulation experiments, characterized in that, The raw materials of the similar material are proportioned by weight as follows: sand 20-25, gypsum 5-10, fly ash 10-15, pumice 2-4, expanded perlite 1-3, glass short fiber 0.5-2, water reducing agent 0.5-2, and water 4-6.
2. A method for preparing soil-like surrounding rock similar characteristic materials for simulation experiments, characterized in that, The process includes the following steps: S1. Using dimensional analysis, a similarity ratio design is carried out between actual engineering and tunnel experiments to determine the range of physical and mechanical parameters of the surrounding rock material; S2. Based on the range of physical and mechanical parameters of the simulated surrounding rock material in S1, determine the raw material composition and proportion for preparing the similar material; S3. Add the various similar material raw materials, including sand, gypsum, fly ash, pumice, expanded perlite, glass short fiber, water reducing agent and water, into a mixing tank in a certain order, mix and stir evenly, and pour into a mold to obtain similar surrounding rock material in a wet state. S4. Pour the wet, similar surrounding rock material into the mold to make it fully compacted, let it stand until it is initially set, then demold it and let it air dry naturally to obtain the similar surrounding rock material.
3. The soil-surrounding rock similarity characteristic material and preparation method for simulation experiments according to claim 2, characterized in that, The specific operating steps of S3 are as follows: First, mix sand, gypsum, fly ash, pumice and expanded perlite in the specified amounts, stir slowly for 2-3 minutes using a mixer, then slowly add water to initially moisten the dry material, then slowly add water-reducing agent, and finally add glass short fibers and stir at a constant speed for 5-10 minutes to fully mix the raw materials and obtain similar surrounding rock material in a wet state.
4. The method for preparing soil-surrounding rock similarity characteristic material for simulation experiments according to claim 3, characterized in that, The range of physical and mechanical parameters of the simulated similar surrounding rock material is determined by the actual physical and mechanical parameters of the soil surrounding rock of the tunnel across the active fault to be simulated, combined with the unit weight similarity ratio, geometric similarity ratio and elastic modulus similarity ratio.
5. The soil-surrounding rock similarity characteristic material and preparation method for simulation experiments according to claim 4, characterized in that, The physical and mechanical parameters of the simulated similar surrounding rock material include: density, elastic modulus, Poisson's ratio, and compressive strength.
6. The method for preparing soil-surrounding rock similarity characteristic material for simulation experiments according to claim 2, characterized in that, The sand used for construction has a particle size of 0.35-0.5 mm, the pumice has a particle size of 6-12 mm, and the expanded perlite has a particle size of 3-5 mm.
7. The method for preparing soil-surrounding rock similar characteristic material for simulation experiments according to claim 2, characterized in that, The gypsum is building gypsum, and the fly ash is secondary ash.
8. The method for preparing soil-surrounding rock similar characteristic materials for simulation experiments according to claim 2, characterized in that, The glass short fiber has a length of 8 mm, and the water-reducing agent is a polycarboxylate-based water-reducing agent.