阅读说明：本技术 一种用于裂隙岩体加固的复合灌浆材料配比获取方法 (Method for obtaining proportion of composite grouting material for reinforcing fractured rock mass ) 是由 黄磊 曹桂乾 张鑫平 张欢 于 2021-07-26 设计创作，主要内容包括：本发明提出了一种用于裂隙岩体加固的复合灌浆材料配比获取方法,将一种化学材料分别按不同的质量配比与聚氨酯进行复合,掌握各化学材料分别与聚氨酯进行复合后的力学性能变化规律,选出多种合适的化学材料并与聚氨酯共同进行复合,研发多组不同配比的复合灌浆材料并获取其力学参数值,采用复合灌浆材料对裂隙岩体进行注浆加固试验并观察加固效果,选取加固效果最佳的一组复合灌浆材料,将该组复合灌浆材料的各组分配比确定为新型复合灌浆材料的最佳配比,本发明的一种用于裂隙岩体加固的复合灌浆材料配比获取方法,能够获取一种化学复合灌浆材料的各组分最佳配比,从而配制出性能优良的复合灌浆材料,对裂隙岩体进行有效加固。(The invention provides a method for obtaining the proportion of a composite grouting material for reinforcing fractured rocks, which comprises the steps of compounding a chemical material with polyurethane according to different mass proportions, mastering the change rule of mechanical properties of the chemical material after being compounded with the polyurethane, selecting a plurality of suitable chemical materials, compounding the chemical materials with the polyurethane, developing a plurality of groups of composite grouting materials with different proportions, obtaining the mechanical parameter values of the composite grouting materials, performing grouting reinforcement tests on the fractured rocks by adopting the composite grouting materials, observing the reinforcement effect, selecting a group of composite grouting materials with the best reinforcement effect, determining the proportion of each component of the group of composite grouting materials as the best proportion of a novel composite grouting material, and the method for obtaining the proportion of the composite grouting materials for reinforcing the fractured rocks can obtain the best proportion of each component of the chemical composite grouting materials, thereby preparing the composite grouting material with excellent performance and effectively reinforcing the fractured rock mass.)

1. A method for obtaining the proportion of a composite grouting material for reinforcing fractured rock mass is characterized by comprising the following steps: the method comprises the following steps:

s1, taking a chemical material, compounding the chemical material with polyurethane according to different mass ratios respectively, manufacturing a composite test block of the material and the polyurethane, simultaneously manufacturing a pure polyurethane test block with the same size and shape as the composite test block, carrying out the same physical mechanical test on the two test blocks and obtaining mechanical parameter values, and repeating the steps on other chemical materials respectively;

s2, calculating and selecting the component distribution ratio of a plurality of chemical materials and polyurethane for compounding together according to the mechanical property change rule after the single chemical material and the polyurethane are compounded, manufacturing each group of composite grouting material test blocks with consistent size and shape, carrying out a plurality of physical mechanical tests on each group of test blocks, and obtaining the mechanical parameter values of each group of composite grouting material consolidation test blocks;

s3, selecting 2-3 sets of composite grouting materials with the best mechanical parameter values from the composite grouting materials according to the mechanical parameter values of the composite grouting material consolidation test blocks, preparing the composite grouting materials according to different mass ratios, respectively performing grouting reinforcement tests on fractured rock masses, sampling the reinforced rock masses after grouting reinforcement and maintenance are completed to perform physical mechanical tests, obtaining the mechanical parameter values of the rock masses, and analyzing the reinforcing effect of the composite grouting materials on the fractured rock masses by combining the macro-micro characteristics of a failure surface and a reinforcing transition region after the physical mechanical tests;

and S4, selecting a group of composite grouting materials with the best reinforcing effect, and determining the proportion of each group of composite grouting materials as the best proportion of the novel composite grouting material.

2. The method for obtaining the proportion of the composite grouting material for reinforcing the fractured rock mass according to claim 1, wherein the method comprises the following steps: in step S1, the chemical material includes polyurethane, cellulose nanofibers, colloidal nanosilicon dioxide, unsaturated polyester resin, polyamide fibers, rubber powder, and water glass.

3. The method for obtaining the proportion of the composite grouting material for reinforcing the fractured rock mass according to claim 1, wherein the method comprises the following steps: in steps S1 and S2, the test block can be made into different spatial shapes and sizes, including but not limited to a cylinder, a cube, a sphere, and an i-shape.

4. The method for obtaining the proportion of the composite grouting material for reinforcing the fractured rock mass according to claim 1, wherein the method comprises the following steps: in steps S1 and S2, the physical mechanical tests include, but are not limited to, uniaxial compression test, triaxial compression test, shear test, and tensile test.

5. The method for obtaining the proportion of the composite grouting material for reinforcing the fractured rock mass according to claim 1, wherein the step S3 of analyzing the reinforcing effect of the composite grouting material on the fractured rock mass specifically comprises the following steps:

sampling the reinforced rock mass, carrying out physical mechanical tests on the samples to detect the mechanical properties of the samples, including but not limited to uniaxial compression tests, triaxial compression tests, shear tests, freeze-thaw tests and sound wave tests, and obtaining mechanical parameter values of the rock mass after grouting reinforcement;

selecting a part of a sample damage surface after the test, and utilizing a scanning electron microscope to carry out microscopic observation on the damage surface and the reinforcement transition region to obtain microscopic images of the damage surface and the reinforcement transition region, and observing characteristics of the damage surface, including but not limited to appearance position, roughness, particle shape and uniformity of the damage surface and macro-microscopic characteristics of the bonding transition region, and analyzing the bonding degree and the reinforcing effect of the composite grouting material and the fractured rock mass by combining mechanical parameter values of the rock mass after grouting reinforcement.

6. The method for obtaining the proportion of the composite grouting material for reinforcing the fractured rock mass according to claim 1, wherein the method comprises the following steps: in step S3, the fractured rock mass is obtained by simulating a fractured rock mass by 3D printing.

7. The method for obtaining the proportion of the composite grouting material for reinforcing the fractured rock mass according to claim 1, wherein the method comprises the following steps: in the step S3, the method for obtaining the fractured rock mass is to use rocks with different grain sizes to be uniformly mixed to the reaction container to simulate the fractured rock mass.

8. The method for obtaining the proportion of the composite grouting material for reinforcing the fractured rock mass according to claim 2, wherein the method for compounding the cellulose nanofibers and the polyurethane comprises the following steps:

putting polyether glycol and polyhydric alcohol into a stirring container, keeping the rotating speed at 300-480 r/min, fully stirring for 6-8 min, after uniformly mixing, taking anhydrous ethanol dispersion liquid of cellulose nano fibers, adding the anhydrous ethanol dispersion liquid into the uniformly stirred polyhydric alcohol mixture, adjusting the rotating speed to be more than 6000r/min, continuously stirring for 10min to fully disperse the cellulose nano fibers in the polyhydric alcohol mixture, then taking out the cellulose nano fibers, placing the cellulose nano fibers into a glass container, carrying out ultrasonic treatment on the cellulose nano fibers for more than 60min, and taking the mixed material after the ultrasonic treatment as a component A;

taking isocyanate as a component B;

putting the component A, the component B, the catalyst and the silane coupling agent into a reaction kettle together, filling nitrogen or other inert gases, increasing the temperature in the reaction kettle to 40-60 ℃, keeping the rotating speed at more than 3000r/min, fully stirring for 10 minutes, increasing the temperature to 70-90 ℃, continuing to stir for 20 minutes to fully volatilize the absolute ethyl alcohol, continuing to perform ultrasonic treatment on the absolute ethyl alcohol for 40-60 minutes, and then taking out and placing the grouting material in a glass container to obtain the composite grouting material of the cellulose nanofiber and the polyurethane.

9. The method for obtaining the proportion of the composite grouting material for reinforcing the fractured rock mass according to claim 8, wherein the method comprises the following steps: the catalyst is one or more of dibutyltin dilaurate and tertiary amine catalysts.

10. The method for obtaining the proportion of the composite grouting material for reinforcing the fractured rock mass according to claim 8, wherein the method comprises the following steps: the silane coupling agent is aminopropyl trimethoxy silane or 3-glycidoxypropyl trimethoxy silane.

Technical Field

The invention relates to the field of composite grouting materials for reinforcing fractured rock masses, in particular to a method for obtaining the proportion of a composite grouting material for reinforcing fractured rock masses.

Background

The development degree of the cracks has obvious influence on the stability, physical and mechanical properties, stress transmission and the like of the engineering rock mass, the penetration and development of the cracks easily induce geological disasters such as rock mass collapse, landslide and the like to cause life and property loss and infrastructure damage, and meanwhile, the construction progress and safety of the rock mass engineering are influenced, so that the reinforcement of the rock mass becomes necessary.

The traditional reinforcing methods of the anti-slide pile, the anchor rod, the retaining wall and the like tend to be mature, the methods are mainly used for integrally reinforcing the rock mass through physical and mechanical means, the defects of long construction period, high construction cost and the like exist, and due to the fact that the geological environment is severe and the construction difficulty is high, engineering accidents can be caused in the construction process, and casualties are caused. In addition, at present, the cement grouting material is mostly adopted to perform grouting reinforcement on rock body cracks, but the material has long consolidation time, poor corrosion resistance and easy generation of engineering problems such as bubbles, cracks and the like, and influences the reinforcement effect, so that the development of the novel grouting material has practical significance.

At present, the polyurethane grouting material is widely applied to the aspects of foundation reinforcement, leak stoppage, water stopping, curtain seepage prevention, crack repair and the like, has the advantages of good seepage resistance, good corrosion resistance, short setting period, adjustable setting time and the like, is a chemical grouting material with excellent performance, but has poor mechanical properties such as consolidation strength, elastic modulus and the like and more reaction heat release, so that the modification of the chemical grouting material becomes important, and the modified polyurethane composite grouting material can better reinforce fractured rock mass and improve the reinforcing effect.

However, in the prior art, a single chemical material is mainly compounded with polyurethane in the prior art, for example, water glass and polyurethane are compounded to achieve a reinforcing effect, but in practice, the environment of a fractured rock mass is complex, and a grouting material often needs to meet various requirements to achieve a good reinforcing effect, for example, the grouting material needs to meet the requirements of enhancing the impermeability, increasing the compressive strength, increasing the shear strength and the like, the mechanical parameter value of the compounding of the single chemical material cannot meet the requirements, and the reinforcing effect is poor.

Disclosure of Invention

The invention aims to provide a method for obtaining the proportion of a composite grouting material for reinforcing fractured rock mass.

The technical scheme of the invention is realized as follows: the invention provides a method for obtaining the proportion of a composite grouting material for reinforcing fractured rock mass, which is characterized by comprising the following steps: the method comprises the following steps:

s1, taking a chemical material, compounding the chemical material with polyurethane according to different mass ratios respectively, manufacturing a composite test block of the material and the polyurethane, simultaneously manufacturing a pure polyurethane test block with the same size and shape as the composite test block, carrying out the same physical mechanical test on the two test blocks and obtaining mechanical parameter values, and repeating the steps on other chemical materials respectively;

s2, calculating and selecting the component distribution ratio of a plurality of chemical materials and polyurethane for compounding together according to the mechanical property change rule after the single chemical material and the polyurethane are compounded, manufacturing each group of composite grouting material test blocks with consistent size and shape, carrying out a plurality of physical mechanical tests on each group of test blocks, and obtaining the mechanical parameter values of each group of composite grouting material consolidation test blocks;

s3, selecting 2-3 sets of composite grouting materials with the best mechanical parameter values from the composite grouting materials according to the mechanical parameter values of the composite grouting material consolidation test blocks, preparing the composite grouting materials according to different mass ratios, respectively performing grouting reinforcement tests on fractured rock masses, sampling the reinforced rock masses after grouting reinforcement and maintenance are completed to perform physical mechanical tests, obtaining the mechanical parameter values of the rock masses, and analyzing the reinforcing effect of the composite grouting materials on the fractured rock masses by combining the macro-micro characteristics of a failure surface and a reinforcing transition region after the physical mechanical tests;

and S4, selecting a group of composite grouting materials with the best reinforcing effect, and determining the proportion of each group of composite grouting materials as the best proportion of the novel composite grouting material.

Based on the above technical solution, preferably, in step S1, the chemical material includes polyurethane, cellulose nanofibers, colloidal nanosilicon dioxide, unsaturated polyester resin, polyamide fibers, rubber powder, and water glass.

Based on the above technical solutions, preferably, in steps S1 and S2, the test block can be made into different spatial shapes and sizes, including but not limited to a cylinder, a cube, a sphere, and an i-shape.

Based on the above technical solutions, preferably, in steps S1 and S2, the physical mechanical test includes, but is not limited to, a uniaxial compression test, a triaxial compression test, a shear test, and a tensile test.

On the basis of the above technical solution, preferably, in step S3, analyzing the reinforcing effect of the composite grouting material on the fractured rock mass specifically includes:

sampling the reinforced rock mass, carrying out physical mechanical tests on the samples to detect the mechanical properties of the samples, including but not limited to uniaxial compression tests, triaxial compression tests, shear tests, freeze-thaw tests and sound wave tests, and obtaining mechanical parameter values of the rock mass after grouting reinforcement;

selecting a part of a sample damage surface after the test, and utilizing a scanning electron microscope to carry out microscopic observation on the damage surface and the reinforcement transition region to obtain microscopic images of the damage surface and the reinforcement transition region, and observing characteristics of the damage surface, including but not limited to appearance position, roughness, particle shape and uniformity of the damage surface and macro-microscopic characteristics of the bonding transition region, and analyzing the bonding degree and the reinforcing effect of the composite grouting material and the fractured rock mass by combining mechanical parameter values of the rock mass after grouting reinforcement.

On the basis of the above technical solution, preferably, in step S3, the method for acquiring the fractured rock mass is to simulate the fractured rock mass by using 3D printing.

On the basis of the above technical solution, preferably, in step S3, the method for obtaining the fractured rock mass is to use rocks with different particle sizes to be uniformly mixed into the reaction container to simulate the fractured rock mass.

Still more preferably, the compounding method of the cellulose nanofibers and polyurethane comprises the following steps:

putting polyether glycol and polyhydric alcohol into a stirring container, keeping the rotating speed at 300-480 r/min, fully stirring for 6-8 min, after uniformly mixing, taking anhydrous ethanol dispersion liquid of cellulose nano fibers, adding the anhydrous ethanol dispersion liquid into the uniformly stirred polyhydric alcohol mixture, adjusting the rotating speed to be more than 6000r/min, continuously stirring for 10min to fully disperse the cellulose nano fibers in the polyhydric alcohol mixture, then taking out the cellulose nano fibers, placing the cellulose nano fibers into a glass container, carrying out ultrasonic treatment on the cellulose nano fibers for more than 60min, and taking the mixed material after the ultrasonic treatment as a component A;

taking isocyanate as a component B;

putting the component A, the component B, the catalyst and the silane coupling agent into a reaction kettle together, filling nitrogen or other inert gases, increasing the temperature in the reaction kettle to 40-60 ℃, keeping the rotating speed at more than 3000r/min, fully stirring for 10 minutes, increasing the temperature to 70-90 ℃, continuing to stir for 20 minutes to fully volatilize the absolute ethyl alcohol, continuing to perform ultrasonic treatment on the absolute ethyl alcohol for 40-60 minutes, and then taking out and placing the grouting material in a glass container to obtain the composite grouting material of the cellulose nanofiber and the polyurethane.

Still more preferably, the catalyst is one or more of dibutyltin dilaurate and tertiary amine catalysts.

More preferably, the silane coupling agent is aminopropyltrimethoxysilane or 3-glycidoxypropyltrimethoxysilane.

Compared with the prior art, the method for obtaining the proportion of the composite grouting material for reinforcing the fractured rock mass has the following beneficial effects:

(1) according to the method for obtaining the proportion of the composite grouting material for reinforcing the fractured rock mass, the optimal proportion of each component of a novel chemical composite grouting material can be obtained, so that the composite grouting material with excellent performance is prepared, and the fractured rock mass is effectively reinforced;

(2) according to the method for compounding the cellulose nanofibers and the polyurethane, the stirring speed and the stirring time are increased, and ultrasonic treatment is performed twice, so that the cellulose nanofibers can be fully dispersed in the grouting material and further fully compounded with the polyurethane.

(3) The method for obtaining the proportion of the composite grouting material for reinforcing the fractured rock mass can fully integrate the advantages of all components, make up for the deficiencies of poor mechanical properties, large reaction heat release and the like of the polyurethane grouting material, modify the polyurethane grouting material, improve the mechanical properties such as the compressive strength, the shear strength, the impermeability and the like of the fractured engineering rock mass, enhance the stability of the rock mass and meet the requirements of actual engineering.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic flow chart of a method for obtaining a proportion of a composite grouting material for reinforcing a fractured rock mass according to the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

As shown in figure 1, the method for obtaining the proportion of the composite grouting material for reinforcing the fractured rock mass comprises the following steps:

step S1, compounding the single chemical material with polyurethane: taking a chemical material, respectively compounding the chemical material with polyurethane according to different mass ratios to prepare a composite test block of the material and the polyurethane, simultaneously preparing a pure polyurethane test block, carrying out the same physical mechanical test on the two test blocks and obtaining mechanical parameter values, repeating the step on other chemical materials respectively, and mastering the change rule of the mechanical property after compounding the single chemical material with the polyurethane;

in step S1, the specific process of grasping the law of change in mechanical properties after the chemical materials are compounded with polyurethane respectively is as follows:

s101, manufacturing a pure polyurethane test block, wherein the test block can be manufactured into different spatial shapes and sizes including but not limited to a cylinder, a cube, a sphere and an I shape according to test requirements;

step S102, selecting a chemical material, compounding the chemical material with polyurethane in different mass ratios within a certain range, and if the chemical material respectively accounts for 5%, 10%, 15%, 20%, 25% and 30% of the total mass of the composite material, selecting the corresponding mass ratio range and compounding method according to the physical and chemical properties of the material, and fully mixing the material with the polyurethane to enhance the compounding effect;

in step S102, chemical raw materials for developing a novel composite grouting material are selected, including polyurethane, cellulose nanofibers, colloidal nanosilicon dioxide, unsaturated polyester resin, polyamide fibers, rubber powder, and water glass.

Further, the compounding manner of the various chemical materials and the polyurethane in this embodiment is as follows:

(1) polyurethane-water glass composite

The materials required for the composite test of the water glass and the polyurethane comprise: isocyanate, polyol, water glass (5-30 percent) with different mass proportions, a catalyst, a silane coupling agent, a chain extender and the like.

Firstly, water glass (5-30%) with different mass proportions and polyol are uniformly mixed at room temperature to be used as a component A material of the polyurethane-water glass composite material, and isocyanate is used as a component B material. And then pouring the component A, the component B, the catalyst, the chain extender and the silane coupling agent into a polyethylene plastic cup at the same time, stirring at room temperature, and uniformly stirring to obtain the polyurethane-water glass composite material.

(2) Polyurethane-cellulose nanofiber composites

Putting polyether glycol and polyhydric alcohol into a stirring container, keeping the rotating speed at 300-480 r/min, fully stirring for 6-8 min, after uniformly mixing, taking anhydrous ethanol dispersion liquid of cellulose nano fibers, adding the anhydrous ethanol dispersion liquid into the uniformly stirred polyhydric alcohol mixture, adjusting the rotating speed to be more than 6000r/min, continuously stirring for 10min to fully disperse the cellulose nano fibers in the polyhydric alcohol mixture, then taking out the cellulose nano fibers, placing the cellulose nano fibers into a glass container, carrying out ultrasonic treatment on the cellulose nano fibers for more than 60min, and taking the mixed material after the ultrasonic treatment as a component A;

taking isocyanate as a component B;

putting the component A, the component B, the catalyst and the silane coupling agent into a reaction kettle together, filling nitrogen or other inert gases, increasing the temperature in the reaction kettle to 40-60 ℃, keeping the rotating speed at more than 3000r/min, fully stirring for 10 minutes, increasing the temperature to 70-90 ℃, continuing to stir for 20 minutes to fully volatilize the absolute ethyl alcohol, continuing to perform ultrasonic treatment on the absolute ethyl alcohol for 40-60 minutes, and then taking out and placing the grouting material in a glass container to obtain the composite grouting material of the cellulose nanofiber and the polyurethane.

The catalyst is one or more of dibutyltin dilaurate and tertiary amine catalysts, and the silane coupling agent is aminopropyltrimethoxysilane or 3-glycidoxypropyltrimethoxysilane.

The tertiary amine catalyst includes N, N-dimethylcyclohexylamine, bis (2-dimethylaminoethyl) ether, N, N, N ', N' -tetramethylalkylenediamine, N-ethylmorpholine and the like.

By improving the stirring speed and the stirring time and carrying out ultrasonic treatment twice, the cellulose nano-fibers can be more fully dispersed in the grouting material and then fully compounded with polyurethane.

(3) Polyurethane-colloidal nanosilica compounding

The materials required by the composite test of the colloidal nano-silica and the polyurethane comprise: isocyanate, polyol, colloidal nano-silica, a catalyst, a silane coupling agent, a chain extender and the like.

Mixing colloidal nano-silica with different mass ratios with polyol, uniformly stirring for 5-10 min to serve as a component A, taking isocyanate as a component B, simultaneously adding the component A, the component B, a catalyst, a chain extender and a silane coupling agent into a reaction vessel in the test process, stirring at the room temperature of 20-30 ℃, and stirring for 5-10 min to obtain the polyurethane-colloidal nano-silica composite material.

(4) Polyurethane-unsaturated polyester resin composite

The materials required for the compounding test of the unsaturated polyester resin and the polyurethane comprise: isocyanate, polyol, unsaturated polyester resin, catalyst, silane coupling agent, chain extender and the like.

Mixing isocyanate, polyol and silane coupling agent, stirring for 5-10 min to obtain a polyurethane solution, taking unsaturated polyester resin with different mass ratios, adding the unsaturated polyester resin, a chain extender and a catalyst into the polyurethane solution, stirring, and stirring for 5-10 min to obtain the polyurethane-unsaturated polyester resin composite material.

(5) Polyurethane-polyamide fiber composite

The materials required for the composite test of the polyurethane fiber and the polyurethane comprise: polyurethane, polyamide fiber 800-1000 meshes, ethanol and distilled water.

The polyamide fiber is taken, impurities on the surface of the polyamide fiber are cleaned by using ethanol, then the polyamide fiber is washed by using fresh distilled water to remove excessive ethanol, and the polyamide fiber is dried in a vacuum oven at 50 ℃ to remove ethanol and water. Then, the polyamide fiber was treated with air plasma at room temperature at a power of 50w, a pressure of 1atm and a speed of 8mm/s to improve the adhesion. And finally, adding the treated polyamide fiber into polyurethane, stirring for 30min, and uniformly mixing to obtain the polyurethane-polyamide fiber composite material.

(6) Polyurethane-rubber composite

The materials required for the rubber and polyurethane composite test comprise: fluororubber powder (the particle size is less than or equal to 200 mu m), isocyanate, polyol, catalyst, silane coupling agent, chain extender and the like.

Adding fluororubber powder with different mass percentages (5-30%) into polyol, stirring, adding isocyanate, a catalyst, a chain extender and a silane coupling agent after stirring for 5-10 min, and continuously stirring for 3-5 min to obtain the polyurethane-rubber composite material.

Step S103, curing the compounded material to be completely solidified, manufacturing a plurality of test blocks of the compound material, wherein the space shape and the size of the test blocks are the same as those of pure polyurethane test blocks, including but not limited to cylinders, cubes, spheres and I-shaped test blocks, and curing and molding the test blocks;

step S104, carrying out the same physical and mechanical tests on the composite material test block and the pure polyurethane test block, wherein the physical and mechanical tests include but are not limited to a uniaxial compression test, a triaxial compression test, a shear test and a tensile test, obtaining mechanical parameter values of the composite material test block and the pure polyurethane test block, and mastering the mechanical property of the composite material formed by compounding the chemical material and the polyurethane;

s105, repeating the steps S101 to S104 on other chemical materials respectively, counting and collating various test data, and mastering the change rule of the mechanical property of the single chemical material compounded with the polyurethane;

step S2, compounding multiple chemical materials and polyurethane together: according to the change rule of mechanical properties after a single chemical material and polyurethane are compounded, calculating and selecting the component proportion for compounding a plurality of chemical materials and the polyurethane together, researching and developing a plurality of groups of composite grouting materials with different proportions, numbering the composite grouting materials, respectively detecting the indexes of the composite grouting materials such as viscosity, density, acidity and alkalinity and the like, respectively manufacturing composite grouting material test blocks of each group after the composite grouting materials of each group are cured to be completely solidified, carrying out a plurality of physical and mechanical tests on the test blocks of each group, and obtaining the mechanical parameter values of the composite grouting material solidified test blocks of each group;

in step S2, compounding multiple chemical materials with polyurethane, developing multiple sets of composite grouting materials with different proportions, and obtaining mechanical parameter values of the composite grouting materials of each set are as follows:

step S201, selecting a proportion or a proportion range corresponding to the optimal mechanical property of each group of materials according to the mechanical property change rule mastered in the step S1 after the single chemical material and the polyurethane are compounded, wherein the proportion or the proportion range can be selected according to a plurality of main mechanical indexes, such as compressive strength, tensile strength, shear strength, Poisson' S ratio and elastic modulus;

step S202, determining the proportion or proportion range corresponding to the optimal mechanical property of each group of materials according to the step S201, selecting the component proportion of a plurality of chemical materials and polyurethane for compounding together by calculation, fully mixing the chemical materials, preparing a plurality of groups of composite grouting materials with different proportions and numbering the composite grouting materials respectively;

step S203, detecting physical characteristic indexes of each group of composite grouting materials respectively, wherein the physical characteristic indexes include but are not limited to the viscosity of the composite grouting materials tested by a viscosity tester, the density of the composite grouting materials tested by a densimeter, the pH value of composite grouting liquid tested by a pH tester and the like, and judging the characteristic indexes such as the fluidity, the viscosity and the like of the composite grouting materials;

step S204, after each group of composite grouting materials are cured to be completely solidified, test blocks corresponding to each group of composite grouting materials are respectively manufactured, test blocks with different spatial shapes and sizes including but not limited to a cylinder, a cube, a sphere and an I shape can be manufactured according to test requirements, and the test blocks are cured and molded;

step S205, carrying out various physical mechanical tests on each group of test blocks, including but not limited to uniaxial compression test, triaxial compression test, shear test and tensile test, counting and analyzing each group of test data, and obtaining mechanical parameter values of each group of composite grouting material consolidation test blocks;

step S3, observing the reinforcing effect of the composite grouting material: selecting 2-3 groups of composite grouting materials with excellent performance from the mechanical parameter values of the composite grouting material consolidation test blocks, preparing the composite grouting materials according to different mass ratios, wherein if single chemical materials respectively account for 5%, 10%, 15%, 20%, 25% and 30% of the total mass of the composite grouting materials, other chemical materials change along with the change of the mass ratio of the composite grouting materials, the prepared composite grouting materials are respectively used for grouting and reinforcing a fractured rock mass, after grouting reinforcement and maintenance are completed, the reinforced rock mass is sampled to carry out a physical mechanical test, the mechanical parameter values are obtained, and the reinforcing effect of the composite grouting materials on the fractured rock mass is analyzed by combining macro-micro characteristics of a fracture surface and a reinforcing transition region after the physical mechanical test;

in step S3, the concrete process of performing a grouting reinforcement test on the fractured rock mass by using the composite grouting material and observing the reinforcement effect of the composite grouting material is as follows:

s301, sampling a natural rock mass sample containing a fracture network, simulating a fracture environment by using well-graded broken stones, or simulating rock mass fractures by using a 3D printing technology, selecting 2-3 groups of composite grouting materials with excellent performance from the natural rock mass sample according to mechanical parameter values of consolidated test blocks of the composite grouting materials, preparing the composite grouting materials according to different mass ratios, and pouring the composite grouting materials into the rock mass fractures by using a grouting tool for maintenance;

in step S301, the obtaining of the concrete contents of the rock mass fracture includes:

(1) sampling natural rock mass sample containing fracture network

Sampling a natural rock mass sample containing a fracture network, grouting and reinforcing the sample by using grouting equipment, maintaining the sample, and mechanically processing the sample after the maintenance is finished to obtain a reinforced sample, wherein the sample can be processed into different space forms according to test requirements.

(2) Simulation of fracture environment by using well graded broken stone

And (4) taking rocks with different grain sizes and screening the rocks to obtain a plurality of rocks with different grain sizes. According to test requirements, calculating the proportion of rocks with different particle sizes, obtaining crushed stone particles with good gradation, uniformly mixing the crushed stone particles into a reaction container to simulate a rock fracture environment, and then grouting and reinforcing the crushed stone particles by using grouting equipment and maintaining and forming the crushed stone particles.

(3)3D prints simulation rock mass crack

Designing distribution characteristics of rock body fractures such as fracture occurrence probability distribution, fracture size probability distribution, fracture width probability distribution, fracture density and the like according to test requirements, then establishing a three-dimensional digital model of the rock body fractures by utilizing computer modeling software, carrying out slicing processing on the established three-dimensional digital model, selecting proper printing materials and printing equipment to carry out 3D printing work, wherein the printing materials are required to simulate a real rock body, so that a plurality of identical printing models containing fracture networks are obtained, one printing model is taken to carry out a mechanical test, mechanical parameters of the printing model are obtained, so that the reinforcement effect is evaluated, grouting reinforcement is carried out on each printing model by using grouting equipment, and curing and forming are carried out.

Step S302, sampling the rock mass after grouting reinforcement and maintenance, and carrying out physical mechanical tests on the samples to detect the mechanical properties of the samples, wherein the physical mechanical tests include but are not limited to uniaxial compression tests, triaxial compression tests, shear tests, freeze-thaw tests and acoustic wave tests, the types of the tests can be determined according to actual requirements and test conditions, and the mechanical parameter values of the rock mass after grouting reinforcement are obtained;

specifically, the development of the related physical mechanical test should meet the related standard requirements, and the related documents such as the engineering rock mass test method standard GB/T50266-2013 and the like can be referred to, and if updated later, the related documents should be executed according to the latest standard requirements;

step S303, selecting a part of the tested sample destruction surface, carrying out microscopic observation on the destruction surface and the reinforcement transition region by using a scanning electron microscope, obtaining microscopic images of the destruction surface and the reinforcement transition region, observing characteristics of the destruction surface, including but not limited to appearance position, roughness, particle shape and uniformity of the destruction surface and macroscopic and microscopic characteristics of the bonding transition region, analyzing the bonding degree of the composite grouting material and the fractured rock mass by combining mechanical parameter values of the grouted and reinforced rock mass, and analyzing the reinforcing effect.

And step S4, selecting a group of composite grouting materials with the best reinforcing effect, and determining the proportion of each group of composite grouting materials as the best proportion of the novel composite grouting materials.

Further, in step S4, the optimal reinforcing effect means that the composite grouting material can meet certain mechanical property requirements, and the grouting reinforcing effect can meet the actual engineering requirements, for example, the rock body after grouting reinforcement has higher compressive strength, or mechanical parameter indexes such as impermeability and shear strength can meet the actual engineering requirements.

The invention provides a method for obtaining the optimal proportion of a novel composite grouting material for reinforcing fractured rock mass, which can obtain the optimal proportion of each component of a novel chemical composite grouting material, thereby preparing the composite grouting material with excellent performance and effectively reinforcing the fractured rock mass. Meanwhile, the method can fully integrate the advantages of all components, make up for deficiencies of poor mechanical properties, large reaction heat release and the like of the polyurethane grouting material, modify the polyurethane grouting material, improve the mechanical properties such as compressive strength, shear strength, impermeability and the like of the engineering rock mass containing cracks, obtain good reinforcing effect, enhance the stability of the rock mass and meet the requirements of actual engineering.

All the situations that the composite material of the present invention can meet the actual engineering requirements or the test requirements are included in the protection scope of the present invention.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.