CN-121048992-B - Grouting device for precast fractured rock mass sample and preparation method

CN121048992BCN 121048992 BCN121048992 BCN 121048992BCN-121048992-B

Abstract

The invention relates to the technical field of geotechnical engineering, and discloses a grouting device and a preparation method for a prefabricated fractured rock mass sample, wherein the device comprises a slurry preparation mechanism, a sample maintenance mechanism and a grouting mechanism; the slurry preparation mechanism is used for preparing slurry, a viscosity sensor is arranged in the slurry preparation mechanism, a temperature and humidity adjusting assembly is arranged in the sample maintenance mechanism, the grouting mechanism comprises a grouting chamber, a pressure sensor, a grouting assembly and a clamp, the grouting chamber is detachably connected in the sample maintenance mechanism, the clamp and the pressure sensor are both arranged in the grouting chamber, one end of the grouting assembly is communicated with the slurry preparation mechanism, a telescopic grouting pipe is arranged at the other end of the grouting assembly, and the telescopic grouting pipe stretches into the grouting chamber. The invention can directly carry out constant temperature and constant humidity maintenance on the premise of not moving the sample, and the success rate of sample preparation is improved by adopting two-step cutting.

Inventors

ZHANG SHIZHONG
YANG CONGXIN
Lin Taijie
LI ZIHENG
Xu Jiaotao
FAN GANGWEI
LUO TAO
GAO XINYAO

Assignees

中国矿业大学

Dates

Publication Date: 20260508
Application Date: 20250905

Claims (10)

1. A grouting device for prefabricating a fractured rock mass specimen, comprising: the slurry preparation mechanism is used for preparing slurry, and a viscosity sensor (5) is arranged in the slurry preparation mechanism; The sample maintenance mechanism is internally provided with a temperature and humidity adjusting assembly; The grouting device comprises a grouting mechanism, wherein the grouting mechanism comprises a grouting chamber (10), a pressure sensor (13), a grouting assembly and a clamp, the grouting chamber (10) is detachably connected in the sample maintenance mechanism, the clamp and the pressure sensor (13) are both arranged in the grouting chamber (10), one end of the grouting assembly is communicated with the slurry preparation mechanism, the other end of the grouting assembly is provided with a telescopic grouting pipe, and the telescopic grouting pipe stretches into the grouting chamber (10).
2. The grouting device for a precast fractured rock mass specimen according to claim 1, wherein the slurry preparation mechanism comprises: The reaction kettle (1) is internally provided with a plurality of viscosity sensors (5), and the grouting chamber (10) and the grouting assembly are respectively communicated with the reaction kettle (1) through a connecting pipeline (9); the motor (3), the motor (3) is installed on the reaction kettle (1), a stirring shaft is installed on an output shaft of the motor (3) through a coupling, the stirring shaft stretches into the reaction kettle (1), and a plurality of stirring impellers (2) are installed on the stirring shaft; the slurry preparation parameter control platform (4), wherein the slurry preparation parameter control platform (4) is arranged on the outer wall of the reaction kettle (1), and the motor (3) and the viscosity sensors (5) are electrically connected with the slurry preparation parameter control platform (4); the first computer (7) is electrically connected with the slurry preparation parameter control platform (4) through a first connecting wire (6).
3. The grouting device for the prefabricated fractured rock mass sample according to claim 2, wherein the sample curing mechanism comprises a curing chamber (17) and a second computer (26), a curing parameter control platform (22) is installed on the curing chamber (17), the temperature and humidity adjusting component comprises an electric heating wire (18), a humidifier (19), a temperature sensor (20) and a humidity sensor (21), the pressure sensor (13), the electric heating wire (18), the humidifier (19), the temperature sensor (20) and the humidity sensor (21) are electrically connected with the curing parameter control platform (22), the curing parameter control platform (22) is electrically connected with the second computer (26) through a second connecting wire (16), and the grouting chamber (10) is detachably connected in the curing chamber (17).
4. The grouting device for the prefabricated fractured rock mass sample according to claim 3, wherein the grouting assembly comprises a grouting pump (8), a grouting parameter control platform (15) is installed on the grouting pump (8), and the grouting parameter control platform (15) is electrically connected with the second computer (26) through a second connecting wire (16); The telescopic grouting pipe and the reaction kettle (1) are respectively communicated with the grouting pump (8) through a connecting pipeline (9), a flow rate sensor (14) is installed on the connecting pipeline (9), and the flow rate sensor (14) and the grouting pump (8) are electrically connected with the grouting parameter control platform (15).
5. A grouting device for a prefabricated fractured rock mass specimen according to claim 3, characterized in that the grouting chamber (10) comprises a base (25) and a cover, the base (25) is detachably connected to the inner bottom wall of the maintenance chamber (17), the cover is detachably connected to the top of the base (25), the clamp is mounted on the base (25), and the clamp is located in the cover; The grouting device is characterized in that a grouting opening (11) is formed in the housing, the telescopic grouting pipe extends into the inner cavity of the housing through the grouting opening (11), the grouting chamber (10) is communicated with the reaction kettle (1) through a connecting pipeline (9), and the pressure sensor (13) is mounted on the inner wall of the housing.
6. The grouting device for precast fractured rock mass samples according to claim 5, wherein the housing comprises a top plate and four vertical plates (23), the four vertical plates (23) are detachably connected to four sides of the top surface of the base (25), the top plate is detachably connected to the tops of the four vertical plates (23), the pressure sensor (13) is mounted on the inner wall of one of the vertical plates (23), and the grouting opening (11) is formed in the top plate.
7. The grouting device for a precast fractured rock mass specimen according to claim 5, wherein the jig comprises a plurality of slidable clamping plates (12), the plurality of slidable clamping plates (12) are slidably connected to the base (25), and the slidable clamping plates (12) are detachably connected to the base (25) through positioning portions.
8. A method of preparing a pre-slit rock mass sample, based on a grouting device for pre-slit rock mass samples as claimed in any one of claims 1-7, characterized by comprising the steps of: Step one, obtaining a complete sample of a test rock mass; Step two, performing first cutting of the sample in a laboratory to prepare a preparation sample, wherein the length of the preparation sample is 1.2-1.5 times of the length of the standard sample size, the width of the preparation sample is 1.2-1.5 times of the width of the standard sample size, and the height of the preparation sample is 1.2-1.5 times of the height of the standard sample size; Step three, cutting a prefabricated crack on the prepared sample according to the preset crack form, direction and opening; Step four, preparing grouting reinforcement materials by using a slurry preparation mechanism, monitoring and feeding back the fluidity of slurry in real time through a viscosity sensor (5), and adjusting the component doping amount of the grouting materials according to the data monitored by the viscosity sensor (5); Step five, placing the prepared sample with the cut prepared cracks in a grouting chamber (10), adjusting grouting positions through a telescopic grouting pipe, enabling the grouting positions to be aligned to the prepared crack positions of the prepared sample, fixing the prepared sample by using a clamp, and filling gaps around the prepared sample and the grouting chamber (10) by using polyurethane foam materials; step six, adjusting the slurry flow rate, the grouting pressure and the pressure maintaining time of grouting to perform preliminary sample grouting; Step seven, opening a grouting chamber (10), taking down polyurethane foam materials, exposing the grouting prepared sample in a sample curing mechanism, adjusting curing temperature, humidity and time in the sample curing mechanism, and curing the grouting prepared sample until the sample is completely coagulated and meets the set test requirement; Step eight, taking down the cured grouting preparation sample, and performing secondary cutting in a laboratory to prepare a precast fractured rock mass grouting standard sample; And step nine, testing mechanical parameters such as strength, elastic modulus and the like of a precast fractured rock mass grouting standard sample on a rock mechanical property testing machine, and evaluating grouting reinforcement effect.
9. The method for preparing a precast fractured rock mass sample according to claim 8, wherein in the step six, initial grouting is performed by adopting a pressure which is 1/5 times of a preset grouting pressure value, and when slurry stops flowing under the initial grouting pressure, the pressure is increased to the preset value, wherein the pressure value is increased by 1 to 5 minutes.
10. The method of preparing a pre-slit rock mass specimen according to claim 8, wherein in the third step, a cutter or a carving machine is used to cut the pre-slit on the pre-specimen.

Description

Grouting device for precast fractured rock mass sample and preparation method Technical Field The invention relates to the technical field of geotechnical engineering, in particular to a grouting device for a prefabricated fractured rock mass sample and a preparation method. Background In the fields of geotechnical engineering, mining engineering and the like, the existence of primary or engineering disturbance cracks in a rock body can cause the deterioration of mechanical properties such as rock body strength, elastic modulus, poisson ratio and the like, so that important influences on the stability of the rock body or engineering quality are generated, and grouting reinforcement of the cracked rock body is one of effective means for improving the mechanical properties of the cracked rock body. How to test the mechanical properties of the fractured rock mass after grouting reinforcement and evaluate the grouting reinforcement effect is a great difficulty frequently faced by engineering technicians in the field. The method is one of effective methods for solving the problems by manufacturing a grouting fractured rock mass standard sample in a laboratory and carrying out mechanical property test. At present, a one-step forming method is mostly adopted for manufacturing the standard sample of the grouting fractured rock mass. Namely, firstly, a complete rock test standard sample (such as a 50mm multiplied by 100mm cylinder sample, a 50mm multiplied by 50mm cube sample and the like) is manufactured, secondly, cracks with required forms, directions, opening degrees and the like are cut on the standard sample, then grouting materials are filled in the cracks, and finally, rock mechanical property test is carried out after the grouting materials are solidified and air-dried. In the prior art, chinese patent publication No. CN114993787A discloses a rock standard sample fracture high-pressure grouting filling device, system and method, and the method comprises the steps of firstly manufacturing a standard sample, then cutting through type fracture, and finally grouting to prepare a prefabricated fracture grouting standard sample. However, in practice, this method has mainly the following drawbacks: firstly, a complete rock test standard sample is manufactured, and then the operation sequence and the method of fracture cutting are performed, wherein the standard sample is small in size and is influenced by the size effect, the cutting load cannot form stable far-field stress in the rock, meanwhile, the energy required by rock fracture is low, the prefabricated fracture can be suddenly unstable and expanded, unexpected deflection or bifurcation of the fracture is caused, and therefore the success rate of the prefabricated fracture sample is low, and the actual sample preparation success rate is low; when the prefabricated crack on the standard sample is a through type crack, the sample before grouting is divided into two parts and needs to be fixed independently, the requirement on the fixing precision is high, the size parameter of the prefabricated crack often deviates from a design value due to the deviation of the fixing positions of the two parts of samples in the actual operation process, and the design requirement of the crack size cannot be met; At present, when grouting is performed on a precast fracture sample, the condition of excessive grouting easily occurs, namely, slurry is easy to adhere and attach at other positions on the surface of the sample besides filling a fracture space, so that the size of the sample after grouting is not a standard sample, and the accuracy of a mechanical parameter test result is reduced. For this purpose, a grouting device for prefabricated fractured rock mass samples and a preparation method are provided. Disclosure of Invention The invention aims to provide a grouting device for a precast fractured rock mass sample and a preparation method thereof, and aims to solve or improve at least one of the technical problems. In order to achieve the purpose, the invention provides the scheme that the grouting device for the precast fractured rock mass sample comprises: The slurry preparation mechanism is used for preparing slurry, and a viscosity sensor is arranged in the slurry preparation mechanism; The sample maintenance mechanism is internally provided with a temperature and humidity adjusting assembly; The grouting device comprises a grouting mechanism, a grouting chamber, a pressure sensor, a grouting assembly and a clamp, wherein the grouting chamber is detachably connected in the sample maintenance mechanism, the clamp and the pressure sensor are both arranged in the grouting chamber, one end of the grouting assembly is communicated with the slurry preparation mechanism, the other end of the grouting assembly is provided with a telescopic grouting pipe, and the telescopic grouting pipe stretches into the grouting chamber. According to the grouting device for the precast fr