Experimental Study And Application Of Self-expansion Pushing Rubber Method For Mining Triaxial Ground Stress Gauge

Ground stress is the basic loading condition in deep rock engineering,which is of great significance to the construction of geotechnical and mining projects.Aiming at the current problem of low success rate of hollow body stress gauge installation,this paper improves and optimizes the guide head structure and stress gauge structure on the basis of the original hollow body stress gauge,and also proposes the use of a chemical expansion material to realize the function of self-pushing glue,which improves the efficiency of ground stress measurement.The main research results are as follows:(1)The method of self-expanding pushing glue for mining triaxial geophones is proposed.By analyzing the currently known principles of pushing glue,analyzing the principles of physical expansion and chemical expansion,and improving the original stress gauge,the original cone guide was optimized as a semicircular ball guide,and the original manual glue pushing method was optimized as a self-expanding glue pushing method.Through the above improvements,it is proved that the improved stress gauge helps to improve the efficiency,reduce the waste of resources and save the cost.(2)The self-expanding pushing glue material for the mining triaxial geophones was developed.By studying the time of expansion as well as the pushing distance.In the physical expansion experiment,the saturation rate of the sodium-based expanded soil and the expansion rate were measured by the homemade physical expansion apparatus;in the chemical expansion experiment,the homemade chemical expansion apparatus was used to conduct preliminary experiments on the chemical propulsion distance,and the ratio of the experimental materials would be optimized to obtain the four factors affecting the propulsion distance in descending order: plant capsules of sodium bicarbonate,glutinous rice capsules containing oxalic acid,water temperature and water volume.(3)The model test verified the feasibility of the self-expanding pushing glue method of the mining triaxial geophones.The physical model tests of chemical glue pushing were conducted in the laboratory to simulate the small holes and glue out of the actual process of measurement.In the process of actual engineering measurement,the internal situation of the hole could not be observed.By installing the improved stress gauge into the model,the amount of glue out of the internal hole and the general direction of the glue were observed,and the time of glue out as well as the amount of glue out were recorded to initially verify the feasibility of self-expansion glue pushing.(4)The self-expansion glue pushing method of mining triaxial ground stress gauge was verified by industrial test.Through the actual measurement process of a coal mine in Yulin,three improved hollow envelope sensors were arranged in three mining areas to measure the stress of the original rock in the mine,and the feasibility of the self-expansion method in actual engineering was verified by using the self-expansion stress meter in actual engineering.The thesis has 39 pictures,21 tables,and 81 references.