Study On Stability And Control Technology Of Tunnel Surrounding Rock In Weak Cementation And Extremely Soft Stratum

Weakly cemented rock is a kind of complex rock mechanics medium with significant plastic deformation under specific environment.Due to the complex characteristics of weak cemented strata and the complicated geological conditions of coal mine roadway engineering,the control of surrounding rock in the process of coal mine construction and production has always been a major problem.Based on the construction of Yingjun No.1 well in Shanghai Miao mining area as the engineering background,through systematic field monitoring,indoor experiment and theoretical analysis,the engineering geological conditions of Shanghai Miao mining area are comprehensively analyzed to determine the physical and mechanical properties and mechanical parameters of coal and rock.In depth study and determine the characteristics and laws of in-situ stress distribution,location and location of shaft and roadway engineering,excavation and support parameters of roadway engineering under the condition of weak cementation and extremely soft lithology,so as to provide basis for mine construction.(1)This paper discusses the engineering geological conditions of Yingjun No.1 well in Shanghai Miao mining area and analyzes the geological structure characteristics.The in-situ stress test is carried out by using hydraulic fracturing method,and the distribution characteristics and Spatial Laws of ground stress with buried depth in weak cemented extremely soft stratum are obtained,including the magnitude,direction and gradient change of ground stress in different layers,so as to select and support the shaft and roadway engineering The structure design provides scientific basis.(2)Systematic laboratory tests on rock mechanics parameters of coal and rock in Yingjun No.1 minefield are carried out.The main test contents include determination of physical parameters,mineral composition and microstructure of coal,determination of water physical property coefficient and determination of mechanical property parameters.It provides a theoretical basis for the mechanical mechanism analysis of surrounding rock deformation,support design and stability analysis of weak cemented extremely soft rock roadway.(3)The main development roadways in Shanghai Miao mining area are analyzed and optimized by numerical simulation.According to the field geological and production technical conditions and combined with the results of rock mechanics physical experiment,the stress and displacement of the excavated roadway and surrounding rock and soil under different conditions of development are analyzed,and the following numerical simulation studies are carried out:numerical simulation analysis of reasonable well spacing,numerical simulation analysis of reasonable tunnel spacing,numerical simulation analysis of reasonable excavation sequence,and adjacent roadways Reasonable excavation stagger distance numerical simulation analysis,shaft bottom yard horse head door numerical simulation analysis.(4)The main development roadways in Shanghai Miao mining area are analyzed and optimized by numerical simulation.According to the field geological and production technical conditions and combined with the results of rock mechanics physical experiment,the stress and displacement of the excavated roadway and surrounding rock and soil under different conditions of development are analyzed,and the following numerical simulation studies are carried out:numerical simulation analysis of reasonable well spacing,numerical simulation analysis of reasonable tunnel spacing,numerical simulation analysis of reasonable excavation sequence,and adjacent roadways Reasonable excavation stagger distance numerical simulation analysis,shaft bottom yard horse head door numerical simulation analysis.