Shear Zones Within Layer Of Basalt And Their Effect On Rock Mass

Based on the earth system science and dynamic evolution theory of the geological environment,the paper uses kinds of methods to analyze the development characteristics, spatial distribution and structure properties of intraformational faulted zones which locate in basalts,hydropower station of Baihetan,to explore the forming reasons and mechanism of LC, and to study the influence to rock mass in scope of the dam,according to lots of field measured data.The research result offers reference basis for study of rock mass mechanics and engineering design.The main contents are following.(1) The terrain landform,hydrology geology conditions and stratum lithology are investigated in detail,which shows that it has great influence of engineering geological environments to the develepment of intraformational faulted zones.(2) The paper tests the intraformational faulted zones and other weak structural planes by 61 prospect tunnels, drilling,surface measuring,filed experiments,and then uses discontinuity network simulation to analyze the development of LC and the rockmass structural characters.The ruesults suggest that the structural planes are grower on the left side than the right,and the most growest tendency is group SE and the trace is relative long.And it has obvious zoning on substances, lagerer undulation,approximate parallel in whole of LC.(3) Apply the theory of geology and rock mechanics,the paper analyzes the development pattern according to the study of development and structural characters of LC.There are four main patters as parallel, conjugate,plumose and broom shape by the results.(4) The numerical calculation is used to study the forming mechanism and development process according to the research of development patterns and regional geological environments of engineering and its evolution. The development of LC is mainly affected by river incision and tectonic movement.With different stadges,there are different development characters and patterns.(5) According to the data of field experiments and testing,using discontinuity network simulation,the paper analyzes what influence the different development characters have to rock mechanics properties.The rock mass strength is proportional to the shear angle and distence,inversely proportional to the length,and the deformation modulus and wave velocities are smaller of LC and their nearby rocks.