Study Of Engineering Properties Of Cutting Slope In Coal-bearing Strata And Reinforcement

This paper take the cutting coal-bearing strata slope in Chenzhou district as the object of the research, based on field investigation, analysis of the deformation and failure mechanisms and the trigger factors of landslides. The result show that:Special engineering characteristics of coal-bearing strata of rock and soil, human disturbance and rainfall are the main factors of slope failure.A series of unconsolidated and undrained tri-axial test for typical coal-bearing soil has been performed, Based on the results of the tests:the shear strength and initial water content of coal-bearing soil have marked correlationship:When the moisture content below20%, with the increase in moisture content, shear strength reduction is small. When the moisture content is higher than20%, the shear strength dramatically reduced with the moisture content increases.A series of Pre-consolidated isotropically consolidated and drained tri-axial tests has been performed, study the important influence of stress release on the coal soil shear strength.The results show that the simple stress release for coal soil shear strength less affected, far less than the moisture content.Cycles of wetting and drying tests have been performed on samples varying from fresh intact to highly weathered carbonaceous mudstone. The results show that the effects on carbonaceous mudstone can be very pronounced, Weathering processes mainly take place in the first cycle. Depending on the weathering grades of coal-bearing strata,there are also differences in the microstructure, there are significant differences in density,particle cementation, the porosity and pore connectivity.Take the Tong-Xin-Qiao slope reinforcement project as an example,then the numerical simulation is made for the each reinforcing phase by using the FEM method, analysis of the slope of the displacement,shear stress distribution and safety factor. The results show that reinforcement measures should be completed in the shortest possible time after the excavation is completed.