Study On Stability Of Artificial Slope In Granite Residual Area

The"Geological Disasters in Guangdong Province"?GDGTKJ2014007?report pointed out that the geological disasters in the Meizhou granite residual soil area in Guangdong caused heavy casualties and property losses.This paper relies on the research project of the Ministry of Land and Resources of Guangdong Province,“Study on the Stability Analysis and Monitoring and Early Warning Technology of Artificial Slope in Meizhou City”,and uses various methods such as literature review,survey statistics,indoor and outdoor experiments and numerical simulation to focus on different sides.The main contents and achievements of the slope characteristics and rainfall conditions on the slope are as follows:?1?The slopes in Meizhou are mainly small and medium-sized,mostly shallow landslides and soil slopes.The frequent occurrence of disasters in this area is due to the widespread distribution of granite residual soil and its special engineering properties;high temperature and rainy climatic conditions,mountainous hilly landforms,and humanity's slope-cutting activities due to the need to develop economy and life.In addition,the situation of slope cutting and rainfall in Meizhou were also counted,which provided a basis for numerical simulation calculation.?2?Granite residual soil is a kind of structural soil.The residual soil has high shear strength through indoor direct shear test.The single-ring permeation experiment and the literature obtained the saturated permeability coefficient of cohesive soil,gravel cohesive soil and fully weathered granite at 1.78×10^-5,3.14×10^-5 and 5.00×10^-6.In this paper,the reliability of Geo-studio software is verified by the soil water characteristic curve experiment and the slope volume water content experiment,and the rainfall warning threshold of Guitian Village is 90mm/day,which is consistent with the actual situation.?3?Using the obtained regional slope cutting and rainfall data,after using Geo-studio modeling calculation,it is recommended that the slope height of the Meizhou granite residual soil slope is 4m,the cutting angle is controlled within 70°;when the cutting height is 6m,the cutting is performed.The slope angle should be as low as 65°;when the slope height is 8m,10m,12m,the slope should be controlled within 60°,50°and 45°respectively.When the cutting angle is set to 45°,it is recommended that the cutting height should not exceed 12m.When the cutting angle is 60°,the cutting height should be controlled within 8m;in addition,it is not recommended that the cutting angle exceeds 70°.The slope warning value of the slope with a slope height of 10m and an angle of 45°is 200mm/day,and the slope warning value of the slope with a slope height of 10m and an angle of 50°is 160mm/day,and the height of 10m is 55°.The rainfall warning value is 100mm/day.In the influence of pre-rainfall on the slope,the decisive effect is the size of the previous rainfall;in addition,the slope of the rock and soil with small permeability coefficient is greatly affected by the previous period of rainfall,and it is necessary to be wary of the post-peak type without rainfall..It is recommended to use the stepped type and the straight type for the slope type,and the less the number of steps,the more stable the slope is.?4?In the impact of the previous rainfall on the slope,the decisive effect is the size of the previous rainfall;the slope of the rock and soil with a small permeability coefficient is greatly affected by the previous period of rainfall;it is necessary to guard against the post-peak rainfall without large rainfall.It is recommended to use the stepped type and the straight type for the slope type,and the less the number of steps,the more stable the slope is.