The Study On The Stability And Monitering Technology Of Granite Residual Slope In Rongxian Town Of The Southeast Guangxi Province

Rongxian county situates in the southeast of Guangxi province with a complex geological environment.Because of the abundant rainfall and the intensive human engineering activities excited,Rongxian has become a region of geological hazards-prone.In order to provide a scientific reference for the prevention and control plan,monitoring and early warning of the regional geological hazards,the occurrence condition of geological hazards should be understood.In this paper,the stability of granite residual slope was analyzed by statistical method,simulation analysis method and artificial rain tests.Then the characteristics of slope failure types were summarized;the main factors influencing the stability of slope were found;the variation features of the internal physical parameters(water infiltration process parameters rate and pore water pressure)were attained.The monitoring technology of slope was also discussed.The main results are as follows:(1)There are 4 classifications of geological hazards as:landslide,collapse,unstable slope and debris flow which almost all are small.(2)The development and distribution of geological hazards in Rongxian county are mainly affected by the lithology,engineering characteristics,rainfall and human engineering activities.Specially,the stratum lithology and engineering characteristics are the major internal factors.(3)The reaction between soil and water caused by rainfall infiltration is reflected by the increase of soil water content and the fluctuation of pore water pressure.However,grain size composition and rainfall intensity can significantly influence the progress of soil and water.(4)The horizontal and vertical displacement of slope will increase accompanied by the increase of rainfall intensity and duration.The horizontal displacement mainly occurred in the near-surface layer,the greatest variation of horizontal displacement occurs in the top and toe of slope toe and the horizontal displacement decreases with depth.The variation of vertical displacement mainly concentrates on the top of slope.(5)The order of impact of rainfall types on horizontal displacement is:incremental type>semi strong type>descending type>uniform type;under the same rainfall and duration conditions,the influence of the four rainfall types on the vertical displacement is uniform.The main deformation of slope is vertical displacement.(6)Based on the monitoring data of residual granite slope in Rongxian county,landslide deformation characterized by the seasonal change has an obvious corresponding relationship with rainfall.For example,the displacement increases remarkably in the rainy season,whereas the slope tends to be stable in other season.