| Rainfall-induced landslide is one of the prominent natural disasters in Zhenjiang area.It is due to the reasons of widespread hilly mountains,complex structure and heavy rainfalls.In the past five years,dozens of landslides have been caused by rainfall,which causing huge losses and casualties.So in this article,the law of landslide development in Zhenjiang area was studied;the relationship between rainfall factor and landslide was analyzed.The saturated-unsaturated model of rainfall infiltration was established.and the slope stability was analyzed using finite element method;the stages of landslide evolution and deformation were divided by monitoring data.At last,the Intensity-Duration curves of rainfall threshold in Zhenjiang area were established based on empirical rainfall threshold method,and some suggestions for rainfall-induced landslide treatment were put forward.The main achievements of this article are as follows(1)Firstly,by regional geological survey and data collection,the general situation of landslide development and the relationship between rainfall and landslides were summarized,and the distribution,material composition and failure characteristics of slopes were determined.Rainfall characteristics in Zhenjiang area were summarized.By analyzing the relationship between annual rainfall,monthly rainfall,daily rainfall and landslide frequency,it was concluded that the rainfall factor has a good correlation with landslide(2)Based on saturated-unsaturated seepage theory,rainfall infiltration process of slope was simulated.The changes of pore water pressure,groundwater level,and stability coefficients in the process of rainfall infiltration were analyzed.The mechanism of rainfall-induced landslide was studied,and it was found that the internal factors included its geotechnical physical and mechanical properties,special topography and geological structure conditions,while the external factors included artificial activity and rainfall(3)Based on the monitoring data of landslide displacement,the process of paomashan landslide was analyzed to determine the temporal and spatial evolution rules of landslide.The process of landslide about accumulative displacement,deformation rate and acceleration has been analyzed.The landslide process was divided into three phases including initial deformation,uniform deformation and accelerated deformation(4)The data of landslide and rainfall in the study area were statistically analyzed.By analyzing the relationship between rainfall intensity and rainfall duration,I-D curve of landslide rainfall threshold was determined,using empirical rainfall threshold method.Based on binary Logistic regression analysis,the I-D curve was optimized and standardized to obtain the IMAP-D curve of standardized rainfall threshold in Zhenjiang.The influence factors of the 1-D curve were analyzed.The effects of permeability,fracture and rain pattern on the curves were discussed,and then appropriate treating methods were suggested for landslide. |
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