| China is a country with frequent landslides, which ha s caused serious problems for the country’s modernization and people’s lives. There are quite a lot of cities and towns in the country which suffer from the harm of landslides, the average annual economic losses are countless every year. Meanwhile, many national key construction projects are affected by the landslide in the process of construction. According to statistics, about 90% of the landslides are related to rainfall, how to use the rainfall information to forecast the landslide has become a problem which needs to be solved urgently at present. By using the Shenzhen local community landslide monitoring area as the object of our study combined with landslide early warning theory and methods of research, the rainfall type landslide early warning and forecast system is established in the region, which has good academic and social significance and a certain value to the regions of similar monitoring landslide.The main research work and its results are as follows:Based on saturated-unsaturated seepage theory, the change of pore water pressure under the influence of rainfall is studied by using th e finite element method in a typical rainfall landslide in Shenzhen city. The resu lts of the study indicate the uniform rainfall makes the most significant effect on slope; Rainfall intensity, duration, permeability coefficient are closely related to the slope seepage variation; Antecedent rainfall has an important influence on the distribution of internal flow of the slope under rainfall.Based on shear strength theory of saturated-unsaturated soil,different rainfall parameters are studied to know about their influence on slope stability. The research results show that the uniform rainfall makes the greatest impact on the overall stability of slope; Rainfall intensity, duration, permeability coefficient make great effect on slope stability. Antecedent rainfall has an important influence on overall stability of the slope under rainfall.Early warning system of rainfall-induced slope in Shenzhen native community is studied. The simulation analysis is carried out to obtain slope intensity-duration curve( I-D curve), according to the curve, rainfall early-warning threshold is obtained; By applying the rainfall as the external incentive, the relationship between the overall safety factor of slope and maximum increment of displacement in monitoring points is obtained, then early-warning threshold of deformation can be get; When the effective cumulative rainfall goes over the rainfall warning threshold, slope goes into the warning stage of deformation, then we apply the early-warning threshold value of the deformation to judge the landslide risk grade, which is a new early warning method. The early-warning system of slope in the Shenzhen local community is established in the final.Based on the early-warning theory of slope, site monitoring program is developed. Slope monitoring scheme based on early warning theory is designed combined wireless sensor with selected wired sensors through an advanced technology, what is more, the application of the design monitoring scheme will make certain significance to the monitoring of similar landslide in villages and towns. |
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