Numerical Simulations on the Landslide Motions of an Inclined Soil Layer Caused by Rain Infiltration and Bedrock Exfiltration

• Main Authors: Shin-LinChen, 陳新霖
• Other Authors: Chyan-deng Jan
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/bn3rnd

碩士 === 國立成功大學 === 水利及海洋工程學系 === 104 === Landslides are the mass movement caused by gravity down the slope on hillsides, and can threaten people's lives and properties. Landslides and its movement mainly are controlled by change in internal the pore water pressure. Rain infiltration and bedrock exfiltration can change pore water pressure within the soil layer, thereby causing the soil slides. In this study, we developed a model that describe the velocity of block sliding down an inclined plane governed by Newton’s equation of motion and diffusion equation, considering the dilatancy angle and friction coefficient could vary with block displacement. Then we can use this model to analyze the soil layer motion along an infinite slope influenced by rainfall infiltration or bedrock exfiltration, respectively. Results show that the sources of excess pore pressure that control the types of landslide motion. Under rainfall infiltration conditions, the motion of landslide can be categorized into stationary and rapid sliding, and that into stationary, rapid sliding and intermittent slipping caused by bedrock exfiltration conditions. In addition, this study extended infinite slope theory that soil layers can slide a certain distance on a slope to a horizontal plane, further using this model to clarify the relationships between the displacement of block, rainfall infiltration and bedrock exfiltration. Results show that when the block occurs rapid sliding, horizontal sliding distance could be a linear relationship with respect to the intensities of rainfall infiltration and bedrock exfiltration. Also, when the block occurs intermittent slipping, the displacement of intermittent slipping will be a linear relationship with respect to the amount and intensity of bedrock exfiltration. The model develop in this study can provide useful information and thereby refined the prediction, prevention and mitigation of geological disasters.