Numerical study of slope creep in the water storage area of the reservoir

• Main Authors: Sih-Siao Lin, 林思孝
• Other Authors: 林宜清
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/35675652621386201041

博士 === 國立中興大學 === 土木工程學系所 === 105 === Creep is a slow deformation behavior in the long-term under gravity for slope, which is different from the normal fast sliding behavior of the slope. The creep behavior is progressive, and it is not easy to cause significant influence in a short time. But for rock slope with special material characteristics such as argillite or slate slope, the slope strength will be affected in the flooding conditions leading a larger displacement deformation, and the impact of the surrounding is also greatly improved. If the type of slope is located within the flooded area of the reservoir, in addition to flooding due to rainfall, the reservoir water may also make part of the slope soaked for a long time and result in the slope strength weakened. It will cause landslide and impact the reservoir operation and safety. In this study, PFC3D is used to simulate the argillite slope in the upper reaches of the dam site, and the physical model and the local test result are integrated to confirm the rationality of numerical simulation. In order to study the slope behavior in detail, the Burgers Model is added in the numerical simulation to simulate the creep behavior to be closer to the actual slope sliding behavior. The deformation mechanism of the slope just like "squeeze - uplift - fragmentation - sliding" was also found from the simulation results. In this paper, we discuss the friction coefficient and the bond stiffness and strength between the slope particles. And in order to describe the sliding mechanism of the layered slope in detail, stratified simulation and parameter setting are used to understand the difference between the simulation results under different stiffness and strength conditions of the rock and the weak surface, and to find out the key factors that affect the simulation results. In addition, the depth of the sliding surface can be grasped by the observation data of the shape acceleration array, and it can be used as the basis for the numerical simulation to understand the parameters set in line with the site. Due to the continuous observation function of the shape acceleration array, the significant displacement changes during heavy rains were successfully retrieved, and the numerical simulation results about slope strength weakening can be verified. The observed phenomenon about slope creep in the usual but obviously sliding during the heavy rain which can be used as an important exposition of sliding mechanism of argillite slope. Therefore, the creep slope in the submerged area of the reservoir can be evaluated by the integrated way of this study in the future. First, the physical model and field drilling and survey data were used to confirm the rationality of numerical simulation. Next, a continuous observation such as the shape acceleration array is set up to master the long-term creep behavior of the slope and the short-term displacement change caused by flooding. The data can be fed back to the numerical simulation using the Burgers model, and sliding trend can be predicted in the future as a reference for reservoir planning and management.