Study in Groundwater-Induced the Safety Factor Variation of Highway Slopes in Tseng-Wen Reservoir Watershed

• Main Authors: Keng-FengChang, 張耕逢
• Other Authors: Der-Her Lee
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/93906549518111299335

碩士 === 國立成功大學 === 土木工程學系碩博士班 === 101 === Under the influence of the greenhouse effect, in recent years, the rainfalls of Taiwan become heavier and more concentrated. Recently, more famous for the 2009 Typhoon Morakot brought a large number of Taiwan's southern mountain rains, causing many mountain road slope failure. Groundwater is one of the main factors causing slope failures, when the water table rises due to rainfall events, slope’s resistance fall, causing collapse or slide occurred. In order to understand how groundwater changing affects highway safety factor in Tseng-Wen Reservoir Watershed, we selected Taiwan Provincial Highway N.O. 3 348k and 350k +724 m for investigation and monitoring. The research contents drilling operations, records of groundwater changes, rainfall monitoring, the stratum displacements in slopes. Drilling operations finished in April 2012, the copper ring samples and core specimens were tested to obtain the material properties of the Stratum and mechanical parameters for numerical analysis. Monitoring starts from April 2012 to June 2013, using monitoring data to establish the relationship between changes in rainfall and groundwater and changes, determine slope sliding direction and depth. Compared to slope ZWSlope-2, slope ZWSlope-1 has a more significant relationship which rainfalls affect groundwater changes; slope ZWSlope-1 haven’t measure clear stratum displacements yet, the sliding position of slope ZWSlope-2 is between colluvium and shale. Numerical analysis contains 3D finite difference software and 2D limit equilibrium method, using 3D finite difference software obtained degrees sliding surface, then analyze the relationship of groundwater level and safety factor, also name the water level with safety factor equal to 1 as critical water level. Slope ZWSlope-1’s critical water level is 1.3m below the ground, slope ZWSlope-2’s critical water level is 1.5m below the ground.