- 學位論文
中橫公路東段沿線邊坡穩定性與其受工程地質特性影響
Stability of Slope Neighboring East Section of Central Cross-Island Highway and Influences with Engineering Geological Characteristics.
摘要
岩石工程道路邊坡經現地調查獲得的可靠、直接的岩石材料種類與不連續面參數，為確保工程設計施工、設施營運維護及環境水土保持之關鍵資訊。本研究調查中橫公路東段沿線邊坡，里程從台14甲線32 k+800至台8線190 k，總長度約86.9 km，中間邊坡運動活躍，崩塌災害阻斷公路時有所聞，公路阻斷率高，交通效能無法恒常確保。本研究利用國際岩石力學學會建議的不連續面描述項目，調查公路沿線的不連續面特性，結合Q法岩體分類，最後透過赤平投影分析邊坡失穩型態，並嘗試以光達技術作為地質調查的新工具，探討工程地質特性對於公路沿線邊坡災害之影響，進而找出影響邊坡穩定性因子，建立沿線岩體工程特性參數，對於搶災與復建工作以及水土保持作業，將會有極大的助益。調查結果可將破壞模式分為三類，第一類受不連續面高度影響，以岩楔、傾覆、落石以及平面滑動為主，里程分布範圍從台8線190 k至159 k；第二類受重力作用與河道側蝕影響，發生淺層岩屑崩滑及部分不連續面控制之破壞形態，里程分布範圍從台8線159 k至125 k+500；第三類受向源侵蝕及河道側向侵蝕作用，引致淺層及深層滑動，里程分布範圍從台8線125 k+500至台14甲32 k+800。
並列摘要
Reliable and direct information of rock slope materials and discontinuities parameters from field investigation are the key issues to high quality engineering design, structure maintenance and soil/water conservation. This study investigated the slopes of east section of the Central Cross Island Highway, from mileage 32k+800 on Tai-14-Chia Highway to 190k on Tai-8 Highway, with total distance 86.9 km. The active slopes movement alone the roadside often obstruct the highway, totter the traffic performance within the area. In field investigation, this study followed the process suggested by International Society of Rock Mechanics and Q-system to describe the rock discontinuities and rock mass qualities, accordingly. Spherical projection is utilized to analyze the possible types of slope movement. Meanwhile, the validity of ground LiDAR as a new technology to inspect engineering geological characteristics and its impacts on slope movement, to find the factors influence slope stability and to obtain the rock mass engineering properties along the highway is tested. This work can provide tremendous help on disaster relief, reconstruction and soil/water conservation. Our works show that the slope failure modes can be divided into three categories. In the first category, the slopes contain discontinuities that cause wedge failure, toppling failure, rock fall failure and planar failure. This category prevail in mileage 159~190k on Tai-8 Highway. The second category suffered from gravity and lateral erosion, causing debris slide and occasionally toppling failure, wedge failure and plane failure distributed from mileage 125k+500 to 159k on Tai-8 Highway. The third category of failure modes are debris slide and deep seated landslide induced by headward and lateral erosion ranging between mileage 125k+500 Tai-8 Highway and 32k+800 Tai-14-Chia Highway.