中橫公路崩積土石堆之力學特性與其穩定性研究

The Mechanical characteristics and Stability Analysis of colluvium Located at the central cross-lsland Highway in Taiwan

蔡光榮(Kuang-jung Tsai)

《中華水土保持學報》 18卷2期 (1987/11) Pp. 122-155

https://doi.org/10.29417/JCSWC.198711_18(2).0011

摘要

本硏究計畫計分二期，第一期乃就中橫公路徳基梨山區段內，嚴重影響路基安全及邊坡安定與德基水庫淤砂之大型崩積土石區或棄土石區進行野外各項基本調査與資料之蒐集整理後加以分析，以俾作爲第二期計畫之推展依據，經初期調查後，第二期計畫選定該公路沿線面積較大且沖淤激烈之成武溪兩岸崩積土石區爲本計畫之研究試驗地區。本文旨在針對成武溪試驗地區兩岸之細部地質概況，崩積土石堆風化後之力學特性與一般物理性，土石堆坡面之沖蝕情形，成武溪之河床質與水理特性和棄土石（崩積土）之堆積型態與位置進行調査探討後，再行選定一嚴重崩落流失地區或坡面進行野外地層鑽探，且配合鑽探用薄壁鋼管採取不擾動試體以求取各堆積土層之強度參數，同時亦加埋PVC地下水位觀測管，以探討地下水位高低浮動契化對各土層之透水性，坡面逕流量與坡面沖蝕溝發展導致崩積土石堆邊坡破壞之關係，進而將上述所得之各項資料輸入已開發完成之電腦軟體程式進行邊坡安定性分析，俾作爲該公路沿線兩岸選取变土石區之基本參考依據，以及現行崩積土石區穩定工程構造物之設計參考資料，進而達到穩定該公路上下邊坡與路基及減少水庫淤泥來源而延續水庫之壽命。

關鍵字

邊坡穩定 ； 崩坍 ； 滑動 ； 崩積土 ； 地下水

並列摘要

This project has been scheduled to conduct field investigations and laboratory experiments for two years, The piled colluvium with potential soil movement caused by water erosion and slope failure was selected as a key experiment district in the first year of this program. At piled collurium areas, both old and new piles are easily weathered and subjected to water erosion since loose, disturbed materials are less stable than the original consolidated strata As a result, the debris piles being along the Chen-wu creek potentially create water erosion problems, sediment yields, and slope instabilities which are detrimental to the Dergi reservoir and central Cross Island highway. The Colluvium piled on the embankments of the Chen-Wu creek have been choiced as an importment experiment district. Factors contributing to water erosion and slope movement from the above debris piles are:1) poor location of the piles, 2) Improper placement and/or protection of stockpiled debris materials, 3) the destruction of natural soil structure and exposure of disturbed soil on steep slopes for an excessive length of time, 4) scouring occures on the toe of the piles. Hence, the detailed geological investigations and topography survey used to decide the location of boring holes. Observations of groundwater table fluctuation within the holes surrounded by the PVC pipes indicate the relationships between the slope failures and groundwater movement in the study. The method of slope stability analysis executed by the second year of this program was based on the data collected from field investigations and soil mechanical laboratory tests within these two years. The stability analysis of colluvium piles was computerized through the software packages which was developed during the period of this project. It is expected that this research can provide a guidline used to stabilize the slope stability of the highway, decide the suitable location of debris piles, and decrease the sediment yields into the Dergi reservoir in the future.

並列關鍵字

Slope Stability ； Slumping ； Sliding ； Colluvium ； Groundwater