順向坡滑動面調查與判釋方法之研究 -以新北市某路段護坡工程為例

The investigation and definition of dip slope sliding surface -A case of slope protection project in New Taipei city

陳嘉娸(chia-chi Chen)

指導教授 ： 陳水龍

國立臺北科技大學/工程學院/土木與防災研究所/碩士(2014年)

https://doi.org/10.6841/NTUT.2014.00664

摘要

順向坡滑動為台灣最常見的坍方災害之一，所造成的嚴重性係因其滑動發生突然，且崩塌滑動速度極高，常難於預知而造成重大災害，尤其自從高速公路國道三號在七堵(2K+800~3K+100)附近發生順向坡滑動災害後，引起國人高度重視，且不論於緊急搶修或長期整治，皆須調查滑動面深度，如未能有效掌握滑動面深度，往往造成設計工法無法有效發揮其功效，且再次造成邊坡滑動，故對於有效掌握滑動面深度對崩塌地整治工程成功與否為重要之關鍵。
然而因台灣地區山坡地質破碎且風化情形嚴重，順向坡地質構造明顯及地下水入滲與季節水位變化，易對邊坡工程之穩定性產生影響，即便已裝設傾度管監測邊坡滑動情形，但往往受旱季或監測時程不足等其他因素影響，監測儀器所得之資料未能完全掌握滑動面深度，進而使已整治之邊坡再次造成崩塌及破壞；如能將監測感應器安裝於最適當之位置(滑動面位置)，方能即時掌握邊坡滑動情形或變位趨勢，故針對滑動面調查階段之工作極為重要。
本研究系對於順向坡滑動面判釋方法加以綜合整理，以一代表性案例說明為即時掌握及得到正確之滑動面深度，運用滑動規模、岩心檢視及地球物理探測等方式研判滑動面深度，並於地下埋設自動化監測儀器前，依據調查出滑動面可能之深度位置安裝傾斜感應器(sensor)，而非以往固定每3m深度埋設1處傾斜感應器，即可盡早並有效掌握順向坡是否有滑動之虞及其正確滑動深度；後續再依據監測資料變位結果，檢視其滑動面深度以得到較準確的判釋；並利用STABL邊坡穩定分析軟體，以試驗結果反推分析方法求得滑動弱面之實際參數，以供後續邊坡設計符合其正確性。

關鍵字

順向坡 ； 滑動面 ； 邊坡滑動 ； 崩塌地 ； 監測

並列摘要

Dip slope landslides are one of the common disasters in Taiwan. It causes serious damage because it occurs suddenly with high speed, and is hard to predict. The dip slope landslides has gained national attention after the Chi-Du National highway no.3 landslide. For the purpose of emergency response and for long-term landslide control; the glide depth must is be investigated. Without the exact information of glide depth, the remedial method could be inefficient and the slide could happen again without prior knowledge. Therefore, the investigation of glide depth is essential for improving the effectiveness of landslide improvement projects.
The slop stability could be influenced by the geological structure of slope and underground water table. Even when inclinometers are installed to monitor the sliding of the slopes, the data could be affected by many factors such as dry season or insufficient monitoring intervals All these factors makes the glide depth measurements imprecise; this could lead to further occurrence of slides and damage on the renovated slope. Thus, the investigation of sliding slope is very important. If the monitoring sensors could be established in proper positions on sliding surface, the slide and displacement could be promptly and well monitored.
In this study, the methods of identifying the sliding surface of dip slope is summarized, and a representative case will be examined, using the magnitude of the slide, rock core examination and monitoring to identify the glide depth. This study shows that the possibility of slide could be well predicted and the depth of slides could be accurately monitored, if the sensors are established in whereabouts the slide could occur, instead of setting 1 sensor per 3 meters deep in the traditional method. The collected data of displacement would allow for accurate examination of the glide depth afterwards. In addition, the slope stability analysis software STABL is used to obtain the parameters of weak planes, using the results of experiments and back analysis, in order to contribute to the accuracy of follow-up projects.

並列關鍵字

dip slope ； sliding surface ； slope slide ； landslide ； monitoring

參考文獻

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