考量參數不確定性之坡地穩定性分析－以新庄潛在大規模崩塌為例

坡地工程於實務上常須面對複雜的地質環境與參數獲得不易的挑戰，導致參數具有高度不確定性，其不確定性連帶會影響分析評估結果。本研究認為除傳統分析時所得之安全係數外，若能進一步計算出在既有參數不確定性下邊坡破壞之機率密度函數，將可提供工程師或決策者於防災應用之參考。因此，本研究以新庄潛在大規模崩塌為例，利用地質調查成果及觀測數據為基礎，建立本區域沿著潛在滑動方向的地質剖面圖，並研判可能具有Zone 1、Zone 2及Zone 3等三個潛在滑動塊體。分析時根據室內試驗成果，適度考量各參數之不確定性程度，再設定七種水位情境並配合蒙地卡羅法進行分析。分析成果顯示Zone 3潛在滑動塊體的安全係數為最低，當地下水位於破碎岩層間變化時，約有0.01~11.89%的破壞機率，然而地下水位高於崩積層底部後，其破壞機率提高至11.89%以上，且隨著水位抬升而呈急遽增加趨勢。

關鍵字

參數不確定性；穩定性分析；新庄；潛在大規模崩塌

並列摘要

Due to the inherent complexities of geological condition and lack of complete information about parameters, uncertainties exist in specifying the values of these parameters in the numerical model rendering potential failure to obtain the authentic model output under consideration. In addition to the safety factor obtained from the traditional analysis, the probability density function of the slope failure under the existing parameter uncertainty can be further calculated, which will provide the reference of the engineer or the decision maker in practical application. Based on the results of investigation and monitoring data, a geologic profile of the landslide along the axis parallel to the direction of movement was constructed and three potential landslides, Zone 1, Zone 2 and Zone 3, were identified. Geologic investigation and monitor results were employed to investigate seven water table conditions and estimate the resultant factor of safety for each potential landslide zone using the Monte Carlo method. Results of the analysis demonstrate that the safety factor of Zone 3 is the lowest. Once the water table fluctuates within the fractured bedrock layer, the likelihood of failure is roughly 0.01 to 11.89%. As the water table reaches the base of the colluvium layer, the likelihood of failure exceeds 11.89%.

並列關鍵字

Parameter uncertainty ； stability analysis ； Xinzhuang ； potential largescale landslide

國際替代計量

考量參數不確定性之坡地穩定性分析－以新庄潛在大規模崩塌為例

全文下載

主題瀏覽