以非連續體變形分析法探討山崩運移距離之可靠度分析

Investigating the Reliability-based Run-out Distance of a Landslide Using DDA

林雅程(Lin, Ya-Chang) ； 吳建宏(Wu, Jian-Hong)

《中華防災學刊》 14卷2期 (2022/09) Pp. 169-176

摘要

本研究蒐集2010年4月25日發生於國道三號3.1公里的崩塌事件在崩塌前、後的地形高程、地層分布與節理位態等資訊，詳細分析崩塌的特性，依此建立幾何模型與後續參數變異；本研究利用非連續體變形分析法（Discontinuous Deformation Analysis, DDA）模擬邊坡崩塌的結果與實際情況具有極高之相似度，若經過調整參數的變異性，例如材料參數或幾何構造之後便會得到不同的山崩運移距離，再經過點估計法，將可計算出不同情境下各種運移距離的機率、平均值與標準差，將其繪製成常態累積機率分布圖。接著，將滑動影響區域範圍依超越機率劃分為五種危害等級（極高、高、中、低、極低）。本研究以DDA結合點估計法繪製的常態累積機率分布圖與山崩運移危害等級分類圖的方式，建立以非連續體數值分析法進行山崩運移距離之可靠度分析。

關鍵字

運移 ； 可靠度分析 ； 非連續體變形分析法 ； 點估計法 ； 國道三號地滑

並列摘要

This study collected information on the topographic data before and after the landslide, geological stratum, and joint attitude of the slope collapse event that occurred at the 3.1k of National Highway 3 on April 25, 2010. In this study, the characteristic of the landslide was analyzed in detail to generate the geometric model and the variation of parameter for the sequential numerical simulations. The final deposition pattern of the landslide using Discontinuous Deformation Analysis (DDA) is similar to the actual situation. Different run-out distances of the landslide with the adjustment of variability of the parameters, such as material parameters or joint geometry can be obtained. By point estimation method, the probability, average, and standard deviation of landslide run-out distances under different scenarios can be obtained to draw a probability curve of excess. We divide the landslide impact area into five hazard levels (extremely high, high, medium, low, and extremely low) according to the probability of excess. In this study, integrating the normal cumulative probability distribution of landslide run-out distance, which is obtained by DDA and point estimation method, and the landslide migration hazard classification, we establish the reliability analysis on the landslide run-out assessment using discrete element method.

並列關鍵字

Run-out distance ； reliability analysis ； DDA ； point estimation method ； Freeway No. 3 landslide

參考文獻

羅佳明、鄭添耀、林彥享、蕭震洋、魏倫瑋、黃春銘、冀樹勇、林錫宏與林銘郎 (2011)，「國道 3號七堵順向坡滑動過程之動態模擬」，中華水土保持學報，第 42 卷第 3 期，第 175-183 頁，臺灣。

大地工程學會 (2011)，「國道 3 號 3.1 公里崩塌事件原因調查工作總結報告」，交通部，臺灣。

石根華 (裴覺民譯)( 1997)，「數值流形方法與非連續體變形分析」，清華大學出版社，北京，中國。

Xiaoping Sun, Peng Zeng, Tianbin Li, Sheng Wang, Rafael Jimenez, Xianda Feng, Qiang Xu(2021), “From probabilistic back analyses to probabilistic run-out predictions of landslides: A case study of Heifangtai terrace, Gansu Province, China.”, Engineering Geology, Vol.280