A numerical simulation for creeping behavior of a slope

本研究以數值模型探討邊坡潛變之受力機制與位移情況。本研究區位於陳有蘭溪流域豐丘七號野溪段，邊坡模型剖面取2014年航照判釋後之數值地形DEM為依據。本研究進行現地勘查判斷地質強度指標與地層分層訊息，並進行地電阻剖面法與表面波震測法探測地層並比較之，輔助推估地層分界。受力機制模擬則透過連續體有限差分FLAC程式來進行，選擇Hoek-Brown組成律與適當的地質強度參數，建置研究區位二維邊坡數值模型之基線案例(baseline case)。本研究再以基線案例為基礎進行參數敏感性分析。參數包括組成律、地質強度指標(GSI)與潛變參數等，討論影響邊坡穩定的幾個因素。本研究也以地質強度指標與潛變黏滯力參數減少方式代表弱化行為，進行地質弱化與河道下切之潛變演化模擬，並探討潛變型態差異性與邊坡穩定性。本研究因現地資料不足受限，雖無法提供預測之用途，但初步建立的邊坡潛變分析程序，相關分析參數可供後續相關研究之參考。This study applied a numerical model to explore the mechanism and displacement of a slope. The research area is located at the Fengqiu No.7 torrent in Chenyulan watershed.The slope profile was obtained based the 2014 DEM from aerial photograph interpretation.This study conducted field investigation to determine the geological strength index and information of stratification.The electrical resistivity tomography was performed to detect boundary of the strata.This finite difference code, FLAC, was applied to build a 2-dimensional slope numerical model for the study location. Hoek-Brown constitutive law and appropriate geological strength index were selected to establish the baseline case. Based on the baseline case, the parametrical studied was performed.The parameters include constitutive law, geological strength index (GSI), and the viscosity coefficient in the creep model.In this study, the weakening behavior is represented by the reduction of geological strength index and viscosity. Simulation for slope creep evolution of geological weaken and incised river, discuss the difference of creep type and slope stability. Although this study is limited by the lack of geological data, the results are not suitable for prediction. However, the preliminary procedure to analyze the creeping behavior of a slope was established and can be a reference for future research.第一章 緒論 1 1.1 研究目的與動機 1 1.2 研究內容與流程 3 1.3 研究流程圖 4 第二章 文獻回顧 5 2.1. 地質參數選擇 5 2.2. 模型建置 6 2.3. 參數分析 7 2.4. 地質弱化與河道下切模擬 8 第三章 研究材料與方法 9 3.1 FLAC程式簡介 9 3.2 判釋圖層資料與繪製地形剖面圖 11 3.3 現地勘查與地球物理探測推測地層相關資訊 18 3.4 建置基線案例(Baseline case)邊坡數值模型 22 3.5 地質強度與潛變參數選擇 23 第四章 潛變參數分析 26 4.1 組成律參數分析 26 4.2 地質強度指標參數分析 27 4.3 潛變黏滯係數參數分析 28 4.4 地質弱化與河道下切潛變參數分析 28 第五章 分析結果與討論 32 5.1 潛變相關參數分析 32 5.1.1 組成律參數分析 32 5.1.2 地質強度指標(GSI)參數分析 36 5.1.3 潛變黏滯係數參數分析 39 5.2 地質弱化與河道下切潛變參數分析 42 第六章 結論與建議 67 6.1 結論 67 6.2 建議 68 參考文獻 69 附件 7