A Study of the Stabilization of Dip Rock Slope Using DDA

[[abstract]]本論文研究之目的為利用不連續變形分析法（DDA）具有完整之塊體運動架構、模擬不連續塊體間之接觸碰撞行為之能力、以及很適合於模擬節理岩體或塊體大位移之特點，並使用林志森博士指導翁啟鐘所發展之不連續變形分析法視窗化程式『DDA—2003』，針對順向岩石邊坡節理位態、岩體參數與邊坡穩定之關係加以分析探討，希望藉此對於不連續變形分析法應用於分析順向岩坡穩定時之適用性與可行性有更多的瞭解，並期待可做為日後坡地開發之相關分析與設計工作之參考。 本研究考慮一些具簡單節理位態之順向節理岩石邊坡為工程案例，利用『DDA-2003』視窗化程式進行邊坡穩定數值模擬分析，在案例分析過程中探討（1）邊坡坡角α、（2）岩層節理面傾角β、（3）節理面摩擦角δ、（4）節理面間距、（5）邊坡開挖以及（6）岩栓設置等不同的變數對順向岩坡穩定性之影響。從研究分析之結果中發現節理面傾角β、邊坡坡角α與節理面摩擦角δ之間的大小關係，是控制邊坡穩定之最重要的變數條件。另外，開挖之邊坡以打設岩栓做為擋土設施，將使邊坡穩定性提高。本論文所使用之DDA程式已能模擬岩坡地質條件及岩坡開挖施工之程序，且對於模擬邊坡產生大變位後之滑動過程，有其明顯之優越性，能提供做為觀察岩坡破壞變形過程之參考，惟對於模擬岩體節理行為之彈簧模式，需再深入研究以獲得更接近真實節理面之力學行為。[[abstract]]The purpose of this research is to find the relationship among the attitude of dip rock slope, rock mass parameters and slope stability using Discontinuous Deformation Analysis (DDA) method which has the original characteristics including the complete kinematic structure of block movements, the capability of simulating the contact and impact behaviors of discontinuous blocks, and the suitability of simulating the large displacement of joint rock masses or blocks. This research uses a DDA program , 『DDA—2003』, which was written in Visual BASIC program language. The program was developed by Wong Chichong under the advise of Dr. Chihsen T. Lin. From the obtained analytical results of this research, it is hoped that more applications to the stabilization problems of dip rock slope using DDA method could be studied in the future on the analytical and designing works. This research considers some engineering examples with simple joint attitudes of dip rock slope, and employs the『DDA-2003』 program as a tool of numerical simulation to analyze the rock slope stability. This research focuses on the understanding of the influence of the factors including (1)slope angle α, (2)joint dipβ, (3)joint friction angle δ, (4)joint spacing S, (5)excavation of slope, and (6)installation of rock anchors, to the stabilization of dip rock slope. The analytical results showed that the joint dipβ, slope angle α and joint friction angle δwere the most important influence factors for the slope stability and the installation of rock anchors could apparently improve the stability of the slope. The DDA program used in this research demonstrates its capability to simulate rock slopes with variable geological conditions and the excavated procedures. Especially, the program also has the great advantage to observe the deformations of rock slopes in any construction stage. However, the spring model of the program to simulate the joint behavior of rock masses needs to be further revised in order to improve the simulation ability of rock joint behaviors