摘要:
为解决岩体结构面损伤的各异性问题及边坡多滑面分析中数值模型的选取问题，借鉴DDA计算位移的优势，考虑块体间相对位移，提出动态强度折减DDA法(Dynamic Strength Reduction Discontinuous Deformation Analysis,简称DSR-DDA)的边坡多滑面搜索，通过对不同破坏程度下岩体结构面动态折减不同的强度及动态变化边坡多滑面分析中的数值模型，以解决数值分析中岩体结构面损伤的各异性问题及边坡多滑面分析中数值模型的选取问题。利用倾斜平面滑块经典案例测试位移阈值，验证方法的可行性及计算精度，并将其应用到抚顺西露天矿岩质高边坡多滑面稳定性分析中，且与自主研发的GeoSMA-3D系统进行耦合。研究结果表明:在设定位移阈值为1mm时，DSR-DDA与理论解误差在0.5%以内，满足计算要求。后续得到了抚顺西露天矿边坡最危险滑落面(对应安全系数为1.136)，与分析现场监测位移得出的潜在滑落位置基本一致，并在首次滑坡后的数值边坡模型基础上，得到了次级滑落面位置(对应安全系数为1.189)，与常规分析得出的结果大相径庭，佐证了边坡多滑面稳定性分析中数值模型需动态变化的必要性。DSR-DDA法与GeoSMA-3D系统识别出的关键块体耦合效果良好，从块体理论角度印证了DSR-DDA法的实用性。抚顺西露天矿边坡破坏模式为牵引式滑动破坏，中下部油母页岩对边坡稳定性起关键作用，故不可继续开采剩余油母页岩，以免引起边坡上部大面积滑坡及矿坑-城市边界滑坡。
Abstract:
This research aims to solve the problem of the different degrees of damage in rock mass structural surface and the numerical model selection problem in slope multi-slip surface analysis. With the advantage of the DDA dis- placement calculation,considering the relative displacement between blocks,the slope multi-slip surface search by dy- namic strength reduction-discontinuous deformation analysis method ( hereinafter referred to as DSR-DDA) is pro- posed. Through dynamically reducing different strengths of rock mass structural planes under different degrees of dam- age and dynamically changing the slope multi-slip surface analysis numerical model,the problem of the different degrees of damage in rock mass structural surface and the numerical model selection problem in slope multi-slip surface analysis can be solved. The tilting plane slider classic case is used to test displacement threshold,and also applied to the stability analysis of multi-slip surface of rock high slope in Fushun Western Open-pit Mine,coupled with the self- developed GeoSMA-3D system. The results show that when the displacement threshold is set to 1 mm,the error be- tween DSR-DDA and the theoretical solution is within 0. 5% ,which satisfies the calculation requirements. The most dangerous slip surface (corresponding to a safety factor of 1. 136) of the Fushun West Open Pit Slope is obtained,and it is basically consistent with the potential slip position obtained by analyzing the displacement of the on-site monito- ring. Based on the numerical slope model after the first landslide,the position of the secondary slip surface ( corre- sponding to a safety factor of 1. 189) is obtained. The results are quite different from the con-ventional analysis,which proves the necessity of the dynamic change of the numerical model in the slope stability analysis. The DSR-DDA meth- od has a good coupling effect with the key blocks identified by the GeoSMA-3D system. It proves the practicability of the DSR-DDA method from the perspective of block theory. The failure mode is traction sliding failure,and the middle and lower oil shale plays a key role in slope stability. Therefore,to avoid causing large-scale landslides at the upper part of the slope and landslides at the pit-city boundary,it is not possible to continue the mining of remaining oil shale.
百度学术
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