基于逆向工程建模方法的危岩体稳定性数值模拟分析

高陡岩质边坡危岩体失稳机理与稳定性评价一直是学者们关注的重点问题。相比于以定性分析为主的传统稳定性评价方法,数值模拟分析方法在危岩体稳定性评价工作中得到越来越广泛的应用。而如何快速准确地建立复杂三维精细化地质模型,尽可能还原岩体结构特征信息,并与数值模拟软件进行无损对接,进而定量评价危岩体稳定性仍是目前急需解决的问题。在野外现场调查结果的基础上,对浙江神仙居景区神龙瀑景点处的地质灾害隐患点进行高精度三维激光扫描,基于逆向工程建模软件Geomagic Studio,对扫描获取的点云数据进行模型重建,借助有限元网格划分软件Hypermesh对曲面模型进行三维实体化和网格划分处理,再导入数值模拟软件FLAC3D中进行计算。结果表明,神龙瀑边坡受拉破坏危岩体后缘裂隙最大拉应力接近抗拉强度,且存在明显位移,极有可能发生滑移-坠落。然后通过FLAC3D内置FISH语言进行二次开发,计算结构面塑性破坏单元数目在总单元数目中的占比,得出危岩体失稳概率为20%以上。该结果与现场灾害调查、数值分析结果相互印证,预测了危岩体的潜在破坏范围,提出了相应的防治措施建议。上述分析结果可为当地旅游管理部门的灾害防治工作提供理论依据和指导。

NUMERICAL SIMULATION ANALYSIS OF STABILITY OF UNSTABLE ROCK MASS WITH REVERSE ENGINEERING MODELING METHOD

The stability analysis of unstable rock mass in steep slope has always been the focus of researchers' interests. The traditional stability evaluation methods are based on qualitative analysis. The numerical simulation can accurately establish complex 3D geological model rapidly and analyze the stability of unstable rock mass quantitatively, with the support of reverse engineering modeling method. Based on the geological survey results, the paper scans the potential geological hazard points of Shenlong Waterfall Slope in Shenxianju, and gives a model reconstruction of the scanned data through the Geomagic Studio software. It uses Hypermesh to process the surface model, simultaneously calculates the obtained grid data and carries out the finite difference numerical simulation calculation with FLAC3D. According to the results, the maximum tensile stress of the unstable rock mass is close to its tensile strength. It is likely that rockslide-rockfall can occur. In addition, the paper uses the FISH language in FLAC3D to calculate the failure probability of the unstable rock mass based on the proportion of the number of plastic failure elements in discontinuities. The results show that the probability of failure is more than 20%. The results correspond well with the results of the geological survey and numerical analysis. The paper also forecasts the failure of the unstable rock mass, and proposes the preventive and control measures. The paper can provide the theoretical basis and have certain reference value for the disaster prevention works of the local tourism administrative department.