融合工程地质资料与GNSS高精度监测信息的黑方台党川黄土滑坡稳定性研究

Stability evaluation of Dangchuan loess landslide in Heifangtai based on integration of engineering geological data and GNSS high-precision monitoring information

针对当前滑坡稳定性评价方法难以准确获取评价结果的突出问题,本文提出了一种融合地下水、工程地质钻孔信息及灌溉资料等工程地质资料与GNSS观测的黄土滑坡稳定性评价方法。首先,基于高分辨率影像、高精度DEM、地层地貌等多源异构数据,建立滑坡精细三维地质模型体;然后,将滑坡外部高精度GNSS监测数据作为模型外部约束条件,进一步构建起融合工程地质资料与GNSS观测的黄土滑坡稳定性综合评价模型。本文方法能够将滑坡外部大地测量高精度监测数据与工程地质数值模拟手段有机融合,实现了滑坡外部形变信息与内部变形机制的有效耦合。通过我国典型黄土滑坡域甘肃黑方台党川实际发生的两起滑坡失稳事件验证表明,本文方法可有效地提高滑坡稳定性评价结果的精度及可靠性,获取了与试验区域滑坡实际失稳情况相一致的结果:HF06/07 GNSS监测点首先失稳,其次是HF09监测点失稳,最后是HF05监测点失稳。基于本文方法获取的滑坡失稳顺序与实际滑坡发生顺序高度一致,显著优于现有的滑坡失稳数值模拟法。

Slope stability analysis is an efficient method for landslide risk reduction.However,it is still a challenging task owing to the unilaterally assessment approach applied to practical issues.To overcome this problem,a new stability evaluation of loess landslide based on integration of engineering geological data(high-precision DEM,groundwater level,drilling information in engineering geology and irrigation information)constrained by external high-precision GNSS monitoring information is proposed.Firstly,a fine 3 D geological model of landslide which can reflect the real nature characteristics is constructed by using Arcgis-Rhinoceros-Griddle based on high-resolution image,high-precision multi-source monitoring information,engineering geological borehole information,groundwater level information and field investigation.Then,a comprehensive evaluation model for landslide stability by coupling the landslide displacement evolution process with the dynamic disaster mechanism,which can ascertain the cause of landslide failure and the catastrophe mechanism,is constructed with constraints of the high-precision GNSS monitoring data from the outside of the landslide.Data obtained from monitoring before instability of three landslides in Dangchuan,Heifang,Gansu province are selected for model verification.The results show that HF06/07 GNSS monitoring site first becomes unstable,followed by HF09 GNSS monitoring site,and HF05 GNSS monitoring site is the last one that slides.It indicates that compared with the numerical simulation method of engineering geology,the results obtained by the developed technique in this chapter are better consistent with the actual monitoring situation.And the sliding sequence of landslide is also in high agreement with the actual sequence.All the obtained achievements in this paper demonstrate the organic coupling of the external high-precision monitoring information and the internal physical and mechanical evaluation model provides a new idea and perspective for the stability evaluation of loess landslide,and helps to well understand the deformation evolution mechanism of loess landslide.