基于多层次物理力学参数的小区域地震滑坡危险性评估——以长江上游石棉县城及周边为例

通过实地调查、遥感解译、资料收集等手段，获取滑坡崩塌体编录、松散堆积层、地质单元的岩土体物理力学参数，使得滑坡编录、地质调查数据与区域Newmark位移模型有机结合。研究表明，在滑坡编录等3个层次中，由第一层次到第三层次，物理力学参数精度逐渐下降，这也反映了滑坡编录在危险性评价中所占据的重要性，更能与实际相吻合。通过对长江上游石棉县城地质灾害潜在危险性的评估，得出了不同尺度峰值加速度下危险性分布区域与规律，经与危险性线性拟合，在峰值加速度a=0.3时，区域危险区面积呈大规模急剧上升，为区域毁灭性灾难的临界值。同时，石棉县城随着峰值加速度数值增大，危险区从滑坡编录控制逐渐过渡到坡度控制，显示了多层次物理力学参数下危险性评估的合理性。 

RISK ASSESSMENT OF SEISMIC LANDSLIDE WITHIN SMALL REGION BASED ON MULTI-LEVEL PHYSICAL AND MECHANICAL PARAMETERS: A CASE STUDY OF SHIMIAN AND ADJACENT AREAS IN THE UPPER REACHES OF YANGTZE RIVER

Compared to the risk assessments of seismic landslide before, this paper achieves the landslide and collapse inventory, loose accumulated layer and the physical and mechanical parameters of rock soil mass of geological units by field survey, remote sensing interpretation and data collection. It makes an organic integration of landslide inventory, geological survey and regional Newmark displacement model. During three degrees of the landslide inventory, it can been seen that the physical and mechanical parameters get smaller gradually from the first degree to the third degree, which also inflects the importance of the landslide inventory for risk assessment and that it accords better with reality. The dangerous areas and regular under different peak acceleration are got by assessing the potential risk of geological hazard in Shimian City on the upper Yangzi River. Through the linear fitting of risks, when peak acceleration is 0.3, the dangerous areas increase greatly on the large scale that is the critical value of the regional devastating disaster. Meanwhile, the dangerous area gradually transit from that under the control of landslide inventory to that of slope, which shows the validity of the risk assessment under multi-level physical and mechanical parameters.