数值模拟在地震小区划滑坡灾害评价中的应用

工程场地地震安全性评价、特别是在地震小区划工作中,对地震滑坡的评价通常采用定性分析方法,因此,对其影响范围未给出定量的评价结果。本文以吕梁新城地震小区划滑坡评价为例,通过对该区的地质条件、地貌特征的研究,针对具有典型特征的剖面,选取地震力、内聚力、摩擦角作为影响因子,采用离散单元法(DEM)对潜在滑坡体的稳定性进行了数值模拟计算,得到了可能失稳的滑坡体潜在滑动的影响范围。并在此基础上通过对已知滑坡与潜在滑坡剖面结构特征的类比,对整个研究区内滑坡体的影响范围进行了评价。研究结果可为吕梁新城的规划提供依据,也可为同类工程中地震滑坡灾害的定量评价提供参考。

Application of Numerical Simulation in the Landslide Hazard Assessment of Seismic Micro-zonation

In seismic safety evaluation seismic landslide assessment is commonly conducted by qualitative analysis, especially in the seismic micro-zonation work, so quantitative evaluation result of the scope of such hazard is not given. In the paper, taking Lvliang new town as the case study, we selected profiles with typical features through analyzing the geological conditions of the study area. Potential stability of landslides is calculated by the discrete element method, with seismic force, cohesion, friction angle as factors, getting the sliding sphere of influence of the possible instability of the landslides. Considering the potential landslides with the same structural features having the same instability, we inferred the influence scope of the entire study area by analogy the profile characteristics and structural characteristics of the known landslides and the potential landslides. The results provide basis for the planning and sitting of Lvliang new town, and also provide a reference method for quantitatively evaluating the seismic landslide geological hazard in similar projects.