非连续变形分析方法及其在灾害防治研究中的应用

为了探究地震诱发地质灾害的特征,用非连续变形分析方法(DDA, discontinuous deformation analysis)模拟了地震诱发崩塌、滑坡和防浪堤破坏的过程,着重探讨了地震对灾害发生过程及其运动能力的影响.在DDA程序中,整合了灾害冲击力的计算,结果表明:DDA方法可以计算滑体在地震作用下的运动情况;竖向地震动能够显著增强近断层极震区滑坡的运动能力,可以很好地模拟地震诱发灾害的全过程, 真实反应出危岩崩塌体、滑坡、防浪堤坝的破坏特征,能够计算运动物体对既有建筑物的冲击力,冲击力的最大值远远超过了静态侧压力值;文中算例结果显示最大冲击力是静态侧压力的4倍多,该成果可为灾害防护建筑物的选址、设计等从可靠和经济的角度提供技术指导. 

Discontinuous Deformation Analysis Method and Its Applications to Disaster Prevention

In order to explore the characteristics of geological hazards induced by earthquake, the discontinuous deformation analysis (DDA) was used to simulate the failure processes of rock collapses, landslides, and breakwaters under the earthquake loading. Particularly, the influence of the earthquake loading on hazard processes and motions was studied, and new modules were integrated into the current DDA code to obtain the interaction forces. The results show that DDA can be applied to evaluation of landslide mass mobility. The vertical ground motion can remarkably amplify the mobility in the near-fault area. DDA has advantage in the whole-process simulation of landslide induced by earthquake. The simulation results can reflect the characteristics of the failure processes of collapses, landslides and breakwaters faithfully. In addition, DDA is also able to calculate the impact force of failure masses on structures. The peak value of the impact force is much larger than the static lateral pressure, and is four times more than the static lateral pressure in the case study. Hence, the DDA can provide technical guidance for site selection and design of disaster protection from the perspective of reliability and economy.