Abstract: The deterministic method is currently adopted in offset-resisting design for fault-crossing linear engineering project. However, it considers merely the maximum displacement of the fault, and thus cannot meet the actual demand of anti-disaster designing. In this paper, we develop a probabilistic method for evaluation of the potential abrupt displacement on various positions of the fault. This method combines the distribution of the maximum displacement positions and the distribution of displacements on both sides of the positions with the recurrence model of strong earthquake. As a case study, the risk of potential offset on the Shengzhuang-Changtuan segment of the normal fault on the northern boundary of Huailai-Zhuolu Basin in future 100yr was estimated quantitatively. This estimation provides the potential offset along the active fault under different probability levels. The result of this study may provide basic data for offset-resisting design of fault-crossing linear engineering project.

Key words: active fault, potential ground offset, probabilistic assessment

摘要： 目前跨活动断层的线状工程的抗断设防仍采用确定性评价方法,考虑的是最大位错量,与抗御灾害的风险设计的实际要求不相符.文中将断层上最大位错点的位置分布及最大位错点两侧的位错展布,与可产生地表突发位移的强震复发模型联合,建立了评估活动断层各部位的地表潜在突发位移的概率性评价方法.最后,以怀涿盆地北缘正断裂中的沈庄-长疃段为例,对其未来100a潜在突发位移的危险性做出定量评估,给出了断层段上各点不同超越概率水平下的潜在位移.这一研究结果,可为跨断裂的线型工程进行抗御地表潜在突发位移的风险设计提供参考.

关键词: 活动断层, 地表潜在突发位移, 概率性评价