Abstract: The exploration and seismic risk assessment of active faults in 20 capital cities of China will be carried out during the period of the 10^th“Five-Year Plan”. This paper elaborates the essential contents and key points of the technical guiding document for this project,“the Working Guideline for Exploration and Seismic Risk Assessment of Active Faults in Urban Areas (on Trial)”,demonstrating the scientific,commonly applicable,inclusive,operable,and restrictive attributes of the regulation,defining the main objects of the exploration engineering: the active fault and the seismic active fault,explaining the connotation of the working areas and the target areas,as well as the difference of the working method in these two areas,analyzing the three level scientific problems which the project would face and the five steps that should be taken in executing process,and discussing the points of attention in each step and countermeasures that should be taken. This paper emphasizes the necessity of the middle-phase checking during the exploration,and points out that this project is the continuing,developing and deepening of all the earthquake hazard prevention work that has been done before.

Key words: active fault, seismic active fault, seismic risk assessment, seismic hazard assessment

摘要： “十五”期间即将实施20个省会级城市的活断层探测与地震危险性评价工程。文中对该工程的技术指导性文件“城市活断层探测与地震危险性评价工作大纲(试行)”的基本内容和领会要点进行了阐述。对“工作大纲”的5大属性(科学性、普适性、包容性、可操作性、约束性)作了说明,对探测工程的主要对象活断层和地震活断层进行了界定,对工作区和目标区的内涵及工作途径的差别做了解释。分析了工程所面对的3个层次的科学问题和实施过程中的5个步骤,并对每个步骤中需要注意的事项和应采取的对策分别进行了探讨。文章阐述了探测过程中安排中期验收的必要性,指出本工程是以往各震害防御工作的延续、发展与深入。

关键词: 活断层, 地震活断层, 地震危险性评价, 地震危害性评价