Abstract: Essential problems of seismic zoning and reexamination of engineering site-intensity are the determination of potential earthquake source and parameters of seismicity. The study on active fault plays an important role in this field. A Fuzzy Synthetic Judgement model is built by using fuzzy set, probability and mathematical statistics in this paper. The characteristics of the FSJ modle are as the follows: 1) put forward preliminary plan to quantitize geological data (especially for active fault data); 2) determine potential earthquake source in different intensity objectively; 3) obtain potential earthquake source with time limited from the second degree fuzzy synthetic judgement; 4) make it possible to compare the seismic risks for potential earthquake sources in same grade in terms of calculating results; 5) reflect uncertainty of result caused from subjective judgement and errors of original data in the result B=(b₁, b₂,b₃, 64); 6) provide useful and objective information for the further seismic risk analysis.For the purpose of doing second fuzzy synthetic judgement in which time factor is involved. Earthquake Reduce Process is selected in the FSJ modle as the action of time factor. Moreover,weighting coefficient for every factor is obtained from the synthetical results of equal weighting coefficient, expert's judgement and quantity of original data.Taking North China as the example for the FSJ modle, the results demonstrate that the FSJ modle is significant of embodying the heterogeneity of seismicity in time and space, and is valuable to determine potential earthquake source objectively and quantitatively.

Key words: Active fault, Potential earthquake source, Fuzzy synthetic judgement

摘要： 确定潜在震源区及其震级上限是地震区划工作中的重要一环,而活断层的研究在这一领域中具有重要的意义。本文采用概率数理统计和模糊数学方法建立了活断层模糊综合评判模型,对活断层的定量化研究、潜在震源区研究中的不确定性分析以及充分反映地震活动的时空不均一性方面作了初步的探索性研究。并以华北地区为例进行了试算,取得了较好的结果。

关键词: 活断层, 潜在震源区, 模糊综合评判