Abstract: Seismic refraction method is tentatively used in the exploration of urban active faults where strong interference of surface waves exists and it is difficult to use seismic reflection survey. Original seismic refraction data are calculated and inversed by using time-terms, curve of differential time-distance and finite-difference tomography, to investigate the effect of the new technique in the exploration of urban active faults.In this paper, velocity structures and interface structures are obtained after the shallow seismic refraction data in the western segment of Xushui fault of western Zhengzhou are calculated and inversed by using the above-mentioned three calculation methods, and structural characteristics and depths of main geologic strata are got by integrating inversion results and features of seismic phases. The results of these three methods are similar, and they are confirmed by drilling data in the profile. The seismic refraction method can be used in the exploration of urban active faults.

Key words: urban active fault, seismic refraction exploration, western Zhengzhou

摘要： 在城市活断层勘探中,对于面波干扰大、地震反射波法难以开展工作的区域,可尝试利用地震折射波法进行探测,并对折射波法探测的原始记录采用时间项、差异时距曲线和有限差分成像等方法进行综合计算、分析,以探索折射波法在城市活断层勘探中的应用成效。文中针对郑州市须水断层西段浅层地震折射波法勘探记录,利用时间项、差异时距曲线和有限差分成像等计算方法,获取剖面速度结构与界面构造;综合震相特征、计算结果等资料确定主要地层的界面深度和构造特征,3种方法都取得了相近的结论。后又通过在测线上4个钻孔资料的验证,认为3种方法的计算结果与钻孔资料相吻合,说明折射波法勘探在城市活断层探测中的应用是可行的。

关键词: 城市活断层, 地震折射波法, 郑州市西区