倾斜断层面上的折射波时距曲线特征及解释方法对比

CHARCTER OF TIME-DISTANCE CURVES AND CONSTRAST OF INTERPRETATION METHODS OF REFRACTION OVER SLANTWISE FAULT INTERFACE

地震折射波法以其能够确定折射界面的速度而广泛用于工程地质勘查中,但因其解释受到地表条件及界面形态等多种因素的影响而表现出多解性。本文推导出倾斜断层界面上的折射波时距方程,设计不同类型的断层模型,正演计算出折射波传播路径及时距曲线,进而分析断层对折射波的影响,用以作为指导野外实际数据解释的理论依据。同时,采用t0-差数法和哈雷斯法解释得到速度和深度,通过比较分析其与理论模型的误差,分析了解释方法的适用性。

The shallow seismic refraction which can ascertain the velocity ot the retractton layer is widely used in engineering geology exploration. However, its interpretation result is of ambiguity by the effect of the ground surface conditions and the underground structure. We have derived time-distance curves equation of refraction wave over slantwise fault interface in this paper. Meanwhile, we design some different types of fault models, calculate raypath and time-distance curves of refraction wave and analyze the effect of fault on refraction wave so as to instruct the interpretation of actual data. Moreover, we apply the tO and Harles method to obtain velocity and depth and analyze the applicability of interpretation method by analyzing errors between the model and interpretation result.