针对目前广泛用于解决工程地质问题的浅层地震勘探特点,通过对浅层小尺度介质进行地震波数值模拟,揭示地震波在不同浅层介质模型中的波场特征和传播规律。为浅层地震勘探野外数据采集前合理选择观测系统提供指导性的方案,并能对地震勘探成果解释的合理性给予客观评价。在分析各种数值模拟方法特点的基础上,选择具有精度高、易模拟复杂结构的有限元法对百米尺度的浅部模型进行地震波数值模拟。通过与实际采集的共炮点记录对比,主要波组的特征具有较好的相似性。说明用有限元法模拟浅层复杂结构的地震波场是有效和可行的。
Currently shallow seismic prospecting method is widely applied in engineering geological exploration. Through using seismic wave numerical simulation in shallow small-scale medi- um, the characteristic and propagation rule of seismic wave in some different shallow medium models is revealed in this paper. It can guide the reasonable observation system before field collection of shallow seismic prospecting, and also can objectively evaluate the rationality of seismic prospecting interpretation. On the basis of comparing with some numerical modeling methods, the finite element method which has high precision and easily simulates complex structure in shallow model is employed in this paper. Through comparing with actual common-source point records, the characteristics of main wave groups are similar with each other. So using finite element method in shallow complex structure is valid and viable.