饱和土介质中地震波在水、气分界面上的反射与透射  

SEISMIC REFLECTION AND TRANSMISSION COEFFICIENTS AT AN AIR-WATER INTERFACE OF SATU-RATED POROUS SOIL

作　　者：周新民[1] 夏唐代[1] 徐平[1] 邹振轩 

机构地区：[1]浙江大学岩土工程研究所,中国杭州310027 [2]浙江省地震局,中国杭州310013

出　　处：《地震学报》2006年第4期372-379,共8页Acta Seismologica Sinica

摘　　要：基于修改的Biot模型,研究地震波在气饱和土中的传播特性以及地震波在饱和土中气、水界面上的反射和透射.从理论上分析气饱和土与水饱和土的特性差异,根据界面连续条件推导了反射系数与透射系数的一般计算式;通过数值算例分析了气饱和土中波的传播特性,并分析了饱和土中P1波入射气、水界面时反射系数和透射系数与入射角及频率的关系.结果表明,波在气饱和土中的传播与水饱和土中有较大差异;频率和入射角度对反射系数与透射系数均有较大影响;并获得了波传播的某些新认识.这对地震工程的波动勘测技术和场地反应分析具有理论及实际意义.Based on the modified Biot＇s theory of two-phase porous media, a study was presented on seismic reflection and transmission coefficients at an air-water interface of saturated porous soil media. The major differences between air-saturated soils and watersaturated soils were theoretically discussed, the theoretical formulas of reflection and transmission coefficients at an air-water interface were derived. The characteristics of propagation and attenuation of elastic waves in air-saturated soils were given and the rela- tions among the frequency, the angle of incidence and the reflection, transmission coefficients were analyzed by using numerical methods. Numerical results show that the propagation characteristic of the wave in air-saturated soils is great different from that of wave in water-saturated soils. The frequency and the angle of incidence can have great influences on the reflection and transmission coefficients at interface. Some new cognition about the wave propagation is obtained and the study suggests that we may carefully pay attention to the influence of air on the dynamic analysis of seismic wave.

关 键 词：地震波 气饱和土 传播特性 反射与透射 

分 类 号：TU435[建筑科学—岩土工程] TU315.31[建筑科学—土工工程]