摘要
基于已建立的非饱和土中的波动方程,第1次从理论上推证出非饱和土中存在4种体波,即1种S波和3种P波(P1波、P2波和P3波),并导出了4种体波的波速以及衰减的解析表达式,分析了4种体波的波速、衰减与频率以及饱和度之间的关系。结果表明:3种P波中P3波波速最小,衰减最大;P1波波速最大,衰减最小;P2波则介于二者之间。4种体波都具有弥散性,一般而言,波速随频率的提高而有所减小,而衰减则有所增大。随含气量的提高,P1波的波速减小,P2波和S波的波速增大,而P3波则受含气量的影响很小;P1波和P3波的衰减都有所减小,但变化不是很显著,P2波的衰减基本不随含气量的变化而变化,S波几乎不存在衰减现象。
Based on the wave propagation equation in unsaturated soils, four kinds of waves (i.e., one is S wave, and other three are P waves, P1 wave, P2 wave and P3 wave according to the wave velocity) are found in unsaturated soils through theoretic deduction. Analytic expressions for wave velocity and attenuation are proposed. Numerical analysis about the relations between the wave velocity ,attenuation and the frequency, saturation degree is carried out. The results show that the velocity of P3 is minimum and the attenuation of it is maximum, the velocity of P1 is maximum and the attenuation of it is minimum, and the velocity and attenuation of . P2 are between other two waves. All four kinds of waves are dissipative waves. In general case, the velocity becomes slower with the the frequency heightening, and the attenuation becomes greater. With the gas content becoming higher, the velocity of P1 becomes lower and velocity of P2 and S becomes higher, the velocity of P3 is not affected by gas content very much, the attenuation of P1 wave and P3 wave become less, but not very much. The attenuation of P2 wave is not varied with the change of gas content basically and the attenuation of S wave is very small.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2004年第3期354-358,共5页
Rock and Soil Mechanics
基金
归国留学人员基金资助项目。
关键词
非饱和土
波传播
混合物理论
unsaturated soils
wave propagation
theory of mixture
