Dynamic Responses of Saturated Soil Foundation Subjected to Plane Wave Based on Nonlocal-Biot Theory

doi:10.16183/j.cnki.jsjtu.2020.149

Abstract

Abstract:

To investigate the influence of pore size effect on dynamic response of saturated soil foundation, a model for predicting the dynamic response of the ground surface of the saturated soil foundation under incident P wave and SV wave is proposed based on the nonlocal-Biot theory. The analytical solution is obtained using the wave function expansion method. The influence of pore size described by nonlocal parameter, input frequency, and the incident angle on the dynamic response of displacement and stress is discussed in detail. The results show that at low frequencies, the calculation results of the nonlocal-Biot theory are basically the same as those of the classical Biot theory. At high frequencies, the surface displacement and stress change significantly with nonlocal parameters, that is, at high frequencies, the effect of pore size on the surface response cannot be ignored. The influence of incident wave frequency on the ground-surface response is related to pore size, that is, the larger the pore size, the more significant the frequency effect. The influence of SV wave on the dynamic response of ground surface is larger than that of P wave. Besides, the total reflection phenomenon is observed at an incident angle of 45° for the incident of SV wave. The results obtained in this work can provide reference for studying the problem of wave propagation in half-space saturated soil foundation.

Key words: saturated soil, nonlocal-Biot theory, pore size, pore dynamic stress, nonlocal parameter

CLC Number:

TU312

WANG Ning, DING Haibin, TONG Lihong, JIANG Yalong. Dynamic Responses of Saturated Soil Foundation Subjected to Plane Wave Based on Nonlocal-Biot Theory[J]. Journal of Shanghai Jiao Tong University, 2021, 55(6): 663-671.

Figures/Tables 10

Fig.1

Tab.1

Expression of coefficient matrix

系数	P波	SV波
G₁_i	$k αi 2$ ( $k αi 2$ τ²-1)(λ_c+μ+ξ_iαM+μcos2θ_αi)	[-1+τ²(k²- $ν αi 2$ )][k²(λ_c+αMξ_i)- $ν αi 2$ (λ_c+2μ+αMξ_i)]
G₁₃	μ $k b 2$ ( $k b 2$ τ²-1)sin 2θ_β	-2jkμν_β[-1+τ²(k²- $ν b 2$ )]
G₂_i	-μ $k αi 2$ ( $k αi 2$ τ²-1)sin 2θ_α₁	2jkμν_αi[-1+τ²(k²- $ν αi 2$ )]
G₂₃	μ $k β 2$ ( $k β 2$ τ²-1)cos 2θ_β	μ(k²-k⁴τ²+ $ν b 2$ +τ² $ν b 4$ )
G₃_i	$k αi 2$ M(ξ_i+α)	M(k²- $ν α 1 2$ )(α+ξ₁)

Tab.1

Fig.2

Tab.2

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Fig.8

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参数	数值	参数	数值
土颗粒密度ρ_s/(kg·m^-3)	2650	渗透系数k/(m^-2)	1.0×10^-8
流体密度ρ_f/(kg·m^-3)	1000	黏滞系数η/(Pa·簚s)	1.0×10^-3
孔隙比n₀	0.30	Biot 参数α	0.9982
泊松比ν	0.30	Biot 参数M/MPa	5859.2
土颗粒模量K_g/GPa	36.0	弯曲因子ξ	1
流体体积模量K_f/GPa	2.0	孔隙半径a/μm	23
拉梅常数λ/MPa	49.7