P波作用下土体孔隙尺寸及结构非均匀效应对圆形衬砌动力特性的影响

Influence of soil pore size and structure heterogeneity on the dynamic characteristics of circular lining subjected to P-wave

基于应变梯度非局部Biot理论,以深埋圆形衬砌为研究对象,利用波函数展开法和饱和土与衬砌间的边界条件,得到隧道衬砌在P波作用下的动力响应解析解。研究了不同入射P波频率下,非局部参数与尺寸因子对动应力集中系数(DSCF)的影响规律。结果表明,入射波频率较低时,非局部参数和尺寸因子对DSCF几乎没有影响,随着入射波频率的增大,非局部参数和尺寸因子对DSCF的影响会越来越明显,且非局部参数与DSCF呈负相关,尺寸因子与DSCF呈正相关;衬砌内动应力最大处均出现在衬砌右侧;随着频率的增加,衬砌内DSCF沿径向呈现明显的波动,非局部参数和尺寸因子对衬砌内环向应力的分布模式影响不大。

Based on the strain gradient nonlocal Biot theory,the analytical solution of the dynamic response of the tunnel lining under the action of P-wave is obtained by using the wave function expansion method and the boundary conditions between saturated soil and lining with the deeply buried circular lining as the research object.The influence of non-local parameters and size factors on the dynamic stress concentration factor(DSCF)is investigated for different incident P-wave frequencies.The results show that when the incident wave frequency is low,the non-local parameters and size factor have almost no effect on the DSCF.As the incident wave frequency increases,the effects of the non-local parameters and size factor on the DSCF become more and more obvious.The non-local parameters are negatively correlated with the DSCF,and the size factor is positively correlated with the DSCF.The maximum dynamic stresses in the lining appear on the right side of the lining.With an increase of frequency,the DSCF in the lining shows obvious radial direction and the dynamic stresses in the lining appear in the right side of the lining.The maximum dynamic stresses in the lining all appear on the right side of the lining,With an increase of frequency,the DSCF in the lining shows obvious fluctuation along the radial direction,and the non-local parameters and size factor have little influence on the distribution pattern of the cyclic stresses in the lining.