非饱和土中圆柱形衬砌隧道的瞬态动力响应

在以往关于圆柱形衬砌隧道的瞬态动力响应中，衬砌周围土体大多假定为弹性介质或饱和介质。然而，自然界中的土体大多为非饱和介质。考虑土体与衬砌结构的动力相互作用及动荷载引起的附加质量密度的影响，研究了瞬态荷载作用下非饱和土中无限长深埋圆柱形衬砌隧道的动力响应。基于多孔介质混合物理论和连续介质力学理论，建立了非饱和土中圆柱形衬砌隧道受到瞬态荷载作用时衬砌及周围土体的控制方程，利用Durbin数值反演法得到了衬砌及土体在时间域的动力响应。数值分析了饱和度对瞬态荷载下径向位移、径向应力、环向应力和孔隙水压力的影响。结果表明：饱和度对衬砌及周围土体的瞬态响应影响显著；饱和度对径向位移沿径向的衰减影响较小，对环向应力和孔隙压力沿径向的衰减影响较大。

Transient dynamic response of cylindrical lined cavity in unsaturated soil

Most soils in nature are unsaturated media, however, most of the soil was assumed to be elastic or saturated media in the previous studies on the transient dynamic response of circular lined tunnels. In this paper, considering the dynamic interaction between the soil and the tunnel lining and the additional mass density caused by dynamic load, the transient dynamic response of a deeply buried cylindrical lined tunnel with infinite length in saturated soil is studied. Based on the porous medium mixture theory and continuum mechanics theory, the controlling equations of the tunnel lining and unsaturated soil are derived when the cylindrical lined tunnel is subjected to transient load. The dynamic response of lining and unsaturated soil in time domain is obtained by using Durbin numerical inversion method. The effects of different saturation degrees on radial displacement, radial stress, hoop stress and pore water stress under transient load are presented and discussed. The results show that (a) the saturation degree has a significant influence on the transient dynamic response of lining and unsaturated soil; (b) the saturation degree has a less influence on the radial attenuation of radial displacement, but has greater influence on the radial attenuation of hoop stress and pore pressure.