【摘要】 以南昌地铁过江隧道为工程背景,考虑水土两相耦合作用,采用等效连续介质理论建立层状土体结构计算模型,运用有限差分方法求解层状饱和土体中衬砌结构对地震波的动力响应,分析了衬砌厚度、周边地基加固深度对地震动力响应的影响规律。计算结果表明,分层土体中的地下结构对地震波的动力响应要比均质土体中的动力响应要大;随着衬砌厚度的增加,衬砌结构的整体变形逐渐变小,衬砌结构内力增大,特别是剪力和弯矩的增幅较大;隧道衬砌内力和变形随着衬砌周边土体加固范围增大和加固土体的弹性模量的提高而减小,其中提高衬砌周边加固土体的弹性模量对地震减震效果显著,就南昌赣江过江隧道工程而言,衬砌结构周边土体加固范取1.5 m,土体弹性模量提高到原来的2倍时比较经济合理。更多还原

【Abstract】 With the crossing river tunnel of Nanchang subway as the engineering background,considering the coupling effect of soil and water,the calculation model to layered soil structure is developed by using equivalent continuum theory,and dynamic responses of the lining structure embedded in layered saturated soil subjected to seismic wave were solved based on the finite difference method. Then,the influence rulers of the lining thickness and the reinforcement depth of the surrounding foundation on the seismic dynamic responses are analyzed. The calculation results show that the dynamic response of the lining structure embedded in layered soil is larger than that in the homogeneous soil. With the increase of lining thickness,the overall deformation of the lining structure decreases gradually,and the internal forces of lining structure increase,especially the shear and bending moment increase obviously. The internal force and deformation of tunnel lining decreases with the increase of the surrounding soil depth and the elastic modulus of the reinforced soil. Moreover,the seismic mitigation effect is obvious while the elastic modulus of the reinforced soil around the lining is increased. The depth of reinforced soil range of 1.5 m and soil elastic modulus increased to 2 times of that of the original are more economical and reasonable for the Nanchang crossing river tunnel project.更多还原