【摘要】 饱和可液化土中地下结构在强震作用下会由于土层液化而上浮,从而对地下结构造成破坏。可液化土在地震结束之后,将由于超静孔隙水压力的消散而产生固结变形,而地下结构在土层震后固结过程中的响应是一个值得研究的问题。以地下结构在土层震后固结过程中的垂直位移为重点,应用非线性动力两相体有限元方法研究饱和可液化土和地下结构相互作用体系在地震后土层固结过程中的响应。研究结果表明,地下结构的上浮趋势不会在地震结束时立即结束,而是在土层超静孔隙水压力经过一段时间的重分布及消散以后停止,之后地下结构有一定的沉降位移,但沉降位移远小于上浮位移,因此地下结构在震后会残留向上的垂直位移。文中还讨论了土层的应力路径响应、水压消散过程及截断墙与土层渗透系数对地下结构在震后固结过程中响应的影响,试图讨论饱和可液化土中地下结构在震后固结中响应的机理。更多还原

【Abstract】 The underground structures in saturated liquefiable soils may be subjected to floatation due to earthquake induced liquefaction.After earthquake,the excess pore pressure shall dissipate and the liquefied soil will experience the process of consolidation.The post-earthquake behavior of underground structures in liquefiable soils is not clear and deserves investigation.Nonlinear coupled dynamic finite element method was used to investigate the response of the liquefiable soil-underground structure system,focusing on the vertical displacement of the underground structure.It was found that the uplift behavior of the underground structure did not cease to develop when the earthquake stopped;instead,it terminated after the excess pore pressure was dissipated to some extent and the underground structure started to settle afterwards,but with a magnitude much smaller than the amount of uplift.Residual deformation existed in the underground structure after earthquake.The stress path,the process of excess pore pressure dissipation,and the effects of cutoff walls and coefficients of permeability were also discussed,in an effort to tackle the mechanism of the post-earthquake response of underground structures in saturated liquefiable soils.更多还原