不同围岩和埋深条件下土-结构接触界面对衬砌结构横向地震响应特性的影响分析

Analysis of Influence of Soil-Structure Interface on Transverse Seismic Response Characteristics of Lining Structure under Different Surrounding Rocks and Buried Depths

土与地下结构在强震作用下易发生错动滑移,会对地下结构的抗震性能产生较大影响。为确保隧道的长期安全性,运用有限元分析方法研究不同围岩和埋深条件下土-结构接触面对盾构隧道衬砌结构横向地震响应特性的影响。结果表明:1)随着土质条件的提高,无论土-结构接触界面有无考虑错动滑移情况,隧道衬砌结构的轴力极值均显著增大,而剪力和弯矩极值均显著减小,且由土-结构接触界面错动引起的隧道衬砌结构动内力变化幅度显著减小;随着隧道埋深的增加,由土-结构接触界面错动引起的隧道衬砌结构动内力变化幅度逐渐减小。2)考虑土-结构接触界面错动滑移时,随着土质条件的提高和隧道埋深的增加,隧道衬砌各部位水平滑移量均逐渐减小。3)当隧道围岩条件较差或埋深较浅时,隧道衬砌结构的横截面抗震设计应充分考虑土-结构接触界面对隧道抗震性能的影响。

Dislocation would easily occurs to soil and underground structure under strong earthquake,which has great influence on aseismatic performance of underground structure.Hence,the influences of soil-structure interface on transverse seismic response characteristics of lining structure under different surrounding rocks and buried depths are studied by finite element method to guarantee the long-term safety of the tunnel operation.The study results show that:(1)With the improvement of soil condition,the extreme value of axial force of tunnel lining structure increases significantly,while the extreme values of shear force and bending moment of tunnel lining structure decrease significantly,and the variation amplitude of dynamic internal force of tunnel lining structure induced by dislocation of soil-structure interface decreases significantly;with the increase of buried depth,the variation amplitude of dynamic internal force of tunnel lining structure induced by dislocation of soil-structure interface decreases significantly.(2)When considering the dislocation of soil-structure interface,the better the tunnel surrounding rock conditions and the larger the buried depth are,the smaller the horizontal slip of tunnel lining is.(3)When tunnel surrounding rock condition is poor or the buried depth is small,the influence of soil-structure interface on the aseismatic performance of tunnel should be fully considered in aseismatic design of tunnel lining structure.