饱和砂土中箱型隧道的地震反应分析

Seismic Response Analysis of Box Tunnels in Saturated Sand

摘要:

饱和砂土地基在地震作用下存在液化的潜在危险,液化引起的地基失效可能会导致地下结构的严重震害。以Opensees作为计算平台,对饱和砂土中带中柱箱型隧道的地震反应进行输入不同幅值地震动时的动力数值计算,研究场地和结构的加速度反应及其频谱特性、场地的永久变形、隧道的震后位移以及隧道的内力分布。计算结果表明,饱和砂土中箱型隧道的地震附加内力仍受周围土体的相对位移控制,此外在震后隧道可能会产生侧移和上浮的永久位移,并且可能存在残余内力。

Abstract:

Foundations in saturated sand have the potential to liquefy under the effects of earthquakes,and foundation failure caused by liquefaction can lead to a serious damage of underground structures.Considering Opensees as the computing platform,a dynamic numerical simulation was performed to calculate the seismic response of a box tunnel with mid-columns in saturated sand when seismic waves of different amplitudes were input.Acceleration responses and the spectral properties of ground and structure,as well as the permanent deformation of the ground,aftershock displacement of the tunnel,and internal force distribution of the tunnel,were studied.The results show that the additional internal seismic forces in a box tunnel in saturated sand are controlled by the relative displacement of the surrounding soil.The permanent displacement of the tunnel such as side shift and floating probably appear after the main shock;in addition,remnant internal forces also probably occur.