两个水平密贴地下结构的地震响应分析

为了研究相互邻近的地下结构的地震响应特征,以某新建地铁车站结构和上部密贴的既有公路隧道结构为对象,利用有限元分析软件MIDAS-GTS,对水平密贴的两个地下结构的地震响应进行数值模拟,分析公路隧道结构在有、无地铁车站结构时的地震响应,探讨结构接触面性质对水平密贴结构的地震响应的影响。计算结果表明:1)在设定条件下,地铁车站结构对公路隧道结构水平位移的影响幅度小于5%,但公路隧道顶板与底板的相对水平位移峰值增大了20%,水平加速度峰值增大幅度大于5%,隔墙动应力峰值增大11%,底板结构应力峰值增大150%;2)影响公路隧道结构动力响应的结构接触面性质主要是切向刚度,切向刚度增大,接触面范围内的公路隧道底板下侧的动应力减小,而接触面两侧的公路隧道底板的动应力却有明显的增大。

Analysis on Seismic Response of Adjacent Underground Structures

The seismic response of a newlybulb Metro station and an upper highway tunnel is numerically mmulatea Dy means of finite element software MIDASGTS, the seismic response of the highway tunnel with and without Metro station is analyzed, and the influence on the seismic response of the adjacent underground structure imposed by the characteris tics of the contact face is discussed. The calculation results show that ： 1 ） Under given condition, the influence on the horizontal displacement of the highway tunnel induced by Metro station is less than 5%, the relative horizontal displace ment of the roof slab and bottom slab increases by 20%, the peak horizontal acceleration increases by more than 5% , the peak dynamic stress of the separation wall increases by more than 11%, and the peak stress of the bottom slab in creases by 150%. 2） The tangential rigidity is the main factor that affects the dynamical response of highway tunnel structure. When the tangential rigidity increases, the stress under the bottom slab within the contact face scope decrea ses, while the stress of the bottom slab of the highway tunnel on both sides of contact face increases.