阶梯型综合管廊非一致地震激励下的动力响应

Dynamic Response of Stepped Utility Tunnel under Non‑uniform Earthquake Excitation

基于有限元分析的方法,建立了管廊-土体结构相互作用的三维有限元模型,深入探究阶梯型双层多仓地下综合管廊在非一致地震激励下动力响应特性。通过模态分析,得到了现浇式、平口式和企口式三种接头形式阶梯型双层多仓综合管廊的自振频率和变形特征,计算了地下综合管廊在小震(0.05g)、中震(0.1g)、大震(0.2g)非一致激励条件下管廊整体、廊身和接头的动力响应。结果表明:三种接头形式的管廊均表现为破坏率先发生在接头处的扭剪破坏,且管廊接头处的应力水平要明显高于廊身应力,其中企口式接头尤为显著;在非一致地震激励下,管廊接头两侧点响应时程曲线体现了非常明显的响应非一致性,三种形式接头处的动力响应均以横向(X向)和竖向(Y向)振动为主,以轴向(Z向)振动为辅;随着地震力的提高,管廊顶板轴线上的位移在逐步增大,且平口式和现浇式管廊接头处均出现了明显的位移的突变,突变主要以横向为主,而企口式接头由于其良好的整体性,位移分布曲线较为连续,几乎没有发生突变;管廊的接头处出现明显的应力集中,现浇式和平口式接头的应力集中现象主要出现在角部,企口式接头主要出现在榫卯接头处和角部;现浇和平口式接头会出现“反喇叭口”式的变形和上下错动,而企口式接头的整体性好,几乎未发生上下错动,但应力水平相比其他两种接头形式较高。

Based on the finite element analysis method,a three-dimensional finite element model for utility tunnel-soil structure interaction simulation was established,and the dynamic response character‐istics of the stepped double-layer multi-warehouse integrated utility tunnel under non-uniform seismic stimulation were investigated.Through modal analysis,the natural vibration frequency and deforma‐tion characteristics of the stepped double-layer multi-warehouse integrated utility tunnel with three joint forms of cast-in-place,flat and tongue-and-groove were obtained.The dynamic response of the utility tunnel was calculated for the entire tunnel,tunnel body and joints under the non-uniform excitation of the small earthquake(0.05g),medium earthquake(0.1g)and large earthquake(0.2g).The result shows that:for the three kinds of joint types,the torsional shear failure occurred first at the joint,and the stress level at the joint of the utility tunnel was obviously higher than that of the utility tunnel body,of which the tongue-and-groove joint was particularly obvious;Under the non-uniform seismic excita‐tion,the response time history curves of the points on both sides of the utility tunnel joints showed very obvious inconsistency in response.The dynamic responses of the three types of joints were mainly transverse(X)and vertical(Y)vibrations,and supplemented by axial(Z)vibrations.The displace‐ment along the roof axis of the utility tunnel increased gradually with the increase of the seismic force,and there was an obvious mutation of displacement at the joints of the flat and cast-in-place utility tun‐nel.The mutation was mainly in the transverse direction.The displacement distribution curve was con‐tinuous and has nearly no mutation for the tongue-and-groove joint because of its good integrity.There was obvious stress concentration at the joints of the utility tunnel.The stress concentration phenome‐non of cast-in-place and mouth joints mainly appeared at the corner,and that of the tongue-and-groove joints mainly appeared at the mortise,tenon and corner.Cast-in-place and flat-mouth joints showed"re‐verse bell mouth"deformation and up-and-down displacement.The tongue-and-groove joints illustrat‐ed nearly no up-and-down dislocation except a higher stress level because of its good integrity.