地表荷载对地铁车站箱体影响实测及有限元分析

Field Observation and Finite Element Analysis of Metro Station Boxes due to Ground Loading

对天津地铁1号线西站车站及隧道在地表荷载作用下产生的沉降进行了现场监测和有限元分析,由于变形缝的存在使结构沉降表现为非连续性;地表荷载下基底土体产生塑性应变导致卸荷后结构仍存在不可恢复的残余变形;侧向地表荷载会导致结构产生较大的倾斜差异沉降并使结构扭转.在此基础上研究了地表荷载位置、结构埋深因素对于存在变形缝的地铁结构箱体变形的影响.结果表明:变形缝的存在会削弱结构刚度、加剧结构沉降以及结构间的差异沉降,并且不同荷载位置下结构的沉降特点也各不相同.此外,对于浅埋结构,荷载位置距结构越远,结构的变形越小,且结构埋置越深地表荷载对结构的影响也越小.

The settlement due to ground loading was observed in the West Railway Station subway station of Tianjin Metro Line 1. Besides,the deformation characteristics of structure were analyzed by field measurements and finite element method. The results show that the settlement curve is discontinuous at the structural deformation joint. After the removal of ground loading,the structure suffers from unrecoverable residual deformation,since the ground load-ing causes the plastic strain of the surrounding soil. The lateral ground loading leads to differential settlements and hence twists the structure. Furthermore,the effects of the loading location,buried depth of the structure on the de-formation of the discontinuous metro station boxes were studied. It is found that the structural deformation joint can weaken the structure stiffness and increase the settlement and differential settlement of the structure. The deformation characteristics also vary with different loading locations. Additionally,for shallow tunnel,increasing the distance of loading location can reduce the deformation of structure,and the influence of loading decreases with the increase of the buried depth of the structure.