内套钢拱架加固水工隧洞的结构受力与变形有限元分析

Finite Element Analysis of Structural Stress and Deformation of Internally-fixed Steel Arch for Hydraulic Tunnel Reinforcement

钢拱架在水工隧洞维修加固中作为后加固结构,与衬砌内壁之间不可避免地存在一定宽度的间隙。本文提出使用微膨胀砂浆填充间隙的方法,并根据间隙是否经微膨胀砂浆填充建立2个钢拱架加固隧洞的三维有限元模型,分析不同宽度的间隙是否经微膨胀砂浆处理条件下加固结构受力与变形的变化规律。结果表明,间隙的存在会劣化钢拱架的加固效果,衬砌状态的劣化程度随间隙宽度增大而增加,使用微膨胀砂浆填充不同宽度的间隙均明显提高钢拱架的加固效果。

In the maintenance and strengthening of hydraulic tunnels,steel arch is usually adopted as a post-reinforcement structure.While gaps with certain width are inevitably existed between the arch and the inner lining wall.It is proposed to fill the gaps with small expansion mortar.Then,three-dimensional finite element models of a steel arch reinforced hydraulic tunnel with or without the filling of gaps with small expansion mortar are established.The stress and deformation of the reinforcement structure with different gaps and with or without the mortar filling are analyzed.The results show that the gaps will deteriorate the reinforcement effect of the steel arch,and the deterioration degree of the lining will increase with the increase of the gap width.Filling of the gaps with different widths using the small expansion mortar can significantly improve the reinforcement effect of the steel arch.