重叠盾构隧道施工中两隧道相对位置变化的影响模型试验研究

Research by Model Test on Effects of Relative Position Change of Overlapping Tunnels with Shield Method

以深圳地铁7号线笋岗—洪湖区间隧道重叠段为背景,采用室内相似模型试验,研究两隧道相对位置变化时新建隧道对既有隧道受力及位移的影响。试验结果表明:净距一定,两隧道上下重叠时新建隧道开挖对既有隧道拱顶位移及拱顶、拱底附加内力的影响最大,且对拱顶内力的影响大于拱底;随两隧道角度的减小,既有隧道结构附加内力最大值由拱顶向拱腰转移。

Taking the overlapping section of Sungang-Honghu interval tunnel on line 7 of Shenzhen metro as the background,the indoor similar model test was adopted to study the influence of the newly built tunnel on the force and displacement of the existing tunnel when the relative position of two tunnels changed.The experimental results indicate that in the case of constant clear distance and the overlapping tunnels are in a vertical position,the newly built tunnel has the greatest influence on the vault displacement and the additional internal force of the vault and the arch bottom of the existing tunnel,and the influence on the internal force of the vault is greater than that of the arch bottom.With the decrease of the angle of two tunnels,the maximum additional internal force of the existing tunnel structure is transferred from the vault to the hance.