用于估计多隧道开挖地面沉降的解析解(英文)
Analytical solution for estimating surface settlements induced by multiple tunnel excavation
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摘要: 对于均质弹性地基中单隧道和多隧道开挖施工,本文给出了用于计算二维和三维地面沉降的近似的显式解析解。该解析解是对点荷载下Mindlin位移解进行积分并利用泰勒级数展开而得。利用该解析解,可以计算多个任意相对位置的隧道掘进引起的地面沉降。对于隧道开挖面不同支护程度的情况,可以采用一个原位应力释放度(系数)来模拟。通过一个单隧道开挖的弹性有限元计算对比,对简化的解析解进行了检验,两者计算结果的差距在9%以内。简化解析解的有效性,通过两种情况(两条相互平行隧道和两条相互垂直隧道)的计算得到验证。Abstract: The derivation of an approximate explicit analytical solution was presented to calculate three-dimensional surface settlements due to the excavation of either single or multiple tunnels in a homogeneous elastic soil.This solution was based on the integrated form of Mindlin’s equations and Taylor’s series expansions.Surface settlements due to the construction of tunnels with an arbitrary orientation during the tunnel advancement with and without supporting pressure could be modelled by using a stress relief coefficient.The derived analytical solution was verified by carrying out a three-dimensional finite element analysis of a single tunnel excavation.The discrepancy between the simplified approximate solution and the finite element analysis was less than 9%.The usefulness of the simplified approximate analytical solution was demonstrated by analyzing two parallel and two cross tunnels.