盾构施工引起土体位移的数值模拟分析

盾构施工不可避免地对周围土体造成影响，其影响主要表现为引起土体的隆起和沉降。利用FLAC^3D模拟盾构隧道施工对周围土体位移的影响，并计算出竖向位移。考虑了盾构施工过程中的开挖未支护和支护后对土体位移的影响，对比了各施工阶段对土体位移的影响。分析了土体最大位移发生的部位。结果表明，开挖未支护的竖向位移一般表现为土体沉降，开挖支护后的竖向位移一般表现为隆起。土体沉降的最大竖向位移，一般发生在拱顶位置，土体隆起的最大竖向位移，一般发生在拱底位置。

Numerical simulation of soil displacement caused by shield construction

Shield construction whose influence mainly for soil uplift and subsidence inevitably impacts on the surrounding soil, and the influences of this method on surrounding soil displacement can be simulated using FLAC^3D, and also in this way the vertical displacement can be calculated. The effects that the excavation with support or not has exerted on the soil displacement during the shield tunnel construction are considered, the effects of various construction stages on soil displacements are com pared and the maximum displacement of soil of the site is analyzed. The results show that soil subsid ence is generally performed as a result of the excavation of vertical displacement without support. On the other hand, the uplift is generally performed as a result of one with support. Moreover, the maxi mum vertical displacement of soil settlement mostly occurs in the vault while its soil uplift mostly oc curs in arch bottom.