隧道施工引起地面沉陷的几何非线性分析

GEOMETRIC NONLINEARITY ANALYSIS OF GROUNDSURFACE SETTLEMENT CAUSED BY TUNNELLING

本文首次提出了用邓肯一张（Ｄｕｃａｎ－Ｃｈａｎｇ）模型和几何非线性（Ｇｅｏｍｅｔｒｉｃｎｏｎｌｉｎｅａｒｉ－ｔｙ）相结合来研究浅埋隧道新奥法施工引起地面沉陷的非线性有限元方法和理论公式，研制了相应的有限元程序。该法的主要特点是用有限变形来描述浅埋地下洞室开挖后洞周地层的运动，同时用能较好模拟土体非线性性态的邓肯—张模型来表征地层的特性。这样，洞周地层的材料特性和运动特性都得到了较好的描述，从而使对地下工程的分析前进了一步。

The nominear finite element method based on the theory of Ducan-Chang model andgeometric nonlinedrity are first used to analyse the grouiidsurface settlement caused byNATM in shallow buried tunnel and the corresponding FEM program is developed.Themain characters of the method are using the theory of finite deformation to describe themovement of surrounding ground in shallow buried tunnel under excavation and usingDucan-Chang model to imitate the nonlinear property of ground;Thus,both the materialand movement properties of surrounding ground of tunnel are well described and the analysis of underground engineering is advanced a step.