偏压、错台小间距隧道施工位移场动态模拟分析

Dynamic simulation analysis of displacement field of bias closely spaced tunnel with altitude difference

采用三维非线性有限元法,对偏压、错台的浅埋小间距隧道在不同开挖顺序下的动态施工过程进行了模拟。通过对位移场的分析,研究了其施工力学特性。由于两隧洞之间的相互影响,并行小间距隧道对围岩的扰动程度大于两独立隧道作用的叠加;相互影响对中间岩柱的作用最为明显,对洞周、地表影响相对较弱。两洞开挖顺序不同,最终位移场的分布规律相同,但量值上存在一定差异。研究给出了在偏压、错台情况下的两洞开挖的合理顺序。

A three-dimensional nonlinear finite element analysis is performed to simulate the observational construction procedure of bias closely spaced tunnels with altitude difference. The main works are focused on the displacement field to investigate the construction mechanics features under alternative construction sequences. The results present more deterioration of adjacent rock for parallel tunnels with small distance than superposition of two independent tunnels because of the interaction; and the interaction effect more on pillar than ground surface and tunnel periphery. Though the construction sequences are different, the basic features of final displacement field are consistent; they are just different in quantity. The preferable construction sequence under the presented condition is given.