基于有限元分析的高地应力软岩隧道蠕变特性研究

摘要

Due to its large deformation,long deformation time,and significant creep effect,the high ground stress soft rock tunnel is a great challenge for tunnel design,construction and operation,and the creep property is deeply researched for Erlang Mountain Tunnel in Kangting-Nyingchi Section of Sichuan-Tibet Railway by numerical simulation.The results show that the larger the burial depth of the tunnel is,the larger deformation rate of the surrounding rock during initial period,and the deformation rate becomes stable 2 ～ 3 months after completion of tunnel surrounding rock excavation.The creep trends to accelerate 180 days after completion of the excavation when the burial depth is 1 500 m and 2 000 m.%高地应力软岩隧道变形量大,变形时间长,蠕变效应显著,给隧道的设计、施工和运营带来巨大的挑战,运用数值模拟的方法,深入研究了拟建川藏铁路康定至林芝段二郎山隧道蠕变特性.结果表明:隧道的埋深越大,围岩初期的变形速率越大,隧道围岩在开挖完成后2～3个月变形趋于稳定,在埋深为1500 m和2000m时,开挖完成后180天,隧道围岩有加速蠕变的趋势.