小净距隧道坍塌堆积围岩段施工数值分析

摘要

雷公浦小净距隧道的出口段堆积有较厚的坍塌堆积围岩,结合该隧道的工程实际情况,选取K70+ 520断面采用Plaxis软件进行数值模拟研究.模拟结果表明:小净距隧道坍塌堆积围岩段采用3台阶法进洞存在稳定性问题；两侧拱脚塑性点分布较多,土体容易出现破坏；最大位移出现在后行左洞顶部,而最大受力部位出现在先行右洞左拱腰处.研究结论可为类似条件下工程的设计、施工和研究提供借鉴.%Leigongpu small interval tunnel export section have accumulated thicker collapse tunnel surrounding rock,combined with the condition of the actual project,selecting K70 + 520 section to numerical simulate by Plaxis software.Numerical simulation results show that the collapse of surrounding rock by piling up steps 3 into holes exist stability problems.Both sides plastic point distribution is more,soil prone to destruction.The maximal displacement appeared in the crest of left hole later,the maximum stress position appeared in the first right hole left arch waist place.Research results can provides beneficial reference for similar project design,construction and research.