基于概率统计法的隧道围岩变形稳定时间及二衬施作时机研究

摘要

隧道围岩变形稳定时间及二衬施作时机的科学确定是隧道设计和施工的关键技术难题.基于拱顶下沉监测数据,对某公路隧道Ⅴ级围岩29个监测断面和Ⅳ级围岩23个监测断面围岩变形基本稳定时间进行分析.结果表明:25个Ⅴ级围岩监测断面和21个Ⅳ级围岩监测断面的时态曲线满足指数函数;通过概率统计分析,发现各断面围岩变形基本稳定时间虽不尽相同,但分布频率符合正态分布;由此推求出该隧道Ⅴ级和Ⅳ级围岩基本稳定时间分别为49天和40天,与工程实际较为一致.本文的研究成果可为围岩稳定性分析、初期支护参数优化和二次衬砌施作时机选择提供理论依据.%Tunnel rock deformation settling time and facilities for the timing of the second lining scientific certainty are the key to the tunnel design and construction technical problems.Based on the vault settlement monitoring data,Grade Ⅴ 29 monitoring section and Grade Ⅳ 23 monitoring cross section deformation of surrounding rock deformation are of basically stable time with a highway tunnel analyzed.The results show that the 25 Ⅴ level monitoring section of surrounding rock and 21 level Ⅳ surrounding rock monitoring section of temporal curves meet exponential function.By probability statistics analysis,the cross section of surrounding rock deformation basically stable time is different,but the distribution of frequency accords with the normal distribution Hence the tunnel Ⅴ level and level Ⅳ surrounding rock stability time is basically 49 days and 40 days respectively,which is consistent with the engineering practice.In this paper,the research achievements of supporting parameters for stability analysis of surrounding rock are obtained,and the early timing optimization and secondary lining do provide a theoretical basis.