基于回归分析的小径距隧道围岩稳定性研究

Study on Stability of Small-distance Tunnel Based on Regression Analysis

为了更好的掌握小径距隧道的变形特点,以某市某小径距隧道为工程背景,采用指数函数、对数函数、双曲线函数三种形式对监测数值进行拟合,分析隧道拱顶及净空位移趋势,得出最优拟合函数,研究结果表明:指数函数U=Ae(-B/T)的相关系数较高,通过指数函数可以很好地预测围岩的变形趋势;围岩的变形主要分为三个阶段,急剧变形阶段,缓和变形阶段,稳定阶段,左洞的拱顶下沉以及净空收敛量均大于右洞,小净距隧道后行洞开挖对先行洞产生了显著的影响,通过对三类典型断面的分析提出二次衬砌的合理支护时机,研究结果可为类似工程提供参考。

n order to better grasp the characteristics of the tunnel deformation path, it is taken a small- distance tunnel of a city as the engineering background, by using the exponential function, logarithmic function and hyperbolic function forms to fit the numerical monitoring. It is analyzed the tunnel vault and the arch waist displacement trend, the best fitting function. The results show that： exponential function U= Ae （-B/T） , high correlation coefficient, deformation prediction of surrounding rock can be tendency very well by the exponential function; The deformation of surrounding rock is mainly divided into three stages, rapid deformation stage, moderate deformation stage, and stable stage; the left tunnel vault and clearance convergence is greater than the right tunnel; Small-distance tunnel after tunnel excavation produced a sig- nificant impact on the first hole. Through the analysis of three typical sections, it puts forward appropriate support time two lining, and the research results can provide reference for similar projects.