基于温度比拟法的隧道衬砌水压精细化模拟分析

Refined Simulation Analysis of Water Pressure of Tunnel Lining Based on Temperature Analogy Method

为验证温度比拟法在隧道衬砌水压计算中的精度与可行性,在隧道开挖未支护、施作衬砌以及围岩注浆3种工况下,将该法的计算结果与理论解析法轴对称解、流固耦合法进行对比.针对高速公路典型双车道马蹄形断面建立含有隧道防排水系统的精细化模型,研究衬砌外水压力在隧道横断面和纵断面上的分布规律.结果表明:施作衬砌后,衬砌外水压力明显增大,围岩注浆则可在围岩和衬砌之间形成水压过渡缓冲区,使衬砌外水压力减小;衬砌外水压力在纵向排水管以上呈周期性分布,在排水节间中部最大,在环向排水管处最小;横断面水压则呈现倒葫芦形,在拱脚处最小,在拱顶和仰拱处较大;在既定的计算假设下,温度比拟法与轴对称解的最大误差为0.3%,与流固耦合法的最大误差为14.8%,满足工程精度要求.

In this study,the distribution of a lining＇s water pressure is calculated under different construction states including excavation,lining construction,and grouting to verify the accuracy and feasibility of the temperature analogy method in water pressure calculations. The results were compared with those of the theoretical analytical method and fluid-structure coupled method. Subsequently,the distribution of the lining＇s water pressure on transverse and longitudinal section was numerically explored through a refined model that includes a drainage system of a double lane highway tunnel. The results indicate that the water pressure of the lining significantly increases after lining construction and that a grouting circle can effectively reduce water pressure. The longitudinal distribution presents the characters of periodic variation above the longitudinal drain pipe,maximum water pressure occurs in the centre of two annular drain pipes,and minimum water pressure occurs in annular drain pipes. The transverse distribution presents an inverted gourd shape,minimum water pressure occurs in the arch foot,and maximum water pressure occurs in the vault and invert. Under the given computationalassumptions,the maximum error between the temperature analogy method and theoretical analytical method is 0. 3%,and the maximum error between the temperature analogy method and fluid-structure coupled method is 14. 8%. Hence, the calculation precision satisfies the required engineering accuracy.