某大断面双线隧道围岩量测分析研究

围岩量测的目的旨在收集可反映施工过程中围岩动态的信息,据此判定隧道围岩的稳定状态,以及所定支护结构参数和施工的合理性。文章通过对某特长大断面双线隧道的拱顶下沉、水平收敛等监测数据的收集整理,并利用图表进行分析研究。结果表明:隧道开挖后围岩的变形具有时间相关性和空间相关性。基本变形规律为急剧变形—缓慢增长—基本稳定三个阶段,并且具有变形较均匀、收敛速度快、变形小、拱顶下沉较水平收敛变形大的特征,这是地质条件、施工技术、周围环境综合作用的结果。监控量测结果表明,隧道围岩自稳能力和支护结构较强。围岩变形分析动态反馈于施工中,取得了令人满意的结果。

Surrounding Rock Measurement of a Large Cross-Section Two-Lane Tunnel

The purpose of surrounding rock measurement is to collect information reflecting the dynamics of surrounding rock during construction,judge the stability of surrounding rock and determine reasonable parameters for the support structure and construction.Based on the analysis of monitoring data regarding the crown settlement and horizontal convergence of a two-lane tunnel with a large cross-section and the utilization of excel analysis,it is concluded that the deformation of surrounding rock is correlated with time and space after tunnel excavation.The basic deformation law contains three stages: 1) rapid deformation stage;2) slow-increasing deformation stage;and 3) nearly stable stage,with such features as uniform deformation,rapid convergence and larger crown settlement compared with horizontal convergence.These deformations are the result of many factors such as geological condition,construction technology and ambient condition.The results indicate that the tunnel has a high self-supporting capability and that the reinforcement structure is strong.The analysis of rock deformation was used for the tunnel construction and satisfactory effects were obtained.