花岗岩中深埋隧道扰动区应力测试与分析

Measurement and Analysis of Disturbed Zone Stress in Granite of a Deep Tunnel

在深埋隧道施工过程中,掌子面推进将引起围岩内部应力的重新分布,洞壁附近围岩处于扰动状态,确定扰动区应力对于深埋隧道结构设计和安全施工有着极为重要的作用。在阐述扰动区应力主要测试方法的基础上,使用钻孔式测试方法得到了某深埋隧道花岗岩围岩中扰动区应力及其随时间的变化过程,提出了使用双曲线拟合确定扰动区应力测试稳定值对应时刻的方法,研究了水平方向和垂直方向扰动区应力测试稳定值的分布特征。结果表明,与其他扰动区应力测试方法相比,钻孔式测试方法具有快捷、方便、实用的特点,可用于确定深埋隧道围岩扰动区应力。

During the construction of a deep tunnel,the stresses in surrounding rocks will be redistributed due to the pushing of the tunnel wall while the stresses in wall rocks reach to a disturbed state.Therefore,it is quite important to determine the disturbed zone stress for the design and construction of the deep tunnel.After discussing the features of various techniques used in the measurement of disturbed zone stresses,the borehole measurement technique was used to determine the magnitude and the change with time of the disturbed field stresses in the granite of the deep tunnel.The technique for estimating the detected stable instant of disturbed zone stresses was then proposed by the use of the hyperbolic fitting method.The distribution features of the measured stable disturbed zone stresses in the horizontal and vertical directions were thereafter analyzed.The results show that compared with other methods,the borehole measurement technique is more quick,convenient and feasible,and especially suitable to measure disturbed field stresses in deep tunnels.