摘要
随着国家铁路大规模建设,所遇见的大埋深软岩隧道逐渐越来越多,而当前研究忽略软岩力学参数演变过程,导致分析与工程实际产生较大误差。本文以新乌鞘岭隧道为依托,通过试验得到3组三轴压缩试验数据,分析试验下三轴应力和应变软化对软岩的影响,提出综合考虑三轴应力和应变软化共同作用下软岩隧道的力学参数变化规律。结果表明:不同应力下的围岩力学参数值变化较大;试样的残余强度是峰值强度的64%,且塑性区与残余区的临界处塑性剪切应变为0.015 4;综合考虑三轴应力和应变软化共同作用下对软岩隧道的力学参数影响规律,更加接近当前施工时围岩的变化规律。
With the large-scale construction of the national railway,more and more deeply buried soft rock tunnels have been encountered.However,the current research ignores the evolution process of soft rock mechanical parameters,resulting in a large error between the analysis and the actual engineering.Based on the new Wushaoling Tunnel,three sets of triaxial compression test data are obtained through the test,the influence of triaxial stress and strain softening on soft rock under the test is analyzed,and the change law of mechanical parameters of soft rock tunnel under the combined consideration of triaxial stress and strain softening is proposed.The results indicate that the mechanical parameters of surrounding rock vary greatly under different stresses.The average residual strength of the sample is 64%of the average peak strength,and the plastic shear strain at the critical point between the plastic zone and the residual zone is 0.0154.The comprehensive consideration of the combined effects of triaxial stress and strain softening on the mechanical parameters of soft rock tunnels is closer to the variation law of surrounding rock during current construction.
作者
李赛
LI Sai(China Railway Fifth Survey and Design Institute Group Co.Ltd.,Beijing 102600,China)
出处
《铁道建筑技术》
2023年第9期114-118,共5页
Railway Construction Technology
基金
国家自然基金面上项目(52178391)。
关键词
软岩隧道
应力
应变软化
三轴试验
soft rock tunnel
stress
strain softening
triaxial test
