摘要
基于某公路隧道Ⅴ级围岩区段三台阶法开挖项目,采用有限差分软件FLAC3D构建地层-隧道结构模型,分析隧道不同开挖阶段的围岩主应力场、竖向位移场、塑性区,基于数值模拟结果,结合模拟结果采用正交试验分析法,对围岩稳定性影响因素进行敏感性分析及排序。结果表明:随台阶分步开挖,围岩拱脚逐渐出现应力集中,拱顶沉降主要发生于上台阶开挖阶段,拱脚、拱肩塑性区向深部发展;为提高开挖稳定性,建议减小上台阶高度、提高中下台阶高度,以保证开挖稳定性,可调整为上台阶3.1 m、中台阶3.4 m、下台阶3.4 m;通过极方差分析,得出稳定性影响因素敏感性排序为弹性模量、黏聚力、泊松比、内摩擦角。
Based on an excavation project with three-step method ofⅤlevel surrounding rock section of a highway tunnel,the finite-difference software FLAC3D was used to build a strata-structure model to analyze the main stress field,vertical displacement field and plastic zone of the surrounding rock at different excavation stages of the tunnel.Combined with the simulation results,the sensitivity analysis and sorting of the factors affecting the stability of the surrounding rock were carried out by orthogonal test analysis.The results show that with step excavation,stress concentration gradually occurs at the arch foot of surrounding rock,the arch roof settlement mainly occurs at the excavation stage of the upper step,and the plastic zone of arch foot and spandrel develops to the depth.It is recommended to reduce the height of the upper step and raise the height of the middle and lower steps,which can be adjusted to 3.1 m,3.4 m,and 3.4 m.Through the polar variance analysis,the sensitivity of the factors influencing stability was sorted as elastic modulus,cohesion,Poisson's ratio and internal friction angle.
作者
王旭阳
WANG Xuyang(The 4th Engineering Co.,Ltd.,China Railway 18th Bureau Group,Tianjin 300350,China)
出处
《路基工程》
2025年第4期207-212,共6页
Subgrade Engineering
