摘要
深埋圆形隧道的开挖支护是与时间相关的复杂力学过程。为了描述这一过程,假设隧道围岩为Burgers体与Drucker-Prager准则组合的黏弹塑性模型。隧道开挖支护完成瞬时围岩表现为弹塑性,此时考虑中主应力的影响,推导出原岩应力和支护反力共同作用下的应力场;随后,假设此应力场保持不变,隧道围岩表现出随时间变化的蠕变性能,进一步推导出深埋圆形隧道考虑剪胀性能的围岩蠕变位移解析式;结合实际算例,分析围岩剪胀角与支护反力对深埋圆形隧道围岩蠕变位移的影响规律。结果表明,剪胀角的变化会对隧道围岩蠕变位移产生较大影响,而支护反力并不能完全控制高地应力作用下的深埋隧道围岩位移随时间的持续增加。
The excavation and supporting of a deep circular tunnel is a complex mechanical process related to time.To describe this process,the surrounding rock of the tunnel is supposed to a viscoelastoplastic combination model of a Burgers body and Drucker-Prager criterion.At the instant time that the excavation and supporting were finished,the surrounding rock of the tunnel performs as a elastoplastic material.Under this condition,the influence of intermediate principal stress was considered,and the stress field under the combined action of the primary rock stress and supporting force could be obtained.With the assumption of constant stress field,the surrounding rock exhibits creep properties of time-dependence.Furthermore,the analytical solution to the creep displacement of the surrounding rock was deduced considering shear dilatancy for the deep-buried circular tunnel.A practical engineering instance was given and the regularities that the supporting force and dilation angle of the surrounding rock affect the creep displacement in deep circular tunnel were analyzed.The results show that the change of dilation angle could produce significant influence on the creep displacement,while the supporting force could not completely control the sustained increase of displacement of the surrounding rock with time in the deep circular tunnel.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2012年第A02期3586-3592,共7页
Chinese Journal of Rock Mechanics and Engineering
基金
西部交通建设科技项目(2011318775680
2011318493720)
湖北省自然科学基金项目(Y024041F01)
关键词
隧道工程
黏弹塑性
中主应力
强度准则
剪胀
蠕变位移
支护反力
tunneling engineering
viscoelastoplasticity
intermediate principal stress
strength criterion
shear dilatancy
creep displacement
supporting force
