摘要
输水隧洞衬砌顶拱欠厚和局部预应力锚索失效在实际工程中可能会叠加出现,并对工程运行安全造成影响。以某大型输水隧洞为例,选取两个典型洞段,采用仿真技术研究顶拱欠厚条件下一束和两束锚索失效对应力状态的影响。结果显示:顶拱欠厚和锚索失效会对局部区域产生影响,环向为欠厚范围内,纵向为锚索布设间距内;个别锚索失效不会使洞段环向应力大幅度降低,但可能导致顶拱内侧应力超标;内衬纵向应力在张拉阶段产生,充水影响不大;锚索补张拉会使环向压应力得到有效补偿,但纵向开裂将难以恢复;锚索失效部位外侧应力超标,可能导致混凝土开裂,应做好防渗工作。
The insufficient crown thickness of the tunnel lining and the failure of the local prestressed anchor cable may be superimposed in the actual project,which will affect the safety of the project operation.In this paper,a A large water conveyance tunnel is taken as an example.The linings of two tunnel sections with different degrees of insufficient crown thickness are selected.The finite element simulation is used to study the influence of the failure of one and two anchor cables on the stress state under insufficient crown thickness.The simulation result show that the crown thickness and the failure of the anchor cable will affect the local area.The circumferential direction is within the insufficient crown thickness range and the longitudinal direction is within the spacing of the anchor cable.The failure of individual anchor cables will not greatly reduce the circumferential stress of the tunnel section,but the internal water pressure may lead to excessive stress inside the top arch and concrete cracking.The longitudinal stress of the lining is generated in the tension stage,and the water filling has little effect.The tension of anchor cable will effectively compensate the circumferential compressive stress,but it will be difficult to recover once the longitudinal crack occurs.The external stress of the anchor cable failure site exceeds the standard,which may lead to concrete cracking,and the anti-seepage work should be done well.
作者
周秋景
胡银涛
张国盛
李建波
程恒
ZHOU Qiujing;HU Yintao;ZHANG Guosheng;LI Jianbo;CHENG Heng(China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Engineering Construction Branch,Qinghai Huanghe Hydropower Development Co.,Ltd.,Xining 810000,Qinghai,China)
出处
《水利水电技术（中英文）》
北大核心
2023年第S01期129-136,共8页
Water Resources and Hydropower Engineering
基金
国家重点研发计划项目(2021YFC3090102)。
关键词
隧洞衬砌
预应力锚索
仿真技术
应力分析
欠厚
tunnel lining
Prestressed anchor cables
simulation
stress analysis
insufficient crown thickness
