摘要
研究目的:西南地区某双线公路隧道下穿水电站既有引水隧洞,施工风险高。本文以此为工程背景,首先对其开展风险分析,并提出可能的应对措施,在此基础上,针对重点风险,采用LS-DYNA研究引水隧洞在不同围岩等级、不同间距下公路隧道爆破施工的振动影响规律,分析不同支护方案下既有引水隧洞的不均匀沉降变形规律,进一步采用扩展有限元揭示引水隧洞的裂缝扩展机制和展布形态。研究结论:(1)围岩级别越高、间距越小,结构振动响应越大;(2)现有间距37 m,公路隧道钻爆施工引起的引水隧洞振动速度峰值不满足规范要求;(3)公路隧道下穿造成引水隧洞产生不均匀沉降,沉降过大时会引起引水隧洞产生环向张开裂缝;(4)双层小导管超前支护和深孔全断面预注浆可以有效控制不均匀沉降,使引水隧洞不会产生裂缝;(5)本研究成果可为隧道下穿引水隧洞的工程设计和实施提供新思路。
Research purposes:A double-line highway tunnel in Southwest China runs through the existing diversion tunnel of the hydropower station with high construction risk.First of all,risk analysis is carried out and possible countermeasures are put forward.On this basis,aiming at the key risks,LS-DYNA is used to study the vibration influence law of the road tunnel blasting construction under different surrounding rock levels and different spacing,the uneven settlement and deformation law of the existing diversion tunnel under different support schemes is analyzed,and the crack propagation mechanism and distribution pattern of the diversion tunnel are further revealed by the extended finite element method.Research conclusions:(1)The higher the level of surrounding rock and the smaller the spacing,the greater the structural vibration response.(2)The existing spacing is 37 m,and the peak vibration velocity of the diversion tunnel caused by highway tunnel drilling and blasting construction does not meet the requirements of the specification.(3)The underpass of the highway tunnel causes uneven settlement of the diversion tunnel.When the settlement is too large,it will cause the diversion tunnel to produce circular opening cracks.(4)The double-layer small pipe advance support and deep hole full-face pre-grouting can effectively control the unevenness subsidence,and the diversion tunnel will not produce cracks.(5)The research results can provide new ideas for the engineering design and implementation of the tunnel underpassing the diversion tunnel.
作者
刘德军
仲飞
胡群芳
姚小云
王飞
张杨
LIU Dejun;ZHONG Fei;HU Qunfang;YAO Xiaoyun;WANG Fei;ZHANG Yang(China University of Mining and Technology,Beijing 100088,China;Shanghai Institute of Disaster Prevention and Relief,Tongji University,Shanghai 200092,China)
出处
《铁道工程学报》
EI
北大核心
2021年第3期65-71,共7页
Journal of Railway Engineering Society
基金
国家自然科学基金项目(51878658,51508584)
同济大学岩土及地下工程教育部重点实验室开放基金项目(KLE-TJGE-B1705)
中国矿业大学(北京)越崎杰出学者奖励计划资助。
关键词
下穿
引水隧洞
爆破振动
裂缝扩展
扩展有限元
underpass
diversion tunnel
blasting vibration
crack extension
extended finite element method
