摘要
保证掌子面的稳定是实现软弱围岩隧道机械化全断面施工的前提,合理的超前支护措施及参数是控制掌子面稳定性的有力手段。针对目前隧道超前支护设计方法不完善且多依赖于工程经验的现状,提出隧道超前支护体系定量化设计方法。基于经典楔形体模型,推导了考虑四种常用超前支护措施(掌子面喷混凝土、超前管棚、掌子面锚杆、掌子面预注浆)时掌子面稳定系数K的计算公式,提出了掌子面喷混凝土支护力P1、掌子面锚杆支护力P2、管棚支护下围岩压力折减系数α1、掌子面预注浆加固后围岩黏聚力增大系数α2的计算方法,制定了隧道超前支护体系设计流程,并以郑万高速铁路荣家湾隧道为背景验证了该计算方法的合理性。研究成果可以为软弱围岩隧道超前支护体系设计、优化提供理论支撑。
Ensuring the stability of the tunnel face is the precondition of realizing the mechanized full-face excavation of tunnel in soft surrounding rock,and reasonable advance support measures and parameters are powerful means to control the tunnel face stability.To address the current incomplete design method of advance support that mostly depends on engineering experience,a quantitative design method for the advance support system was proposed in this paper.Based on the classic wedge-prism model,the formulas for safety factor calculation of the tunnel face were derived,in which four advance support measures(i.e.,shotcrete,pipe roof,face bolt,and pre-grouting)were considered.Meanwhile,the calculation methods of shotcrete support force P1,reduction factorα1 of rock pressure under pipe roof,supporting force P2 of face bolts,cohesion increase factorα2 of surrounding rock after pre-grouting and the design flow of advance support system were proposed.In addition,the rationality of the calculation method was validated against the case of the Rongjiawan Tunnel on Zhengzhou-Wanzhou High-speed Railway.The proposed model can provide theoretical support for the design and optimization of the advance support system of a tunnel in soft and weak surrounding rock.
作者
王明年
张霄
赵思光
王志龙
刘大刚
童建军
WANG Mingnian;ZHANG Xiao;ZHAO Siguang;WANG Zhilong;LIU Dagang;TONG Jianjun(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotoug University,Chengdu 610031,China;School of Civil Engineering,Southwest Jiaotoug University,Chengdu 610031,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2020年第8期146-154,共9页
Journal of the China Railway Society
基金
中国铁路总公司科技研究开发计划(2017G007-H,2017G007-F,K2018G014)
国家自然科学基金(51878567,51878568)。
