摘要
为解决高地温隧道衬砌结构受力特性不明晰问题,以川藏线桑珠岭超高地温隧道为工程依托,采用现场试验和热-力耦合数值计算手段,研究二次衬砌在高地温环境下的力学特性和安全特性,提出高地温隧道荷载设计方法。结果表明:高地温隧道二次衬砌施作后10 d内应力变化较大,20 d后趋于稳定;最大拉应力位于拱顶处,最大压应力出现在边墙处;高地温隧道荷载修正系数可表示为围岩初始温度的多项式关系;衬砌内外侧压应力均随围岩温度升高呈现出增大趋势,但各点增大速率存在一定的差异,拉应力值随温度呈波动增长;最小安全系数出现在拱顶,随围岩温度的升高而降低,当温度高于60℃时,存在被破坏的可能性;二次衬砌最大裂缝宽度位于拱顶处,随着温度升高,裂缝宽度增大。
At present,the mechanical characteristics of lining structure of high geothermal tunnel are not clear.The field test and thermal-mechanical coupling numerical simulation are carried out to study the mechanical properties and the safety characteristics of secondary lining under high geothermal environment of Sangzhuling Tunnel on Sichuan-Tibet Railway.Meanwhile,the load design for high geothermal tunnel is proposed.The results show that:(1)The stress of secondary lining varies rapidly in 10 days and becomes stable after 20 days.(2)The maximum tensile stress locates at crown,while the maximum compressive stress appears at sidewall.(3)The load correction coefficient of high geothermal tunnel can be expressed as the polynomial relationship of the initial temperature of surrounding rock.(3)The stress of secondary lining shows an increasing trend with the increase of the surrounding rock temperature,but there is a difference in the rate of increase at each point;the tensile stress fluctuates with the temperature.(4)The minimum safety factor appears at crown and decreases with increasing temperature of the surrounding rock;when the temperature is higher than 60°C,there is a possibility of damage.(5)The maximum crack width locates at the crown,and it increases as the temperature increase.
作者
王明年
王奇灵
胡云鹏
王翊丞
刘大刚
WANG Mingnian;WANG Qiling;HU Yunpeng;WANG Yicheng;LIU Dagang(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,Sichuan,China;Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,Sichuan,China)
出处
《隧道建设（中英文）》
北大核心
2019年第11期1769-1780,共12页
Tunnel Construction
基金
国家自然科学基金(51578458,51878567)
中国铁路总公司科技研究开发计划课题(2017G006-B)
关键词
高地温隧道
二次衬砌
荷载模式
受力特性
安全特性
high geothermal tunnel
secondary lining
load mode
mechanical characteristics
safety characteristics
