摘要
针对衬砌裂缝在列车荷载影响下的疲劳扩展行为,以疲劳断裂力学和可靠性理论为基础,对开裂衬砌裂缝的疲劳扩展可靠性进行研究。首先,分析衬砌开裂模式及影响裂缝扩展的应力强度因子类型,基于Paris公式建立基于裂缝深度的衬砌极限状态方程;然后,依托某运营铁路隧道,利用ANSYS有限元软件建立含开裂衬砌隧道-地层耦合动力的数值模型,计算列车荷载影响下的裂缝尖端应力场和应力强度因子,运用蒙特卡洛法求解不同深度裂缝在衬砌服役期内的可靠性指标。结果表明:列车荷载对裂缝尖端应力场影响显著,当隧道拱顶存在10 cm裂缝且不考虑列车荷载时,拱顶衬砌裂缝尖端最大主应力为-3.47 MPa,而考虑列车荷载后则为-7.26 MPa;不同初始裂缝条件下,裂缝尖端应力强度因子幅值不拒绝服从正态分布规律,其均值和标准差随裂缝深度的增加而增大;开裂衬砌可靠性指标会随服役时间的增加而降低,且初始裂缝深度越大,衬砌的可靠性指标值越小、服役时间越短。
In view of the fatigue propagation behavior of lining cracks under the influence of train load,the fatigue propagation reliability of cracked lining cracks was studied based on fatigue fracture mechanics and reliability theory.Firstly,the cracking mode of lining and the type of stress intensity factors affecting crack propagation were analyzed,and in accordance with the Paris formula,the limit state equation of lining based on the crack depth was established.Then,on the basis of an operating railway tunnel,the ANSYS finite element software was used to establish the numerical model of tunnel-ground coupled dynamic with cracked lining.The stress field and stress intensity factor at the crack tip under the influence of train load were calculated,and the reliability indexes of cracks with different depths during the service life of lining were solved through the Monte Carlo method.The results show that the train load has a significant effect on the stress field at the crack tip.When there is a 10 cm crack in the vault and the train load is not considered,the maximum principal stress at the crack tip of the vault lining is-3.47 MPa,whereas when the train load is considered,it is-7.26 MPa.The amplitudes of stress intensity factors at the crack tip do not refuse to obey the normal distribution law under different initial crack conditions,and their mean value and standard deviation increase with the increase of the crack depth.The reliability index of cracked lining decreases with the longer of service time,and the greater the initial crack depth,the smaller the lining reliability index and the shorter the service time.
作者
王大鹏
王景春
张先萌
张振波
徐强
WANG Dapeng;WANG Jingchun;ZHANG Xianmeng;ZHANG Zhenbo;XU Qiang(School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang Hebei 050043,China;School of Safety Engineering and Emergency Management,Shijiazhuang Tiedao University,Shijiazhuang Hebei 050043,China)
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2023年第6期95-102,共8页
China Railway Science
基金
国家自然科学基金资助项目(51608336)
河北省教育厅在读研究生创新能力培养资助项目(CXZZBS2022120)。
关键词
隧道
开裂衬砌
疲劳扩展
列车荷载
可靠性分析
Tunnel
Cracked lining
Fatigue propagation
Train load
Reliability analysis
