Influence study on the mining tunnel line cracks by vibration of metro train

Because test work on site is difficult, it was rarely report about influence study on operation metro tunnel lining crack by train vibration. By test work on site, this text study the influence rule of lining crack by train vibration cyclic loading, which analyze form dynamic strain and vibration acceleration, it focus test vibration performance of tunnel whole section. This study concludes as follows: when the train passed test section, dynamic strain amplitude of tunnel vault is less than dynamic strain amplitude of tunnel sidewall, the discrepancy amplitude is about 15%. Lining crack show the non-continuum characteristics by train vibration, which crack shows instantaneous tensile phenomenon and do not rebound into original width size. The tear function on lining crack made crack width and depth continuous development. Vertical vibration of tunnel sidewall is greater than vertical vibration of tunnel vault, and vertical vibration of tunnel vault is greater than vertical vibration of tunnel haunch. The tear function on tunnel lining crack cause by train vibration mainly focus on frequency band of 50Hz, 350Hz, 480Hz, 650Hz, 720Hz. Therefore, if want to decrease influence on tunnel lining crack by train vibration, it need use corresponding vibration reduction measures to decrease vibration quantity from above frequency band. ©, 2015, Editorial Office of China Civil Engineering Journal. All right reserved.