Abstract Statistical analysis is conducted on the distribution of cracks in the secondary lining of the Anding Tunnel of the Yuxi-Mohan Railway, and a simulation method closer to the actual load is proposed to study the development law and control factors of cracks in the secondary lining. Orthogonal test is conducted to study the lining cracks under three levels of four factors (concrete strength grade, lining thickness, steel bar diameter, and protective layer thickness).The results indicate that the distribution of cracks in the lining on site shows that the cracks are mainly distributed at the arch foot and arch hance, secondarily at the crown, with fewer cracks at the spandrel, and the longitudinal cracks account for 63% and 18% and 19% for circumferential and slanting cracks, respectively. The occurrence order of damage to various parts of the lining is arch foot, crown, arch hance, and spandrel, while their degrees of crack development are sorted as follows: arch foot>arch hance>crown>spandrel. The influence degrees of secondary lining structural parameters on the width of arch foot crack are sorted as follows: concrete strength grade>protective layer thickness>lining thickness>steel bar diameter. As the factor level increases, the influence of concrete strength grade,lining thickness, and steel bar diameter gradually decreases, while the influence trend of lining thickness is opposite.
Abstract：
Statistical analysis is conducted on the distribution of cracks in the secondary lining of the Anding Tunnel of the Yuxi-Mohan Railway, and a simulation method closer to the actual load is proposed to study the development law and control factors of cracks in the secondary lining. Orthogonal test is conducted to study the lining cracks under three levels of four factors (concrete strength grade, lining thickness, steel bar diameter, and protective layer thickness).The results indicate that the distribution of cracks in the lining on site shows that the cracks are mainly distributed at the arch foot and arch hance, secondarily at the crown, with fewer cracks at the spandrel, and the longitudinal cracks account for 63% and 18% and 19% for circumferential and slanting cracks, respectively. The occurrence order of damage to various parts of the lining is arch foot, crown, arch hance, and spandrel, while their degrees of crack development are sorted as follows: arch foot>arch hance>crown>spandrel. The influence degrees of secondary lining structural parameters on the width of arch foot crack are sorted as follows: concrete strength grade>protective layer thickness>lining thickness>steel bar diameter. As the factor level increases, the influence of concrete strength grade,lining thickness, and steel bar diameter gradually decreases, while the influence trend of lining thickness is opposite.
ZHU Xingyu LIU Zheng ZHANG Zhiqiang FENG Ying
.Study on the Influence Law of Structural Design Parameters of the Railway Tunnel on Secondary Lining Cracks[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(5): 1-10
2023, Vol. 60 