| Along with the blooming development of China’s economy, public’s requirement for the highway and railway infrastructures has also gradually increased.Transportation networks is improving and completing all over the country, and this has brought the focus of engineering constructions to regions with high latitude and altitude that have severe cold weather and harsh climate.Tunnels is a vital part of the transportation networks. Currently the damages caused by severe cold is a common harm for the existing highway and railway tunnels. These problems not only jeopardize the tunnel structure, but also hazard the safety and operation of transportation networks.Frost heaving, water leaking, icing, and trench freezing of tunnels have been troubling the construction and operation of China’s railway. Although previous researches have investigated the mechanism of tunnel’s cold damages, as well as the temperature field of wall rock and the calculation of heave force, the frost damage issue has not been solved fundamentally. With the improvement of technology and growing engineering experience, the need and wish of clarifying the mechanism of frost damages and eradicating the tunnel hazards have become increasingly urgent.Taking the frozen earth tunnels in areas with high altitude and extreme cold climate as the research background, this paper studied the cracking problem of tunnel lining caused by frost heaving. Applied with both the similarity model test and the numerical simulation analysis, the paper investigated a common lining cracking scenario that is caused by accumulated cavity water behind the tunnel lining, by which the water would freeze into ice and leads to frost heaving as the temperature drops.Based on the hypothesis of partially accumulated cavity water behind the lining,the paper used the similarity model test to simulate different locations of cavity water behind the lining, and studied the regularities of frost heaving for the arch’s vault, springing, the side wall, the foot of the wall, and the inverted arch.By using the ANSYS Finite Element Analysis software to further investigate the test, the paper analyzed and inducted the data results from the simulation test,and summarized the regularities of frost heaving force’s distribution at different cavity water locations.Freezing water expands behind the lining, tunnel lining as a whole will produce frost heaving forces, but heaving force values and the role of water in different positions generated by the location are not the same.In the heaving water barrier lining position suffered moment it is different, but the maximum effect of frost heave force generating position and a maximum position is consistent.The distribution of tunnel lining suffered frost heaving pressure and generating a moment about substantially similar symmetrical. Frost crack occurring position is generally produced in the form of cracks or surface frost heave force is maximum stress concentration to the main longitudinal cracks. Behind the lining of frozen product expansion is the main reason leading to the lining cracks. |
