Frost heaving force computational model of tunnel with frozen rock containing #br#
fissures and rock- hydraulic- ice pressure in situ test in cold region
Yan Jian1,2 He Chuan1 Zhou Zihan1 Kou Hao1 Ma Gaoyu1
1. MOE Key Laboratory of Transportation Tunnel Engineering, Southwest Jiaotong University, Chengdu 610031, China；
2. School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031,China
Abstract：To investigate the frost heaving force and build a reasonable calculation model of the fractured rock tunnel in the cold region, taking the Queer shan tunnel in the project of North line of Sichuan-Tibet highway as a case study, the water pressure gauge, the soil pressure box and the multi-points platinum resistance temperature sensor was carried out to test the frost heave force in situ. Considering the hydrostatic pressure, a theoretical model of the frost heaving force in a circular crack tunnel is proposed at the macro level. Finally, the calculation results are compared with the in-situ test results. The results show that the in-situ measurement for frost heaving force is reasonable and easy to implement,owing to considering the rock-water-ice in freezing process along with the change of time and temperature characteristics and avoid the discussion on the fractured rock mesoscopic structure model. And the water pressure test shows that the hydrostatic pressure decreases linearly with the increase of radial depth before freezing of fractured rock, and the water in the cracks is forced out and and formed a pressurized zone in the surrounding rock with radial direction of 1.5-2m. Meanwhile,the hydrostatic pressure is decreases significantly and to the minimum near the structure. The frost heaving pressure is 0.615～3.355MPa by the in-situ measured ,with the smallest at the vault and the largest at the hance. The frost-heaving pressure is about 0.46MPa calculated by the theoretical model. Therefore, after removing the water pressure, the calculation results by the theoretical model of the macro frost heaving force of the circular crack are close to the engineering practice.
严健 何川 周子寒 寇昊 马杲宇. 寒区裂隙冻岩隧道岩-水-冰力原位测试及冻胀力模型[J]. 土木工程学报, 2020, 53(S1): 300-305, 311.
Yan Jian He Chuan Zhou Zihan Kou Hao Ma Gaoyu. Frost heaving force computational model of tunnel with frozen rock containing #br#
fissures and rock- hydraulic- ice pressure in situ test in cold region. 土木工程学报, 2020, 53(S1): 300-305, 311.
