Calculation of Frost Heave Force and Analysis of Frost Heave Mechanism Induced by Water Accumulation in Voids behind Tunnel Lining in Cold-regions
This study investigates the issues of lining cracking and spalling caused by frost heave of accumulated water in voids behind lining in cold-region tunnels.Theoretical research on the calculation of frost heave force of accumu-lated water in voids behind tunnel lining was conducted.By introducing a frost heave force calculation model that ac-counts for drainage conditions,the freezing process of accumulated water in circular wedge-shaped voids under tem-perature fluctuations was analyzed,and the mechanism of frost heave force formation was revealed.The results show that the frost heave force increases with the height of the void but changes insignificantly with the void length.For voids outside the waterproof layer,the drainage coefficient is 0,and no frost heave force is generated during freezing.For voids inside the waterproof layer,when the drainage channel freezes first(drainage coefficient=1),the closer the drainage channel is to the bottom of the void,the larger the drainage coefficient and the bigger the frost heave force in the void.Freezing of water in the void begins at the thinnest edge and progresses toward thicker regions of the void.Under daily cyclic temperature fluctuations,the melting process of ice in the void is homology to the freezing process,that is,the phenomenon of freezing and thrawing first.Under daily periodic fluctuations,the freeze-thaw and water recharge-freeze processes in voids inside the waterproof layer lead to a gradual increase in frost heave force.
Cold-region tunnelsWater accumulation in voidsFrost heave forceDrainage conditions
万方数据
维普
