Abstract:

The drainage at tunnel portal in cold region is easily frozen, and the ground water loss is serious. Hence, the drainage scheme of seepage well instead of traditional insulation outfalls is proposed for tunnel portal based on existing seepage well drainage system of highway subgrade and drainage experience. And then traditional seepage well structure is optimized considering to the special drainage structure in cold region and harsh natural conditions. Finally, three seepage well drainage schemes corresponding to different hydrogeological conditions are designed, and the setting parameters of every scheme and calculation formulas for structural size are given. The water percolates and flows to underground directly in the seepage well drainage system, which is superior to the traditional one in terms of water storage, green and environmental protection, and avoiding water frozen and evaporation.

Key words: cold region, tunnel portal drainage, seepage well drainage, green and environmental protection