Natural Ventilation Capability of Ventilation Duct of Embankment in Permafrost Region

Aimed at duct-ventilated embankments in permafrost regions of Qinghai-Tibet Plateau,on-way friction resistance and local resistance losses in the ventilation duct system were analyzed using engineering fluid mechanics.Based on the driving force of natural ventilation in the ventilation duct system being equivalent to the wind pressure difference between two side slopes of embankment,the calculated formulae of wind velocity considering the on-way friction loss and local resistance loss in the ventilation duct system were gotten.The results show that ventilation capabilities of ventilation duct of various embankments can be calculated quickly by applying the formulae which are convenient to engineering application.Compared with the conventional duct-ventilated embankment,the duct-ventilated embankment installed self-windward vent in the inlet of ventilation is favourable to cool down the embankment and underlying foundation soil.