Field experiment Study on ventilation characteristics of block stones embankment in Qinghai-Tibet Railway

摘要

The forced convection in the blocky stone layer plays a major impact on the temperature field of embankment in Qinghai-Tibetan Plateau. Thus, a field test on air flow inside the blocky stone layer has been carried out to make clear the ventilation characteristics. The results show that pore-air velocity in embankment slope of following wide side is in well accordance with the external wind, and the temperature in sunny slope is higher than in shaded slope. The variation of velocity in sunny slope is larger than shade in summer, which is inverse in winter. The time of air flow through an embankment was calculated by the Bernoulli Equation, and the results show that the air can flow though the embankment in less than a minute, indicating the pore-air velocity in blocky stone layers is mainly inflected by atmospheric wind field and blocky stone layers have good ventilation ability. So, it is advisable to consider the ventilation ability in analyzing the temperature field of block stones.