基于气动效应的特长隧道断面优化探讨

铁路隧道净空面积的确定，不仅应考虑隧道建筑限界和机车车辆限界，还要考虑列车通过隧道时诱发的空气动力学效应。基于一维、可压缩、非定常的流动假设，推导得到车内瞬变压力、洞口微气压波和空气阻力计算公式，并结合这3个指标对现有城际铁路、高速铁路隧道设计规范进行论证和优化。结果表明： 针对大于10 km的特长隧道，在一定长度范围内，且在提高列车密封水平、增加洞口微气压波缓冲结构的情况下，可对特长隧道净空断面进行优化。

Optimization of Cross section of Extra long Tunnel Based on Aerodynamic Effect

Apart from the construction clearance and the rolling stock clearance, aerodynamic effects should also be considered in the determination of railway tunnel cross section. In this paper, the formulas of transient pressure in train, micro pressure wave and air resistance are obtained based on assumption of one dimensional, compressible and unsteady flow. According to the indices of transient pressure in train, micro pressure wave and air resistance, the existing design codes of inter city and high speed railways are demonstrated and optimized. The results show that the cross section of an extra long tunnel(more than 10 km) can be improved under the conditions of a certain length, seal level improvement of train and microbarometric wave buffer structure at tunnel portal.