柴达木盆地沙漠公路设计流量公式研究

在中国水文分区中,沙漠地区一般被划分为非产流区,在公路设计中仅设置少量桥涵来满足路基、路面的排水要求,而不考虑洪峰流量,对非产流区也不提供设计流量公式。然而,在青海省柴达木盆地几条沙漠公路的实际运营中,却发现路基水毁频繁,经济损失严重。针对这种特殊水文现象,我们从设计理念、路基填料、暴雨、植被覆盖度等几个方面分析了水毁原因,发现暴雨是引发水毁的主要外因。因此将2012年最新的青海省公路系统柴达木区流量公式与两种小流域暴雨流量公式进行计算比较,通过分析计算偏差,对柴达木区流量公式进行了适度修正,最终得到能满足公路测量设计要求的柴达木盆地沙漠公路设计流量公式。

Research on Design of Discharge Formula for the Qaidam Desert Highway

According to the current domestic study of the hydrological regionalization, desert regions generally is divided into non-flow producing area and only a small amount of bridge and culvert is set to meet the basic requirements of roadbed drainage, the peak flow is not considered in bridge design and flow formula are not provided for the non-flow producing area. However, we found that roadbed of several highways in Qaidam Desert of Qinghai province designed with this concept has been encountering damage by flood frequently, which led to severely economic loss. We carefully analyzed the design concept, subgrade filling, storm and the vegetation coverage and found that storm was the main external factor which caused water damage. By comparing with the latest Qaidam flow formula in 2012 and two other domestic small watershed rainstorm flow formula, the Qaidam flow formulae was modified. Finally, we got a set of flow formula which may meet highway survey and design requirements in the Qaidam Desert.