基于“容积法”的海绵城市道路计算关键步骤分析及优化

摘要:

本研究针对基于容积法的海绵城市道路设计中两处不够完善的计算过程进行了分析,并根据分析结果对计算过程进行了优化和补充。改进后的容积法能够考虑：1)海绵城市设施下垫面对雨量径流系数的影响；和2)海绵城市设施服务范围对实际调蓄容积的影响。随后,本研究以某一城市主干路为案例,采用容积法及改进容积法分别对其进行了海绵城市调蓄容积的计算,结果显示：针对同一场地,通过改进容积法计算的年径流总量控制率小于常规容积法,常规容积法计算结果偏不安全。同时,改进容积法的计算通过强调分散式布置海绵城市设施,鼓励增大服务面积继而增大调蓄容积,从而提高年径流总量控制率,与海绵城市强调分散式源头控制的理论更加一致。

Abstract:

This paper discusses two key steps during the sponge city design based on the volumetric method and analyzes their corresponding influence on the results, and then improves theses two steps accordingly: the improved volumetric method (IVM) additionally consider: 1) the impact of the sponge city facilities on the rainfall runoff coefficient; and 2) the impact of the sponge city facility service area on the actual storage volume. Next, a case study of an arterial road is carried out based on original volumetric method (OVM) and IVM respectively. The results show that the total annual runoff control rate calculated by IVM is less than that of OVM. The IVM puts more emphasis on the decentralized layout of sponge city facilities, and increases the storage volume by increasing the service area and ultimately increases the total annual runoff control rate. IVM is more consistent with the sponge city’s principle: emphasizing on decentralized source control.