CUI Zhong-jie,QING Xiao-xia.Calculation Method for Inlet Setting of Road Grass Swale[J].China Water & Wastewater,2021,37(20 20):0.
Calculation Method for Inlet Setting of Road Grass Swale
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第37卷
Number:
20 20
Page:
0
Column:
Date of publication:
2021-10-17
- Abstract:
- The current design code in China lacks a systematic design and calculation method for inlet setting of road grass swales. Calculation formula of inlet width was proposed by using the Urban Drainage Standards Manual of the United States for reference. When the rejection rate was determined, the calculated inlet width should be restricted by the maximum design flow of the grass swale. Based on the method of calculating the spacing of gutter inlet, the formula of calculating the spacing of inlet was proposed, and influence of road longitudinal slope on relevant parameter values in the formula was clarified. Based on hydraulic calculation method, a method for calculating the inlet angle of the road grass swale was put forward. The calculation results showed that the inlet angle would decrease gradually with the increase of the longitudinal slope of the road. Based on Fluent software, the two-dimensional hydraulic characteristics of the inlet were simulated. Compared with traditional rectangular openings, openings with the calculated angular could improve the hydraulic conditions at the inlet. The inlet flow velocity increased to about 1.4 times, which significantly improved the water collecting capacity of the grass swale. In addition, the internal flow velocity decreased by about 30%, which reduced the influence of influent on scouring of plants and soil in the grass swale.
Last Update:
2021-10-17