Hydraulic Performance of Vertically Depressed And Non-Depressed Grate

ABSTRACT

Traffic loads, environmental and aging process, erosion and settlement of road shoulders, and overlaid carriageways, are some of the possible causes of vertical depression (occur unintentionally) of grated inlets. Presently, no studies have been conducted to establish the effects of vertical depression on the efficiency of grated inlets in Malaysia. This study attempts to improve the understanding and the impact of vertical depression on the hydraulic characteristics of gully grates. It also attempts to establish empirical equations describing the relationship of relevant parameters, such as hydraulic efficiency and Froude number. A full scaled physical model was constructed to replicate the actual condition on site. The site studied is located 500 m from the exit of Bandar Baharu toll, Kedah (Malaysia) that is approximately 9.8 km from Universiti Sains Malaysia, Engineering Campus. Experimental results showed that vertical depression reduces the hydraulic efficiency by 6% to 10% for a 20 mm depressed single grate.

KEYWORDS:

• Gully grates
• gully inlets
• vertical depressed grates
• efficiency
• urban drainage

Acknowledgements

The authors would like to acknowledge and thank Universiti Sains Malaysia which has provided financial support [Short Term Grant no: 304.PAWAM.60313050] for their continuous cooperation in supporting this research.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Universiti Sains Malaysia Short Term Grant [304.PAWAM.60313050] and Malaysia Research Universiti Network (MRUN) Grant [Grant no:203/PAWAM/67216002].