Reliability Analysis of Grate Inlets

Street inlet is a drainage structure with an opening used to collect stormwater runoff
from the street pavement and discharge it into a stormwater drainage system. In
Malaysia, urbanization has led to the use of concrete structures and pavement which
reduce the infiltration rate of stormwater into the ground. During a high stormwater
event, the street inlet fails to intercept the water and lead to street ponding. This
research is conducted to investigate the hydraulic efficiency of three grate inlet
designs used in Malaysia and develop a reliability model to determine the probability
of failure of the grate inlets. In this experimental study, a full scale of half way
roadway flume was used to simulate flows of the stormwater into the grate inlets.
The efficiency of each grate inlets was analysed at different approaching flows.
Results showed that the ability of each inlet to capture and intercept the flow is
varies, thus resulting in different hydraulic efficiency.