Conference Agenda

Urban flooding due to climate change-induced abnormal rainfall has caused recurring global damage, including in South Korea. One of the potential casualty causes is the dislodgement of manhole covers occurred by the lift of air-water mixture like geyser. To address this, the government mandated the installation of manhole fall prevention frames; however, it is hard to find standard designs or guidelines for such frames in the literature. This study utilized CFD to conduct four simulations based on flow rates from rainfall, ranging from minimum overflow conditions to extreme rainfall scenarios. Through these simulations, conditions were differentiated between manhole backflow causing the cover to open and a continuously closed state. These assumed conditions were then applied to different types of manhole fall prevention frames, where numerical analysis was performed to evaluate the stability and performance of each design. The results revealed that impact forces significantly increase under high-intensity rainfall, emphasizing the need for robust frame designs. This study recommends setting a minimum strength threshold of 4 kN to ensure the frame's reliability even under extreme conditions, such as an hourly rainfall of 60 mm. These findings provide critical insights for standardizing fall prevention frame designs and mitigating climate changerelated risks.