15 December 2014

Better protection against floods

Hurricanes are devastating. Aside from the high, sustained wind speeds, they usually bring with them heavy rain, which can quickly lead to the breaching of flood defences in susceptible areas. Now, US and UK researchers have reviewed hurricane flood defence barriers and technologies with a view to helping engineers find improved designs.

Writing in the International Journal of Forensic Engineering, Haijian Shi of Pepco Holdings in Washington DC and Kong Fah Tee of the Department of Civil Engineering, at the University of Greenwich, in Kent, UK, explain that barriers can protect property and save lives during hurricane season. Flood walls, gates and joints are the mainstays of their design, however budgetary constraints, geographical limitations and constructability often limit the implementation of the most effective barriers in some regions.

The team has surveyed the T-walls, I-walls, Pile-braced wall systems, sluice gates, and sector gates that are commonly used in hurricane flood defences. From their analysis of the civil engineering and construction of these defences, the team has devised a six-point checklist for the design of hurricane defences that should be implemented to make the most effective barrier. These six factors should be considered when designing and constructing hurricane defences: seepage analysis, global stability, short-term and long-term settlement (or subsidence), soil structure interaction, fluid structure interaction, durability.

“Hurricane protection barriers can be effective in preventing surging water from breaching and flooding cities,” the team reports. “They can also mitigate erosion to the shore and thereby can help maintain the stability of the shore.” An optimised and informed approach to the engineering of these defences can make vulnerable sites much safer within the budgetary and geographical constraints of a given coastal region.

Shi, H. and Tee, K.F. (2014) ‘Review of design and construction of hurricane protection barriers’, Int. J. Forensic Engineering, Vol. 2, No. 2, pp.144–151.

Better protection against floods is a post from: David Bradley's Science Spot

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