Dalian 2005

alian Summer Research Program 2005

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Sophie Johnson

University of Virginia

Civil Engineering

Chattanooga, Tennessee

E-mail: sophie@virginia.edu

Topic: Experimental Study of Beach Profile Changes Induced by Waves

Mentor: Zou Zhili

Abstract

This paper presents an experimental study that seeks to further the understanding of how time varying wave forcing can shape a nearshore region and, in particular, create alongshore uniform sandbars. Regular waves, irregular waves, and wave groups were tested in a 58m long wave flume with a moveable bed. Correlations between the wave heights and the locations of sand bars, when present, were analyzed. Three different regular waves and one wave group formed fairly symmetrical, well defined sandbars. The location of these sandbars moved further from the shoreline as the waves broke further out with larger waves. The six irregular waves tested formed berms right past the still water level. Irregular waves with periods greater than 1.2seconds formed very wide sandbars. Different irregular waves than the ones tested would be necessary in order to create alongshore sandbars. Ripples were also created during tests, and the length and height seemed in increase as the water became shallower.