WAVE-BASIN STUDY OF RUNUP ON BEACHES FROM SIMULATED UNDERWATER EXPLOSIONS NEAR SHORE.
Final rept. Apr 64-May 68,
NAVAL CIVIL ENGINEERING LAB PORT HUENEME CALIF
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Laboratory data are presented for the runup on a uniform slope of the leading waves of an axially symmetric, dispersive train of surface gravity waves. The waves emanated from an impulsive disturbance, simulating an underwater explosion. A significant aspect of the test conditions was the limited dispersion of the wave train, resulting from the relatively short propagation distance and the relatively large area covered by the wave-generating disturbance. Two general classes of wave trains were studied, distinguished by an initial rise of the water surface a crest at the front of the wave train in one case and an initial fall trough in the other. In both cases, the first wave in the wave train produced the greatest runup. The dominance of the first wave was more marked in the larger disturbances higher waves. The more important leading-crest case simulated an explosion of the shallow-water type. This type is expected from explosions of large but not unrealistic magnitude in relatively shallow coastal waters. On a 114 slope, the leading crest did not break and the ratio of runup to wave height was constant 3.3 for ratios of wave height to water depth at the toe of the slope Hd sub o varying from 0.003 to 0.073. On a 120 slope, the leading crest broke with Hd sub o greater than 0.035 the runup of nonbreaking leading crests was 5 to 25 less than on the 114 slope, and breaking decreased the runup still further. Author
- Physical and Dynamic Oceanography