Effectiveness of Small Onshore Seawall in Reducing Forces Induced by Tsunami Bore: Large Scale Experimental Study
Mary Elizabeth Oshnack*, Francisco Aguíñiga**, Daniel Cox*, Rakesh Gupta*, and John van de Lindt***
*Oregon State University, Corvallis, Oregon 97331-3212, USA
**Texas A&M University-Kingsville, Kingsville, Texas 78363-8203, USA
***Colorado State University, Fort Collins, CO 80523-1372, USA
Tsunami force and pressure distributions on a rigid wall fronted by a small seawall were determined experimentally in a large-scale wave flume. Six different seawall heights were examined, two of which were exposed to a range of solitary wave heights. The same experiment was done without a seawall for comparison. The measured wave profile contained incident offshore, incident broken, reflected broken, and transmitted wave heights measured using wire resistance and ultrasonic wave gauges. Small individual seawalls increased reflection of the incoming broken bore front and reduced force on the rigid landward wall. These findings agree well with published field reconnaissance on small seawalls in Thailand that showed a correlation between seawalls and reduced damage on landward structures.
-  T. Arikawa, “Behaviors of concrete walls under impulsive tsunami load,” Proc. International Conference on Coastal Engineering, American Society of Civil Engineers, 2008 (in press).
-  American Society of Civil Engineers (ASCE), “Minimum Design Loads for Buildings and Other Structures,” ASCE Standard ASCE 7-06, 2006.
-  T. E. Baldock, D. Cox, T. Maddux, J. Killian, and L. Fayler, L. “Kinematics of breaking tsunami wavefronts: A data set from large scale laboratory experiments,” Coastal Engineering, Vol.56, pp. 506-516, 2008.
-  CCH 2003 Department of Planning and Permitting of Honolulu Hawaii, “City and County of Honolulu Building Code,” Chapter 16 Article 11. July, 2003.
-  R. A. Dalrymple and D. L. Kriebel, “Lessons in Engineering from the Tsunami in Thailand,” The Bridge, National Academy of Engineering, Vol.35, pp. 4-16, 2005.
-  Federal Emergency Management Agency (FEMA), “Coastal Construction Manual,” (FEMA 55), Federal Emergency Management Agency, 2000.
-  IBC 2003 International Code Council, INC. “International Building Code 2003,” Country Club Hills, IL, 2002.
-  P. Lukkunaprasit and A. Ruangrassamee, “Building Damage in Thailand in the 2004 Indian Ocean Tsunami and Clues for Tsunami-Resistant Design,” The IES Journal Part A: Civil and Structural Engineering, Vol.1 No.1, pp. 17-30, 2008.
-  D. H. Peregrine, “Water-Wave Impact on Walls.” Annual Review of Fluid Mechanics,” Vol.35, pp. 23-43, 2003.
-  A. Pomonis, T. Rossetto, N. Peiris, S. Wilkinson, D. Del Re, R. Koo, R. Manlapig, and S. Gallocher, “The Indian Ocean Tsunami of 26 December 2004: Mission Findings in Sri Lanka and Thailand,” United Kingdom: Institution of Structural Engineers, 2006.
-  Ramsden, “Forces on a Vertical Wall Due to Long Waves, Bores, and Dry-Bed Surges,” Journal of Waterway, Port, Coastal, and Ocean Engineering, ASCE, Vol.122, No.3, pp. 134-141, May-June 1996.
-  A. Ruangrassamee, H. Yanagisawa, P. Foytong, P. Lukkunaprasit, S. Koshimura, and F. Imamura, “Investigation of Tsunami-Induced Damage and Fragility of Buildings in Thailand after the December 2004 Indian Ocean Tsunami,” Earthquake Spectra, Vol.22, S377-S401, 2006.
-  M. Saatcioglu, A. Ghobarah, and I. Nistor, “Performance of Structures in Thailand During the December 2004 Great Sumatra Earthquake and Indian Ocean Tsunami,” Earthquake Spectra, Vol.22, S355-S375, 2006.
-  N. I. Thusyanthan and S. P. Madabhushi, “Tsunami Wave Loading on Coastal Houses: a Model Approach,” New Civil Engineering International, September 2008, pp. 27-31, 2008.
-  Uniform Building Code (UBC), “1997 Uniform Building Code,” California, 1997.
-  H. Yeh, I. Robertson, and J. Pruess, “Development of Design Guidelines for Structures that Serve as Tsunami Vertical Evacuation Sites,” Washington State Department of Natural Resources, Olympia, WA, 2005.
This article is published under a Creative Commons Attribution-NoDerivatives 4.0 Internationa License.