Pulau Pinang merupakan negeri Malaysia yang paling terjejas dalam kejadian Tsunami Lautan Hindi pada tahun 2004. Oleh sebab kawasan tepi pantai dibangunkan dengan pesat sejak kebelakangan ini, lebih banyak nyawa dan harta benda akan dituntut sekiranya dilanda lagi oleh tsunami. Setakat ini, garis panduan untuk bangunan yang berkebolehan untuk menahan impak tsunami masih belum digubal di Malaysia akibat daripada kekurangan pengetahuan mengenai topik-topik tsunami. Dalam kajian ini, ciri-ciri gerakan tsunami ke atas darat dan daya gelombang ke atas bangunan di Pulau Pinang telah dikaji. Bangunan setingkat, dua tingkat, tiga tingkat dan empat tingkat telah diskalakan pada nisbah 1:100 dan dilanda oleh tsunami pada pelbagai ketinggian ombak tsunami dalam flum ombak sepanjang 40m. Data-data daripada eksperimen menunjukkan bahawa ciri-ciri landaan tsunami ke atas model bergantung kepada nisbah ketinggian antara model dan ketinggian nominal gelombong. Daya ombak tsunami mencapai nilai maksimum dengan kemuncak ombak dan halaju yang tinggi. Daya ombak mendatar bergantung pada jumlah keluasan permukaan bangunan yang terdedah terhadap ombak tsunami, manakala daya ombak tegak dalam kejadian tsunami tidak bergantung kepada ketinggian sesebuah bangunan. Ungkapan sedia ada dari Asakura et al. (2000) adalah lebih tinggi darpida keputusan kajian yang diperolehi. Berdasarkan keputusan eksperimen, taburan tekanan ombak tsunami terhadap permukaan depan dan belakang bangunan di Pulau Pinang telah dicadangkan.
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Penang Island was the most severely affected state in Malaysia during the devastating event of 2004 Indian Ocean Tsunami. As the coastal areas of the state have been developed rapidly over the years, it is foreseen that even more lives will be claimed and more properties will be damaged should the next tsunami hit us. To date, proper design of tsunami-resistant structure is yet to be formulated due to the lack of knowledge on tsunami impact topics. In this research study, tsunami runup characteristics and wave forces of tsunami on idealized beachfront building at Penang Island were investigated. Single-storey, double-storey, 3-storey and 4-storey building were down scaled at a ratio of 1:100 and subjected to tsunami bores of various runup heights in a 1m x 1m 40m long wave flume. The experimental results reveal that the nature of the wave attack on building model depends largely on the relationship between model height and nominal height of the incoming wave. It is observed that both resultant vertical and horizontal force occurs when nominal height of the wave is achieved by the flow when the velocity head of the flow is still significant. Tsunami horizontal force acting on a building depends largely on the total exposed area of the building to incoming wave flow. Vertical forces acting on the structures during tsunami wave flow consisted of both uplift and downward forces which magnitudes do not depend on the height of building. Pressure distribution prediction formulae proposed by Asakura et al. (2000) exhibit similar trend with the experimental results, but may overestimate the maximum pressure magnitude. Based on the experimental results, tsunami wave pressure distribution for both front and back faces of the building located in Penang Island are proposed.
Runup characteristics and wave forces of tsunami on an idealized beachfront building at Penang Island / Tan Kang Chin