Sejak kebelakangan ini, tsunami telah berlaku di seluruh dunia dan Malaysia juga tidak dikecualikan. Pemahaman kesan tsunami terhadap prestasi struktur yang terletak di daratan masih kurang kerana ciri-ciri tsunami yang sukar diramal. Oleh itu, pendekatan teori bagi penentuan daya tsunami sukar digunakan. Bangunan dengan papak lantai ternaik biasa dijumpai di perkampungan sekitar pantai di Malaysia. Konsep rekabentuk papak lantai ternaik telah digunakan untuk bangunan rintang tsunami. Dalam kajian ini, kerja-kerja penyelidikan diberi tumpuan kepada penyiasatan daya dan tekanan tsunami ke atas bangunan yang mempunyai papak lantai ternaik serta tanpa papak lantai ternaik. Bangunan yang keluasannya 10 m x 10 m serta ketinggian lantai sebanyak 3.5 m telah diambil kira. Model telah dikecilkan dengan skala 1:100. Pemodelan fizikal dilakukan dalam flum ombak 1 m dengan 1 m dan 40 m panjang. Walau bagaimanapun, model bangunan telah dibezakan oleh ketinggian papak lantai. Keputusan eksperimen menunjukkan bahawa model bangunan yang mempunyai papak lantai tinggi tidak berfungi untuk mengurangkan daya mendatar tsunami melainkan papak lantai ternaik diletakkan tinggi daripada ketinggian ombak. Selain itu, dalam pengiraan daya paduan mendatar, adalah disyorkan bahawa jumlah keluasan yang terdedah kepada serangan ombak perlu mengambil kira kedua-dua permukaan hadapan bangunan dan permukaan bawah lantai papak ternaik. Pengiraan daya paduan mendatar yang menggunakan ungkapan beban sedia ada daripada FEMA P646 (2008), Asakura et al. (2000) dan Okada et al. (2005) didapati lebih tinggi berbanding dengan keputusan ujikaji yang diperolehi. Ini menunjukkan bahawa ungkapan beban yang dicadangkan tidak boleh digunakan untuk menganggarkan beban tsunami ke atas bangunan yang terletak di kawasan pantai Pulau Pinang. Berdasarkan keputusan eksperimen, taburan tekanan tsunami ke atas permukaan depan dan belakang bangunan telah dicadangkan.
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Recent years, tsunamis have been making scenes worldwide and Malaysia is no exception. Since the characteristics and behaviours of tsunami in the run-up zone are fundamentally unpredictable, the understanding of the impact of tsunami on the performance of structures located onshore is still lacking. Hence, theoretical approach for the determination of tsunami-induced forces cannot be easily applied. Buildings with elevated floor slab are commonly found in villages along Malaysia coastline. The elevated floor slab design concept is adopted for tsunami resistant building. In this study, the research work focuses on the investigation of tsunami forces and pressures on building with elevated floor slab and non-elevated floor slab. Buildings of 10 m x 10 m in plane area with floor height of 3.5m were taken into consideration. The model is scaled down using 1:100 scale. Physical modeling was conducted in 1 m by 1 m and 40 m wave flume. However, building models were distinguished by 0 m, 1.5 m and 3 m elevated floor slab. The experimental results reveal that building models with elevated floor slab does not serve the purpose of reducing horizontal force unless the elevated floor slab is located above the nominal wave height. Besides, in calculating the horizontal resultant force, it is recommended that the total exposed area of wave attack should take into consideration both the front surface of the building as well as bottom surface of the elevated floor slab. The horizontal resultant force estimated using proposed loading expressions by FEMA P646 (2008), Asakura et al. (2000) and Okada et al. (2005) tend to overestimate as compared to the experimental results obtained. This indicates that the proposed loading expression are not applicable for estimating tsunami force on building located in Penang coast area. Based on the experimental results, pressure distribution of tsunami on front and back faces of building are proposed.
Performance of buildings with elevated floor slab subjected to tsunami forces in Penang, Malaysia / Law Chung Leong