Seismic Evaluation of High Rise Structures in Malaysia

摘要

Structural design in Malaysia has traditionally not considered earthquake and hurricane loading. The occurrence of several tremors in neighbouring countries has necessitated a relook at the seismic reliability of the existing structures. Major cities like Kuala Lumpur, Penang and Johor may have structures with significant seismic risk. The first step towards mitigation is an effective risk assessment. In this work two methods were used to assess the risk of the buildings namely Rapid Visual Screening and Extended analysis. The former was done by adopting the FEMA-154 procedure, which assigns the basic score depending on the building type, modified based on the number of storeys, the vertical and the plan irregularity, the year of code, Pre or Post benchmark and soil type. 95 structures were evaluated and the final score indicates that three buildings are at risk. The extended analysis started with simple vertical load analysis (the current practice) and then the earthquake and the wind loading were imposed. The integrity of the structures was evaluated in terms of serviceability deflections using UBC 1997, IS 875-3-1987 and IS 1893. Under wind loads, the permissible deflections were exceeded at 40 m/s for 87 m height buildings; at 45m/s for above 70 m height buildings; at 50 m/s for buildings above 59.5 m height. Higher value of ground accelerations (>0.1 g) results in exceedance of the serviceability values of deflections.