Special emphasis on seismic resistant design of non-seismically designed buildings in Hong Kong

Buildings in Hong Kong were and still are traditionally designed without seismic provisions. Researches on seismic effects of buildings in Hong Kong have been carried out. Seismic performance of existing buildings and structural members has been examined theoretically and experimentally. This has exposed various deficiencies in the resistance of existing buildings against moderate seismic action. This paper aims to highlight some of the relevant researches carried out at The Hong Kong Polytechnic University and by the local researchers. Special emphasis is on the unique characteristics of buildings in Hong Kong including, inter alia, geological profile leading to the soil amplification effect, transfer structures, vulnerability of low-rise buildings, no separation between adjacent buildings, enclosed balconies with additional loading and poor detailing of structural members. Strengthening strategies for structural members are recommended including confinement of columns by high performance ferrocement and strengthening of beam-column joints by ferrocement jackets and diagonal reinforcements or by ferrocement jackets with chamfers. Practical approaches to mitigate the seismic risk are suggested including the use of dampers and structural control devices. Fluid dampers are also proposed to link adjacent buildings for seismic mitigation.