Seismic Analysis of Reinforced Concrete Structures in Low to Moderate Earthquake Zones of Peninsular Malaysia

Abstract

It is fortunate that Peninsular Malaysia is relatively free from direct earthquake effect, except for far field seismic effect from Sumatra 350 km away, on its western seaboard side. Hence, the majority of local reinforced concrete structures are not designed to resist earthquakes specifically. There is no provisions in the British Standards used, i.e. BS 8110:1987 for seismic design considerations. In May 2010, when UK has withdrawn BS 8110 among other structural codes, it has adopted Eurocodes as the mainstay of concrete design standards, including Eurocode 8 for earthquake-resistance design of structures. It has specific rules as a design provisions for concrete buildings. The Institution of Engineers Malaysia has embarked on a study and development of a design standard for earthquake design for reinforced concrete building structures, which is still on-going. The intention is to address the fears and concerns of Malaysian public in the light of swaying highrise buildings and light damages to some reinforced concrete structures, due to strong intensity earthquakes felt from the 2004 Aceh, 2005 Nias and 2009 Padang earthquakes in Sumatra. Of more immediate concern is local earthquake in the vicinity of Bukit Tinggi fault-line, currently inactive, lying a mere 30 km away from city centre of Kuala Lumpur. This paper gave an insight into how the Eurocode 8 [1] (BSI, BS EN 1998-1:2004: Eurocode 8: Design of Structures for Earthquake Resistance—Part 1: General Rules, Seismic Actions and Rules for Buildings, p. 230, 2004) can be applied for Malaysian practices in analysing reinforced concrete building structures. A sample seismic analysis is carried out comparing the outcome using Eurocode 8 and UBC-97 [2] (International Code Council, Uniform Building Code, International Conference of Building Official, p. 442, 1997), based on a local earthquake scenario. Reference is also made to the Component Attenuation Model developed by Australian researchers, which has been touted as accurate and reliable in formulating expected peak ground accelerations in Peninsular Malaysia. This will be a useful input into analysing reinforced concrete structures in a relatively low to moderate earthquake zone.