Liquefaction potential of soils at Iskandar Malaysia Region

Liquefaction had been extensively studied right after the representative Niigata Earthquakes in 1964. The terminologies, conceptual understanding, procedures and analyze methods have been proposed as a new modern engineering branch after that. Peninsular Malaysia is supposed to be seismically free since it is located on Stable Sunda Plate. The low seismicity is still being detected as the Sumatran active fault and Sumatran subduction zone are close to Peninsular Malaysia. This paper presents a preliminary study on the liquefaction potential of the soils at Iskandar Malaysia Region, particularly in Pasir Gudang, Johor area. The general soil profile of the study area consists of sand, silt, clay and gravel. However, the main constituent is loose to medium dense sand which is susceptible to liquefaction phenomena. The ground water level of this area is shallow which range from 2.8 m to 3.8 m depth. Both conditions fulfil the basic criteria of simplified procedure. Assessment of soil liquefaction potential as earthquake's secondary had been carried out using semi-empirical procedures on stress approach. The range of safety factor against liquefaction was found between 0.74 till 2.41. It can be concluded that by using the peak ground acceleration of 0.16g which corresponds to 10% and 2% probability of exceedance in 50-year hazard levels, the Pasir Gudang area is liquefiable with the range of liquefaction potential of 1.6 to 5.64, known as "low severity" to "high severity". The liquefaction severity map developed for Iskandar Malaysia Regions, in particular the Pasir Gudang area could be used as input for preliminary seismic design