and Mase [6,7] conducted the experimental studies of soil liquefaction using shaking table.
Mase  investigated the effect of grain size distribution and cyclic load to the liquefaction potential of Opak River sandy soil.
In general, the previous studies were focused on reporting the earthquake impacts and interpreting the liquefaction potential by the empirical approaches and the general experimental studies.
The objective of this study is to present the dynamic testing of soil liquefaction during a short shaking duration.
Furthermore, the grain size distribution graph and other standard graphs of liquefaction investigation are matched in Figure 2 .
All tests were conducted at a shaking duration of 8 seconds, which was addressed to study the effect of short shaking duration to the liquefaction stages.
In this condition, sandy deposit behaves as liquid and it is refered to as liquefaction condition.
Das  concluded that there is no unique criterion for quantitative evaluation of the liquefaction potential.
The effects of initial stress ([[sigma].sub.i]) and pore pressure ([u.sub.i]) are in term of soil resistance against liquefaction which will be described later.
The liquefaction phenomena have occurred in some area of Padang during Padang earthquake of 30 September 2009.
The identified soil liquefaction on sites in Padang then is plotted in the map of Padang City (Figure 3).
It can be seen that the liquefaction mostly found along riverbanks and beaches that generally consist of sands and/or silts deposits.