mag

Malaysia Water Research Journal
SEEPAGE SIMULATION ON PUTRAJAYA EARTH FILL DAM
Muhammad Rizal Razali (1) , Saad Sh Sammen (2) , Azzlia Mohd Unaini (2) &
Thamer Ahmed Mohammed Ali (2)
(1)
Corporate Planning Division, National Hydraulic Institute of Malaysia, Selangor,
Malaysia,
e-mail: mrizal@nahrim.gov.my
(2)
Faculty of Engineering, University Putra Malaysia, Selangor, Malaysia
ABSTRACT
A seepage simulation is focused on clay core-rock fill dam all the time. In this
study Putrajaya dam taken as a case study, the saturated stable seepage
computation model was used to analyse Putrajaya dam seepage problem. Two
dimensional finite element model of the clay core-rock fill dam was established
by the Geo-Slope/SEEPW Software. The numerical simulation computation was
carried on dam seepage situation under the different conditions. A proposed
model is describing the flow pattern and seepage behaviour through the dam.
The flow is assumed to be two-dimensional and under steady-state condition.
The non-linear differential equation governing the flow is solved using an iterative
finite element scheme. The finite element formulation is computer-implemented
into a flexible computer program called SEEPW. The results show that the seepage
amount through the dam was equal to 3.5620 x 10-8m3/sec.
Keywords: Seepage, Hydraulic Conductivity, Finite Elements, Modelling, SEEP/W
1 INTRODUCTION
It was found (Hasan, 1999) that from 1000 of dams being built today, almost
10 of the dams are failed or the ratio of 1:100. From the records available, more
than 200 dams that failed in the 20th century which is involved the dam’s size of
either more than 15 meters high or less than 15 meters high. Of the total failures,
30 incidents are recorded between years 1950 to 1959, and 25 incidents are
recorded between the years 1960 to 1965. Since 1998 the number of unsafe
Dams in United States has risen by 33% to more than 3500, while federally owned
Dams are in good condition and there have been modest gains in repair, the
number of Dams identified as unsafe is increasing at a faster rate than those
being repaired. US$10.1 Billion is needed over the next 12 years to address all
critical non-federal Dams which pose a direct risk to human life should they fail
(ASCE, 2005).
There are many type of dam failure but the two common failure mode are
hydraulic failure (overtopping) and piping or seepage. According to ICOLD, The
International Commission on Large Dams, the most common causes of failure of
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