mag

Malaysia Water Research Journal
86
Figure 3. Seepage measurement chamber location – SC 02
The type of spillway is labyrinth with reservoir capacity of 24 million cubic
meter and maximum flood discharge at spillway is 904m3/s. The main purpose of
the dam is to provide recreational facilities to Putrajaya communities.
4 METHODOLOGY
In this study, the analysis computation was used for dam’s seepage by GEO-
SLOPE/SEEPW finite element software. This software’s function includes; process
kinds of non-uniform nature soil layer distribution and complex dam situation;
set assign head and current capacity, water-proof boundary, and so on many
kinds of boundary conditions; compute saturation line automatically; output
equipotential line, streamline, saturation line, kinds of computed result curve and
seepage quantity, slope fall of seep export and etc.
The boundary conditions were hydraulic conductivity, pore water pressure,
and reservoir levels. We can find pore water pressure at different point by
multiplying the piezometric reading with unit weight of water which is 9.81 kN/
m3. SEEP/W divided the entire flow domain into a finite element mesh. Each
element in the mesh must be associated with a soil type .in some points it is
needed to forecast the seepage fluxes across some sections. We can predict
the critical section for the seepage rate and usually it is located at filter outlet of
the dam. It has been noted several times earlier that in seepage analyses only
the head (H) or flow (Q or q) can be specified as a boundary condition. There
are, however, situations where neither ‘H’ nor ‘Q’ is known. A typical situation is
the development of a downstream seepage face such as illustrated in Figure 4
Institut Penyelidikan Hidraulik Kebangsaan Malaysia (NAHRIM)
National Hydraulic Institute of Malaysia (NAHRIM)