PROJECT FEATURES
The main features of the Murum HEP are a 146.3m
high roller compacted concrete dam (RCC), a
2,160m3/s capacity ungated spillway, twin
2.65km power tunnels and two power intakes,
an ecological power station and a 944MW
surface powerhouse over 13km downstream from
the main dam (see Figure 12 and Figure 13). The
main project features are outlined below:
Main Dam
The main dam is located in a straight river reach
of the Murum River and the dam axis is an arc
line 430.3m long. The main dam is a 140m high
RCC with crest length of 473m and fill volume of
1.61 million m3 (approximately 4 million tonnes)
of concrete, is one of the highest RCC dams in
Malaysia. Conserving ‘Batu Tungun’ an unusual
rock formation revered by the local community,
the beddings and alternation of hard sandstone,
greywacke, siltstone, mudstone and shale geology
of the site including vast amount and supply of the
cement and fly ash posed some serious challenges
to the design and construction of the RCC dam.
The Batu Tungun rock formation is considered
by the project affected Penan community to
be sacred. It was of paramount importance,
therefore, that the construction design kept Batu
Tungun, located on the right abutment of the
dam axis (see Figure 10), intact out of respect
for the community’s belief. In order to preserve
Batu Tungun, an alternative dam axis on the right
abutment was considered and the dam crest was
carefully re-designed after an extensive geological
mapping survey, rock mass stability assessments,
consultation and thorough analysis on the dam
axis under this restriction had been done.
Construction of a haul road, dewatering in
the foundation (see Figure 11) and control of
surface run-off were some of the difficulties
faced by the contractor during the initial stages
of construction. In addition, the high temperature
and rainy climate had a great influence on RCC
construction. During construction, weather
conditions and air temperature were strictly
monitored. Where rainfall exceeded 3mm within
one hour, placing or roller compacting was
Figure 10: Batu Tungun, a rock formation sacred
to the local Penan community in Murum.
Figure 11: View of riverbed: Dewatering concerns
(Prior Excavation)
stopped. Otherwise, it would increase the water to
cement ratio thus affecting the quality of concrete.
In order to achieve construction economy and
maintain the project schedule, considerable
efforts were made in design and construction
of the RCC dam, including extensive laboratory
and trial tests on RCC materials to guarantee
the quality of interlayer combinations.
Murum Main Dam
Maximum Height
Crest Level
Crest Length
RCC Volume
Upstream Slope
Downstream Slope
146.3masl
546.3masl
473m
1.61 M m3
1H:0.02V below
470masl
1H:0.00V Above
470masl
1H:0.75V
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