Geoscience Reference
In-Depth Information
Figure 6.27
Cross-section of the Bakun access road pile embankment.
6.5.4 Pile mat-JHS system
Another version of the piled support system is the used of mini piles known as the pile
mat-JHS system. This system of mini concrete piles and mats is actually similar to the
pile-raft system. JHS system is in general a kind of pile-raft system consisting of square
plates resting on mini concrete piles with a pin connection. Each pile-plate component
is connected to the other components with connectors made of polyethylene. There are
3 to 4 connectors at each side of the plate. Each plate has dimension of 90 cm by 90 cm
with an average thickness of 8 cm. Details of the system are shown in Figure 6.28.
Theoretically the whole system is capable of withstanding the embankment load
and reducing the settlement to a certain amount. The longer the piles, the larger will
be the reduced settlement of the system. The one interesting problem is the interaction
of the plates and the soil under it and of the piles and soil around them. Because of the
flexibility of the plate to plate connection, part of load is transferred to the soil below
it and part goes to pile-soil interaction. Analysis of the JHS system is still in progress
and is not yet available. However, a field trial of performance using this system at
a site in Central Kalimantan reported by Rahadian
et al
. (2003) and Djajaputra and
Shouman (2003) does not seems to be satisfactory.
