The site's steep hillside and geotechnical terrain, including rocks as large as 10 feet by 20 feet
by 12 feet. After research from the developer's
geologist recently, it was determined that five
boulders would need to be removed from the hillside
for the safety of nearby home owners in case of a
seismic event.
The size of the boulders and their location were the
main problems to overcome in removing them.
Blasting was not an option due to the proximity of
the homes. The developer contacted So. Cal
Sandbags, an erosion control specialist. That
company tried jackhammers and breakers, as well as
backhoes, digging trenches and footings, to no avail.
Rebel Rents was then contacted and they suggested
using an DARDA Hydraulic Rock and Concrete Splitter,
powered by 500 bar pump. The splitting cylinder was
placed into a drilled hole. Using hydraulic pressure, a
wedge is pushed forward into the hole and forces
the counter wedges surrounding it against the inner
walls of the borehole. When tension increased
beyond tensile strength of the rock, a split occurred,
allowing the boulders to be split and removed
piecemeal, in about two weeks.