3. Dimension Stone
• Quarried dimension
stone has been
used as a building
material dating to
6000 BC in Jericho
• Used extensively
for foundations,
bridges, aqueducts,
road surfacing, and
military
fortifications
4. One of the most common applications of dimension stone has been
construction of gravity retaining walls, usually in mountainous areas
with steep bedrock slopes.
Machu Picchu, in Peru
Apennine highway in Italy Tioga Pass near Yosemite
5. • Nimrod’s Castle
was built by
European
Crusaders in the
12th Century using
basalt blocks and
limestone
• Earthen mounds
were often built
over tels, or rubble
piles, from
previous cities or
citadels, to gain
elevation
advantage for
defense
6. • Low porosity
crystalline rock,
such as granite,
has always been
desirable because
of its superior
durability
• Massive rocks
tend to be less
intensely jointed
or weathered, but
also
• Harder to
excavate
7. • Cyclopean masonry rock retaining wall supporting a
highway in the Andes Mountains of Peru. Note tunnel
at middle right excavated in rock to convey river flow.
8. RQD
• Rock Quality Designation index, or RQD, was introduced by Don
Deere in 1963. It judges rock quality based solely on
measurements of recovered rock core (above left) in 10 foot
increments, based on percent recovery and percentage of the
pieces longer than 4 inches.
9. RQD
• RQD = Σ pieces > 4” long (100)
total length cored
• 100-90 Excellent
• 90-75 Good
• 75-50 Fair
• 50-25 Poor
• <25 Very poor
the reported RQD value varies along
the scan line of the recovered core
10. • The Rock Mass Rating (RMR) System, or Geomechanics
Classification, was introduced by Dick Bieniawski in
1972-73. It has been continually refined, base don case
studies of actual excavations.
11. • “Rock” is a subjective term. Karl Terzaghi
arbitrarily defined hard rock as any natural
material having qu > 4000 psi, which is same as
structural concrete.
12. • Even the hardest rocks are perturbed by
discontinuitities; such as these sheet joints,
which are essentially tensile fractures, which
form a never ending series of blocks.
