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EARTHQUAKE
RETROFIT STUDY (Voids in block walls)
A
large ongoing earthquake retrofit project is
underway at a large medical college hospital.
During the upgrades, it was found that many of the
concrete block walls in the basement were not
adequately filled with grout. The project was
delayed since it was necessary to install the
earthquake retrofit supports in only grout filled
blocks. To support the ongoing upgrades, we were
called upon to provide geophysical services in
marking which blocks in the basement walls were
grout filled and which were empty.
The
survey area had many obstacles (beams, pipe
chases, air ducts, electrical conduits, and
hanging ceilings). GPR traversing was performed at
each of the proposed support installation
sites in an attempt to identify filled blocks
or blocks with voids. Following the
delineation of grouted blocks and voids, drill
holes were conducted at several
locations and were successful in validating
the GPR results.
900
MHz Antenna in use at the site |
