Storrow Drive is a major
cross-town expressway
in Boston, Massachusetts,
and is maintained by
the Massachusetts
Department of
Conservation &
Recreation (DCR).
A portion of Storrow
Drive eastbound drops
into a tunnel beneath
Storrow Drive westbound.
This 55-year-old
section — the
Storrow Drive Tunnel
— carries 103,000
vehicles a day through
Boston’s Back Bay
neighborhood, and it was
showing serious signs
of decay. This year,
DCR began interim
repairs to the tunnel.
The structural members
in the roof of the
eastbound tunnel show
unusual indications
of structural distress.
|
The structural engineer
for DCR, Simpson
Gumpertz & Heger Inc.
(SGH), designed an
instrumentation program
consisting of strain
gages and temperature
sensors to evaluate strains
induced by in-service live
loads and loads from
controlled load tests.
Strains resulting from
changes in temperature
will also be evaluated.
The aim of the program
is to help evaluate
questions about
the current level of
safety for vehicular
traffic and indications
of incipient cracks in
the girder webs where
the diaphragm beams connect.
The results of the work
will provide a better
understanding of the
mechanisms causing
apparent structural
distress in the girders
|
Storrow Drive, looking west. At left center is one of the eastbound Storrow Drive Tunnel exits.
so that the most effective mitigation
scheme can be implemented.
SGH retained Geocomp to provide
instrumentation and monitoring
services.
|
Geocomp installed 20 uniaxial strain
gages and 6 strain gage rosettes on
the web and flanges of girders at
|
|
