| This tunnel project is
the largest highway construction job ever undertaken in the United States...at a cost over
$11 billion dollars! One sensitive issue of
such a significant project is how construction noise will impact local businesses and
residences. A unique, open-air collection of restaurants, shops and offices, is
located adjacent to a section of the project requiring working underneath an overhead
highway, while a densely populated residential area is located on the opposite side.
Thus, the noise impact upon the markets and residences is even greater from the direct
construction noise as well as the reflected noise off the deck.
It was determined that BBC-13-2" Acoustical Curtain
Panels would offer the required noise reduction. BBC-13-2" Acoustical Curtain
Panels are a combination of a 2" thick vinyl-faced Quilted Fiberglass Sound Absorber
and a 1 lb PSF reinforced loaded vinyl noise barrier. Modular Panels are constructed
with grommets for attaching to the framework as well as exterior grade hook and loop
fasteners for joining adjacent panels together. Over 400 such panels are
manufactured and shipped within a three week period. As the panels were being
installed, preliminary sound level testing showed a 9 to 10 dB(A) reduction in noise
levels even before the entire job site was buttoned up. This was just the kind of
noise reduction promised to the local community.
Many other sections of the massive project have also utilized
the Curtain Panels with even better results since they were not located below an overpass,
with completed sections showing noise reductions up to 12 dB(A). A common treatment
is to have the Curtains installed on fence posts inserted in pre-cast concrete highway
barriers. This allows for the noise reduction treatment to be easily relocated along
with the highway barriers.
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