HomeMy WebLinkAboutCT 94-02; Pacific Pointe; Tentative Map (CT) (10)GORDON BRICKEN & ASSOCIATES
CONSULTING ACOUSTICAL **<! ENERGY ENGINEERS
January 17, 1995
MR. DENNIS HENDRICKSON
LUCAS AND MERCIER DEVELOPMENT
29712 Avenida de la Banderae
Rancho Santa Margarita, California 92688
SUBJECT! ADDENDUM TO ACOUSTICAL REPORT 94/16Q-R
SIX UNIT SUBDIVISION - -. _CTEY__OF CARLSJBAD
Dear Mr. HendricJcson;
It has been brought to our attention that residents near
your project are concerned with railroad noise increasing due to
reflected sound energy off of your project.
Sound energy travels in a fashion similar to light.
Sound and light travel in straight lines (rays) away from the
source. They do not turn corners. If sound or light is directed
towards a reflective surface, the energy will return from that
surface at an inverse to the approach angle. In other words, if a
sound or light source is pointed directly at, and perpendicular to,
a reflective surface, the energy will return along its original
path. If a sound or light source is pointed at a 45 degree angle
to the reflective surface, then it will return in a direction 90
degrees away from its original path of travel.
In the case of railroad noise, only sound energytravelling more or less parallel to the ground could be reflected
towards other structures. However, reflected railroad sound energy
travelling parallel to the ground will be blocked from further
travel by the train itself. Only sound energy moving upward from a
train could be reflected back over the train. Unless the
potentially impacted buildings are much taller than the sound
reflecting building, the reflected sound energy will continue to
1621 East Seventeenth Street, Suits K • Santa Ana, California 92701 • Phone (714) 835-0249
FAX (714)835-1957
o 95/025
travel upward and over the potentially impacted buildings, Thus,
there is little chance of reflected sound energy impacting other
residences when a train is between the project and such residences.
Finally, the worst case sound reflection conditions
described above would only occur for a large, perfectly flat
reflective wall erected parallel to, and directly adjacent the
railroad tracks for a significant distance. This project will not
erect any flat reflective surfaces of any dimensions large enough
to create significant reflections at other properties.
Additionally, the existing structures between the railroad tracks
and the project will not only break up sound energy travelling
towards the project, but will also break up any sound energy
reflected back from the project.
The proposed six unit project will not produce adverse
sound reflections from the railroad and will not increase overall
railroad sound levels. The project will not create any adverse
sound impacts on surrounding properties.
If you have any questions regarding this matter, please
do not hesitate to call.
Prepared by:
Christopher Jean
Staff Engineer
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