Does anybody have any further information on Earth Systems? Contact
info, typical turn around time, etc... Any other Geotech Co. info from
california would also work if they do the same type of service.
Greg Effland, P.E.
From: Structuralist [mailto:dennis.wish(--nospam--at)gte.net]
Sent: Wednesday, January 17, 2001 5:44 PM
To: aec-residential(--nospam--at)polhemus.cc; SEAINT Listservice; se-practice
Subject: Obtaining Near Source Values
I saw this issue come up a few times and thought I would tell you
geotechnical company is doing in my area. Earth Systems is our local
Geotechnical resources. When the 97 UBC was adopted, Earth Systems
service where they would provide the soil type and Near Source
the property you were designing on. They charge a nominal fee of
$100.00 and include the following information specific to your
Seismic Zone Factor, Z
Soil Profile Type
Seismic Source Type
Closest Distance to Known Seismic Source (in Km and miles)
Near Source Factor, Na
Near Source Factor, Nv
Seismic Coefficient, Ca
Seismic Coefficient, Cv
I generally call this in and have the Geotechnical bill the owner or
and include the requirement in my work agreement.
You may wish to check with your local Geotechnical to find out if
a similar service. These are exact values rather than relying upon
approximations from the ICBO maps or approximate values for calling
city. This geotechnical company maintains historic records which
evaluate for these values.
Dennis S. Wish, PE