Under the Alquist-Priolo Act and the policies of the State
Geology Board, the cities and counties have primary responsibility for
implementing the zoning regulations and they can be more stringent than
state law. You should contact the local building department or
planning agency where the project is located to determine their
Definitely. Need planning department's blessing before going further
with the detailed design.
Suresh Acharya, S.E.
Steve Grodin makes some good points on the moral arguments
against creating such a ramp in his email responding to your query. The
policies developed under the law suggest that cities or counties can be
liable for death and injury from earthquakes if they don't carry out
there responsibilities under the law. I'm sure a smart lawyer could
extend that reasoning to the Engineer without much effort.
The Cities of Oakland and Berkeley have had exemptions written
into the law exempting properties damaged by the 1991 Firestorm even
though they may be in the fault zone.
Note also that the zone is defined as within 50 feet of an
active trace so you really have a 100 foot wide zone, centered on the
fault restricted from buildings for human occupancy. If there are
multiple traces, which are not uncommon on the Hayward Fault in the
S.F. Bay Area, the zone can be even wider.
We have a current project where
the entitlement package is indicating the ramp to underground parking
(covered as part of exterior courtyard) is crossing a designated
Alquist Priolo fault trace.
My interpretation would be this is
not permitted. The Architects interpretation is that it is permitted
as this is not an occupied structure (2000 hours per year). I question
this as, apart from the obvious problems of the retaining walls and
ramp plus covering slab suffering differential movement crossing the
fault trace, the courtyard is elevated and it is hard to quantify the
occupancy. The ramp is a means of egress with constant daily vehicle
use, but also hard to quantify occupancy.
Any input from my peers? Am I
reading too much into this? I know pools and hardscape are permitted
to cross the fault trace, but they do not typically form a collapse