DATE:

October 2, 2007 (Tuesday)

TIME:

9:00 a.m. to 11:00  a.m.

LOCATION:

1650 Mission St., Room 431

Note:

Public comment is welcome and will be heard during each agenda item. Reference documents relating to agenda are available for review at the 1660 Mission Street, 2/F.  For information, please call David Leung at (415) 558-6033.

Present:
Jim Guthrie, S.E.
Ned Fennie, A.I.A.

Other Present:
Anthony Skakal, CSMIP
Carl Petersen, CSMIP
Stephen Harris, S.E.
Derrick Roorda, DeSimone
David McCormick, SGH & SEAONC
Mark Sinclair, Degenkolb
Robert LaRose, Port of SF
David Leung, DBI  

Absent:
 


 

1.0

Call to Order and Roll Call
Members: Jim Guthrie, S.E.; Chair; Ned Fennie, AIA.

Meeting was called to order at 9:00 a.m.  Quorum established with 2 member present.

2.0

Approval of the minutes of the Structural Subcommittee regular meeting of July 10, 2007.

A motion to approve the minutes.  Seconded an approved.

3.0

Discussion and possible action on Seismic Instrumentation of New and Existing Buildings:
Presentation by California Strong Motion Instrumentation Program as a public outreach to alert property owners, including details of the installation and maintenance of seismic instruments, specifications for equipments, memorandum of understanding between CSMIP and DBI for commitments of CSMIP for long term maintenance, owner obligations on  size and location of rooms, nature of space, power of connection including battery backup, availability of access to data and draft Administrative Bulletin AB-058.

The following are discussed:

Details of the installation and maintenance of seismic instruments, specifications for equipments, memorandum of understanding between CSMIP and DBI for commitments of CSMIP for long term monitoring,  responsibilities of maintenance, suppliers of the instruments, responsibilities of owner relating to space including size and location of rooms, utilities and  power of connection including battery backup and access to data were discussed.

CSMIP made a powerpoint presentation on the following:

A.

Background:
LA adopt seismic instrumentation similar to SF before 1971 San Fernando earthquake.
After Northridge earthquake, CSMIP found difficulties to retrieve data and assure that instruments are OK to be ready for next earthquake because the instruments, maintenance and installation were not to their standards.
Then came the CSMIP assured approach.

B.

If instuments are healthy, maintenance companies no need to go out.
CSMIP checks once a week.
No routine maintenance required.

C.

Examples of San Francisco buildings instrumented are 1660 Mission and Embarcedero.

D.

AB-058 to be revised to reference the following CSMIP document:
CGS/DGS SYSREQ 2007-TR.

E.

There are two types of instrumentation:

1. Extensive
2. Code minimum: 3 instruments
   Additional instruments required at Director’s discretion.
   If additional are recommended. CSMIP may help to provide.
   Base isolated: 1 above and 1 below
   Instrumentation pattern should be on checklist in AB for peer review.

F.

Threshold to trigger instrument reading: at 1%g.
Threshold to trigger owner notification at 5%g.

G.

How often CSMIP pull data from instrument?

Once a week, functional check every quarter.

H.

Small earthquake will automatically deliver data to stations.
Records sent to owner’s email and available in website, within half hour.

I.

Maintenance companies approved by State.

J.

DBI:   Data available to public but no address.

K.

New projects, CAD-file , location, cabling, type of instruments etc. to be provided to CSMIP.

L.

Engineer may install instruments that give client immediate access.

Draft Administrative Bulletin of AB-058 was also discussed.

4.0

Discussion and possible action on updating Administrative Bulletins AB-014, AB-023, AB-036, AB-046, AB-078, AB-083, AB-084 and AB-085 to 2007 San Francisco Building Code.

AB-083 still refers to 2001 SFBC.
All others have been updated to 2007 SFBC.
A motion to move the updated Administrative Bulletins forward to the full CAC meeting on 10/10/07.  Seconded and approved.

Updating this AB to 2007 SFBC should be a  high prioriy.
It is noted that the AB on new tall buildings were split into several ABs on Peer review, Performance-based designs, etc.  Drafting of these ABs should be in progress.

5.0

No new agenda items.

6.0

Public Comment

No public comment.

7.0

Adjournment.

The meeting was adjourned at 10:40 a.m.