DATE:

April 8, 2008 (Tuesday)

TIME:

9:00 a.m. to 11:00 a.m.

LOCATION:

1660 Mission St., Room 2031

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.
Stephen Harris, S.E.

Other Present:

William Heijn, Berline & Associates
Doug Woods, CAL/OHSA
Bernie Morris, Sheedy
David Bonowitz, DBSE, SEAONC, SEAOC, NCSEA
Ray Lui, DBI
Rick Halloran, DBI
Howard Zee, DBI
Tom Le, DBI

David Leung, DBI

Absent:
 


 

1.0

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

Meeting was called to order at 9:00 a.m.  Quorum established with 3 members present.

2.0

Approval of the minutes of the Structural Subcommittee regular meeting of March 11, 2008.

A motion to approve the minutes.  Seconded and approved.

3.0

Discussion and possible action on surcharge on retaining wall.

At what angle of repose the slope becoming surcharge (2:1, 4:1 or 5:1 per LA amendment building code/) is  discussed. Drainage  is also discussed.

The following code interpretation for SFBC Section 106A.2 Item 5 is  recommended:

“Soil retained at an angle of repose not steeper than 1 vertical to 5 horizontal is not a surcharge and this exemption is applicable.  This exemption shall not apply to retaining walls of any height built on slopes steeper than 1 vertical to 5 horizontal (20% slope).”

It is noted that all code interpretations should be reviewed prior to the next code amendment cycle for possible inclusion in the code amendments.

4.0

Discussion and possible action on AB-023: Tower Crane Site safety Plans.

Recent crane failures in New York , Florida and San Francisco, including climbing operation accidents and current SF Code Amendments and tower crane reviewprocedures were discussed.

CAL/OHSA will issue operational permit after verifying that crane meets ANSI requirement and load lest.

Certification of  operators requires training by CAL/OHSA.

Possible areas for improvement in Crane procedues were noted and include, crane foundations, concrete core strength prior to placing of tie-back anchor bolts(caution to avoid cutting tendons in PC slab), testing/inspection, tieback, anchor bolts in concrete and additional special inspection requirements, co-ordination between design of tower crane tie-in and EOR, continuity of high level CAL/OHSA oversight., separation of  traffic from crane, auditing for engineering  of crane structure including connection, AB-023 not addressing mobile crane are discussed.

AB-023 will be updated to incorporate CAL/OHSA recommendations and input from DBI Special Inspection Group.

5.

Discussion and possible action on 2007 SFBC Section 1604.11.3 to  incorporate applicable provisions of 2001 SFBC Section 1605.4.3.

It is noted that a SEAONC special repair committee has been formed to discuss the level of damage that triggers seismic upgrade and DBI policy.

6.

Discussion and possible action on 2007 SFBC Section 3403.2 to incorporateapplicable provisions of 2001 SFBC Section 3403.2.1.1, exception 1.

It is noted that when the lateral force story shear for type V Group R vertical addition is not increased by 5%, retrofit retrofit is not required per 2001 SFBC.

Now removal of wall for opening, increasing the seismic force in any structural element by 10% per 2007 SFBC, would trigger seismic retrofit of entire building.

Proposals  to revise Chapter 34 for IBC 2009, downloadable from IBC website, are approved in ICC meeting in Palm Spring last month, waiting for adoption in September. Part of the proposal said that work performed in accordance with the International Existing Building Code shall be deemed to comply with the provisions of IBC Chapter 34.

Whether conversion of  non-occupiable to occupiable attic or penthouse should trigger seismic retrofit of entire building is discussed.

7.0

No new agenda item.

Items 4.0 thru 6.0 are continued in next  meeting.

8.0

Public Comment

No public comment.

9.0

Adjournment.

The meeting was adjourned at 11:00 a.m.