Design Memorandum

 

TO: All Design Section Staff 

FROM: J. Kapur

DATE: October 28, 2003

SUBJECT: Column and Shaft Spirals Options

 

The lap splice option for column and shaft spirals shown in BDM Figures 9.2.1-2 & 4 are for deformed bars and wires, and shall not be used for plain bars and wires.  Welded splice is the only option allowed for plain bars and wires.  The attached Figures replace BDM Figures 9.2.1-2 & 4.

 

 

Background

 

The lap splice option for column and shaft spirals is only tested for deformed bars under seismic loads. .  The lap splice option for plain bars and wires is not supported by any test data under seismic loads, and shall not be allowed for column and shaft spirals.  It should be noted that plain bars and wires are seldom used for shaft and column spirals.

 

 

 

If you have any questions regarding these issues, please contact Bijan Khaleghi at 705-7181.

 

JK:dsb

 

MWA/BK

 

Attachment