The Building Code
Building codes are copyrighted.
The code currently adopted by most states is the 2006 International Residential Code (IRC) and it's companion the International Building Code (IBC). You can buy the code from any of the code organizations on the left or through your local building regulations department.
For your convenience the the masonry chimney section of the developing International Residential Code (IRC) is available as a working document at http://www.rumford.com/code/IRC06.html
Chimney Seismic Index
Prepared for FEMA by Jim Buckley