masonry wall design- ig and icr
 

masonry wall design- ig and icr
i would be very grateful if someone could direct me to any websites which give information on the calculation of the gross moment of inertia (ig) of masonry units along with the calculation of the cracked moment of inertia (icr). i require this info for designing cmu walls using the strength design method in accordance with ubc:1997.
regards
mike
for an uncracked section including steel:
ig = [b(kd)^3]/3+[b(h-kd)^3]/3+(n-1)as(d-kd)^2
for many of the variables think of a reinforced concrete section.
w/o steel: ig = [bh^3]/12
for a cracked section:
icr = [b(kd)^3]/3+(npbd)(d-kd)^2 where p is rho.
this information is found in reinforced masonry design by schneider and dickey.
qshake
thanks for the swift response and the info
regards
mike