Seismic Performance of Joist-Pocket Connections. II: Application
By W. Bradford Cross, Assist. Prof., Dept. of Civil Eng., Southern
Illinois Univ. at Edwardsville, Edwardsville IL 62026-1800,
P.E., A.M. ASCE,
and Nicholas P. Jones, Assoc. Prof., Dept. of Civ. Engrg.,
The Johns Hopkins Univ., Baltimore, MD 21218-2686, A.M. ASCE.
Abstract:
It has been known for some time that connections in unreinforced masonry
structures play a major role in the performance of such structures. Few
attempts have been made to analytically address these components. An
understanding of these "pocket" connections will allow for better estimates of
the behavior of brick buildings and provide a useful tool for the design of
seismic retrofit details. Previous investigations have centered on the linear
or nonlinear response of the brick walls themselves, or the floor and roof
diaphragms. The movement between the floor and roof diaphragms and the wall
has not been previously considered. In a companion paper, the development of a
technique for the examination of the seismic performance of joist and beam
bearing connections in unreinforced masonry structures was presented. An
historic brick building that was shaken during the Loma Prieta Earthquake of
1989, is modeled herein using this approach. The effect of motion at the
diaphragm to wall interface is discussed. A discussion of the importance of
several parameters, including bearing length, coefficient of friction,
coefficient of restitution, and distance from end of joist to end of wall is
presented.