Small-Scale Model Experimentation on R/C Assemblies, U.S.-Japan Research Program

The study summarized in this report is concerned with small-scale model testing of components and subassemblies of a reinforced concrete frame - shear wall structure. Correlation with a full-size prototype structure was made possible by replicating portions of tests performed on a full-size building and components at other institutions.

The objectives of this model study are (1) to investigate the feasibility and limitations of small-scale model testing in earthquake engineering, (2) to study the simulation accuracy of specific failure modes in small-scale models, (3) to correlate results of tests at different scales to assess prototype response prediction from experimental studies, and (4) to study the behavior of frame - shear wall structures.

In order to fulfill these objectives, all model test specimens were made to be "exact" replicas of prototype buildings or full-scale components tested by others as part of a U.S.-Japan cooperative research program. The specimens tested included 1:12.5 scale models of two interior and two exterior beam-column assemblies a 7 story isolated shear wall, and a 7 story frame - shear wall specimen.

The test results are used to determine the separate contributions of the wall and the three-dimensional frame to the lateral load resistance of the frame - shear wall structure. It is shown that the frame action contributes considerably more to this resistance than is predicted with conventional analysis techniques. The reasons are the larger than anticipated contribution of the floor slab to bending resistance and an outrigger action of the frame elements surrounding the shear wall.

The small-scale models were found to reproduce the global elastic and inelastic response characteristics of their prototype counterparts very well. Localized failure modes were simulated less accurately, with the model specimens exhibiting usually slower deterioration in strength and stiffness than the prototype.