SP-162 This fact filled symposium, developed in honor of Mete A Sozen, contains 17 highly informative papers. A spectacular addition to all reference shelves. This symposium took place at the ACI Fall convention in Tarpon Springs, Florida in October of 1994. The Sozen Symposium consisted of three sessions with eighteen speakers. The symposium and this SP volume were organized to permit Mete's students and colleagues to honor and thank him for his council and guidance during their studies at the University of Illinois.

Presents nondestructive and destructive dynamic field testing and structural identification studies on actual constructed facilities. The specimens discussed here include a 27-story reinforced concrete (RC) flat-slab building, an RC slab bridge, two 80-year-old steel truss bridges, and three RC slab on steel girder bridges of various ages. The seismic vulnerability of the mid-rise building was evaluated and the test bridges rated by code procedures as well as by field-calibrated comprehensive 3-D FE models developed by structural identification. Experimentally measured and analytically simulated modal flexibilities of the bridges were correlated with deflections obtained under proof-load-level truck-load tests. The rating factors obtained by filed- calibrated models exceeded the corresponding operating rating factors by two and a half to four times for all of the test bridges. These studies revealed our capabilities for evaluating vulnerability or reliability of different classes of facilities. The bridge rating efforts helped to identify and conceptualize a number of unresolved important issues that influence bridge rating and management. Serviceability aspects that emerged as critical were studied through the relative contributions of different mechanisms to bridge deflections.

Force-deformation relationship of high-strength reinforced concrete beam members observed in the laboratory test was idealized by a trilinear relation for use in a nonlinear earthquake response analysis. Methods to evaluate the relationship were examined and the reliability of the methods were discussed with respect to the observed relations. Calculated initial stiffness is shown to significantly underestimate the observed value; a large coefficient of variation was attributed to accidental and shrinkage cracking in the specimen prior to the test. A similar large coefficient of variation was observed in the evaluation of cracking moment. Yield and ultimate moments could be favorably estimated by the theory. An empirical formula was proposed to evaluate yield deformation. An importance of controlling the elastic modulus of concrete in construction is emphasized if a structure is expected to behave as designed during an earthquake.

An experimental program is summarized which is aimed at enhancing the knowledge base regarding seismic behavior, analysis, and design of precast concrete shearwalls. The "emulation design" and "jointed construction" philosophies are described and an idealization of the behavior of precast shearwalls presented. A compendium of connection details for precast concrete shearwalls, seven for vertical joints and four for horizontal joints, is selected for further study; the selection process is described. The connection details are proportioned for a prototype shearwall that is designed as part of a six-story precast concrete office building. A description of all connection details and test procedure is given. Highlights from the cyclic load tests of the vertical joint specimens are documented, including connection resistance, displacement response, initial stiffness, and energy dissipation capacity.

An experimental program was carried out to investigate the behavior of concrete filled steel plate walls. Seven wall-panel specimens were tested under repetitive in-plane pure shear loading. Each specimen was made by connecting a pair of surface steel plates with partitioning webs and tie bars, and filling the boxes so-formed with concrete. The parameters investigated were the thickness of the surface steel plate, the number of partitioning webs and the presence or absence of headed stud bolts. Results describing a restoration force characteristic of a large loop area are presented. Rigidity after the onset of cracking approximates the cumulative value of truss rigidity (rigidity of resistance mechanism consisting of longitudinal and transverse tension chord members of steel plates and compression diagonals of concrete) and in-plane shearing rigidity of surface steel plates. The skeleton curve for the shear stress vs. shear strain relationship could be theoretically idealized into a quadri-linear curve with three control points.