New Technical Reports
by P.C. Tsopelas, P.C. Roussis, M.C. Constantinou, R. Buchanan and A.M. Reinhorn, MCEER-05-0009, October 3, 2005, 210 pages, $35.00
The suite of 3D-BASIS computer programs is widely accepted by the engineering and academic communities for use in the nonlinear dynamic analysis of three-dimensional seismically isolated structures. This report introduces 3D-BASIS-ME-MB, which offers a new capability to analyze multiple superstructures on multiple bases, hence the extension MB. The enhanced 3D-BASIS-ME-MB program is primarily useful in (a) performing analyses for schematic designs where speed in both modeling of the isolated structure and performing multiple dynamic analyses is desired, and (b) verifying the validity of modeling assumptions and the accuracy of solutions of more complex analysis programs such as SAP2000 and ETABS. Two examples of seismically isolated structures are used to verify the validity and accuracy of 3D-BASIS-ME-MB.
by D. Vian and M. Bruneau, MCEER-05-0010, December 15, 2005, 360 pages, $35.00
This report investigates the use of Steel Plate Shear Walls (SPSW) for use in retrofit and new design as a lateral force resisting system in building structures. An experimental program was conducted using single-story, single-bay SPSW frames. The tested specimens used low yield strength (LYS) steel infill panels and reduced beam sections (RBS) at the beam-ends. All specimens resisted quasi-static loading from an imposed input history of increasing displacements to a minimum drift of 3%. The perforated panel reduced elastic stiffness and overall strength of the specimen by 15% and 19%, respectively, as compared with the solid panel specimen.
Analytical models using the Finite Element Method (FEM) showed good agreement with the experimental results. Recommendations are made for the ductile design of these systems and for the use of RBS connections in SPSW anchor beams.
By M.J. Astrella and A.S. Whittaker, MCEER-05-0011, December 15, 2005, 158 pages, $30.00
The study described in this report provides ground work toward the development of performance-based design tools for buildings. The focus is on nonstructural components and building contents. The study assesses the response of different seismic framing systems to a broad range of earthquake ground motions and the impact of framing system choice on the demands of nonstructural components and building contents. This is illustrated through response-history analysis of two conventional hospital buildings located in Southern California, which represent typical 1960’s and 1970’s-era construction, and 10 models of alternate (retrofit) construction. Three bins of earthquake histories with different probabilities of exceedance are used for the response-history analysis. Three types of protective systems are considered in the study: steel yielding devices (buckling restrained braces), fluid viscous dampers and base-isolation. The work complements performance-based earthquake engineering tools currently under development by MCEER, the Pacific Earthquake Engineering Center (PEER) and the ATC-58 project.
By H. Badillo-Almaraz, A.S. Whittaker, A.M. Reinhorn and G.P. Cimellaro, MCEER-06-0001, February 4, 2006, 252 pages, $35.00
The failure of suspended ceiling systems has been one of the most widely reported types of nonstructural damage in building structures during past earthquakes. This report presents the results of research to address this problem. The main objectives were to study the performance of suspended ceiling systems commonly installed in the United States; evaluate improvements in response offered by the use of retainer clips that secure the ceiling panels (tiles) to a suspension system; investigate the effectiveness of including a vertical strut (or compression post) as seismic reinforcement in ceiling systems; and evaluate the effect of different boundary conditions on the entire ceiling system during earthquake shaking. Results are reported using damage states and fragility curves. The fragility curves provide a decision-making tool for performance assessment of suspended ceiling systems.
By Peter Dusicka, Ahmad M. Itani and Ian G. Buckle, MCEER-06-0003, March 15, 2006, 254 pages, $35.00
This report presents the methods and results of experimental and numerical research conducted on built-up shear links intended for the earthquake protection of long span bridges. Large-scale experiments, material evaluations and numerical analyses were used to (1) investigate the performance of built-up shear links fabricated from conventional plate steels, (2) develop design alternatives to improve the performance of the built-up shear links using HPS and LYP steels, (3) evaluate large-strain material properties of plate steels and their influence on the shear link performance, (4) develop a representative numerical model for built-up shear links, and (5) investigate the contributions to the overstrength of the shear links. Design recommendations for built-up shear links in bridges were developed on the basis of this experimental and analytical study.