New american practices for seismic rehabilitation of masonry buildings

A summary of new developments in America for seismic evaluation and rehabilitation of masonry buildings is presented. An overview of newly proposed engineering guidelines is given with an emphasis on evaluation and retrofit of existing masonry buildings. The importance of enhancing booth strength and deformation capacity of masonry wall and pier components through the retrofit process is the central perspective of the paper.(AU)

Seismic response of unreinforced masonry buildings

This paper presents an overview of structural engineering research supported by NCEER on seismic response and behavior of unreinforced masonry buildings. Included are research projects related to improving engineering methods for seismic evaluation and rehabilitation of masonry bearing wall and infill-frame building systems.(AU)

Summary of the ATC-33 project on guidelines for seismic rehabilitation of buildings

An overview is presented on the current state of development for a national effort to write guidelines for seismic rehabilitation of buildings, Much of the introductory material from the 25

draft of a new document under development is presented to help illustrate the approach of the overall effort. This the followed by brief summaries of some of the issues encountered by the document writes in its preparation (AU)

Dynamic response measurements for URM building systems

Results from a instrumental building and a laboratory study are presented that demostrate the dynamic performance of typical unreinforced masonry bearing wall building systems with flexible floor diaphragms. The overall focus of the paper is to suggest ways that present engineering methods for seismic evaluation and rehabilitation can be improved through results of research on dynamic response of masonry building systems (AU)

Out - of - plane strength evaluation of urm infill panels

An out-of-plane strength evaluation procedure for unreinforced masonry infill panels in both undamaged and damaged states is presented. The evaluation method based on an analytical model that considers the development of arching action in panels when subjected to out-of-plane loadings. Strength estimates are compared to a series of experimental results carried out on full-scalespecimens. Test specimens consisted of clay or block infills in a reinforced concrete frame (AU)

A lesson learned from Loma Prieta on Vulnerability of URM construction east of the rockies

A two - story unreinforced masonry structure located within 15 Km of the epicenter of Loma Prieta responded with litte damage despite roof accelerations as large as 0.79g. The historical building has constructed of clay brick masonry bearing walls, and timber floor and roof systems. Measure of response of the building during the earthquake is used with measured material data to infer how similar construction east of the Rockies might perform during a future seismic event (AU)

Quasi - dynamic analysis for the seismic evaluation of structures with flexible diaphragms

A simplified 3-D quasi-dynamic seismic analysis used to evaluate stress states at identified times of peak dynamic responses of structures with flexible diaphragms is presented. The quasi-dynamic seismic analysis consists on stracting the accelerations predicted by the time.step integration analysis of two 2-D discrete MDOF dynamic models of a given structure (each discrete model corresponding to one of the principal orthogonal directions of the structure) at given times of interest. These accelerations are imposed on a 3-D finite elements mesh of the structure as equivalent static forces. Accelerations at the diaphragms are asusumed to act over the same tributary areas of the diaphrams considered in the 2-D discrete dynamic models (AU)