Seismic evaluation of 1940s asymmetric wood‐frame building using conventional measurements and high‐definition laser scanning

Abstract

SUMMARYThis study presents results from shake table experiments of a wood-frame building conducted at the University of California, Berkeley. A 13.5-ft×19.5-ft two-story wood-frame building representing San Francisco 1940s design of a residential building with a garage space on the first story (house-over-garage) was tested. The test building was subjected to scaled ground motion based on Los Gatos record from Loma Prieta 1989 earthquake. The strong motion time history was scaled to match design spectra of a site in Richmond district of San Francisco. The test results demonstrated the seismic vulnerability of the test building due to soft story mechanism and significant twisting when shaken in two horizontal directions. In addition to conventional instrumentation for measuring acceleration and position of selected points of the test building, high-definition laser scanning technology was employed to assess global and local anomalies of the building after the shake table tests. The analysis conducted in this study showed very good correlation between conventional data recorded from position transducers and the laser scans. These laser scans expanded limits of conventional data at discrete points and allowed analyzing the whole building after shaking.

Laser Scanning, Modeling, and Analysis for Damage Assessment and Restoration of Historical Structures

“…In that regard, a unique study of the accuracy of laser scans compared to conventional measurements on a shaking table test of a seismically vulnerable two-story wood house over garage due to soft story and torsional effects was conducted [4]. This paper extends the ideas presented earlier [3][4][5] and uses laser scans as a tool to capture as-found geometry of historic structures. The geometry is used in generation of accurate finite element (FE) models to be used for detailed structural assessment, seismic analysis, and development of retrofit strategies.…”

“…The HDS has been extensively used for documentation and damage assessment of test structures subjected to earthquake loads at the University of California, Berkeley (UCB) [3]. In that regard, a unique study of the accuracy of laser scans compared to conventional measurements on a shaking table test of a seismically vulnerable two-story wood house over garage due to soft story and torsional effects was conducted [4]. This paper extends the ideas presented earlier [3][4][5] and uses laser scans as a tool to capture as-found geometry of historic structures.…”

Effectiveness of Different Techniques on the Seismic Retrofitting of Existing RC Framed Buildings in Saudi Arabia

“…The loading is monotonic with the effects of the cyclic behavior and load reversals being estimated by using a modified monotonic forcedeformation criteria and with damping approximations. Static pushover analysis is an attempt by the structural engineering profession to evaluate the real strength of the structure and it promises to be a useful and effective tool for performance based design [13,14]. This study focuses on performance based design of three multistory reinforced-concrete framed buildings in Madinah, Saudi Arabia, subjecting them to monotonically increasing lateral forces with an invariant height wise distribution until the preset performance level (target displacement) is reached.…”

Applications of laser scanning to structures in laboratory tests and field surveys

“…At UCB, Mosalam et al . () conducted a unique study of the accuracy of laser scans compared with conventional measurements on a shaking table test of a seismically vulnerable two‐story wood house over garage due to soft story and torsional effects.…”