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Full-Text Articles in Engineering

Post-Earthquake Assessment And Numerical Modeling Of Freestanding Heritage Structures, M. Khalid Saifullah, Christine E. Wittich Jan 2019

Post-Earthquake Assessment And Numerical Modeling Of Freestanding Heritage Structures, M. Khalid Saifullah, Christine E. Wittich

Civil Engineering Faculty Publications

Historic and heritage structures are particularly vulnerable to earthquakes, where damage or collapse can not only lead to loss of a structure but also the loss of irreplaceable heritage. Many heritage structures can be classified as freestanding (detached) structures, including unreinforced masonry walls, classical multi-drum columns, and statue-pedestal systems. However, the seismic response of freestanding structures (sliding, rocking, rock-slide, overturning) is poorly predicted by existing methods due to geometric non-linearities as well as sensitivity to interface conditions and modeling parameters. Previous studies have focused on analytical modeling of simplified systems and/or experimentation under controlled laboratory conditions. In contrast, this ...


Post-Fire Damage Geospatial Assessment Via Point Clouds Of A Highway Bridge Structure, Yijun Liao, M Ebrahim Mohammadi, Richard L. Wood, Christine E. Wittich Jan 2019

Post-Fire Damage Geospatial Assessment Via Point Clouds Of A Highway Bridge Structure, Yijun Liao, M Ebrahim Mohammadi, Richard L. Wood, Christine E. Wittich

Civil Engineering Faculty Publications

This paper discusses the quantitative post-fire damage assessment of a steel girder bridge via point clouds. In this case study, the point cloud was collected using light detection and ranging (lidar) for a detailed geometric and shape analysis. The out-of-plane deformation was analyzed to locate and quantify buckling across the length of the steel girders.


Efficient Intensity Measures Of Slide-Rocking Structures For Precariously Balanced Rocks, Taylor J. Knickerbocker, Christine E. Wittich Jan 2019

Efficient Intensity Measures Of Slide-Rocking Structures For Precariously Balanced Rocks, Taylor J. Knickerbocker, Christine E. Wittich

Civil Engineering Faculty Publications

Precariously balanced rocks (PBRs) and other fragile geologic features are important in both the engineering and seismological communities since they are indicative of the maximum ground motion at a site over the rock’s lifetime. Precariously balanced rocks are individual or stacks of freestanding rocks that tend to respond in rigid body modes when subject to seismic excitation – namely, rocking, sliding, slide-rocking, and free-flight, which can lead to overturning. The seismic response of freestanding structures, such as PBRs, is known to be extremely sensitive to small changes in geometry, position, and earthquake excitation. As such, deterministic methods are limited in ...


Damage Assessment Of A Sixteen Story Building Following The 2017 Central Mexico Earthquake, Yijun Liao, Richard L. Wood, M Ebrahim Mohammadi, Kanchan Devkota, Christine E. Wittich Jan 2019

Damage Assessment Of A Sixteen Story Building Following The 2017 Central Mexico Earthquake, Yijun Liao, Richard L. Wood, M Ebrahim Mohammadi, Kanchan Devkota, Christine E. Wittich

Civil Engineering Faculty Publications

The 2017 M7.1 Central Mexico Earthquake caused significant infrastructural damage in the Mexico City area. The earthquake contained a significant pulse in the long period, resulting in numerous buildings severely damaged or collapsed. This paper discusses a reinforced concrete building which was still partially occupied post-earthquake. The building’s interior walls were examined to have substantial damage, including some extensive cracking. In January 2018, the authors visited the structure and collected detailed assessment data. The data collection included ground-based lidar scans and recorded ambient vibrations of the damaged structure using accelerometers. Eleven scans were collected from the four exterior ...