Reseach Assistant Professor of Mechanical and Civil Engineering

Research

Earthquake Engineering

I wear two hats in my research position, one as an earthquake engineer and the other as an observational seismologist. As an earthquake engineer, my work is motivated by the recognition that continued commercial development of high-sensitivity, low-cost sensors will lead to a dramatic expansion in observational vibration monitoring eventually making it possible to image full, time-varying, seismic wavefields in buildings. We are extending wave propagation and tomographic methods developed for seismological applications to the instrumented, built environment for detection and location of shaking-induced damage events such as steel beam connection fractures and brace-element connection failures. In earthquake engineering we are developing new techniques to detect damage in buildings using different types of wave propagation responses from vibration sources. We conduct numerical and observational experiments with earthquake, explosion, and ambient vibration waveform data from sensor deployments in existing buildings.

Projects
  • Structural monitoring through community participation in the Community Seismic Network, involving members of the community who host small, inexpensive seismometers in order to achieve deployments of tens of thousands of sensors in seismically active regions. [Published Studies]
  • Simulation of building response to damage with small-scale scenarios imposed in finite-element models of existing buildings that also have sensors deployed on multiple floors recording vibration data.
  • Development and testing of a high-frequency method of detecting a failure event in buildings that uses the properties of reciprocity and time-reversed reciprocal Greens functions. [Published Studies]
  • Application of time-domain waveform interferometric techniques for system identification of buildings using earthquake and ambient vibration recordings. [Published Studies]
  • Development of multi-tiered, portable, wireless accelerometer system for instrumenting large civil structures such as buildings, bridges or dams. [Published Studies]

Seismology

As a seismologist, I am constructing frameworks to describe the geophysical environments that lead to initiation and evolution of young continent-continent collision at transpressional plate boundaries. Observations are provided by the deployment of dense arrays of seismometers in the field and on the seafloor. In both cases, our studies provide new insights into the types of failure and deformation mechanisms that can occur within the brittle-plastic spectrum of these systems, particularly within transition regions.

Projects