Dr. DesRoches' Research

School of Civil and Environmental Engineering

Unseating of the Gavin Canyon Under crossing during the 1994 Northridge earthquake

Current Research Projects
	Analytical Study of Friction Pendulum Isolators Modified for Bridges The objective of this analytical study is the development of quantifiable models for the nonlinear finite element programs, which will enable the evaluation of the betterments introduced with CRBTC and DCB. The experimental study of this research aims to characterize lateral force-deformation relationship, observe limitations and capabilities in terms of loading and provide recommendations for improved design of FPS, CRBTC and DCB.
	Seismic Risk Assessment of Transportation Network in Charleston, SC The objective of this analytical study is the development of quantifiable models for the nonlinear finite element programs, which will enable the evaluation of the betterments introduced with CRBTC and DCB. The experimental study of this research aims to characterize lateral force-deformation relationship, observe limitations and capabilities in terms of loading and provide recommendations for improved design of FPS, CRBTC and DCB.
	Seismic Performance of Wharve-Soil-Crane Systmems The objective of this analytical study is the development of quantifiable models for the nonlinear finite element programs, which will enable the evaluation of the betterments introduced with CRBTC and DCB. The experimental study of this research aims to characterize lateral force-deformation relationship, observe limitations and capabilities in terms of loading and provide recommendations for improved design of FPS, CRBTC and DCB.
	Large Scale Testing and Analysis of Cranes The objective of this analytical study is the development of quantifiable models for the nonlinear finite element programs, which will enable the evaluation of the betterments introduced with CRBTC and DCB. The experimental study of this research aims to characterize lateral force-deformation relationship, observe limitations and capabilities in terms of loading and provide recommendations for improved design of FPS, CRBTC and DCB.
	Analysis of Honeycomb Shape Memory Alloys Honeycombs, one type of cellular materials, have been widely used in modern engineering in applications ranging from light-weight structural sandwich panels to packaging and protective padding. This study evaluates the uniaxial compressive behavior of SMA honeycomebs. SMA honeycombs not only retain the characteristic honeycomb ability, but also capitalize on the superelastic effect of SMA material as cell walls. Numerical models of SMA honeycombs under uniaxial compression loads have been first successfully performed to investigate the effect of thickness-to-length ratio on the post-buckling or post-yielding behavior.
	Testing and Analysis of Shape Memory Alloy Bracing Systems Shape memory alloys (SMAs) are unique metallic alloy which can undergo large deformations while reverting back to their undeformed shape through either the application of heat (shape memory effect) or the removal of the load (superelastic effect). An innovative hybrid damper is developed that combines the high initial stiffness characteristic of steel and superelastic effect of SMA in order to undergo large deformation and recover permanent structural deflection.

Recently Completed Research Projects
	Seismic Fragility Assessment of Retrofitted Bridges in the Central and Southeastern United States The research aims to provide enhanced understanding of the impact of various retrofit stragies on the seismic performance of typical CSUS bridges. A primary objective is the development of a methodolody for generation of retrofitted bridge fragility curves that would facilitate the comparison of bridge retrofits and would permit a network assessment for effective retrofit selection and prioritization based on transportation network performance.
	Cyclic Behavior of Shape Memory Alloys: Characterization and Optimization for Structural Response Modification The research focuses on the characterization of the material properties of large diameter NiTi shape memory alloys under loadings and strain levels equivalent to those undergone by structural members during an earthquake.The experimental results are being used develop simplified phenomenological which can be incorporated into structural engineering platforms such as OpenSEES.
	NEESRS-Zipper Frame Testing and Analysis The study investigates pounding in bridges from an analytical perspective. Various models are compared based on their effectiveness in representing impact and certain revisions in the current design procedures are suggested.
	New Contact Models with Nonlinear Damping for Pounding Simulations The study investigates pounding in bridges from an analytical perspective. Various models are compared based on their effectiveness in representing impact and certain revisions in the current design procedures are suggested.
	Evaluation of the Performance of Steel pedestals under Low Seismic Loads The comrehensive study is motivated for recommending the best practices of steel pedestals subjected to low-to-moderated seismic loads.The performance of steel pedestals under low seismic loads is evaluated both experimentally and analytically. One of the major testing goals is to determine the structural properties and vulnerability of the steel pedestals. The analytical studies define the bearing stiffness properties of the steel pedestals to determine the displacement demands of the bridge system.
	Seismic Response and Analysis of Multiple Frame Bridges Using Shape Memory Alloys This research shows an agreement in the results of the simplified SMA models and the more complex SMA models. The research also shows that SMA devices are more effective at higher ambient temperatures. Comparisions done during the research show that SMA devices are more effective compared to steel restrainers, metallic dampers and the viscoelastic dampers under different conditions.