Research

Multi-Hazard Resilience

The structural design decisions that we make for buildings and bridges subjected to extreme forces (such as earthquakes, fires, hurricanes) greatly affect how many deaths, how much damage, and how long a recovery time a community will have following an extreme event. One of my research areas examines multi-hazard resilience for structures in various contexts. In this section, research topics are listed in reverse chronological order (from the time that the research started). Our research began at the element level (e.g. columns and connections), broadened to the system level (entire buildings), and has recently progressed to the community level (examining the effect of buildings on the community in an extreme event).

Innovative LFS Plates for Enhanced Structural Performance

Stimulated by the study of web shear buckling of flat plates, the team has developed the concept of low-frequency sinusoidal (LFS) plates, which have the advantage of exceptional shear strength, reduced (or elimination) of transverse stiffeners, and economy in comparison to both flat and corrugated plates. The LFS frequencies are “much lower than those used in…

Adaptable Aquatecture: Kinetic Umbrellas for Coastal Defense

Traditional forms of armor are relatively low in cost, but they are frequently associated with numerous adverse social and environmental consequences such as unattractive, restricting public access to beaches, fostering a false sense of security, and adversely affecting the natural ecosystem. An innovative structural system, kinetic umbrellas, are designed for hard countermeasures against nearshore hazards.…

Web Shear Buckling

Thin steel plates are commonly used as structural elements in buildings, bridges, towers, aircrafts, etc. Due to their slenderness, these plates are susceptible to buckling under shear loading, thus limiting their capacity. The recent research shows that many existing models do not represent the true mechanics of ultimate shear buckling. This project will investigate and…

Community Resilience

A community is comprised of a complex and dynamic system of infrastructure and networks. The infrastructure serves the human needs and in an extreme event, ideally this infrastructure remains operable; but most infrastructure are not designed to resist low probability – high consequence events. In addition, the functionality of infrastructure such as buildings and bridges…

Probabilistic Approach to Fire Design

Fire is a particularly dangerous event not only because the structural response is not fully understood, but also because it may be a primary or secondary event caused by many other hazards (e.g. earthquake, blast). The fire safety design of buildings is typically the responsibility of the architect, not the engineer. This fire design is…

Fire Following Earthquake

Citizens and policy makers are organizing themselves to enable the development of “resilient” communities. This means that our communities, which are highly dependent on our infrastructure, not only need to withstand major events such as large earthquakes, but also recover quickly from that event so that functionality is restored. Thus, we need to consider all…

Steel Bridges Subject to Fire

In recent decades, due to rapid development of urban ground transportation system, as well as increasing transportation of hazardous material, bridge fires have become a major concern in the U.S. Fire hazard in bridges can result in significant economic and public losses. Traffic on fire damaged bridges is usually hard to detour and significantly affect…

Steel Connections for Fire

In a steel framed building, the connections support the floor beams and provide overall stability to the structure; and in a fire scenario, the performance of the connections plays a crucial role on the response of the structure as a whole. Furthermore, a recent survey has shown that where partial floor collapse ensued in steel…

Steel Columns with Thermal Gradients

Beam-columns are defined as members that are subject to axial load (P) plus bending moment (M). In a fire, perimeter columns act as beam-columns even though they may not have been designed to resist moment. Perimeter columns are found on the perimeter of a building or adjacent to an opening (e.g., shaft) in the floor…

Self-Centering Steel Frames for Earthquake Resilience

Current design practice for earthquake-resistant buildings produces systems that meet basic life safety requirements, but post-earthquake damage costs are enormous. For example, direct losses of more than $40 billion have been estimated for the 1994 Northridge earthquake in California, even though this earthquake was not large in magnitude. New earthquake- resistant structural systems that withstand…