To evaluate any urban transportation system based on economic, environmental and social sustainability indices, one needs a modeling system that replicates the behaviour of travellers under various land use and transportation scenarios. As a part of my research such modeling systems have been developed for our cities. These models should be sensitive to the short-term decisions of individuals, such as choice of transport mode, route and departure time; medium to long term decisions like choice of work place and residence; and land use policies of the planning bodies.

Highway bridges exposed to harsh environmental conditions and located in active seismic regions shows a cumulative increase in earthquake induced damage along their service lives. While environmental degradation mechanisms are typically continuous throughout the lifetime, earthquake shocks are intermittent that depend on the seismicity of the region. Among the different aging mechanisms commonly observed in bridges, this study focuses on corrosion deterioration of critical bridge components such as bridge piers.

In recent decades, particularly after the industrial revolution, the emissions of greenhouse gas (CO2) has substantially increased. The continued increase in the CO2 concentration can lead to an increase in global temperature (see Fig. 1). It is important to note that, the increase in temperature has an effect on the rate of corrosion and consequently, the seismic performance of the bridges may be affected by this variation. In fact, numerous studies have attempted to explain the effects of climate change and global warming on corrosion and maintenance cost of highway bridges.

Civil infrastructure systems such as highway bridges play an essential role in the sustained economic growth and social development of any country. During their service life, highway bridges are continuously exposed to multiple chemical and physical stressors such as corrosion deterioration along with intermittent seismic threats. These deterioration effects, if not effectively monitored and managed, can cause significant reduction in structural functionality and safety especially during extreme event such as earthquakes.

Shear failure is one of the most critical failure modes in reinforced concrete (RC) structures as it is brittle in nature involving the rapid deterioration of strength with increasing widths of the shear cracks. In order to effectively design these structures, it is essential to develop accurate simulation models which can predict their complete nonlinear behaviour. With the development of accurate simulation models, better decisions (retrofitting or demolition) can also be made regarding existing structures during seismic assessments.

Prestressed concrete (PC) members degrade rapidly when the steel strands are subjected to corrosion thereby decreasing the lifespan of the PC structure. Another problem with the use of steel strands is the loss of prestressing force in steel strands which can go up to 24% for prestressed members. Due to this there has been considerable research during the last decade to replace steel strands with Fiber Reinforced Polymer (FRP) strands, which exhibit lower long term losses and are not susceptible to corrosion.

In India, traditional base isolation devices such as rubber pads have been used for more than two decades to reduce the response of structures due to the horizontal components of seismic waves. Such base isolation systems are generally not suitable for providing adequate protection against the vertical components of seismic waves and also result in large relative horizontal displacement between the foundation and the super-structure during seismic events.

The infrastructure of a country plays a major role in its growth and prosperity. It is vital to protect critical infrastructure from natural and man-made hazards to ensure safety of people and minimise environmental and economic impact. One such emerging hazard that requires immediate attention in India is the blast loading of structures due to detonation of high-explosives.

India is looking towards nuclear power as a viable clean energy option to meet its growing energy demands. A target has been set in India’s climate action plan to increase the current capacity of nuclear power from 5 - 63 GW. However, concerns related to seismic safety of nuclear power plants (NPPs) first need to be addressed. One of the possible mitigation measures could be to use seismic isolation to reduce the seismic risk to NPPs.

Geomaterial