This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
The effects of flexible and rigid protective barriers adjacent to underground structures (such as tunnels and pipelines) subjected to surface explosions will be investigated in the proposed project. The centrifuge is an attractive tool for this type of experiments, since the effects of a blast scale as the cubed of the centrifuge scaling factor, such that a small quantity of explosives can be used in a centrifuge model to create the same effects as a much larger quantity of explosives on a prototype scale. The results from centrifuge model tests will be used to calibrate a three-dimensional numerical model, which will be used to simulate the surface blast, using explicit dynamic analyses technique.
The use of a geotechnical centrifuge to conduct tests where the effects of blasts are simulated on models is well-documented in technical literature. Numerical analyses have also been recently employed to simulate effects of explosions. This project includes synergistic use of physical and numerical modeling to understand the role of different barriers in mitigating the effects of explosions.
The project will continue the PI?s earlier work in which the potential mitigating effects of flexible barriers immediately adjacent to underground structures were reported. Limitations to the beneficial effects identified in earlier research will be further investigated. Once calibrated, the numerical model will be utilized to understand the influence of various parameters, such as stiffness and thickness of barrier, relative density of soil, size and location of explosion, etc.
This project will provide an understanding of the influence of soil parameters and protective barriers on damage caused by surface blasts on underground structures. The interaction between soil, barrier, and underground structure due to dynamic loading such as explosions is not well-understood. A study utilizing both centrifuge and numerical modeling is expected to provide valuable understanding.
This project will be undertaken as Research in Undergraduate Institution (RUI). An undergraduate research assistant will work on this project with the PI and will gain valuable research experience, especially from collaborative work with Rensselaer Polytechnic Institute (RPI). The activities of this project will be shared with undergraduate and graduate students at Manhattan College (a predominantly undergraduate institution) as well as students from local high schools, who participate in summer engineering programs at the College. An estimated total of 120 students will be impacted by the project.
Live video broadcasts of the experiments from RPI will be shown to students (high school, undergraduate and graduate) at Manhattan College. The strong visual elements in the proposed study (experiments involving blasts and animation from numerical model) and the emphasis on topical issue (terrorist threat) are expected to appeal to students and demonstrate to them ways in which the Civil Engineering profession can contribute to Homeland Security.
