The research objective of this research project is to develop a unified, scalable approach for soil liquefaction deformation analysis from micro to macro-scale.The overarching research goal is to identify and quantify the physical and environmental parameters that affect the cyclic response of granular soils at the micro- and meso-scale particularly and relate them to the macro-scale (i.e. field) response and deformations.
The objective of this program is to develop a novel type of "slurry" cut-off wall for levees that possesses multiple risk mitigation applications,including seepage resistance, high seismic resistance, constructability, and sustainable fabrication. This interdisciplinary project is expected to bring about new approaches that addresses the performance of broad geotechnical infrastructure systems such as levees and embankments, but potentially also other systems such as, piles, below grade pipes and underground infrastructure that have common features of soil/structure/materials interactions and are often subjected to large imposed deformation and water seepage.
This project is focused on better characterizing pile-driving induced vibrations and understanding their attenuation. Emphasis is given on quantifying the effect of soil type, hammer and pile combination and number of cycles on the soil settlement. This is achieved by a combination of field testing measurements and 3D finite element numerical analyses, to develop vibration thresholds in terms of soil peak particle velocity for different soil types. Among the truly unique aspects of the project is that measurements during pile driving are not collected only at the ground surface as has been done in the past, but at different distances and depth from the moving pile tip.
The objective of this project is to study the effectiveness of an EPS geofoam compressible inclusion as a seismic isolator against seismic lateral pressures. Twocentrifuge testshave been performed on small scale physical models of retaining structures with and without EPS compressible inclusions, generating the first centrifuge data that highlight the seismic isolation capabilities of the material. Finite elemet numerical analyses have also beenperformed that were validated against the experimental data and were subsequently used to model the seismic response of retaining walls.
In this research project, ground motion intensity measures that are critical for predicting levee response have been established. The variability of levee response in terms of soil liquefaction triggering and seismic slope stability has been investigated and regressions have been developed to serve as guidelines for selection of ground motions for levee embankments.
This project focuses on developing a decision-making methodology that helps users prioritize mitigation efforts and predict levee system performance for selected seismic event scenarios.The proposed methodology will track uncertainties associated with (1) levee geometry, soil stratigraphy and soil properties, (2) the interpolation method, and (3) the calculation of the joint probability of failure due to multiple scenarios. The impact of soil spatial variability on levee response and validation of the developed GIS-based tool is assessed by performing field Vs (shear wave velocity) measurements for assessing the spatial variability of soil materials.