Lakshmi N. Reddi Professor, (past)

The objective of this research is to develop basic understanding of the effect of vibrations on phase separation of immiscible contaminants in soils saturated with Non-Aqueous Phase Liquid (NAPL) and water. Exploratory studies conducted by the principal investigator indicate that vibrations induced in a soil medium saturated with NAPL and water can successfully separate and dislodge the NAPL phase. The proposed study will include a series of laboratory tests to evaluate the vibratory phase separation of NAPL ganglia as a function of vibration frequencies. The attenuation of vibratory phase separation will be assessed Dynamic criteria will be developed for phase separation and mobilization of immiscible ganglia in Soil-NAPL-water systems.During the one-week visit, the collaborators expect to (1) gather field information on which to develop the experimental basis of future research, (2) observe the placement of filters and overall construction procedures as an aid to understanding discrepancies between field observations and laboratory results, (3) formulate assumptions for the modeling component of the proposed research project, and (4) prepare an outline of the modeling and experimental components of the proposed research for review by tunneling industry consultants and by KOSEF prior to submission of a formal proposal to NSF and KOSEF. A number of soil structures, both above ground and subsurface, require filters for protection against erosion and piping. Fine particle accumulation in filters leads to buildup of pore pressure which can be large enough to cause damage to such structures as retaining walls, dams, and tunnels adjacent to the clogged filters. Field conditions in the subway system in Seoul, Korea, offer an excellent opportunity to test the fundamental particle transport models currently being developed by the PI The proposed collaborators have considerable experience in the field of the proposed research. This project is relevant to the objectives of the US-Korea Program which seeks to increase the level of cooperation between US and Korean scientists and engineers through the exchange of scientific information, ideas, skills, and techniques and through collaboration on problems of mutual interest and benefit.

• Performance of soil and geosynthetic filters and drainage layers
• Particle erosion and transport in soils
• Immiscible fluid phase dynamics in soils
• Seepage and contaminant transport through lagoon liners (compacted clay and GCLs)
• Basic research on upscaling using fractals and random networks
• Stochastic and Uncertainty Analyses

East Asia and Pacific Program, Engineering-civil, Geomechan, Geotech & Geoenvirn, Materials Research