Cement Deep-Soil Mixing
Professor K.K. “Muralee” Muraleetharan, School of Civil Engineering and Environmental Science, University of Oklahoma, and his team, which includes engineers from Iowa State, San Jose State University, UCLA, UCDavis, Earth Mechanics, Inc. and Advanced GeoSolutions, are studying a technique called “cement deep-soil mixing”, which strengthens clay soil to improve the performance of bridge pilings. The research project is a first step in a long-term process of understanding and improving the seismic behavior of pile foundations in soft clays. For structures undergoing seismic retrofit with pile foundations in weak soils, improving soils may be the only option.
According to Muraleetharan, innovative centrifuge and full-scale field tests using NEES sites at UCLA and UC Davis, simplified analysis methods and sophisticated, fully-coupled, simulation techniques are being used to understand and improve the seismic behavior of pile foundations in soft clays. As part of the study, the researchers are working in Miami, OK because the soft red clay soil is similar to soil in San Francisco and the New Madrid, which are some of the target applications for the project. The test hopes to determine if movement in the soil around iron piles that support bridge stanchions in earthquake zones may be controlled by adding certain amounts of cement. Testing will be conducted in mid-October. (NSF Award #0830328, “NEESR-SG: Understanding and Improving the Seismic Behavior of Pile Foundations in Soft Clays,” Muraleetharan, principal investigator, and Gerald Miler, Sri Sritharan, Steven Vukazich, and Amy Cerato, co-principal investigators.)