EAPSI:Laboratory Scale Testing of the Thermal Improvement of Soft Clays

Bengochea Pedro O, Blacksburg VA

Investigators

Abstract

The main objective of this summer research is to study how soft clays are able to gain strength by the injection of high temperatures. This newly developed concept is called thermal consolidation. The researcher will work under the supervision of Dr. Chang-Young Yune at the Gangneung-Wonju National University in South Korea and Dr. Guney Olgun from Virginia Tech in the USA. Dr. Yune is a world-renown expert in soft clay engineering and has developed a consolidation chamber to study the compression of soft clays. This is a one-of-a-kind experimental setup that will allow the researcher to inject a range of high temperatures into a variety of clayey soils to assess how this increase in temperature affects the strength of the soil. The improvement of soft soils is of paramount importance because it will enable the construction of heavy structures on soft soils. The thermal consolidation will be conducted by circulating hot fluid in a piping system that goes down and up through a borehole contained in a consolidation chamber. Clay particles increase in volume due to thermo-elastic expansion, which causes a reduction in pore volume between the clay particles, and a subsequent increase in strength. This experimental study will allow the researcher to understand the behavioral mechanisms of pore pressure development, drainage, and strength gain during the thermal improvement. The thermal improvement of soft clays represents a major scientific and engineering breakthrough to improve in-situ conditions of soft clay deposits for the construction of buildings with heavy structural loads. The expected findings will also positively impact the engineering practice by reducing the costs associated with in-situ ground improvement of soft clay deposits. The summer research will lay the foundations for more detailed experimental and analytical studies to further investigate the thermo-mechanical phenomenon related to thermal improvement of soft clays. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the National Research Foundation of Korea.