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

今年夏天的主要研究目标是研究软粘土如何通过注入高温来获得强度。这种新发展的概念被称为热固结。这位研究人员将在韩国江陵元州国立大学的张英云博士和美国弗吉尼亚理工大学的古尼·奥尔贡博士的指导下工作。Yune博士是世界著名的软粘土工程专家，他开发了一个固结室来研究软粘土的压缩。这是一个独一无二的实验装置，将允许研究人员向各种粘土中注入一定范围的高温，以评估温度的升高如何影响土壤的强度。软土的改良是至关重要的，因为这将使在软土上建造重型结构成为可能。热固结将通过管道系统中的热流体循环进行，管道系统通过固结室中的钻孔上下移动。粘土颗粒由于热弹性膨胀而体积增大，这导致粘土颗粒之间的孔隙体积减小，从而导致强度增加。这项实验研究将使研究人员了解在热改善过程中孔压发展、排水和强度增加的行为机制。软粘土的热改良是一项重大的科学和工程突破，可以改善软粘土沉积物的就地条件，用于建造结构荷载较大的建筑物。预期的发现还将通过降低与软粘土矿床原位地基加固相关的成本，对工程实践产生积极影响。夏季的研究将为更详细的实验和分析研究奠定基础，以进一步研究与软粘土热改善相关的热机械现象。该奖项由东亚和太平洋暑期学院项目资助一名美国研究生的暑期研究，由NSF和韩国国家研究基金会共同资助。

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.