Experimental Study on Unconfined Compression Strength and Split Tensile Strength Properties in relation to Freezing Temperature and Loading Rate of Frozen Soil

doi:2012.26.6.19

J. Ocean Eng. Technol. > Volume 26(6); 2012 > Article

J. Ocean Eng. Technol. 2012;26(6):19-26.
DOI: https://doi.org/10.5574/KSOE.2012.26.6.019

Seo Young-Kyo,Choi Heon-Woo

Department of Ocean Engineering Korea Maritime University,Department of Ocean Engineering Korea Maritime University

동결 온도와 재하속도에 따른 동결토의 일축압축 및 쪼갬인장 강도특성

서영교,최헌우

한국해양대학교 해양공학과,한국해양대학교 해양공학과

Keywords: Frozen soil, Uniaxial compression test, Indirect tensile test, Freezing temperature, Axial strain rate, Initial tangent modulus

핵심용어: 동결토, 일축압축시험, 간접인장시험, 동결온도, 축 변형 속도, 초기탄성계수

Abstract

Recently the world has been suffering from difficulties related to the demand and supply of energy due to the democratic movements sweeping across the Middle East. Consequently, many have turned their attention to never-developed extreme regions such as the polar lands or deep sea, which contain many underground resources. This research investigated the strength and initial elastic modulus values of eternally frozen ground through a uniaxial compression test and indirect tensile test using frozen artificial soil specimens. To ensure accurate test results, a sandymud mixture of standard Jumunjin sand and kaolinite (20% in weight) was used for the specimens in these laboratory tests. Specimen were prepared by varying the water content ratio (7%, 15%, and 20%). Then, the variation in the strength value, depending on the water content, was observed. This research also established three kinds of environments under freezing temperatures of $-5^{circ}C$, $-10^{circ}C$, and $-15^{circ}C$. Then, the variation in the strength value was observed, depending on the freezing environment. In addition, the tests divided the loading rate into 6 phases and observed the variation in the stress-strain ratio, depending on the loading rate. The test data showed that a lower freezing temperature resulted in a larger strength value. An increase in the ice content in the specimen with the increase in the water content ratio influenced the strength value of the specimen. A faster load rate had a greater influence on the uniaxial compression and indirect tensile strengths of a frozen specimen and produced a different strength engineering property through the initial tangential modulus of elasticity. Finally, the long-term strength under a constant water content ratio and freezing temperature was checked by producing stress-strain ratio curves depending on the loading rate.