Effect of Ultralow Temperature on Expansion, Strength, and Modulus of Cement-Stabilized Soil: Case Study for LNG Underground Storage in Singapore

Singapore has a relatively high water table. When liquefied natural gas (LNG) storage systems are built in soils below the water table in Singapore, the engineering properties of the surrounding soils could be improved through cement stabilization. Due to the extremely low temperature (T) of LNG (approximately -162 degrees C), the effect of ultralow T on the physical and mechanical properties of cement-stabilized soil in case of accidental LNG leakage should be investigated. However, existing studies on cement-stabilized soils are limited to T above -20 degrees C. Therefore, in this study laboratory experiments to quantify volumetric expansion, unconfined compressive strength (UCS), and Young's modulus (E) of cement-stabilized soils at -40 degrees C, -80 degrees C, and -120 degrees C were conducted. The experimental results indicated that the stabilized soils' volumetric expansion reached <= 2.6% at -120 degrees C. The UCS and E of the stabilized soils increased from 0.9 to 27.6 MPa and from 99.8 to 2,669 MPa, respectively, and the T decreased from 24 degrees C to -120 degrees C. In summary, the ultralow T induced limited volumetric expansion (<3%) for cement-stabilized soil and significantly increased its strength and E, which indicated that cement soil stabilization could be beneficial for underground LNG storage systems in Singapore when exposed to accidental LNG leakage.

Automated summary

Singapore's high water table can be improved by cement stabilization when liquefied natural gas (LNG) storage systems are built underground. However, there is limited research on the effect of ultralow temperature on cement-stabilized soil. This study conducted laboratory experiments to investigate the physical and mechanical properties of cement-stabilized soils at temperatures as low as -120 degrees C.