TENSILE STRENGTH CHARACTERISTICS OF HYDRATE-BEARING SOIL

The tensile strength characteristic of hydrate-bearing soil is important for evaluating the stability of hydrate-bearing layer during hydrate exploitation. Adopting the clayey silt as host sediment,the hydrate-bearing soils were synthesized by using tetrahydrofuran(THF)instead of methane. Meanwhile,the tension tests were performed in controlled temperature environment. The results show that when hydrate saturation,dry density and content of fine grain have significant influences on the tension strength. As hydrate saturation increases,the tension strength exhibits an increase tendency with exponential function. The influences of dry density and fine grain content are related with the hydrate saturation. At the low hydrate saturation,the increase in dry density and fine grain content can improve the tensile strength. At the high hydrate saturation,the tensile strength lowers with the increasing dry density and fine grain content. In addition,the acoustic wave for hydrate-bearing soil is measured. The relationship between tensile strength and acoustic wave characteristic is analyzed,which is useful for estimating the tensile strength of hydrate-bearing soil in the future.