四氢呋喃水合物沉积物静动力学性质试验研究

利用研制的天然气水合物沉积物合成与力学性质测试一体化试验设备，以粉细砂土和蒙古砂土作为沉积物骨架，对四氢呋喃(THF)水合物沉积物进行了静动三轴试验，获得了水合物分解前后沉积物样品的应力-应变关系、强度和液化特性，对两种骨架的水合物沉积物的性质进行了对比，同时将水合物分解后的沉积物与对应的饱和土的动三轴试验结果进行了对比。结果表明：水合物沉积物均表现为塑性破坏；围压越大，水合物沉积物强度越高；水合物分解导致沉积物的强度大幅降低；水合物分解后沉积物液化所需的时间较饱和水沉积物缩短

Experimental study of static and dynamic properties of tetrahydrofuran hydrate-bearing sediments

By using the integrated experimental apparatus for syntheses of gas hydrate sediment and triaxial tests, a series of static and dynamic tests are conducted on the tetrahydrofuran (THF) hydrate with fine sand and Mongolia sand as the skeleton. The stress-strain curves, strength and liquefaction characteristics of the sediments before and after hydrate dissociation are obtained. The mechanical properties of the two kinds of hydrate sediments with fine sand and Mongolia sand as the skeleton, as well as the liquefaction characteristics of the sediment after dissociation of hydrate and the corresponding saturated sand are compared. It is shown that the hydrate-bearing sediments all behave as plastic failure, strength of which the increases with the formation of hydrate and the confining pressure. The dissociation of hydrate can lead to the great decrease of the strength of the sediments. The liquefaction of the sediment after dissociation of hydrate needs shorter time relative to the corresponding saturated sand