水合物沉积物试验岩样制备及力学性质研究

水合物沉积物现场取心及原位力学试验技术难度大、成本高,室内制备岩样是目前对其力学性质研究的主要手段。采用三轴压力室内直接合成和混合制样两种方法,分别以覆膜砂和膨润土为基质试验制备水合物沉积物岩样,并进行三轴压缩力学试验。结果表明:尽管沉积物中水合物对基质骨架颗粒存在一定胶结作用,但水合物沉积物的力学性质仍主要由基质的性质决定,覆膜砂基质水合物沉积物的力学性质明显好于膨润土沉积物;水合物沉积物的强度及弹性模量随着围压的增加而增加,但泊松比与围压无明显相关性。

Experimental sample preparation and mechanical properties study of hydrate bearing sediments

As the original coring and in-situ mechanical experiment are difficult and expensive,the experimental preparation of hydrate bearing sediments is the main approach to studying its mechanical properties.Using the direct synthesis in triaxial cell and compound method respectively,the precoated sand and bentonite base hydrate bearing rock samples were prepared,and the triaxial tests were carried out.The results show that although the hydrate in sediments has certain cementation to rock skeleton particles,the mechanical properties of hydrate bearing sediments mainly depend on the base material.And the precoated-sand hydrate deposits are significantly better than the bentonite sediments.The strength and elastic modulus of hydrate bearing deposits increase with the confining pressure increasing,but the Poisson’s ratio has no obvious correlation with confining pressure.