天然气水合物主要以胶结物形式存在深海能源土颗粒之间,对能源土强度影响显著,因此研究水合物胶结接触力学特性对能源土力学性质研究有重要作用,而其中的关键是水合物胶结模型及胶结参数的确定。首先,引入并讨论了一种微观胶结接触模型及其对于能源土胶结接触力学特性的适用性;其次,通过文献资料系统分析,获取不同温度、压力及水合物密度条件下天然气水合物的强度与弹性模量表达式;最后,进一步研究了水合物微观胶结模型中的胶结参数,该类水合物微观胶结参数取决于能源土中水合物埋藏深度(赋存环境压力)、温度、水合物密度,这些宏观参量容易确定。
Methane hydrate (MH), which has significant influences on the strength of methane hydrate bearing soils, exits mainly in the form of cement materials between soil particles. Hence, the study of bond mechanical behavior of MH between soil particles is significant to the research of methane hydrate bearing soils, of which the keypoint is the determination of the micro-contact model and corresponding bond parameters of MH. First, a micro-bond contact model is introduced to reflect the contact properties of the soil particles. Second, the strengths and elastic modulus of MH (such as the tensile strength, compressive strength, shear strength and torsion strength) are obtained through the literatures about methane hydrate triaxial tests. Finally, micro bond parameters needed by the contact model are obtained. The results show that the micro bond parameters of gas hydrate are determined by the saturation and strength parameters of gas hydrate, which can be obtained through the temperature, density of hydrate and its burial depth which are easy to be determined.