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填充型水合物的砂性能源土试样可视为特殊的散粒体材料,即砂粒和水合物颗粒混合物,具有明显的非连续特征。为研究填充型水合物的能源土力学特性,初步探索了甲烷水合物在不同温度、反压条件下加荷模式的离散元模拟方法。离散元模拟中,将水合物块体视为由大量颗粒通过强胶结作用凝聚而成的整体,室内试验中的内部孔隙水压作用转化为水合物颗粒间的胶结力,故需要合理确定颗粒间胶结模型参数来实现反压的影响作用。通过参数反演建立了宏观强度、刚度参数与平行胶结模型的微观胶结参数间的宏、微观关系,基于已有室内甲烷水合物三轴试验资料,确定了给定温度和反压条件下的微观胶结参数取值,随后进行离散元单轴压缩试验。离散元单轴压缩试验模拟获得的水合物强度特性,与室内三轴试验结果符合较好;通过建立的宏、微观参数间的关系,实现了不同温度、反压下的水合物加荷模式的模拟。为进一步提出深海能源土离散元数值试验成样方法——孔隙填充水合物生成技术,形成含填充型水合物的能源土试样,研究其力学和变形特性奠定基础。
The sand-filled energy source soil samples filled with hydrates can be considered as special particulate materials, ie sand and hydrate particle mixtures with distinct discontinuities. In order to study the energy and soil mechanics characteristics of filled hydrates, the discrete element simulation method of methane hydrate loading under different temperature and pressure conditions was preliminarily explored. Discrete element simulation, the hydrate block as a large number of particles formed by the strong agglomeration of aggregates formed by the internal experiment pore pressure hydration into the cement between the hydration particles, it is necessary to properly determine the intergranular Cementing model parameters to achieve the effect of back pressure. Through the inversion of parameters, macroscopic and microscopic relations between macroscopic strength and stiffness parameters and the micro-cementation parameters of parallel cementing model were established. Based on the triaxial test data of existing methane hydrate, the microscopic The parameters of cementation parameters, followed by discrete element uniaxial compression test. The strength characteristics of hydrates obtained by the discrete element uniaxial compression test are in good agreement with the results of the triaxial tests in the laboratory. The relationship between the macro and micro parameters is used to obtain the hydrate loading patterns under different temperatures and pressures simulation. In order to further put forward a sample formation method for numerical simulation of discrete elements in deep-sea energy soils-pore-filled hydrate formation technology, a sample of energy-bearing soil containing filled hydrate was formed, and its mechanics and deformation characteristics were studied.