深海能源土宏观力学性质离散元数值模拟分析  

Numerical simulation of macro-mechanical properties of deep-sea methane hydrate bearing soils by DEM

作　　者：蒋明镜[1,2] 肖俞[1,2] 朱方园[1,2] 

机构地区：[1]同济大学土木学院地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《岩土工程学报》2013年第1期157-163,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家杰出青年基金项目(51025932);教育部博士点基金(20100072110048);国家自然科学基金项目(10972158)

摘　　要：首先,引入笔者等[16-17]所提出的微观胶结模型用以反映能源土颗粒之间水合物微观胶结接触力学特性;其次,采用C++语言将模型程序化,建立同商业软件PFC2D的程序接口,将模型引入离散单元法中;然后,通过简化计算方法确定胶结宽度随水合物浓度的变化规律,进而确定水合物微观胶结参数;最后,根据所确定的胶结参数,针对不同水合物浓度试样进行能源土宏观力学特性离散元双轴试验模拟,并从应力应变、体积应变、水合物对能源土弹性模量的影响等方面与Masui等[4]所进行的能源土室内三轴试验进行对比分析。结果表明:所选择胶结模型及微观胶结参数能有效反映深海能源土宏观力学规律;能源土峰值强度、弹性模量均随水合物浓度增加而增加,体积膨胀随水合物浓度的增加越来越显著。First, the micro-bond contact model proposed by Jiang et al. is employed to describe micro-bond contact mechanical properties of hydrate between methane hydrate bearing soil particles. Second, in order to introduce the model to the DEM commercial software PFC2D, a program interface is established by using C＋＋ to program the model. Third, based on the saturation of hydrate, cemented width is obtained through a simplified method, and micro bond parameters are determined. Finally, based on the micro parameters of methane hydrate, many biaxial tests with different hydrate contents are carried out to simulate the mechanical properties of the soil. In addition, comparisons are made between triaxial experimental observations done by Masui et al. and numerical simulation f/om aspects of stress-strain, volumetric strain and elastic modulus of the soil. The results show that the macro-mechanical properties of deep-sea methane hydrate bearing soils are reflected reasonably by using the selected bond contact model and micro bond parameters, that the peak shear strength and elastic modulus of deep-sea energy soils increase with the increasing content of hydrate, and that the volumetric dilate is more pronounced.

关 键 词：深海能源土 微观胶结模型 离散单元法 

分 类 号：TU43[建筑科学—岩土工程]