| 基于微观胶结厚度模型的深海能源土宏观力学特性离散元分析 |
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| 引用本文： | 蒋明镜,贺洁,周雅萍.基于微观胶结厚度模型的深海能源土宏观力学特性离散元分析[J].岩土力学,2013,34(9):2672-2681. |
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| 作者姓名： | 蒋明镜 贺洁 周雅萍 |
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| 作者单位： | 1. 同济大学 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 |
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| 基金项目： | 国家杰出青年科学基金项目(No.51025932)；国家自然科学基金项目(No.10972158)；教育部博士点基金(No.20100072110048)。 |
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| 摘 要： | 首先，引入蒋明镜等提出的考虑水合物胶结厚度的深海能源土粒间微观胶结模型，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，并将其引入离散单元法中；然后，对选定的水合物饱和度经过实际二维离散元模拟调算，得出相应的水合物胶结尺寸，以修正水合物临界胶结厚度、最小胶结厚度及胶结宽度，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，针对不同水合物饱和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、体变、剪胀角等方面与Masui等所进行的能源土室内三轴试验进行对比分析。结果表明：采用考虑粒间胶结厚度的水合物微观胶结模型，能够定性反映深海能源土的宏观力学特性，能源土试样的峰值强度、黏聚力和剪胀角均随水合物饱和度的增加而增加，但水合物饱和度对内摩擦角的影响规律不明朗；能源土试样的峰值强度、残余强度及体积剪缩量随着有效围压的增大而增大；剪胀角随有效围压的增大而减小。
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| 关 键 词： | 深海能源土 微观胶结厚度模型 离散单元法 |
| 收稿时间： | 2012-10-18 |
Distinct element analysis of macro-mechanical properties of deep-sea methane hydrate-bearing soil using micro-bond thickness model |
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| JIANG Ming-jing
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HE Jie
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ZHOU Ya-ping.Distinct element analysis of macro-mechanical properties of deep-sea methane hydrate-bearing soil using micro-bond thickness model[J].Rock and Soil Mechanics,2013,34(9):2672-2681. |
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| Authors: | JIANG Ming-jing HE Jie ZHOU Ya-ping |
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| Institution: | 1. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China; 2. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China |
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| Abstract: | First, the micro-bond contact model considering hydrate cementation thickness of the deep-sea methane hydrate soil proposed by Jiang et al. was applied to describe micro-bond contact mechanical properties of hydrate between methane hydrate soil particles. Second, the model is introduced into the discrete element method (DEM) by using C++ language to program it. Third, based on the selected hydrate saturation, the corresponding hydrate cementation size is obtained through actual adjustable calculation of two dimensional DEM simulation to revise the values of hydrate critical bond thickness, minimum bond thickness and bond width, then micro-bond parameters are determined. Finally, based on the parameters of methane hydrate, many biaxial tests with different hydrate saturations are carried out to simulate the mechanical properties of deep-sea methane hydrate soils. In addition, comparisons are made between triaxial experimental observations done by Masui et al. and numerical simulation from aspects of stress-strain, volumetric, dilatancy angle of methane hydrate soils. The results show that the macromechanical properties of deep-sea methane hydrate soils are reflected qualitatively by using hydrate micro bond model considering bond thickness; peak shear strength, cohesive force and dilatancy angle of deep-sea energy soil increase with increasing content of hydrate; but the influence of hydrate saturation on internal friction angle is uncertain; peak shear strength, residual shear strength and volume shrinkage increase with increasing effective confining pressure while dilatancy angle decreases. |
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| Keywords: | deep-sea methane hydrate-bearing soil micro-bond thickness model distinct element method |
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