| 不同应力路径下水土耦合超固结黏土分叉分析 |
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| 引用本文： | 陈立文,孙德安.不同应力路径下水土耦合超固结黏土分叉分析[J].岩土力学,2011,32(10):2922-2928. |
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| 作者姓名： | 陈立文 孙德安 |
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| 作者单位： | 上海大学 土木工程系，上海 200072 |
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| 摘 要： | 基于超固结黏土三维弹塑性本构模型，导出水-土耦合部分排水条件下饱和黏土应变局部化的萌生条件，求出在不同应力路径下，单相和水-土耦合条件下超固结土分叉的三维解析解和数值解。理论分析表明，应力罗德角 为-30°、15°和30°时，无论是单相条件，还是水土耦合两相介质条件，该模型均无分叉现象产生；应力罗德角为0°时，单相条件下该模型有分叉现象产生，水土耦合不排水条件下该模型无分叉现象出现，水-土耦合部分排水条件下分叉与否则与参数选取有关；应力罗德角为-15°时，无论是单相条件，还是水-土耦合条件，该模型均有分叉现象产生。利用嵌入了上述本构模型的有限元软件ABAQUS，对单相和水-土耦合条件下的多单元立方体应变局部化分叉现象进行数值分析。分析表明，在应力罗德角为 30°时，单相条件和水土耦合条件下都无分叉现象产生；应力罗德角为15°时，单相条件下有分叉现象产生，水-土耦合不排水条件下无分叉现象出现，水-土耦合部分排水条件下何时分叉则与渗透系数大小有关；应力罗德角为-15°和0°时，单相条件和水土耦合条件下该模型均有分叉现象产生。同一应力路径下数值解相对于理论解更易出现分叉。
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| 关 键 词： | 超固结土 本构模型 部分排水 分叉 数值模拟 |
| 收稿时间： | 2010-11-15 |
Bifurcation analysis of overconsolidated clays with soil-water coupling along different stress paths |
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| CHEN Li-wen,SUN De-an.Bifurcation analysis of overconsolidated clays with soil-water coupling along different stress paths[J].Rock and Soil Mechanics,2011,32(10):2922-2928. |
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| Authors: | CHEN Li-wen SUN De-an |
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| Institution: | Department of Civil Engineering, Shanghai University, Shanghai 200072, China |
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| Abstract: | Based on a three-dimensional elastoplastic constitutive model. for overconsolidated clays, an acoustic tensor and discriminator of bifurcation for strain localization under partially drained conditions are given. The analytical and numerical solutions to the model along different stress paths are resolved. The theoretical analysis shows that, there is no bifurcation occurring at the Lode angles of -30°, 15°and 30° for both single-phase and soil-water coupling two-phase materials. At the Lode angle of 0°, the bifurcation occurs for the single-phase and doesn’t occur for the soil-water coupling under undrained condition; while whether bifurcation occurs is related to the parameter under partially drained condition. There is bifurcation occurring at the Lode angle of -15° for both the single-phase and soil-water coupling. Numerical simulations on a cubic specimen for the bifurcation for the single-phase and soil-water coupling are carried out by use of a nonlinear finite element analysis software ABAQUS with the model being implemented. The numerical analysis shows that, there is no bifurcation occurring at the Lode angles of 30° for both single-phase and soil-water coupling. At the Lode angle of 15°, bifurcation occurs for the single-phase and doesn’t occur for the soil-water coupling under undrained condition; while the time when bifurcation occurs is related to the permeability under partially drained condition. There is bifurcation occurring at the Lode angles of -15° and 0° for both the single-phase and soil-water coupling. Bifurcation of numerical solutions is more likely to occur than that of analytical solutions along the same stress paths. |
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| Keywords: | overconsolidated clay constitutive model partially drained condition bifurcation numerical simulation |
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