| 董辉,马一跃,傅鹤林,王智超,陈铖.颗粒离散元模拟堆积碎石土变形的参数灵敏度分析[J].计算力学学报,2015,32(2):192~199 |
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| 颗粒离散元模拟堆积碎石土变形的参数灵敏度分析 |
| Particles discrete element simulation accumulation of gravel soil deformation parameter sensitivity analysis |
| 投稿时间：2013-11-28 修订日期：2014-03-10 |
| DOI：10.7511/jslx201502009 |
| 中文关键词: 滑坡 堆积碎石土 虚拟试验 细观参数 灵敏度分析 |
| 英文关键词:landslide alluvial gravel soil virtual test micro-parameters sensitivity analysis |
| 基金项目:国家自然科学基金(51108397,51308485);湖南省自然科学基金(2015JJ2136,2015JJ6038)资助项目. |
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| 中文摘要: |
| 采用颗粒离散单元方法,实现任意形状块石的模拟,基于室内试验数据标定滑坡坡体物质的堆(残、坡)积碎石土的细观参数,并考虑试样尺度效应,对影响堆积碎石土宏观变形特征的细观参数进行虚拟试验敏感度分析。研究表明,①以三轴剪切试验获得测试数据并标定颗粒离散元细观参数具有相对误差在5%以内的可靠性;②虚拟模型1(101 mm×200 mm)与模型2(300 mm×600 mm)对标定的细观参数具有尺度效应,但其相对误差控制在9%以内;③离散元颗粒间的摩擦系数与碎石土的内摩擦角、抗剪强度及残余强度为非线性正相关,摩擦系数每增加0.1,峰值主应力差平均增加118.85 kPa,残余强度平均增加90.44kPa; ④围压越大,材料的剪胀性越弱,围压在100 kPa~500 kPa时,剪胀特征值K在3~6之间变化,随着围压增加,模型破坏时的粘结力以近线性增加;⑤杨氏模量越大,碎石土的抗剪强度越大,但两者之间并不成线性关系,且不同杨氏模量对材料的残余强度没有显著影响。 |
| 英文摘要: |
| The author uses the granular discrete element method to simulate the arbitrary shape stone and calibrate the mesoscopic parameters of gravel soil which was mainly constituted by weathering, unloading, alluvial, deluvial, etc. Calibration is based on indoor triaxial compression experiments measured data at the same time considering the scale effect of sample. This paper analyzed the sensitivity of the mesoscopic parameters which affection the accumulation of gravel soil macro deformation characteristics through the virtual experiment. Studies have shown that:① The mesoscopic parameters of gravel soils based on indoor experimental calibration relative error is within 5%.② The size of the virtual experiment include model 1(101 mm×200 mm) and the model 2(300 mm×600 mm). The model 2 to mesoscopi parameters calibration has scale effect, but the relative error controlled within 9%.③ There are nonlinear positive relationships between the coefficient of friction of discrete element particles and the angle of internal friction, and the shear strength, and the residual strength. When the friction coefficient increased by 0.1, the peak deviator stress average increased 118.85 kPa and the residual strength average increased 90.44 kPa.④ The greater the confining pressure, the weaker the material dilatancy is, when the confining pressure is changing between 100 kPa~500 kPa, the dilatancy characteristic value K is obtained from 3 to 6. The cohesive force of the damaged model nearly increases linearly as confining pressure increases. ⑤ The greater the Young's modulus, the greater the shear strength of the gravel soil is, but there is not a linear relationship between them. Moreover, Young's modulus does not affect residual strength of material significantly. |
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