在实际工程中,土拱效应不可避免地受到动荷载的影响。基于Trapdoor模型试验,建立了相应的离散元分析模型,通过比较模型试验结果与数值模拟结果,从应力和变形2个方面验证了数值模型的可靠性,并在此基础上研究了内摩擦角、荷载幅值和荷载频率对土拱效应的影响。为定量衡量土拱效应的退化程度,定义了土拱退化参数α。结果表明,在局部动荷载作用下,土拱会发生退化:随着内摩擦角的增大,土拱退化参数 α逐渐减小,表明土拱效应的退化程度降低;随着荷载幅值和频率的增加,土拱退化参数 α逐渐增大,意味着土拱效应的退化程度增加。
Abstract
In practical engineering, soil arching effect is inevitably affected by cyclic loading. To investigate the effects of internal friction angle, cyclic loading amplitudes, and cyclic loading frequencies on soil arching, a discrete element model was set up based on Trapdoor model tests by PFC2D in this paper. The validity of the discrete element model was verified by comparison between the discrete element results and experimental data of stress and deformation. Furthermore, a degradation parameter α of soil arching was defined to quantify the degradation of soil arching. Results manifested that soil arching did degrade under localized cyclic loading. With the expansion of internal friction angle, the degradation parameter α gradually declined, indicating an attenuation in the degradation of soil arching. In the meantime, the degradation parameter α increased with the growth of cyclic loading amplitudes and frequencies, respectively, implying that the degradation of soil arching intensified.
关键词
局部动荷载 /
离散元 /
土拱效应 /
Trapdoor模型试验 /
相似土
Key words
localized cyclic loading /
discrete element /
soil arching effect /
Trapdoor model tests /
analogical soil
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参考文献
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基金
国家自然科学基金面上项目(51478349);国家自然科学基金青年科学基金项目(42002270)
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