摘要: |
堆石料作为土石坝的主要构筑材料,其在地震作用下的动变形特性受颗粒形状,级配和相对密度等影响。关于颗粒形状对堆石料力学特性的研究,目前主要集中于静力特性的研究,关于动力特性方面的研究相对较少。本文采用水泥净浆浇筑方法制备了不同形状的人工模拟堆石料并进行动力循环三轴试验,研究颗粒形状对动残余应变和颗粒破碎的影响。研究结果表明:采用本文方法制备的人工模拟堆石料可以近似反应天然堆石料的动变形特性;在低围压下,残余体积应变随形状系数的增大而减小,在高围压下,规律相反;轴向残余应变随形状系数Q的增大而先增大后减小;在相同应力条件下,形状系数Q越小,颗粒破碎率越低,并建立了颗粒形状系数和颗粒破碎率与残余应变系数的关系。 |
关键词: 颗粒形状 残余变形 颗粒破碎 人工模拟堆石料 形状系数 |
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Experimental study on the influence of particle shape on the dynamic deformation characteristics of artificially rockfill materials |
YANG Gui, LIU Yu, TANG Chenjing
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Hohai University
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Abstract: |
As the primary material for earth-rock dams, the dynamic deformation characteristics of rockfill materials under seismic action are influenced by factors such as particle shape, gradation, and relative density. Currently, research on the influence of particle shape on the mechanical properties of rockfill materials primarily focuses on static characteristics, with less attention given to dynamic characteristics. This study employs the cement slurry casting method to prepare artificial simulated rockfill materials with varying shapes and conducts dynamic cyclic triaxial tests to investigate the impact of particle shape on dynamic residual strain and particle fragmentation. The findings indicate that the artificial simulated rockfill materials prepared using this method can closely mirror the dynamic deformation characteristics of natural rockfill materials; at low confining pressure, the residual volume strain decreases with the increase of shape coefficient, while under high confining pressure, the pattern is reversed; axial residual strain first increases and then decreases with the increase of shape coefficient; At the same stress level, the smaller the shape coefficient, and the lower the particle breakage rate. The relationship between the particle shape coefficient, particle breakage rate, and residual strain coefficient was established. |
Key words: particle shape residual deformation particle breakage artificially simulated rockfill materials Shape factor |