粒间胶结尺寸对圆形颗粒法向接触响应的影响

发布时间：2018-07-25 19:26

【摘要】：粒间胶结物的存在改变土体颗粒间接触力的传递方式,因此,显著影响天然结构性土体的宏观力学响应和强度。为了研究粒间胶结的几何尺寸对理想圆形颗粒法向接触力学行为的影响,采用有限元方法模拟了圆形胶结颗粒微观抗压试验,分析了粒间胶结厚度和宽度对粒间法向接触应力分布和抗压强度的影响,并将模拟结果与模型试验进行了对比。结果表明,数值试验所得到的峰前荷载-位移曲线与室内试验结果吻合较好。粒间法向接触应力分布不均,中心大,外缘小。塑性区分布与高应力区不重合,塑性区在胶结物中心和外缘之间产生,逐渐向中心和边缘方向扩展。胶结抗压强度随厚宽比增加而降低,相同厚宽比下抗压强度基本一致。
[Abstract]:The existence of intergranular cement changes the transfer mode of contact force between particles of soil, so the macroscopic mechanical response and strength of natural structural soil are significantly affected. In order to study the effect of the geometric size of intergranular cementing on the normal contact mechanical behavior of ideal circular particles, the micro-compression test of circular cemented particles was simulated by finite element method. The effects of intergranular cementation thickness and width on the normal contact stress distribution and compressive strength between particles were analyzed, and the simulation results were compared with the model tests. The results show that the prepeak load-displacement curves obtained by numerical tests are in good agreement with the results of laboratory tests. The distribution of normal contact stress between grains is uneven, the center is large and the outer edge is small. The distribution of plastic zone does not coincide with that of high stress zone, and the plastic zone occurs between the center and outer edge of the cement, and gradually extends to the center and edge. The compressive strength of the bond decreases with the increase of the thick-width ratio, and the compressive strength is basically the same at the same thick-width ratio.
【作者单位】：土木工程防灾国家重点实验室;同济大学地下建筑与工程系;广西岩土力学与工程重点实验室;
【基金】：国家自然科学基金(41572267;51239010) 科技部国家重点实验室基金(SLDRCE 14-B-11) 广西岩土力学与工程重点实验室资助课题(12-KF-02) 国家科技支撑计划课题(2013BA06B02)
【分类号】：TU43

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