钙质砂的干密度特征及其试验方法研究

发布时间：2019-01-19 13:00

【摘要】：最大、最小干密度是评价砂土密实度的重要计算参数。通过钙质砂的最大、最小干密度试验,揭示了钙质砂颗粒破碎对最大干密度的影响,分析了最大、最小干密度随粒径和含水率的变化规律,并总结了钙质砂的最大、最小干密度的测试方法。研究表明,最大干密度随粒径的增大呈现先减小后增加的趋势;在最大干密度的测试中存在明显的颗粒破碎现象,使测试结果偏大;颗粒破碎量随粒径的增加先增加后减小,其中粗砂的破碎量最大;最小干密度随粒径的增大而减小,单一粒组钙质砂最小干密度的最大值仍然小于级配良好钙质砂的最小干密度,同一粒组的钙质砂的最小干密度随含水率的增大呈现出略有减小的趋势。建议钙质砂的最大干密度试验宜采用电动相对密度仪法,最小干密度试验宜采用量筒法。
[Abstract]:Maximum and minimum dry density are important calculation parameters for evaluating sand compactness. Through the test of maximum and minimum dry density of calcareous sand, the effect of particle breakage on maximum dry density of calcareous sand is revealed, the variation law of maximum and minimum dry density with particle size and moisture content is analyzed, and the maximum dry density of calcareous sand is summarized. Test method for minimum dry density. The results show that the maximum dry density decreases first and then increases with the increase of particle size, and there is obvious particle breakage in the test of maximum dry density, which makes the test results larger. With the increase of particle size, the amount of particle breakage first increases and then decreases, among which the coarse sand is the largest. The minimum dry density of calcareous sand decreases with the increase of particle size, and the maximum value of minimum dry density of single grain group of calcareous sand is still smaller than that of well-graded calcareous sand. The minimum dry density of calcareous sand in the same grain group decreased slightly with the increase of moisture content. It is suggested that the maximum dry density of calcareous sand should be tested by electric relative densitometer and the test of minimum dry density by measuring tube method.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;中国科学院大学;广西大学土木建筑工程学院;
【基金】：科技部973计划课题(No.2013CB956104) 国家科技支撑计划项目(No.2014BAC01B01) 国家自然科学基金(No.41572297)~~
【分类号】：TU441

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