黏粒和粉粒的共存对砂土静动力液化影响的试验研究
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摘要
为了研究黏粒、粉粒与砂粒共存的土体中,黏粒和粉粒对砂土抗液化的影响规律,通过静力与动力三轴仪试验系统,对细粒(黏粒和粉粒)含量FC为5%和10%、三种不同细粒配比的试样进行静力与动力三轴试验。试验结果表明:相同细粒含量、不同细粒配比试样的抗液化强度不同;当细粒含量不同时,随着细粒中黏粒或粉粒含量的单调变化,试样所表现出的抗液化规律不同;FC=10%试样的抗液化强度整体高于FC=5%试样的相应强度。随着细粒含量及细粒中黏粒与粉粒相对含量的变化,黏粒与粉粒对砂粒的填充、黏结与骨架作用所占比例不同。
In order to study the influence rules of clay and silt on the liquefaction resistance of sand in the mixture of clay, silt and sand, based on the static and dynamic triaxial tests, the sand specimens with two different fines(clay and silt) contents(FCs), 5% and 10%, and three different fines proportions are investigated by the static and dynamic triaxial system. The test results show that the liquefaction resistance of specimens with the same fines content and different fines proportions are different. When the fines content of the specimens is different, the laws of liquefaction resistance are different with the monotonous change of the clay or silt content in the fines. The liquefaction resistance of the specimens with FC of 10% are higher than that of the specimens with FC of 5%. The clay and silt play roles of filling, bonding and skeleton effects on the sand particles. And with the change of clay and silt content in the fines, the proportion of these three roles is different under different fines contents.
In order to study the influence rules of clay and silt on the liquefaction resistance of sand in the mixture of clay, silt and sand, based on the static and dynamic triaxial tests, the sand specimens with two different fines(clay and silt) contents(FCs), 5% and 10%, and three different fines proportions are investigated by the static and dynamic triaxial system. The test results show that the liquefaction resistance of specimens with the same fines content and different fines proportions are different. When the fines content of the specimens is different, the laws of liquefaction resistance are different with the monotonous change of the clay or silt content in the fines. The liquefaction resistance of the specimens with FC of 10% are higher than that of the specimens with FC of 5%. The clay and silt play roles of filling, bonding and skeleton effects on the sand particles. And with the change of clay and silt content in the fines, the proportion of these three roles is different under different fines contents.
引文
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[2]XENAKI V C,ATHANASOPOULOS G A.Liquefaction resistance of sand-silt mixtures:an experimental investigation of the effect of fines[J].Soil Dynamics and Earthquake Engineering,2003,23:183-194.
[3]董林,王兰民,夏坤,等.含细粒砂性土标贯液化判别方法改进研究[J].岩土工程学报,2015,37(12):2320-2325.(DONG Lin,WANG Lan-min1,XIA Kun,et al.Improvement of SPT-based liquefaction discrimination methods for fines-containing sandy soils[J].Chinese Journal of Geotechnical Engineering,2015,37(12):2320-2325.(in Chinese))
[4]CARRERA A,COOP M R,LANCELLOTTA R.Influence of grading on the mechanical behavior of stave tailings[J].Géotechnique,2011,61(11):935-946.
[5]THEVANAYAGAM S,MOHAN S.Intergranular state variables and stress-strain behaviour of silty sands[J].Géotechnique,2000,50(1):1-23.
[6]SL237-1999土工试验规程[S].1999.(SL237-1999Specification of Soil Test[S].1999.(in Chinese))