| 摘要: |
| 【目的】研究易溶盐含量和基质吸力对非饱和伊犁黄土强度的影响规律，为伊犁黄土地区工程建设提供参考。【方法】利用水膜转移法将配置好的盐溶液加入原状伊犁黄土土样中，制成3种不同易溶盐含量（5，14，26 g/kg）土样，采用非饱和土三轴仪进行3种不同易溶盐含量下控制净围压（100，200，300 kPa）和基质吸力（50，100，150 kPa）的三轴固结排水剪切试验，测定并分析土样强度的变化规律。【结果】 非饱和伊犁黄土的偏应力 轴向应变关系曲线均为硬化型；在相同净围压和基质吸力作用下，易溶盐含量14 g/kg非饱和伊犁黄土的强度最高。非饱和伊犁黄土的有效黏聚力随基质吸力的增大而增大，随易溶盐含量的增加呈先增大后减小的趋势,易溶盐含量5，14，26 g/kg的非饱和伊犁黄土在50，100，150 kPa 3种基质吸力下的有效黏聚力分别为21.30，31.50，40.50 kPa，33.10，44.80，58.10 kPa和19.70，28.30，36.70 kPa。有效内摩擦角随基质吸力的增大基本不变；随易溶盐含量的增加呈先减小后增大的趋势，分别为23.33°，22.35°，23.76°。随着易溶盐含量的增加吸力摩擦角分别为10.76°，14.04°，9.65°，呈先增大后减小的趋势，且增减速率相同。【结论】基于Barcelona模型建立的非饱和伊犁黄土弹塑性模型的剪切屈服面方程，具有可以考虑易溶盐含量和基质吸力两个因素耦合变化的优点，适用于易溶盐含量较高的伊犁黄土。 |
| 关键词: 伊犁黄土 易溶盐 黄土强度 弹塑性模型 屈服面方程 |
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| 基金项目:“十三五”国家重点研发计划项目(2017YFC0405103)；陕西省重点研发计划项目（2017ZDXM-SF-074） |
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| Effects of soluble salt content on strength of original unsaturated Ili loess |
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ZHAO Qingyu,ZHANG Aijun,WANG Yuguo,et al
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| Abstract: |
| 【Objective】This study investigated the influence of soluble salt content and matrix suction on strength of unsaturated Ili loess to provide reference for construction in the Ili loess areas.【Method】 The water film transfer method was used to add salt solution to original Ili loess,and three types of soil samples with soluble salt contents of 5,14 and 26 g/kg were prepared.Unsaturated soil triaxial apparatus was used to determine and analyze the change of soil strength by triaxial consolidation drainage shear test at different net confining pressures (100,200 and 300 kPa) and matrix suctions (50,100 and 150 kPa).【Result】 The partial stress-axial strain curves of unsaturated Ili loess were hardened.Under same net confining pressure and matrix suction circumstance,the strength of unsaturated Ili loess with 14 g/kg soluble salt content was the strongest.The effective cohesion of unsaturated Ili loess increased with the suction of matrices,while increased first and then decreased with the increase of soluble salt content. The effective cohesions of 5,14 and 26 g/kg unsaturated Ili loess under matric suctions of 50,100 and 150 kPa were 21.30,31.50 and 40.50 kPa,33.10, 44.80 and 58.10 kPa,as well as 19.70,28.30 and 36.70 kPa,respectively.The effective internal friction angle remained same with the increase of the matrix suction,while it increased with the increase of soluble salt content with values of 23.33°, 22.35° and 23.76°,respectively.The suction friction angles were 10.76°,14.04° and 9.65° as the increase of soluble salt content,indicating increase first followed by decrease with same rate.【Conclusion】Based on the Barcelona model,a shear yield surface equation of the elasto plastic model of unsaturated Ili loess was established.It has the advantage of coupling changes of easily soluble salt content and suction,and is very suitable for Ili loess with high soluble salt content. |
| Key words: Ili loess soluble salt loess strength elastic-plastic model yield surface equation |
