改良碳酸盐渍土路基填料的力学性质

Mechanical properties of improved carbonate soil roadbed filler

摘要:

针对吉林省西部地区的碳酸盐渍土,基于不同石灰、石灰+粉煤灰改良土的方法,通过界限含水率试验、击实试验、三轴剪切试验研究了石灰、石灰+粉煤灰改良碳酸盐渍土的工程特性和强度特征,并结合土的固结压缩试验分析探讨了改良盐渍土的变形特性。结果表明:掺加石灰和石灰+粉煤灰改良剂可以有效改善碳酸盐渍土的塑性和击实特性；碳酸盐渍土掺加改良剂后,使得石灰和石灰+粉煤灰改良土的抗剪强度有效提升,石灰改良土在掺量达到9%时强度有所降低,而石灰+粉煤灰改良土则随着不同土层不同含盐量的变化,使得改良效果有所不同；改良后的盐渍土由中压缩性土转为低压缩性土,随着养护龄期的增加土的压缩变形降低,采用合理的改良剂掺量能使得改良后的盐渍土压缩性达到最优。

Abstract:

For the carbonate soil in the western part of Jilin province, considering different methods of modifying soil using lime and lime + fly ash, the engineering and strength characteristics of carbonate soil improved by lime and lime + fly ash were studied via limit moisture content test, compaction test, and triaxial shear test. Combined with the analysis of consolidation compression test, the deformation characteristics of the improved saline soil were discussed. Results show that the lime and lime + fly ash modifiers could effectively improve the plasticity and compaction characteristics of the carbonate soil. With the addition of lime and lime + fly ash modifiers to the carbonate soil, the shear strength of the improved soil was increased. When the dosage reached 9%, the strength of lime-modified soil decreased, while the strength of the soil modified by lime + fly ash varied with different salt contents, resulting in different improvement effects. The improved saline soil transformed from medium compressive soil into low compressive soil. With the increase in the maintenance age, the compressive deformation of the soil decreased. The compressibility of the saline soil could reach the best by adding a reasonable amount of modifier.