水电能源科学

为了提高黄土的力学特性和减少传统污染性改良剂的使用，使用木质素和少量石灰(≤4%)综合掺入来改善黄土的力学性能，通过击实试验、无侧限抗压强度试验和直剪试验研究木质素和石灰对黄土物理力学性质的改善，并借助扫描电镜来解释木质素和石灰改良黄土的微观机理。结果表明，木质素和石灰综合掺入会使黄土最大干密度上升和最优含水率下降；木质素率0.7为木质素-石灰改良黄土的最优配比，此配比下的无侧限抗压强度最高提升2.7倍，抗剪强度相较于木质素改良土和石灰改良土有较大提升；木质素-石灰综合改良黄土的微观机理为木质素填充较大土体孔隙和粘结土颗粒，石灰的水化产物包裹土颗粒和木质素颗粒，填充较小孔隙，粘结土颗粒。

In order to improve the mechanical properties of loess and reduce the use of traditional polluting amendments, this paper uses a combination of lignin and a small amount of lime(≤4%) to improve the mechanical properties of loess. The improvement of the physical and mechanical properties of loess by lignin and lime was investigated by compaction test, unconfined compressive strength test and straight shear test, and the micro-mechanism of the improvement of loess by lignin and lime was explained with the help of scanning electron microscope. It was found that the combination of lignin and lime would increase the maximum dry density and decrease the optimum water content of loess. The lignin rate of 0.7 is the optimal ratio for lignin-lime-amended loess, which increases the unconfined compressive strength by a maximum of 2.7 times, and the shear strength by a large amount compared with that of lignin-amended and lime-amended soils. The microscopic scanning point electron microscope images explained the micro-mechanism of the lignin-lime integrated improved loess as follows: lignin fills the larger soil pores and binds the soil particles, and the hydration products of lime encapsulate the soil particles and lignin particles, fill the smaller pores and bind the soil particles.