工业废弃木质素改良路基粉土动力特性及耐久性研究

The soil improvement technology based on reuse of industrial solid wastes is one of the hot and difficult topics in geoenvironmental engineering. The applicant has revealed that using industrial waste lignin to improve the silt has many obvious advantages such as improving the mechanical performances of silt, be beneficial to the waste utilization and the environmental protection. A comprehensive investigation on lignin treated silt is conducted based on the existing researches to study its dynamic properties and long-term durability. The following key problems are expected to be solved: (1) to study the variation of strain, pore water pressure, and modulus of lignin treated silt by conducting dynamic triaxial compression test, and to reveal the dynamic stress-strain characteristics of treated soil; (2) to explore the long-term durability and micro-mechanisms of the lignin treated silt exposed to complex external environment by wet-dry and thaw-freeze cycle testing and microstructure observation; and (3) to analyze the leaching characteristics of organic soluble salts in lignin treated silt, and to evaluate the effects of solute dissolution on the surrounding via column leaching tests and theoretical calculation. Based on these results, an engineering protection method for reducing the harm of these soluble solutes to the surrounding environment is expected to be proposed. The results will expand the engineering application of lignin stabilized subgrade silt, and provide important scientific guidance and theoretical support for improving the technology of silt improvement as well as enhancing the utilization of lignin in China.

工业固废改良土体技术是当前国内外环境岩土工程界研究的热点和难点课题之一。申请人已有研究表明，利用废弃木质素改良粉土，具有提高土体力学性能、废弃物资源化利用和环境保护的显著优点。本项目在已有基础上，系统研究木质素改良路基粉土的动力特性和耐久性能，拟解决以下关键问题：(1) 通过动三轴压缩试验，研究循环动荷载下木质素改良粉土的应变、孔隙水压力和模量的发展规律，明确木质素改良粉土的动应力-应变特征的变化；(2) 通过干湿循环、冻融循环试验和微观结构分析，研究木质素改良粉土在复杂外部环境下的耐久性能，揭示其微观机理；(3) 通过土柱淋滤试验和理论计算，研究木质素改良粉土中有机可溶盐的溶出特性，评价溶质溶出对周围环境的影响，提出相应的工程控制措施。研究成果有益于拓展木质素改良路基粉土技术的应用范围，对提高我国粉土的改良技术和增强废弃木质素的资源化利用提供重要的科学依据和理论支撑。

工业固废改良土体技术是当前国内外环境岩土工程界研究的热点和难点课题之一。申请人已有研究表明，利用废弃木质素改良粉土，具有提高土体力学性能、废弃物资源化利用和环境保护的显著优点。本项目在已有基础上，系统研究木质素改良路基粉土的动力特性和耐久性能，拟解决以下关键问题：(1) 通过动三轴压缩试验，研究循环动荷载下木质素改良粉土的应变、孔隙水压力和模量的发展规律，明确木质素改良粉土的动应力-应变特征的变化；(2) 通过水稳定性、干湿循环试验和微观结构分析，研究木质素改良粉土在复杂外部环境下的耐久性能，揭示其微观机理；(3) 通过现场路基填料取样测试分析，获得木质素改良粉土中重金属浓度，定量评价其对周围环境的影响，提出相应的工程控制措施。研究成果有益于拓展木质素改良路基粉土技术的应用范围，对提高我国粉土的改良技术和增强废弃木质素的资源化利用提供重要的科学依据和理论支撑。