非饱和重塑黄土固结特性试验研究

摘要

Taking disturbed loess of filled project in Yan’an new district engineering construction as the research object , this research calculated the accurate settlement of loess foundation in filled area ,based on the geotechnical engineering design parameters of filled project loess ,indoor Q3 disturbed loess samples were made for consolidation test .Four groups of unsaturated consolidation tests with different controlling matric suction were carried out .Compressive curve of the un-saturated and undisturbed loess sample were obtained .The influence of matric suction to consolidation characteristics of disturbed loess was analyzed .The results show that :For same initial state disturbed loess soil samples ,compressibility coefficient reduces when the matric suction increases ;Compression index of unsaturated and disturbed loess sample was influenced not only by vertical pressure but also by matric suction .Compressibility index reduces when the matric suction increases ;The total vertical strain of disturbed loess sample which control parameters referred to the actual geotechnical engineering design plan was small under the 2 MPa vertical stress .The biggest vertical strain was 0 .7% .%以延安新区工程建设中填方区的重塑黄土为研究对象，以准确计算填方区黄土地基的沉降为主要目标，以工程实际中填方区黄土的岩土工程设计参数为参照，室内制取了 Q3重塑黄土固结样。开展了4组控制吸力的非饱和土固结试验，得到了非饱和重塑黄土的压缩曲线，分析了吸力对重塑黄土固结特性的影响。研究表明：初始状态相同的重塑黄土土样，压缩系数随吸力的增大而减小；非饱和重塑黄土试样的压缩指数除了受竖向压力影响外，也受吸力作用的影响，压缩指数随着吸力的增大而减小；在2 MPa 的竖向应力下，重塑黄土土样总的竖向应变较小，最大的竖向应变为0．7％。