Test Study on Consolidation Character of Unsaturated Loess

Abstract

To calculate accurately settlement of loess foundation in filled area as the main goal, disturbed loess of filled project in Yan’an new district engineering construction in China as the research object, Q3 disturbed loess samples were made indoor for consolidation test by the reference of geotechnical engineering design parameters of filled project loess in actual practical project. Four groups of unsaturated consolidation tests were carried out with matric suction ranging from 100kPa to 500kPa. Compressive curve of the unsaturated and undisturbed loess sample were obtained. The influence of matric suction to consolidation characteristics of disturbed loess was analyzed. Results show: (1) For same initial state disturbed loess soil samples, when matric suction increases from 100kPa to 500kPa, the compressibility coefficient reduces from 0.151MPa-1 to 0.095MPa-1. Compressibility coefficient reduces with increasing the matric suction; (2) 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 increase; (3) The total vertical strain of disturbed loess sample which control parameters referred to the actual geotechnical engineering design plan was small under the 2MPa vertical stress. The biggest vertical strain was 0.7%.