Abstract
This paper investigates the permeability characteristics of compacted loess by focusing on the anisotropy parallel and perpendicular to the compaction. Three tests are conducted on compacted loess: triaxial permeability test under confining pressure consolidation, triaxial permeability test under K0 consolidation, and SEM test. Samples are maintained and tested at different dry densities under saturated conditions. The test results show that the saturated permeability coefficient of compacted loess is exponentially related to the initial dry density under both confining pressure consolidation and K0 consolidation. The fitting equation can estimate the saturated permeability coefficient of compacted loess at different depths. The horizontal saturated permeability coefficient of compacted loess is larger than that in the vertical direction, showing obvious anisotropy. The saturated permeability anisotropy ratio is linearly related to the initial dry density. Comparing and analysing the saturated permeability coefficient, the saturated permeability coefficient of compacted loess under the K0 consolidation condition is smaller than that under the confining pressure consolidation condition. Under the condition of K0 consolidation, the connectivity of vertical and horizontal pores of compacted loess is weakened, the tortuosity is strengthened, and the void ratio is decreased. K0 consolidation makes the flake‐, plate‐, and needle‐like particles in compacted loess rotate continuously parallel to the compaction surface, which enhances the orientation of particles and leads to the saturated permeability anisotropy increase. The research results provide the basis for water field analysis in loess filling engineering.
Highlights
Large-scale hill-cutting and gully-filling and artificial landbuilding projects have been carried out successively in the loess area in China
Consolidation under confining pressure simplifies the stress state of the soil sample in situ to three-dimensional equal stress action, which simplifies the operation of the test, but the stress state of the soil sample does not conform to the actual situation, which will cause errors in the analysis of the water field in soil
Coefficient of earth pressure at rest Q3 (K0) consolidation is a consolidation process in which only axial strain occurs and no radial strain occurs under confining pressure and axial deviator stress, which is in accordance with the actual stress state of soil samples in the soil layer
Summary
E saturated soil hydraulic conductivity is predicted from models by triaxial permeability test data under confining pressure consolidation [2, 3]. Under the condition of triaxial equal confining pressure consolidation, the study of the permeability of soil is not consistent with the actual stress state of soil, which will inevitably produce some errors in the study of the distribution of the water field in soil. Erefore, in this paper, the saturated triaxial permeability tests under confining pressure and K0 consolidation are carried out for compacted loess samples with different dry densities and different consolidation confining pressure to obtain the permeability coefficients. Rough comparative analysis of the permeability coefficient, the difference of saturated permeability of compacted loess under K0 consolidation and confining pressure consolidation is obtained. E research contents are of great significance to the analysis of the water field in compacted loess
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
