Field measurements of permeability for residual soils

摘要

Flow of water through soil voids is an important concern in geotechnical engineering. Generally, the coefficient of permeability determined in the field is different from the coefficient of permeability determined in the laboratory. Factors cited for the differences include sample size effect with respect to the presence of macroscopic defects, non-homogeneity and secondary structures such as cracks and grass roots. There were reports where the field coefficient of permeability is greater than the laboratory coefficient of permeability and in others, the reverse is true. In this paper, field measurements of saturated permeability for Singapore residual soils using double-ring infiltration test, borehole soakaway test and constant-head well permeability test using Guelph permeameter method are examined and compared with permeability measurements in the laboratory.