New laboratory database of hydraulic conductivity measurements on fine-grained soils

Geotechnical databases are vital for engineers wishing to make well-informed, empirical estimations of key soil mechanics parameters. Transformation models linking more difficult-to-measure parameters from readily attainable ones allow engineers to make low-cost a-priori estimations of the more difficult-to-measure parameters. Databases and associated transformation models allow for new test data to be benchmarked against prior knowledge. Other smaller databases (which may represent a specific data subset) can also be benchmarked against larger ones. The use of databases is especially valuable for assessing permeability (or hydraulic conductivity) – an important parameter that exhibits a very large range of variation across different soil types and within datasets obtained from individual laboratory testing campaigns. The issue of parameter uncertainty is often difficult to discount when hydraulic conductivity is a key parameter in a geotechnical model due to said variation. This chapter provides a comprehensive review of the variability and uncertainty of soil hydraulic conductivity with a focus on fine-grained materials, followed by a comparative study on the compilation of fine-grained soil hydraulic conductivity databases and transformation models for hydraulic conductivity making use of the recently established soil hydraulic conductivity database, FG/KSAT-1358. This chapter concludes with recommendations for future development and analysis of soil hydraulic conductivity databases.