One-Dimensional Compressibility Behavior of Overconsolidated Bootlegger Cove Clays: Fid-Bau Portal

One-Dimensional Compressibility Behavior of Overconsolidated Bootlegger Cove Clays

Zapata-Medina, David G. / Galeano-Parra, Diego I. / Arboleda-Monsalve, Luis G.

Accurate compressibility parameters are required for the design of shallow foundations and calculation of building settlements. Current geotechnical practice uses conventional incremental loading (IL) consolidation tests to evaluate soil compressibility. Alternatively, constant rate of strain (CRS) consolidation tests can be used to study soil compressibility, significantly reducing testing time. In this test, excess pore water pressures are measured and continuous load-deformation data is obtained leading to a better definition of the yielding or past pressure of the material. However, laboratory estimation of the at-rest earth pressure coefficient, K₀, is only possible via K₀-consolidation tests in a triaxial cell (pseudo K₀-TX). This paper presents a critical review of the results obtained from pseudo K₀-TX, IL, and CRS tests conducted on overconsolidated Bootlegger Cove clay samples. The discussion is centered on the results of CRS tests performed under strain rates of 1, 10, and 20% per hour and their effects on compressibility soil parameters. The evolution of K₀-values and maximum shear modulus during pseudo K₀-TX testing is also presented. Trimming-induced disturbance was evaluated for all specimens. Sample quality for the K₀-TX tests was better than samples for IL and CRS testing. It was found that CRS testing accelerates the definition of compressibility parameters with respect to conventional IL tests, yielding very similar results. However, compressibility parameters based on pseudo K₀-TX tests are more representative of the in situ conditions.