Geotechnical Parameters for the Variegated Soils of São Paulo Formation

M. Caldo, F. Massad

Article

Soils and Rocks, São Paulo, 39(2): 189-200, May-August, 2016 | PDF


Abstract

The purpose of this paper is to present geotechnical parameters of the variegated soils from the São Paulo Formation, aiming in particular to establish correlations between stress history parameters, earth pressure coefficients at rest, deformability modules and resistance obtained through piezocone and dilatometer tests. The performance of in situ tests has, as the major advantage over laboratory tests for obtaining soil parameters of the project site, minimization of sample disturbance effects. Using data from geotechnical investigation carried out during the basic design of the Green Line expansion for the Metrô – SP it was possible to obtain preconsolidation pressure (σ’p), over consolidation ratio (OCR), earth pressure coefficients at rest (K0), Young’s module (Ei), initial shear module (G0), constrained module (M) and undrained shear strength (su) for the variegated soils of the São Paulo Formation. These soils are characterized by interlayered levels of clays and sands, constituting a characteristic with different geotechnical parameters and perched water tables. These characteristics explain some of the knowledge gaps on these soils. Nevertheless, it was possible to validate the correlations between earth pressure coefficients at rest (K0), over consolidation ratio (OCR), Young’s module (Ei), undrained shear strength (su) and preconsolidation pressure (σ’p) through field tests and the results of laboratory testing conducted by other authors.


Submitted on August 20, 2015; Final Acceptance on May 3, 2016; Discussion open until December 30, 2016.