Deriving Stiffness Parameters from 'Simple' in Situ Tests and Relating them with Reference Values on Saprolitic Soils from Granite

摘要

The bonded structure and fabric of residual saprolitic soils from granite have significant influence on their geomechanical behaviour. Typical profiles of Porto urban area have been intensely studied. Extensive in situ testing included: SPT, CPT, DP, PMT, CH (seismic tests) and PLT (under different loading areas). Identification of stiffness properties for geotechnical design based on such field testing method is very much dependent on several factors, from which the strain level will be focused in this paper. The structural particularities of these residual soils influence their pattern of non-linear constitutive behaviour. Deformability modulus derived from robust but relatively "gross" tests (such as SPT, CPT, DP or even PMT) are compared with reference values taken from seismic survey (CH) and load tests (such as PLT) and are situated on stress-strain levels defined from laboratory triaxial tests over high quality undisturbed samples.