Determining Elastic Soil Properties At Small Strains

Geotechnical and geophysical techniques have been combined to determine the elastic<br>parameters of a series of lacustrine clays at a location where series of highway underpasses<br>are to be constructed. Piezocone penetrometer and triaxial tests on borehole core samples<br>allowed variations of the soil structure and the shear modulus /J over a range of larger<br>strains to be measured. The small-strain behavior of p was established from seismic<br>measurements. Extremely low ,U values of less than 50 MPa and Poisson’s ratios near 0.5<br>for small strains were found. Together with experience gained from the first construction<br>phase, these results will be used to optimize the design of construction process.