Comparison between results of dynamic & static moduli of soil determined by different methods

A comprehensive study was carried out to investigate static and dynamic soil properties for a high rise building in Jeddah, Saudi Arabia. A total of 21 boreholes were drilled to a maximum depth of 100 m including the performance of Standard Penetration Tests and core measurements for rock formations. Pressure-meter tests were performed to determine Young, ES and shear, G moduli while shear wave velocity were measured through cross-hole method. The dynamic shear modulus Gmax and Poisson’s Ratio (υ) could be estimated directly through relations with shear wave velocity. Three boreholes at three locations were prepared during drilling for carrying out pressure-meter tests every 5.0 m from ground surface down to 60.0 m. Other two locations at the site were chosen to perform cross-hole tests. These tests were performed from ground surface down to 55.0 m at intervals of 1.50 m. A comprehensive comparison was established between the results of Young and shear moduli determined from pressure-meter, cross-hole and S.P.T. It was observed that the values of ES and G determined via pressure-meter are much less than those of Ei and Gmax determined via cross-hole tests. It was also observed that the results of shear wave velocity, estimated via S.P.T correlations, have a wide range but are in fair agreement with the results of cross-hole tests.