Initial Elastic Modulus Degradation Using Pressuremeter and Standard Penetration Test Results at Two Sites

Abstract

In-situ testing was performed at two sites consisting of pre-bored pressuremeter testing, seismic surface wave testing to develop a shear wave velocity profile, and Standard Penetration testing during the soil boring phase in order to evaluate the feasibility of using large shallow foundations for a project. This study focuses on a comparison of the in-situ direct measurements of soil stiffness obtained from this testing program. The small strain modulus obtained from the seismic surface wave test results is compared to the intermediate strain modulus obtained from both the initial loading pressuremeter modulus and reload pressuremeter modulus. The modulus calculated from blowcount correlations is compared to that of the pressuremeter modulus. The comparisons made from this relatively small data set reveal several trends within the data that are discussed and possible explanations posed. The results of the study are mostly inconclusive due to the small data set. Finally, recommendations are given to further investigate the trends that are revealed.