Comparative Study of Shear Modulus in Calcareous Sand and Sabkha Soils

Abstract

The estimation of various soil moduli has always been a fundamental component of geotechnical engineering. Since most design works involve assessment of ground response to stress applications, an accurate estimate of the soil modulus is deemed imperative for computational geotechnics. Due to the non linearity of the stress-strain response of soils, the shear modulus is always a function of strain amplitude thus making the quantification of shear modulus critical when it comes to consideration of strain level induced by both loading scheme and soil properties. The comparison between the static and dynamic shear modulus as well as between various tools used to measure the shear modulus was rarely carried out on carbonate sands originating from marine sediments. This paper focuses on a comparison between small strain shear modulus (Go) measured using the down-hole seismic test (DH) and the seismic cone penetration test (SCPT) and estimated shear modulus (Go) obtained using available correlations with SPT and CPT. The comparison is conducted on unconventional soils comprised of Sabkha soils and cemented calcareous sands for a site in Abu Dhabi. The paper also compares the small-strain Go to the “high” strain G derived from cone penetration testing (CPT).