Dynamic Shear Moduli for Dry Sands

Using the Torsional Simple Shear Device, the writers investigated the relationship between the equivalent dynamic shear moduli, Geg and shear strain γ for Ottawa sand, Del Monte sand, Golden Gardens, and Seward Park sands. Based on their experimental findings, the writers propose two equations relating shear moduli to shear strain (below and above 0.03%) as a function of the soil angle of internal friction φ and the effective confining pressure σc. Also, a relationship is proposed that considers the effects of the number of stress cycles on equivalent shear moduli. A nomograph is proposed to assist in the easy determination of equivalent shear moduli for sands. A comparison is made between the writers' findings and the results of previous researchers.