Effect of cyclic shear stress ratio on cyclic behavior of clay under multidirectional shear loading

• DOI: 10.1080/1064119x.2023.2267042
• Publication Date: 2023-11-06T17:09:50Z
• Authors: Hongxu Jin; Daoming Pan; Lin Guo; Li Shi
• Keywords: Shear modulus; Cyclic stress; Overburden pressure; Damping ratio

In offshore engineering, soft clay foundations supporting infrastructure are subjected to significant multidirectional cyclic shear stresses due earthquake or storm loads. To explore the undrained behavior of foundation clays under critical loading conditions, a series tests were conducted using variable-direction dynamic system. By controlling amplitude ratio (η) two mutually perpendicular in horizontal plane, both unidirectional and stress paths achieved. The strength, stiffness, pore water pressure presented discussed by considering effects η (CSR). results suggest that increase CSR accelerates failure, stiffness degradation, accumulation specimens. An η-independent strength curve is established normalizing 0.755η. Although hardly affects modulus x direction (Gx) during first cycle at it parameter (χ) governing shape degradation curve. Additionally, model proposed for predicting evolution normalized residual with respect number cycles, wherein d remains unaffected η.