Estimation of minimum undrained shear strength for flow liquefaction using the CPT

摘要

Sensitive clays, metastable silts and very loose sands can strain soften following earthquake loading resulting in possible instability. This instability is often referred to as flow liquefaction. The minimum undrained shear strength is an important parameter in a stability analysis for soils than can strain soften during undrained shear. However, the estimation of this minimum undrained shear strength is often difficult, especially for sandy soils. Research has shown that the undrained shear strength of soils is usually a function of direction of loading, with compression loading often stronger than simple shear and triaxial extension. For many conditions in practice simple shear often represents the average direction of loading. A method is proposed to estimate the minimum undrained shear strength of soils in simple shear using the CPT.