A shear‐transformation‐zone (STZ) model is proposed for time‐dependent behaviours of clay, in which the viscoplastic deformation is described by the evolution of a temperature‐like state variable. The model is featured by rate‐dependent dilatancy and a unique critical state stress ratio. In its present form, it has nine parameters, most of which can be handily calibrated, and can predict the rate‐dependent undrained shear strength, primary, and secondary creep, as well as stress relaxation for normally consolidated clay under complex stress paths using a single set of parameters. The capabilities of the model have been verified by available experimental results on five different clays.

中文翻译：

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粘土随时间变化行为的剪切转变区模型


针对粘土的时间相关行为提出了剪切转变区（STZ）模型，其中粘塑性变形通过类温度状态变量的演化来描述。该模型的特点是速率相关的膨胀和独特的临界状态应力比。在目前的形式中，它有九个参数，其中大部分都可以轻松校准，并且可以使用以下方法预测与速率相关的不排水剪切强度、初级和次级蠕变，以及在复杂应力路径下正常固结粘土的应力松弛。单组参数。该模型的功能已通过五种不同粘土的可用实验结果得到验证。