Most currently available load-transfer models for axially loaded pile are either highly empirical or oversimplified without rigorous theoretical manner. This paper presents a novel and rigorous load-transfer model for axially loaded piles installed in modified Cam-clay (MCC) soils under undrained loading. The model is formulated in terms of the Lagrangian description based on the rigorous deformation mechanism of the soil around the pile shaft during undrained loading. Considering the boundary conditions and the equilibrium state of the soil, a t–z curve is extracted from the well-established MCC model that is employed to represent the elastoplastic behaviour of soil surrounding the pile. The proposed model is compared with a well-established finite element model and applied to predict the load–displacement behaviour of two well-documented piles to manifest the validity and capability of the model. The results demonstrate that the present theoretical model can well predict the elastoplastic load–displacement response of the pile and is capable of reflecting some important phenomena observed from pile load tests. The present model provides a rigorous, practical, and effective approach for estimation of the load–displacement behaviour of frictional piles installed in clayey soils.

大多数当前可用的轴向荷载桩的荷载传递模型要么是高度经验性的，要么是过于简化的，没有严格的理论方法。本文提出了一种新颖而严格的荷载传递模型，用于安装在不排水荷载下的改良凸轮粘土 (MCC) 土壤中的轴向荷载桩。该模型是根据拉格朗日描述建立的，该模型基于不排水加载过程中桩身周围土体的严格变形机制。考虑到边界条件和土壤的平衡状态，at-z 曲线是从已建立的 MCC 模型中提取的，该模型用于表示桩周围土壤的弹塑性行为。将所提出的模型与一个完善的有限元模型进行比较，并应用于预测两个有据可查的桩的荷载-位移行为，以证明该模型的有效性和能力。结果表明，目前的理论模型可以很好地预测桩的弹塑性载荷-位移响应，并能够反映从桩载荷试验中观察到的一些重要现象。本模型为估计安装在粘土中的摩擦桩的荷载位移行为提供了一种严格、实用和有效的方法。结果表明，目前的理论模型可以很好地预测桩的弹塑性荷载-位移响应，并且能够反映从桩荷载试验中观察到的一些重要现象。本模型为估计安装在粘土中的摩擦桩的荷载位移行为提供了一种严格、实用和有效的方法。结果表明，目前的理论模型可以很好地预测桩的弹塑性荷载-位移响应，并且能够反映从桩荷载试验中观察到的一些重要现象。本模型为估计安装在粘土中的摩擦桩的荷载位移行为提供了一种严格、实用和有效的方法。