桩基荷载传递函数扰动状态模型及应用

基于扰动状态概念，认为桩土界面单元的状态有完整状态和临界状态，受力后界面中处于这两种状态的单元服从随机分布，荷载由它们共同承担．据此建立了相应的桩基荷载传递函数模型．结合不均匀化材料的均匀化理论与概率统计方法，以桩的塑性剪切位移为分布变量，提出了模型中扰动参数的计算原理与方法．模型中，完整状态时的桩土界面单元抗剪强度采用Duncan—Chang模型计算，临界状态时的桩土界面单元承担的应力可采用传统的摩尔-库仑强度理论计算．模型具有参数较少且确定简单的特点，能反映荷载传递函数的性质，如硬化与软化，以及围压的影响．通过与实测数据的对比，验证了本文模型的准确性．最后利用建立的模型，对某工程试桩进行了分析，阐述了本文模型的工程实用价值．

New Model of Load Transfer Function for Pile Analysis Based on Disturbed State Model

Based on disturbed state concept, a new model of load transfer function for pile analysis is established by the idea that the deforming material element between pile and soil can be treated as a mixture of two constituent parts in the intact and critical state, which are assumed to obey random distribution. Starting from the homogenization theory of heterogeneous materials and statistics method, the disturbed parameter of the proposed model has been derived with the plastic displacement of pile as the distribution variable. In the model, shear intensity of elements in intact state can be calculated by Duncan-Chang model and which in critical state by Mohr-Coulomb theory. The model in this paper has few parameters and can reflect the aspects of load transfer function, such as hardening, .softening and affects of confining stress. The well agreement between in-situ data and the predicted data shows that the validity of the model herein. Finally, the model is used to analyze an engineering pile and has practical value.