基于扰动理论修正的桩-土接触面荷载传递模型及其应用  

Investigation Into A Modified Load Transfer Model of Pile-Soil Interface Based on Disturbance Theory and Its Application

作　　者：王友涛 谢康 陈晓斌[2] 张飞 郝哲睿 WANG Youtao;XIE Kang;CHEN Xiaobin;ZHANG Fei;HAO Zherui(China Railway First Group,Xi'an,Shaanxi 200082;School of Civil Engineering,Central South University,Changsha,Hunan 410083)

机构地区：[1]中铁一局,陕西西安200082 [2]中南大学土木工程学院,湖南长沙410083

出　　处：《地质与勘探》2024年第1期140-147,共8页Geology and Exploration

基　　金：国家自然科学基金资助项目(编号:51978674)资助。

摘　　要：利用硬化模型、双曲线模型、指数模型以及软化模型模拟的桩-土接触关系存在参数取值困难、误差大的问题。为深入研究土-结构接触面的强度与变形机理,基于扰动理论,假定完整状态接触单元的抗剪强度服从线弹性模型,而扰动部位则服从塑性模型,建立修正的桩-土接触面荷载传递模型。该模型参数分析表明,参数k、η对模型τ-s曲线形态影响大,而参数τf、ζ对模型τ-s曲线形态影响很小;并通过大型桩-土接触面室内直剪试验,量化接触面上剪切应力与剪切位移的关联性,进一步确定修正桩-土接触模型内部计算参数。结果表明模型τ-s曲线与试验曲线吻合较好,验证了模型的合理性。扰动桩-土接触模型既能描述桩侧应变软化也能描述硬化特性,有助于理解复杂应力条件下桩-土接触面的强度计算与变形机理。The pile-soil contact relationship simulated by the hardening model,hyperbolic model,exponential model,and softening model suffers from the problems of difficult parameter values and large errors.In order to carry out an in-depth study on the strength and deformation mechanism of soil-structure contact surface,a modified pile-soil contact surface load transfer model was established based on the perturbation theory,assuming that the shear strength of the contact unit in the intact state obeys the linear elasticity model,while the perturbed part obeys the plasticity model.The parameter analysis of the model shows that the parameters k andηexert a significant impact on the modelτ-s curve shape,while the parametersτf andζhave little effect on the modelτ-s curve shape.Afterwards,the correlation between shear stress and shear displacement on the contact surface was quantified through a large-scale indoor direct shear test on the pile-soil contact surface,and the internal computational parameters of the modified pile-soil contact model were further determined.The results show that the modelτ-s curves agree well with the test curves,which verify the rationality of the model.The perturbed pile-soil contact model is able to describe both the softening and hardening characteristics of the pile side strain,which helps to understand the strength calculation and deformation mechanism of the pile-soil contact surface under complex stress conditions.

关 键 词：桩-土接触面 扰动状态 直剪试验 荷载传递 本构模型 

分 类 号：TU473[建筑科学—结构工程]