考虑循环弱化的饱和黏土简化非线性模型

发布时间：2018-03-24 09:11

本文选题：饱和黏土　切入点：简化非线性模型　出处：《岩土力学》2015年S1期

【摘要】：随着海洋工程建设的快速发展,海洋环境中的地基稳定性逐渐成为学者和工程师关注的热点问题,建立一个简化的饱和黏土循环加载模型对于长期循环荷载下海上构筑物的设计具有重要意义。针对饱和黏土的循环弱化特性,在Hardin-Drnevich等效非线性模型的基础上,建立了考虑循环弱化的饱和黏土简化非线性模型来描述循环加载下饱和黏土的应力-应变关系,模型中引入了由循环加载期间产生的累积塑性变形控制的强度和模量衰减比公式。通过参数分析,说明了形状参数?与n以及残余衰减比与衰减系数等参数的意义和作用。通过对文献中单向循环试验和双向循环试验结果的模拟,验证了该简化模型可以较好地描述循环加载时饱和黏土应力应变滞回圈的演变规律以及循环加载后饱和黏土的强度和刚度弱化现象。简化模型大大提高了计算效率,与传统的土体弹塑性模型相比更加便于工程应用。
[Abstract]:With the rapid development of marine engineering construction, the stability of the foundation in the marine environment has gradually become a hot issue that scholars and engineers pay attention to. It is important to establish a simplified cyclic loading model of saturated clay for the design of offshore structures under long-term cyclic loading. In view of the cyclic weakening characteristics of saturated clay, based on the Hardin-Drnevich equivalent nonlinear model, A simplified nonlinear model of saturated clay considering cyclic weakening is established to describe the stress-strain relationship of saturated clay under cyclic loading. The formula of strength and modulus attenuation ratio controlled by cumulative plastic deformation during cyclic loading is introduced in the model. The significance and effect of the parameters such as n, residual attenuation ratio and attenuation coefficient. The results of unidirectional and bidirectional cyclic tests in literature are simulated. It is verified that the simplified model can well describe the evolution of the stress strain hysteresis loop of saturated clay under cyclic loading and the weakening of strength and stiffness of saturated clay after cyclic loading. The simplified model greatly improves the calculation efficiency. Compared with the traditional soil elastoplastic model, it is more convenient for engineering application.
【作者单位】：广西大学土木建筑工程学院;广西大学工程防灾与结构安全重点实验室;同济大学地下建筑与工程系;
【基金】：国家自然科学基金(No.51068002,No.41362016) 广西岩土力学与工程重点实验室资助课题(No.13-KF-02,No.14-KF-03)
【分类号】：TU442

【共引文献】