基于非牛顿指数渗流的饱和黏土一维流变固结分析  

One-dimensional Rheological Consolidation Analysis of Saturated Clay with Non-Darcian Flow Based on Non-Newtonian Index

作　　者：刘忠玉[1] 黄家涛 夏洋洋 张家超 崔鹏陆 LIU Zhong-yu;HUANG Jia-tao;XIA Yang-yang;ZHANG Jia-chao;CUI Peng-lu(School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学土木工程学院,河南郑州450001

出　　处：《土木工程与管理学报》2020年第3期1-7,共7页Journal of Civil Engineering and Management

基　　金：国家自然科学基金(51578511)。

摘　　要：为了深入探讨黏性土变形的弹黏塑性和渗流的非达西特性对一维固结进程的影响,分别引入考虑时间效应的统一硬化(UH)本构模型和用非牛顿指数描述的非达西渗流模型,考虑随时间变化施工荷载的影响,修正了太沙基一维固结方程,并给出了有限体积法数值求解格式。通过与相关文献的退化算例进行对比,验证了本文算法的有效性。在此基础上,分析了次固结系数、非牛顿指数、施工荷载和施工工期等参数对饱和黏土流变固结的影响。结果表明:竣工初期地基底部不排水面处孔压异常升高的现象是由饱和黏土的黏滞性引起的,且考虑非牛顿指数渗流和减小施工荷载时,这一现象更为明显;增加施工荷载将使得竣工后地基中孔压的整体消散速度加快;相较于瞬时加载,施工工期对地基流变固结的影响主要体现在初期。In order to study the influence of elastic-viscoplasticity of clay deformation and characteristics of non-Darcian flow on one-dimensional consolidation process,the unified hardening(UH)constitutive model considering time effect and the non-Darcian flow described by non-Newtonian index are introduced respectively.Considering the influence of construction load varying with time,Terzaghi’s one-dimensional consolidation equation is modified,and the numerical analysis is conducted by the finite volume method.The effectiveness of the algorithm is verified by comparing with the degradation examples in related literature.On this basis,the effects of the secondary consolidation coefficient,non-Newtonian index,construction load and construction period on the rheological consolidation of saturated clay are analyzed.The calculated results show that the abnormal increase of pore pressure at the impermeable surface of the soil layer at the initial stage of completion is caused by the viscosity of saturated clay,and this phenomenon is more obvious when the non-Darcian flow described by non-Newtonian index is considered and the construction load is reduced.In addition,increasing the construction load will accelerate the overall dissipation rate of pore pressure in the soil layer after completion.At the same time,compared with instantaneous loading,the influence of construction period on the rheological consolidation of foundation is mainly reflected in the initial stage.

关 键 词：土力学 饱和黏土 非达西渗流 流变固结 有限体积法 弹黏塑性 施工荷载 

分 类 号：TU433[建筑科学—岩土工程]