摘要
基于Richards瞬态非饱和渗流方程和若干合理假定,引入Gardner土-水特征曲线模型,给出均质地基降雨过程基质吸力瞬态解析解并利用有限元方法进行验证。将去饱和系数、饱和渗透系数、储水能力、降雨强度和降雨历时等5个主要参数采用正交分析法水平组合,通过方差分析对比各参数对雨水入渗时基质吸力最大改变量、变化面积和影响深度的影响程度,进而得到影响地基基质吸力变化的主导因素。研究结果表明:降雨入渗过程地基中上部土体基质吸力不断减小,基质吸力变化面积和受影响深度不断增加,深部地基土体基质吸力几乎不变;去饱和系数、饱和渗透系数和储水能力等土体水力参数对基质吸力最大改变量具有高显著性影响,去饱和系数和储水能力对基质吸力变化面积具有显著性影响,饱和渗透系数对基质吸力影响深度具有高显著性影响。研究成果可为实际均质地基工程中降低雨水入渗对地基承载力不利影响的土料渗流特性改良提供技术支持。
A transient analytical solution to matrix suction was obtained for a homogeneous foundation during rainfall infiltration by introducing the Gardner soil water characteristic model and Richards transient unsaturated seepage control equation under few reasonable assumptions,which was verified by the finite element analysis result.Then,orthogonal design method was used for comparing the effectiveness of the five main parameters influencing the matrix suction,which were desaturation coefficient,saturated permeability coefficient,water storage capacity,rainfall intensity and rainfall duration,and the most influential parameters for changing matrix suction are obtained.The variance analysis gave the degrees of impact for each parameter on the maximum changed magnitude,changed area and influenced depth of matrix suction.The results show that: During the rainfall infiltration,the matrix suction in upper foundation decreases gradually,and the changed area and influenced depth of matrix suction increase with time,however the matrix suction in deeper foundation remains constant;Desaturation coefficient,saturated permeability coefficient and water storage capacity have great impact on maximum changed magnitude of matrix suction;Desaturation coefficient and water storage capacity are most influential parameters to changed area of matrix suction;Saturated permeability coefficient are highly significant parameter to influenced depth of matrix suction.The findings of this research will facilitate improvement of seepage characteristics of soils in order to minimize the adverse impact on bearing capacity of homogenous foundation due to rainwater infiltration.
作者
胡惠仁
秦卫星
吴卫东
周作霖
HU Huiren;QIN Weixing;WU Weidong;ZHOU Zuolin(School of Hydraulic Engineering,Changsha University of Science and Technology,Changsha 410114,China;Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province,Changsha 410114,China;Department of Civil,Chemical & General Engineering,the University of Tennessee at Chattanooga,Chattanooga,Tennessee TN37403,USA)
出处
《铁道科学与工程学报》
CAS
CSCD
北大核心
2019年第6期1405-1411,共7页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(51208062)
湖南省交通科技计划资助项目(201140)
关键词
均质地基
基质吸力
影响参数
方差分析
降雨入渗
homogeneous foundation
matrix suction
impact parameters
variance analysis
rainwater infiltration