摘要
为了研究软土在非达西渗流作用下的非线性固结特性,基于孔隙水质量守恒原理,引入非达西渗流速度方程,建立了以超静孔压为变量同时考虑渗透系数变化的软土地基一维非线性固结方程,采用差分格式离散偏微分方程,获得了超孔隙水压力的数值解答,采用Python进行编程,计算考虑沉积作用的土体非线性固结沉降,并与已有文献结果做了对比,同时分析了非达西渗流参数n和启动压力梯度以及排水条件变化对地基土固结性状的影响。研究结果表明:非达西渗流参数n和启动压力梯度i_c越大,非线性固结完成所需时间就越长,但对固结最终沉降大小没有影响,两个参数对超孔隙水压力消散均有阻塞效应,固结过程对参数n的变化更为敏感。双向排水条件下土体平均固结度最终可达到100%,单向排水条件下土层平均固结度仅达到有限值,固结稳定后其地表沉降小于双向排水计算结果。
In order to study the nonlinear consolidation behavior of soft soil under non-Darcy flow effect,an one-dimensional nonlinear consolidation equation of soft soil foundation is established by taking the excess hydrostatic pore water pressure as the variable and considering the variation of the permeability coefficient at the same time through introducing the non-Darcy flow velocity equation based on the principle of mass conservation of pore water,and then the numerical solution of the excess hydrostatic pore water pressure is obtained by means of discretizing the partial differential equation with difference format,while the nonlinear consolidation settlement of soil mass under the consideration of sedimentation is calculated through programming with Python,and then the result is compared with those from the existing literatures.Meanwhile,the larger the non-Darcy flow parameter n and the threshold pressure gradient ic are,the time necessary for the completion of the nonlinear consolidation is to be longer.However,both the parameters have no any influences on the final settlement of the consolidation,but have blocking effects on the dissipation of the excess hydrostatic pore water pressure,while the consolidation process is more sensitive to the variation of the parameter n as well.Under the two-way drainage condition,the mean consolidation degree of soil mass can finally reach 100%,the mean consolidation degree of soil layer can only reach its limited value and the ground surface settlement is less than the result from the calculation made on the two-way drainage after the stabilization of its consolidation.
作者
陈智寿
邱国阳
谈华顺
于光明
CHEN Zhishou;QIU Guoyang;TAN Huashun;YU Guangming(Zhejiang Wenzhou Shenhai Expressway Co.,Ltd.,Wenzhou 325000,Zhejiang,China;Zhejiang Provincial Institute of Communications Planning,Design&Research,Hangzhou 310000,Zhejiang,China;Key Laboratory of Concrete and Prestressed Concrete Structure of Ministry of Education,Southeast University,Nanjing 211189,Jiangsu,China;School of Civil Engineering,Southeast University,Nanjing 211189,Jiangsu,China)
出处
《水利水电技术》
北大核心
2020年第S01期114-121,共8页
Water Resources and Hydropower Engineering
基金
国家自然科学基金项目(51878160,51478109,51678145)
浙江省交通运输厅科研计划项目资助(2017037)
关键词
固结
非达西流动准则
软土
超孔隙水压力
固结沉降
差分方法
nonlinear consolidation
non-Darcy flow criterion
soft soil
excess pore water pressure
consolidation settlement
differential method
