摘要
按照固结度等效的原则,提出将单井涂抹效应对涂抹区内土体渗透性的弱化作用转化为减小单井影响区内土体水平向渗透系数的方法,并讨论单元尺寸对固结度的影响。该计算方法既可减少前处理工作量,又可考虑涂抹效应。结合广州南沙港一真空预压工程,建立三维模型进行有限元计算分析,并通过实测资料和目前常用的平面应变简化方法对计算值进行比较和讨论。研究结果表明,J.C.Chai方法将砂井地基转换为均质地基,所得结果偏保守,而"砂墙"等效方法通过砂井间距来调整渗透系数,会使计算结果偏大,三维有限元法比平面应变方法更能反映砂井地基的固结变形。
Based on the equivalent consolidation degree, the method that considers the smear effects diminishing the permeability of the clay in the smear zone, which can be transformed into the reduction on horizontal permeability coefficient of the soil in the efficient zone, is presented. The influence of consolidation degree induced by the size of element is discussed, in which the work-load ofpreprocessing can be saved and the smear effects are considered. The 3D finite element model is set up; and then the numerical simulation is executed combining with the project of vacuum preloading in Guangzhou Nansha Port. By comparing the results obtained by the usually used plane-strain method and the measured data, it is found that the results with the method proposed by J. C. Chai, which can transform the ground with sand-drains into homogeneous ground, are conservative, while the results with the method of the equivalent sand-walls are over-estimated; and it adjusts the permeability coefficients that are dependent on the intervals of sand-drains layout. The consolidation deformation with 3D FEM of ground installed by sand-drain presents more accurate than that of plane-strain method.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2008年第11期2347-2353,共7页
Chinese Journal of Rock Mechanics and Engineering
关键词
土力学
真空预压
有限元法
计算方法
涂抹效应
soil mechanics
vacuum preloading
finite element method
calculation method
smear effects
