砂井地基径向非线性固结解析

基于砂井等应变固结模型,考虑初始有效应力沿深度变化,忽略井阻和竖向排水固结的影响,应用平均孔隙比与平均有效应力的对数关系,建立砂井非线性径向排水固结的分层计算模型,并求得常荷载作用下的径向排水固结解析解.在变荷载作用下,把变化阶段的荷载划分为一系列不连续的剧加荷载,导出有效应力的递推公式.结果表明,因自重应力随深度增加,土层径向排水平均固结度随其埋深而增大.如把整个厚度范围内自重应力取为平均值,将使计算的沉降量偏小,径向平均固结度偏大.

Analysis of Radial Nonlinear Consolidation of Sand Drain Rround

Based on the equal strain consolidation model of sand drain,and neglecting the well resistance and the vertical drainage consolidation,a layered model for the nonlinear consolidation of sand drain,which accounts for the geostatic pressure varying along depth and the relationship between the average viod ratio and the logarithm of average effective stress,is presented.The analytical solution for the case under the constant loading is obtained,and the iteration formulae of the effective stress for the case under the varying loading are also done by dividing the varying loading into instantaneous ramp loading.It is concluded that the average degree of radial consolidation for a given soil layer increases with its buried depth since the geostatic pressure increases with the lattar.The treatment for simplity that the mean value of the geostatic pressure is adopted could result in a smaller computed value of settlement but a larger one of average radial consolidation degree than the actual.