真空联合堆载预压下竖井地基固结解析解

考虑真空度沿竖井的发展是一个深度的函数，同时堆载所引起的附加应力既随时间变化也随深度变化，还考虑了地基的径竖向渗流以及扰动区土体水平渗透系数的3种变化模式，推导了真空联合堆载预压下竖井地基固结度的一个较普遍的解析解，并分析了在真空度沿竖井线性下降，堆载线性施加和附加应力沿深度梯形分布等情况下的地基固结性状。结果表明，荷载线性施加时，真空度对地基固结度有较大影响，真空度越大，沿深度衰减越慢，固结越快；而在荷载瞬时施加时，真空度对固结度没有影响。在地基井径比和水平渗透系数与竖向渗透系数之比较小时，地基的竖向渗流对地基的固结度有较大的影响。

Analytical solution for consolidation of vertical drains by vacuum-surcharge preloading

A general analytical solution is obtained for the consolidation of vertical sand foundation under vacuum preloading considering simultaneously the variation of vacuum degree, the coupled variation of stress increment with depth and time, the horizontal and vertical drainage and the variation of horizontal permeability coefficient of soil. Furthermore, detailed solutions are obtained for the excess pore water pressure and average degree of consolidation under the particular situation that the vacuum degree linearly changes along the vertical drain depth, the stress increment linearly changes along the column depth and the loading is applied in a single-stage way. Finally, the consolidation behavior of the vertical drain foundation is analyzed. The results show that if the loading is applied linearly, consolidation degrees of foundation have something to do with the vacuum degree, the larger the vacuum is, the faster the consolidation is, the slower the reducing of vacuum is, the faster the consolidation. If the loading is applied instantaneously, consolidation degrees of foundation have nothing to do with the vacuum degree. Ignoring the vertical flow within the soil will under-estimate the consolidation rate. Furthermore, the less the radius ratio is and the less the ratio of horizontal permeability to vertical permeability is, the greater the under-estimated value is.