底部抽真空预压法砂井地基固结解析解

基于谢康和等应变条件砂井地基固结理论和Hansbo砂井固结理论,考虑底部抽真空预压法加固方法中真空作用面位于固结土层底部的实际边界条件,推导出忽略竖向渗流情况下的底部真空预压加固地基固结方程解析解答。根据超孔压固结方程形成过程以及其解析解表达式,分析其与一般负压径向固结解答的区别。通过室内模型试验实测数据与解析模型计算结果的对比表明,不同位置处孔压和固结度计算值与实测结果吻合较好,从而验证了该模型的合理性,同时运用该模型也可有效验证已有关于底部抽真空室内模拟及现场原位试验结果。底部抽真空轴对称固结解析解可为底部抽真空技术的实际工程应用提供基础性的理论支持,推动底部抽真空技术的大规模推广应用。

Analytical solution for consolidation of sand-drained foundation with bottom vacuum preloading method

According to the equal strain axisymmetric consolidation theory of sand-drained foundation developed by Xie and Hansbo, analytical solutions to the axisymmetric consolidation equation with bottom vacuum preloading are derived in this study as the vertical water flow in soil is neglected for the actual loading boundary condition that the vacuum preloading locates at the bottom. Based on the analytical solution formation process of excessive pore pressure axisymmetric consolidation control equation, a comparison between this new developed model and the current solution is carried out gradually. In comparison of the new model outputs and the experimental results by laboratory test, the excessive pore pressure distribution in vertical direction and the consolidation ratio development trends for excessive pore pressure dissipation can be obtained by the new developed analytical model, and it also can be concluded that the calculated results show a good agreement to the laboratory and site experimental results. Therefore, the analytical solution can be further applied to practical engineerings as basic theoretical foundation, which also promotes the application of bottom vacuum preloading method in soft foundation reinforcement engineering.