多级加载下附加应力沿深度变化的单层地基一维固结

在岩土工程中,当天然土层的强度较小时,加载速率过快可能会导致地基失稳。在这种情况下,可以采用多级加载的方式来逐步提高地基强度,使地基在施加下一级更大的荷载时已固结到一定程度。另外,在很多情况下,外部荷载在地基内引起的总附加应力总是随着深度发生变化,而并非保持不变,例如,当土层中地下水位发生变化时即是如此。详细给出了一个考虑多级加载下附加应力沿深度变化的单层地基一维固结的完全显式解析解。然后,选取外部荷载二级施加的特例来分析单层地基的固结性状。最后,通过比较不同的计算项数所得的计算结果来评估所得的级数解的收敛性,以利于工程人员采用本文解时能够获得足够的精度。

1-D consolidation of a single soil layer with depth-dependent stress by multi-stage loading

In geotechnical engineering, when the strength of soft soils is relatively low, a rapid loading rate can lead to ground failure. In this situation, a multi-stage loading scheme can be utilized to achieve higher soil strength by consolidating the soil layer to a certain degree before applying the next, larger load(s). Additionally, the total stress in the soil layer usually varies, and, in many cases, this variation is not uniform with depth, for example, when the loading is applied within a small area over a thick soil layer. In this study, a thorough, explicit analytical solution is presented for the consolidation of a single soil layer using a multi-stage loading with depth-dependent total stress. The particular case of a two-stage loading scheme is selected to investigate the consolidation behavior of a soil layer. Finally, the convergence of the analytical solution is assessed by comparing the calculated results using the various terms of the series to facilitate the use of the solution by engineers and to provide sufficient accuracy.