Ground Strengthening Method by Multistage Local Consolidation

Authors are investigating a ground strengthening method, which effectively consolidates the construction area of requisite minimum in a short time by local consolidation for the soft ground. In this paper, Authors research that the effect of increasing the strength of soft ground by using the three-dimensional elasto-plastic finite element analysis when the area of local loading is gradually changed. First, it was found that the strength of the soft ground just below the local loading surface increased with a short time by the local consolidation and ultimate bearing capacity increases to 2.6 times as much as the initial bearing capacity by the multistage loading. Next, analysis was carried out in the case of the multistage loading with cyclic loading. In the reloading process, loading area is reduced to 1/3 and 1/6 of the loading area of the previous stage. In this case, the ultimate bearing capacity increases to 8.25 times as much as the initial bearing capacity. In conclusion, it was found that the strength of the soft ground just under the loading surface is considerably increased by multistage local loading with reducing the loading area.研究团队针对软土地基开发了一种地基加固方法，该方法可通过局部固结作业在短时间内对最小必要施工区域实现高效固结。本文采用三维弹塑性有限元分析法，探究了局部加载区域逐步变化时软土地基的强度提升效果。首先，研究发现：局部固结加固可在短时间内提升局部加载面正下方软土地基的强度；经多级加载后，地基极限承载力可提升至初始承载力的2.6倍。其次，针对带循环加载的多级加载工况开展了数值分析，在复加载过程中，加载区域分别缩减至前一级加载区域的1/3与1/6；在此工况下，地基极限承载力可提升至初始承载力的8.25倍。综上，研究表明：通过逐级缩减加载区域的多级局部加载方式，可显著提升加载面正下方软土地基的强度。