黄泛区软弱夹层结构地基强夯现场试验

为探究黄泛区软弱夹层地层条件下强夯加固效果，采用4种不同的夯击能在鲁西黄泛平原区进行现场试验，研究了强夯过程中软弱夹层的夯沉量、超孔隙水压力以及强夯前后地基承载力、土质力学性质变化规律。结果表明:超孔隙水压力消散速率非常快，24 h后超孔隙水压力消散90%；强夯加固效果显著，地基承载力最大可提高80%；选择单夯1 800 kN·m夯击能加固经济合理，夯后土体物理性质明显提高；对于黄泛区含有软弱夹层地层结构，可用超孔隙水压力为自重应力10%估算强夯有效加固深度，有效加固深度约为7 m；对比不同夯击能下Menard加固深度公式，在一般夯击能条件下，实际加固深度与Menard加固深度较为接近，在较大夯击能下，Menard公式并不适用；所得结论对该区域地基加固有一定的指导作用。

Field Test of Foundation Dynamic Compaction About Soft Interlayer Structure in Yellow River Flood Area

In order to study on the effect of dynamic compaction about soft interlayer in Yellow River flood plain area in western Shandong, with 4 tamping energy, the change laws of settlement, the excess pore water pressure, the bearing capacity of foundation and the mechanical properties of soil were studied. The results show that the dissipation rate of excess pore water pressure is very fast, and the excess pore water pressure is nearly dissipated by 90% after 24 h, the effect of dynamic consolidation is remarkable, and the bearing capacity of foundation can be increased by 80%, it is more reasonable to select 1 800 kN·m compacting energy, because the physical properties of the soil are obviously improved after compaction. For the Yellow River flood area containing weak intercalated structure, the excess pore pressure can be used as the 10% of self weight stress critical value to estimate the effective consolidation depth and the effective reinforcement depth is about 7 m. Comparing with the Menard formula, under the less compact energy, the actual depth of reinforcement is closer to that; under the larger tamping energy, Menard formula can not be applied. The results of this study can apply some guidance for the foundation reinforcement in this area.