双控动力固结法加固软粘土地基的应用研究

饱和软粘土含水率大、渗透性差，强夯处理时，超孔隙水压力不易消散，常规的排水措施效果不佳，而电渗降水已经被证明是一种有效的软粘土排水措施。本文提出了将电渗降水和强夯法相结合的地基处理方法——双控动力固结法，进行了双控动力固结法的处理试验，并与不降水强夯法和井点降水强夯法进行对比分析。结果表明，电渗法可迅速降低地下水位和地基土含水量，有效避免“弹簧土”的产生，提高单点夯最佳夯击能；可有效抑制夯后超孔隙水压力的急剧上升，并促进超孔隙水压力快速消散；在降水速度和土性改良方面，电渗降水优于井点降水。因此，应用双控动力固结法处理软粘土，有着很显著的加固效果。

Research on Application of Double-Control Dynamic Consolidation Method in Strengthening Soft Clays

High water content and poor permeability of saturated soft clays lead to difficult dissipation of excess pore water pressure in the forced tamping process; for the saturated soft clays, conventional drainage measures are inefficient while the electro-osmotic method has proved to be an effective drainage measure. A double-control dynamic consolidation method, the combination of the electro-osmotic method and the forced tamping method, is proposed in this paper for strengthening soils, and it has been compared with the un-dewatering forced tamping method and the well-point dewatering forced tamping method in a field study of the double-control dynamic consolidation method. The results show that the electro-osmotic method can quickly decrease water level and water content in soils so that the occurrence of ＂spring soil＂ is effectively avoided to increase the optimum tamping energy at single point. In addition, the electro-osmotic method can efficiently suppress the sharp growth of excess pore water pressure after tamping and promote the quick dissipation of the excess pressure. The electro-osmotic method is better than the well-point dewatering method on the dewatering speed and the soil improvement. Therefore, the double control dynamic consolidation method has a significant strengthening effect on the improvement of soft clay.