真空堆载联合预压法加固软基的现场试验

Field Experiment of Vacuum-Surcharge Preloading Method to Improve Soft Subgrade

结合山东日照港集装箱码头辅建区的软基处理工程,开展了现场真空-堆载联合预压试验和监测资料分析研究,并对其加固机理和加固效果进行了探讨.研究结果表明真空预压明显地加快了地基的沉降速率,加速其固结过程,同时产生向内的水平位移,从而使真空-堆载联合预压比超载预压具有更强的抗失稳能力.土体侧向位移量和位移速率与加荷方式及大小密切相关.真空预压的加固深度主要是地表以下竖向排水体范围内受荷载影响的土层.

Based on the field experiment and research work carried out in the Ri Zhao dock in Shan Dong province, the mechanism of improvement of soft subgrade with the vacuum-surcharge preloading method is discussed. Results show that the vacuum preloading can increase the velocity of the settlement and consolidation, and cause more horizontal displacement of the soft subgrade. Thereby, the improved subgrade by the vacuum combined surcharge preloading is stabler than that only by the surcharge preloading. The effective improving depth is in the range of PVD, and the effective depth of vacuum combined surcharge preloading is determined by the stress of surcharge.