真空预压过程中滤膜等效孔径和土颗粒级配对排水板淤堵影响的试验研究

Experimental study on the effect of filter membrane equivalent aperture and grain gradation on drainage clogging under vacuum preloading

采用真空预压法处理吹填淤泥时,塑料排水板滤膜的淤堵会使真空预压效率大大降低。土颗粒的级配和滤膜的等效孔径与滤膜的淤堵有很大关系。本文选用两种不同滤膜等效孔径的排水板和三种不同级配土体进行真空预压室内模型试验,对出水量、孔隙水压力以及土体沉降进行分析,研究滤膜等效孔径和土颗粒级配对排水板淤堵的影响。实验结果表明:粗颗粒在排水板淤堵过程中起主要作用,在粒径相同的条件下,大孔径排水板更不容易发生淤堵。

When vacuum preloading is used to treat dredged soil,the clogging of the plastic drainage plate filter membrane will greatly reduce the vacuum preloading efficiency.This phenomenon is greatly influenced by the grain gradation and filter membrane equivalent aperture.In this paper,laboratory model tests were carried out using two kinds of filter membrane with different equivalent apertures and also using three kinds of dredger soil with diflerent grain gradations.The water output,pore water pressure and soil settlement were compared,and the effect of filter membrane equivalent aperture and soil particle gradation on the clogging of drainage board were analysed.The experimental results show that the coarse particle plays a major role in the clogging of drainage board,under the condition of the same grain size,the drainage plate with large equivalent aperture is less prone to clogging.