联合竖向排水体真空预压处理软土模型试验研究

文章针对当前软土固结排水中所用塑料排水板(prefabricated vertical drain, PVD)存在的缺陷,综合考虑工业废料尾矿砂和农作物秸秆的合理利用,提出以排水板、尾矿砂和棉花秸秆为原材料制成联合竖向排水体(combined vertical drain, CVD);通过自行设计的室内模型试验,研究CVD和普通PVD真空预压处理软土的差异性。试验结果表明:相比于PVD,使用CVD处理软土时真空度衰减平均降低37.11%,孔隙水压力消散最大值提升27.56%,排水速率最大可提高1.5倍,表层沉降增加37.02%;相比于PVD,使用CVD处理后的软土平均含水率多降低6.65%,十字板剪切强度平均值提升8.34 kPa,不同位置土体的物理性质差异更小。试验研究证明,使用CVD处理软土是可行的,具有比PVD更好的排水固结效果。

In this paper, the shortcomings of prefabricated vertical drain(PVD) used in the current consolidation and drainage of soft soil are addressed, and considering the reasonable utilization of industrial waste tailings sand and crop straw, a combined vertical drain(CVD) is proposed using drainage boards, tailings sand, and cotton straw as raw materials. The differences in vacuum preloading treatment of soft soil between CVD and conventional PVD were studied through self-designed indoor model tests. The results show that compared to PVD, the vacuum attenuation of soft soil treated with CVD decreases by an average of 37.11%, the maximum dissipation of pore water pressure increases by 27.56%, the drainage rate can increase by up to 1.5 times, and the surface settlement increases by 37.02%. Compared to PVD, the average moisture content of soft soil treated with CVD is reduced by 6.65%, the average value of vane shear strength increases by 8.34 kPa, and the physical properties of soil at different locations are less different. The study proves that using CVD to treat soft soil is feasible and has better drainage and consolidation effects than PVD.