深层增压式真空预压法处理软土地基室内模型试验

普通真空预压法在处理软土地基时,由于真空度向下传递的过程中受涂抹、井阻等作用,使深层土体获得的真空荷载较小,往往导致深层土体得不到有效的加固。针对这种缺陷提出一种深层增压式真空预压处理软土地基的方法,此方法主要是通过向深层土体增压以扩大深层土体与竖向排水板及其上层土体的压力差,从而加快土体中的孔隙水的渗流速度。另外,由于深层土体因得到增压而其气压高于上层土体及排水板处的气压,这样就会在深层土体和竖向排水板及上层土体之间形成对流,从而带动土体中的孔隙水向上层土体和排水板处流动而提高排水速率。试验表明:经深层增压式真空预压法处理后土体的含水率、累计沉降量、十字板抗剪强度等指标均优于普通真空预压处理的土体,说明深层增压式真空预压能够有效地提高软土地基的加固效果。

LABORATORY MODEL TEST OF TREATING SOFT SOIL GROUND USING DEEP AIR-BOOSTED VACUUM PRELOADING

Because of effect of well resistance and smear,deep soil can not achieve adquate vacuum when adopting the common vacuum preloading to reinforce soft soil.So deep soil can not be reinforced effectively.A method of deep air-boosted vacuum preloading to overcome the shortage of common vacuum preloading was proposed,which could improve the rate of drainage through enlarge the pressure difference between soil and the vertical drain.In addition,convection was produced between deep soil and upper soil with deep air-boosted,the rate of drainage would be improved due to that reason.Compared with the physical indicators of common preloading model test and found that the indicators of the moisture content,cross shear strength,cumulation settlement were better than those of the common vacuum preloading.It concluded that the soft soil could achieved better reinforcement through deep airboosted vacuum preloading.