摘要
传统真空预压法在处理加固吹填土时存在单块加固面积不能过大、密封膜易漏气等问题。针对上述问题提出的将密封膜利用泥封层替代的新型无膜真空预压法可以提高一次性真空预压面积、节省密封膜的使用费用并且解决吹填土堆置的问题。为了探究这种改进的真空预压法的加固效果及其影响因素,进行了室内模型试验和数值模拟研究。通过模型试验研究了不同加载方式抽真空过程中土体的排水量、特定位置处的孔压和土体表层沉降量三者随时间的变化值,并通过对比预压处理前后土体的物性指标得出了无膜真空预压法加固超软吹填土效果较好,并且可以通过分级加载的方式,提高加固效果的结论;通过PFC2D软件进行数值模拟,研究了无膜真空预压过程中土颗粒的运动规律。数值模拟结果表明,土颗粒在真空压力作用下,向排水板附近聚集,可以通过分级加载方式在一定程度上减弱排水板的淤堵,从而达到更好的处理效果。
There are problems when dealing with the dredger fills using the traditional vacuum preloading method, for example, the treated area can not be too large and the plastic-sheet maybe leaks. To solve these problems, the new sheet-free vacuum preloading method is proposed, in which the mud-covering replaces the plastic sheet. This method can improve the treated area, save the cost of plastic sheet and solve the problem of piling up dredger fills. In order to investigate the effect and influence factors of the new vacuum preloading method, laboratory model tests and numerical simulations are carried out. The displacement of soil, the change of pore water pressure at the specific location and the settlement of soil surface in different loading modes are studied. The conclusions are that the effect of the sheet-free vacuum preloading method on the soft soil foundation treatment is good, and the effect of the treatment can be improved by the way of graded loading. The numerical simulation software PFC2 D is used to study the movement of soil particles in the process of sheet-free vacuum preloading. The results show that under the vacuum pressure, the soil particles mainly gather towards the PVDs. It can reduce the clogging of PVDs by graded loading to get better treatment effect.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2017年第S2期189-193,共5页
Chinese Journal of Geotechnical Engineering
关键词
无膜法
真空预压
吹填土
模型试验
分级加载
PFC
sheet-free method
vacuum preloading
dredger fill
model test
graded loading
PFC
