新型无膜真空预压法加固超软吹填土模型试验及数值模拟分析

发布时间：2018-10-11 06:59

【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。
[Abstract]:The traditional vacuum preloading method has some problems such as the single consolidation area can not be too large and the sealing film is easy to leak. In view of the above problems, a new type of vacuum preloading method, which replaces the seal membrane with mud seal layer, can increase the area of vacuum preloading, save the cost of using the sealing film and solve the problem of filling up the earth. In order to explore the reinforcement effect of the improved vacuum preloading method and its influencing factors, laboratory model tests and numerical simulation were carried out. Through model tests, the variation of soil displacement, pore pressure at a specific location and soil surface settlement with time during vacuum pumping with different loading methods was studied. By comparing the physical properties of soil before and after preloading, it is concluded that the effect of vacuum preloading without film is better, and the reinforcement effect can be improved by step loading, and the numerical simulation is carried out by PFC2D software. The motion law of soil particles during vacuum preloading without film was studied. The numerical simulation results show that under the vacuum pressure, the soil particles gather near the drainage plate, and the blockage of the drainage plate can be reduced to a certain extent by the method of graded loading, so that the better treatment effect can be achieved.
【作者单位】：滨海土木工程结构与安全教育部重点实验室;天津大学建筑工程学院;
【分类号】：TU472

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