主动排水固结法气举降水效应模型试验研究

Model test of active drainage consolidation method on air-lift effect

高压气溶胶解构排水固结法是一种新型主动排水技术,通过在设置竖向排水通道的土体内旋射高压气溶胶,起到深部立体排水、深层增压及气举降水三大作用,有效提高了排水效率。针对气举降水作用,采用自主研制的大尺寸气举模型试验装置,分别以下部介质、周围介质、注气气压、注气深度、竖向排水体直径与长度等为变量进行了一系列的试验研究。研究结果表明:周围介质对气举降水深度影响很小、但对降水速度影响很大;注气压力与最大气举降水深度并非正比关系,只有注气压力与竖向排水体直径匹配良好时才能达到最大气举降水深度;当竖向排水体直径一定时,注气深度决定了最大降水深度与降水速率。该研究成果可指导该项主动排水技术的工程实施,也为深入研究气举降水机制提供依据。

Aerosol injection technology(AIT)is a new type of active drainage technology.Aerosol injection is carried out in an injection hole through a rotating pipe with a high-pressure pump,which plays three major roles including deep three-dimensional drainage,deep pressurization and air-lift precipitation to improve drainage efficiency.Aiming at the effect of air-lift precipitation,a large-scale air-lift model test device has been independently developed,and a series of experimental studies has been carried out on variables such as the lower medium,surrounding medium,air injection pressure,air-lift drainage channel size and air injection depth.The research results show that:1)The surrounding medium has little effect on the air-lift precipitation depth but has a great impact on the water level drop speed;2)The air injection pressure is not directly proportional to the maximum air-lift precipitation depth.The maximum air-lift precipitation depth can only be reached when the air injection pressure is well matched with the diameter of the vertical drainage body;3)When the diameter of the vertical drainage body is constant,the air injection depth determines the maximum precipitation depth and precipitation rate.The research results can guide the implementation of AIT and provide a basis for further study on the air-lift precipitation mechanism of AIT.