Experimental Study On Dewatering Technique Of Vacuum Tube Well

Currently, there are various of water-level lowering methods applied in civil construction engineering. All of them can successfully solving the problems of lowering the water level of strata in the area of Beijing. However, it is difficult to drain out perched water, saturated water in aquitard, and relic water between interfaces of aquifers using traditional methods such as tube wells. This problem demand prompt solution. The vacuum technique is proved to be one of the most efficient and effective solution to those aquifers of low permeability. Light well point and ejector well point are two common methods to applying vacuum technique. Recently, deep well vacuum draining is also popularized in South China (usually in draining wells in foundation pit), which has been an good solution to the drain out problems of aquitards.In this paper, vacuum dewatering test session of round track Jinsong combined with the one of Anbei area in the first phase of Beijing No. 10 subway project, are designed to be simulated in the lab, and the working principles, features of performance and scope of application of vacuum technique are further discussed.Also, the compound dewatering system of vacuum well as well as its formation and working principles are introduced. And through analyzing the results of several test schemes, the diffusion rule of vacuity and the variation rule of pore water pressure under vacuum effect in sand aquifer are concluded up. On the other hand, a evaluation is also made between vacuum wells and traditional wells by comparing their water output and drawdown.