低渗透性土层高真空疏干井降水数值模拟

为研究高真空管井在低渗透性黏土层中的降水规律及提高其降水效率的方法,本文使用有限差分软件FLAC3D,对于不同抽水时间,不同真空度,不同井深以及不同双井间距下各种高真空管井降水工况进行系统模拟,重点关注地基孔隙水压力、抽水量的变化规律.根据文中给出的宁波地铁樱花公园站处的土层分布,通过分析不同双井间距下的出水总量与孔压分布规律,给出建议的双井间距.得出结论:淤泥质黏土中管井出水比较困难,且随时间增加降水效率会降低,但当管井真空度增大,井深增大,高真空管井出水量提升;真空负压在低渗透性淤泥质黏土中的水位面以上区域传递速度较快,在水位面以下区域传递受限,高真空疏干井在低渗透性土层中有较好的适用性.

Numerical simulation of high vacuum dewatering in low permeability soil

To study the relevant laws of high vacuum dewatering in low permeability soil and improve the efficiency of dewatering, the finite difference software FLAC3D was used to simulate the dewatering process of high vacuum well under various working conditions including different time, different vacuum degree, different well depth and different distance of the two wells, mainly focusing on the amount of discharge and the pore water pressure. According to the amount of total discharge and the distribution of pore water pressure under different distance of the two wells, suggestion of the reasonable distance of the two wells was given based on the soil profile of Ningbo metro Yinghua Station. It concludes that the low permeability soil is relatively difficult to dewater, but with the increase of the vacuum and the depth of the well, the amount of water pumped out of the low permeability soil increases. The vacuum negative pressure in the low permeability clay passes faster above the water level and the transmission speed is limited below the water level. High vacuum dewatering well has good applicability in low permeability soil layer.