富水区隧道排水网络体系卸压能力研究

Discharge Capacity of Tunnel Drainage Network System in Water-rich Area

为研究富水区隧道排水网络体系对地下水的卸压能力,以豹狸岗隧道为研究背景,基于Flac3D软件进行三维差分建模,探讨水头高度与环向盲管间距对地下水渗流场的影响。结果表明:环向排水盲管可显著削减二次衬砌上部背后水压,但对仰拱处水压力的削减作用可忽略不计;提出了平均减压系数概念,盲管间距对二次衬砌上部平均减压系数影响显著,但对仰拱处平均减压系数基本无影响;保持盲管间距不变时,平均减压系数基本不受水头高度影响。分析二次衬砌平均减压系数与盲管间距关系,揭示不同盲管间距对排水网络体系的卸压效果,确定最优环向盲管间距为5 m。

In order to study the pressure relief capacity of tunnel drainage network system on groundwater in water rich area,based on Baoligang Tunnel project,the three-dimensional difference modeling was carried out by using Flac3D software to study the capacity of tunnel drainage network system for relieving the pressure caused by groundwater in the water-rich area,and the difference between the water-head height and the circumferential blind pipe spacing on the groundwater seepage field was discussed.The results show as follows.The water pressure behind the upper part of the secondary lining can be significantly reduced by the circumferential drainage blind pipe,but the reduction effect on the water pressure at the invert can be ignored.The concept of average pressure relief coefficient is put forward.The effect of the blind pipe spacing on the average pressure relief coefficient in the upper part of the secondary lining is significant,but that in the invert is basically none.The average pressure relief coefficient is basically unaffected by the water-head height when the blind pipe spacing is constant.When the distance between blind pipes is kept constant,the average pressure relief coefficient is not affected by the water-head height.The analysis of the relationship between the average pressure relief coefficient of the secondary lining and the blind pipe spacing reveals the pressure relief effect of different blind pipe spacing on the drainage network system,the optimal circumferential blind pipe spacing is determined as 5 meters.