圆形隧洞渗流量计算的解析方法及其应用

发布时间：2018-10-18 20:23

【摘要】：隧洞在施工过程中,必将导致地下水渗流场的重分布和地下水位线的降低,当前常用的渗流量计算解析方法未考虑水位降低这一影响。首先通过数值计算方法分析隧洞开挖带来的渗流场变化,考虑地下水位线降低对渗流量的影响,提出分别计算隧洞渗流场稳定后开挖降低水位和渗流量的解析公式。结果表明:隧洞开挖过程中,洞周孔压和地下水浸润面随时间逐渐降低,在距离隧洞5倍洞径范围内孔压变化剧烈,地下水位线浸润面降低幅度达到26.3%~56.7%;渗流场稳定后地下水位线降低高度与隧洞半径和初始地下水位密切相关,与围岩渗透系数关系不大;经过与传统解析解和数值解的对比可以看出,提出的解析公式能够方便求解隧洞开挖降低水位和渗流量,且同时适用于初始地下水位线水平分布和倾斜分布条件。
[Abstract]:In the process of tunnel construction, the redistribution of groundwater seepage field and the decrease of underground water level are bound to be caused. The influence of water level reduction is not taken into account in the current analytical method of seepage discharge calculation. Firstly, the variation of seepage field caused by tunnel excavation is analyzed by numerical calculation method. Considering the influence of underground water level reduction on seepage flow, an analytical formula is proposed to calculate the water level and seepage flow after tunnel seepage field is stabilized respectively. The results show that during the excavation of the tunnel, the pore pressure and the groundwater infiltration surface decrease gradually with time, and the pore pressure changes dramatically in the range of 5 times the diameter of the tunnel. The depth of underground water level decreases by 26.3 and 56.7.The decrease of groundwater level is closely related to tunnel radius and initial groundwater level, but has little to do with the permeability coefficient of surrounding rock. By comparing with the traditional analytical solution and numerical solution, it can be seen that the proposed analytical formula can easily solve the tunnel excavation to reduce the water level and seepage discharge, and is suitable for the initial horizontal and inclined distribution of underground water level at the same time.
【作者单位】：武汉大学水资源与水电工程科学国家重点实验室;长江勘测规划设计研究有限责任公司;
【基金】：国家自然科学基金资助项目(51179140,51579194)~~
【分类号】：U452.11

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