平行三孔海底隧道渗流场解析解及影响参数

Analytical solution of seepage field in three-hole parallel tunnel and influence parameters

为研究海底平行3孔隧道渗流场,在单孔隧道渗流基础上采用镜像法推导了半无限平面平行3孔海底隧道渗流场解析式,将其退化为单孔及双孔海底隧道渗流场解析解并结合数值模拟计算结果,对本文解析式进行了验证,并分析了隧道间距、初期支护厚度、注浆圈厚度对隧道涌水量及初期支护后水压力的影响。研究结果表明:由于隧道间相互影响,平行3孔隧道的涌水量和初期支护后水压力相比于单孔隧道均有所下降中间隧道受影响最大;随着隧道间水平间距增大,隧道的涌水量及初期支护后水压力增大,隧道水平间距大于20倍隧道半径时,隧道间相互影响可以忽略;随着左线隧道埋深增大,其涌水量及初期支护后水压力减小,中间隧道涌水量及初期支护后水压力先减小后增大;左线与右线隧道涌水量及初期支护后水压力受彼此隧道间距影响较小。随着初期支护抗渗性能提高,隧道涌水量减小,初期支护后水压力增大。增厚注浆圈、减小注浆圈渗透系数,则隧道涌水量及初期支护后水压力减小。

To study the seepage field of three-hole parallel subsea tunnel,an analytic solution of the seepage field of the three-hole parallel subsea tunnel under the semi-infinite plane assumption was derived by using the mirror method based on the single-hole tunnel seepage field.The analytical solution of the seepage field for the three-hole subsea tunnel can be degenerated to the analytical solution of the seepage field for a single hole and a double-hole subsea tunnel.The numerical simulation results were used to verify the analytical solution of this study.The effects of tunnel spacing,initial lining thickness and grouting circle thickness parameters on tunnel water inflow and initial pressure were analyzed.The results showed that due to the influence of three-hole parallel tunnels,the water inflow of the three-hole tunnel and the water pressure after the initial lining were decreased as compared with the single-hole tunnel and the intermediate tunnel was mostly affected.The water inflow and the pressure after the initial lining of the tunnel increased with the increase of the horizontal distance between tunnels.When the horizontal tunnel spacing was greater than20times the tunnel radius,the interaction between the tunnels can be ignored.With the increase of the depth of the left tunnel,the water inflow and the water pressure after the initial lining was decreased.The intermediate tunnel water inflow and the water pressure after the initial lining was firstly decreased and then was increased.The initial lining impermeability was improved and the water inflow was reduced.However,the water pressure after the initial lining will increase.Thickening the grouting ring and reducing the permeability coefficient can reduce water inflow and the water pressure after the initial lining