Study On Seepage Safety Of Horizontal Directional Drilling Pipe Crossing Dike

Seepage failure is the most common form of destruction of embankments.In the field of underground seepage and engineering seepage,a lot of relevant researches have been done.In the process of directional drilling crossing river embankment,During the construction of directional drilling through the river pipeline project,a hidden and non-linear disturbance zone is formed in the stratum under the river and the river embankment.The additional influence of the non-linear disturbance zone on the seepage field is very complicated.Quantitative analysis is therefore even more difficult.Based on the extremely unfavorable hydrological and meteorological conditions,a numerical simulation model of groundwater flow is established on the basis of the example of Anqing oil pipeline project crossing the Vadong main canal,Zhuangmu River and the second station of the Zhuangmu River into the canal in Hefei.The model is simulated in the face of designed flood,calculate groundwater hydraulic gradient after laying pipe along the pipe wall.In the model,the risk of soil layers disturbed is predicted and stability of river bed is analysed.Based on the method of critical hydraulic gradient,quantitative analysis and research are studied on the possibility of horizontal directional drilling inducing seepage failure through river channel engineering.The results show that the maximum hydraulic gradient of seepage field is much smaller than the allowable hydraulic gradient.It's very unlikely that flood scouring of riverbed in flood cause seepage damage,and the pipeline failure will not occur at the bottom of the river and the pipeline engineering in operation period will not affect the stability of embankment.