Numerical Simulation On Seepage Flow And Investigation On Measurement Of Seepage Prevention In Deep Foundation Pit Of Shawan Hydropower Station, Daduhe, Sichuan

Nowadays, more and more hydro projects have to be built on the overburden layer foundation in rivers, which depths is even hundreds of miters in some projects. As is known, overburden layer is substantially composed of debris and sedimentary deposit which were made in the Quaternary Period and are distributed in the surface of the earth. In many cases, because of its spacious variation of compositions and physical mechanics' characteristics, overburden layer often brings many problems such as seepage instability, differential settlement and excessive deformation. Because of the limitations of experimental means and theoretical methods, the performances of overburden layer are still one-sided and engineering experiences and numerical simulations play an important role in practical projects.Firstly, numerical simulation and investigation were carried out on the key technique problems, such as deep pit excavation process and stability on the basis of relevant engineering stuff and the construction of seepage prevention wall. Then the interrelationship between each key element in seepage fields was found, which were changed with different conductivity of cutoff wall influenced by excavation elevation, construction quality, etc.. Finally, measures and suggestions were supposed to solve these engineering problems.The main contents and results were listed as follows:(1) The plants of Shawan hydropower station are located in the deep channel in the right river bed where the overburden layer was 70m deep or so...