Mechanism Of Drainage System Regulating On Complicated Seepage In Eluvial Slopes

Seepage control is an effective way to improve the slope seepage field, drainage systems are widely used in engineering slope seepage field control, in order to keep soil drying, strengthen shear strength, achieve the purpose of resisting slope sliding. Seepage field with drainage hole is very complex. It involves drainage, the atmosph-eric precipitation, groundwater and other interaction of unsaturated--saturated seepage flow. It is affected by rainfall intensity and pattern, slope’s soil and structure and many factors such as drainage system layout the mutual influence and restriction. Because the drainage control effect on seepage field was not clarified under the influence of multiple factors. It is difficult to reveal the drainage regulation mechanism and determ-ine the main controlling factors. The layout scheme is currently the main stay in rely on the experience and the specification level. Theoretical research is far behind the engineering practice. It brings many problems, such as drain failure, too close, unable to meet the requirements of drainage, etc. Therefore, to carry out drainage of unsatura-ted residual soil complex seepage field regulation mechanism research, effectively guide the related engineering of science has important theoretical significance and engineering practical value.In this article, model is builded through PLAXFLOW modules of finite element software PLAXIS for two-dimensional seepage analysis, soil model using Van Genu-chten unsaturated soil model, the actual situation with thematerial element with scene simulation tools drainage holes and considering the engineering practice of air element method of drainage holes in reference to previous studies using.First of all, using the typical granite residual soil in fujian province in homogen-eous soil slope as an example, on unsaturated residual soil drained and undrained conditions of two kinds of contrast simulation study, author observes whether different rainfall conditions, underground water level and layout the response of the slope seepage field under the condition of the drain. Not laying drainage holes Shipo foot the most prone to damage. Heavy rainfall, long timesustained the greatest impact on the stability of the slope. The slope soil fine particles increased, the rainfall infiltration speed slow, saturation increased. After laying drainage holes can be discharged a portion of infiltration rainwater, significantly reduce the underground water level, the point of saturation of the slope and the flow velocity is decreased obviously, has a positive role in the regulation of seepage field of slope.Secondly, taking Fujian province typical granite residual soil multilayer slope as an example, author analyzed the aperture, the slope drainage hole type selection and layout, the dip of the hole effect of drainage. And the drainage effect along the height direction arrangement of multiple rows of drainage holes of. Within the scope of the project common values, the length of drain holes has greater influence on drainage effect. Drain laying length should be choosed according to the scope of governance of the slope. Scupper aperture less affected, aperture selection Suggestions are put forward. To drain control Angle, can be undertake choosed according to the need to reduce underground water level. When multi-row layout drainage holes in the direction of the slope of the elevation of the water table has a significant regulatory role, and in the groundwater seepage line slowing down, lowering the water level, flow rate slows down each reference point.At the end of the article using an engineering example verifies the drainage holes can effectively drain water out of the slope body, and combined with other strength-ening measures to ensure the stability of slope under different working conditions.