Study On Application Of Combined Drainage Measures Of Precipitation Well And Oblique Drainage Pipe In Slope Hazard

Due to insufficient drainage measures,the groundwater head rises rapidly in the rainy season,resulting in a low safety factor of the slope.Under the combined effects of various unfavorable factors,even the instability will occur.Therefore,the drainage measures for such slopes are very necessary.Based on the slope project of dam light toll station,this paper proposes a joint drainage method for “precipitation well + updip drainage pipe” for the shortcomings of existing slope drainage measures.It has strong operability,maintenance-free and drainage.The effect is good,and the effect of the drainage measures on the seepage field and stability of the slope under different conditions is analyzed by theoretical analysis,numerical simulation and field test around the drainage measures combined with this “well pipe”.Research on its application in slope management,the relevant content is as follows:(1)According to the characteristics of the dam light slope in Shenzhen,a simplified model of soil isotropic is proposed.The finite difference method is used and the python program is compiled.The simplified one-dimensional profile flow and the planar twodimensional flow are calculated.The seepage field changes.The obtained immersion line after the one-dimensional cross-section precipitation is introduced into the calculation stability of Plaxis.When the maximum water level of the precipitation well is the same,the influence of the precipitation well on the slope stability at different elevations is analyzed,and the precipitation well is obtained.The optimal position of single row and multi-row arrangement;for the seepage field characteristics of the planar twodimensional flow of the simplified model,the infiltration surface change and the dewatering and dewatering after the precipitation of the same precipitation well are obtained by different precipitation well layout methods.The law of the soil range.(2)Using the finite element software Plaxis3 D to simulate the variation of the seepage field caused by the “precipitation well + tilting drainage pipe” drainage measures under different working conditions in the dam light slope,and calculate the overall stability of the slope by the strength reduction method.The relationship between the permeability coefficient,the depth of the well and the water seepage of the precipitation well is obtained.The recommended safety value of the single-row precipitation well and the double-row precipitation well is given based on the increased safety factor of different precipitation wells.The theory of seepage and deformation of saturated-unsaturated soils can effectively suppress the increase of groundwater level caused by rainfall infiltration under the actual rainfall conditions,compared with the influence of the settling wells and no precipitation wells on the seepage field and stability of the slope.Increase the safety factor of the slope.(3)According to the characteristics of combined drainage of precipitation wells and inclined drainage pipes,a set of specific single-point precipitation well application schemes is proposed through theoretical analysis,and the selection basis of the structure of the precipitation wells and the inner diameter of the inclined drainage pipes are explained,and the inclination is solved.Drain pipes and precipitation wells cannot be accurately docked.The feasibility of the dredging measures and the correctness of the model calculation are verified by comparing the field application data with the numerical simulation results.