Numerical Simulation Analysis Of Water Seepage Chanals

Reserch of water seepage channels of distribution and influence factor, Not only to ensure the safety of the channel seepage stability and has important practical value to Engineering safety, but also has important theoretical significance.In order to study the conveyance canal seepage problem in geotechnical engineering and its influencing factors of sensitivity, On the basis of Darcy’s law, according to the basic equations of motion rock seepage, combine water channels specific engineering geological conditions of the finite element numerical modeling of flow movement, combined with running two different operating conditions of the channel flow movement numerical simulation, and then analyzes the sensitivity to different factors influence the flow of movement.As a case of studying water channel, Its formation mostly along the quaternary alluvial(Q42al、Q41al)and diluvial(Q3al+pl) layer of loosely packed, Lithology drift gravel sand, gravel sand, clay, silt, etc. Only a few local area visible bedrock exposed, The lithology is Triassic limestones of the system Leikoupo(T2l), Argillaceous dolomite and dolomite and Argillaceous limestone Jialing group(T1j)of lower Triassic limestone, limestone. Draw the following conclusions:High-water run-conditions, seepage quantity per unit length outward drainage canal within 0.394 m3/h, and by seepage discharge of plastic concrete impervious bottom of 0.358m3/h, 90.86% of the total seepage. Wetting the overflow line is located at the lower part of the sand and gravel filling layer, close to the boundary layer and the drift gravel filling sand layer, the inner canal slope at an elevation of 411.00 m.waterhead reduce7.36 m in the plastic concrete impervious. accounting for about 90% reduction of the total waterhead. Each rock layer allows the hydraulic gradient is less than the hydraulic gradient, osmotic stability.Calculation of the low water level condition results showed that outgoing drainage canal seepage discharge within the unit length 0.249 m3/h, and by seepage discharge of plastic concrete impervious bottom of 0.236m3/h. 94.78% of the total seepage flow. Wetting the overflow line is located at the lower portion of drift layer covered with sand and gravel near the bedrock, within the drainage slope 403.50 m elevation. waterhead reduce 4.67 m in the plastic concrete impervious. accounting for about 72% reduction of the total waterhead. Each rock layer allows the hydraulic gradient is less than the hydraulic gradient, osmotic stability.Impervious wall and bedrock permeability coefficient of sensitivity analysis shows:in the better condition of bedrock, permeability coefficient around strong weathering zone(K=1.05×10-3 cm/s)and weak weathered zone(K=1.0×10-4 cm/s), if the plastic concrete impervious wall penetration coefficient control in about K=1×10-5cm/s, Seepage Field conditions can basically meet the design and construction requirements, at this time reduce impervious wall permeability coefficient on flow field has little effect.Impervious wall and bedrock permeability coefficient of sensitivity analysis showed : in the bad condition of bedrock, permeability coefficient around strong weathering zone(K=1.05×10-2cm/s)and weak weathered zone(K=1.0×10-3 cm/s), unit length Seepage discharge will reach around 4m3/ s,the effect of the impervious wall to reduce pressure head is not significant, Larger regions of seepage failure may occur, Impervious wall’s permeability coefficient changes have a little effect on the flow field,if you want to change the situation of Seepage Field in this time, Only deepen plastic concrete impervious.