طرح زهكشي تكيه گاه نفوذپذير سدهاي خاكي

DESIGN OF DRAINAGE SYSTEMS FOR PERMEADLE ABUTMENT OF EARTH DAMS

In the design of earthdams, the abutment of the dam may be a hill with high permeability. The head at the dam upstream controls the flow rate through the abutment. High seepage through the abutment may cause dangerous stability problems. One of the most important problems in the design of drainage systems is the calculation of the seepage through the abutment of the dam. For the drainage of permeable abutment of earthdams, drain pipe or drain channel (filled by drainage materials) can be used in a proper place in downstream slope of abutment. In this study, for drainage of abutment of the berenjestanak eathdam, the method of drain channel at the downstream slope of abutment have been used for determining the location and characteristics of the drain, MSEEP software has been used. To reduce the seapage surface in downstream slope of abutment and increase the flow rate through the drain, the size of this drain channel is caculated as 2m*3m with 0.05m/s for coefficient of hydraulic conducitivity. The best place for constructing the drain channel is the lowest position of the seepage surface.