Document Type : Research Article
Limitation of water flow and seepage from upstream to downstream through the abutments is a major
factor in design of concrete arch dams. In practice, due to the intensive loading imposed on abutments,
the concrete arch dams are usually constructed on the rocky abutments with high degrees of strength
and stiffness. However, the hard rocks have always contained some discontinuities because of their
intrinsic brittle manner. Since these discontinuities are the main ways through which most of seepage
is occurred and thus tend to instability of foundation, their hydraulic and mechanical effects must be
fully considered. In this paper the effects of geometrical parameters such as joints orientation and
initial aperture are studied on hydraulic behavior and seepage through abutments. In addition, the
effect of hydraulic initial aperture which is a hydraulic parameter is treated on the safety of abutments.
The results show that the geometrical parameters have dominant influence on the seepage through
abutments and can also endanger the stability of foundation.