Effects of Joints Spacing on Static Bearing Capacity of Rock Foundations in the case of Punching Failure

In this paper, using distinct element method, static bearing capacity of rock foundations containing one, two and three joint sets is investigated in the case of punching failure. The effect of joints spacing is incorporated to the analyses using a dimensionless factor, named spacing ratio (SR). Different values for SR are selected and variation of the bearing capacity versus SR is monitored. Then, the magnitude of SR in which the bearing capacity does not change significantly, is determined. The findings show that for SR30, the joints spacing do not affect the bearing capacity, significantly. Hence, SR=30 can be used as a criterion for analysis of rock foundations either as an equivalent continuum or a discontinuous medium. Using this criterion will tend to greatly reduce the time required for the bearing capacity analysis of rock foundations.