Abstract
This paper intends to obtain theoretically the bearing capacity of plain concrte. It has been able to be solved with Dr. Cowan's failure criteria. A general idea of "Wedge Theory" is next. In consideration of the partial compression failure, at first, a rigid zone of wedge is thought under the loading part, next, this "wedge" push in. And tensile crack will take place. As soon as the tensile strength reaches the capacity, the "wedge" will move, then the failure will occure. By the way, as though the form of this wedge is assumed of variaty, the failure has to occure at the minimum load, so that the most suitable form of this wedge is caluculated as the solusion of the extremum problems, which is constracted with the previous failure criteria. In this way, the upper and lower limit bounds of the bearing capacity have been studied with kinematic analysis method. And in the results of this analysis, this capacity is sure of the upper bound value according to compare with test results.
