Abstract
This paper is the second report in a series of studies on vertically loaded pile caps. In this paper, twenty eight reinforced concrete pile caps, each with four piles, were tested. The variables involved were spacing of piles, arrangement of reinforcement, type of anchorage and arragement of piles. The results were compared with each other. In regard to the ultimate strength, the experimental results including the those in Part-I were compared with the calculated values according to the equations proposed by others, to the provision for the moment and shear in A. I. J. Building Code Requirements for Reinforced Concrete, to that in A. C. I. Building Code Requirements for Reinforced Concrete and to the equation for the punching shear proposed by authors. Furthermore, forty eight pile caps tested by authors were analyzed by three dimensional finite element method based on elastic theory and the results were comparedwith the experimental results. The following items were clarified : 1. The difference in the arrangement of reinforcement has a little effect upon the extensional rigidity of footing slab, but it can be considered that there is no effect on the initial cracking load, flexural strength and shear strength. 2. The calculated values according to the provision for the moment in A. I. J. Building Code agree well with the experimental results. 3. The calculated values according to the provision for the punching shear in A. I. J. Building Code comform better to the experimental results than those by A. C. I. Building Code provision. The shear strength on the footing acting essentially as a wide beam shall further be investigated. 4. The calculated values according to the equation for the punching shear proposed by the authors agree well with the experimental results. 5. Ohno-Obata's equations to evaluate the flexural and shear strength of the ground-supported reinforced concrete column footing derived from the finite element analysis can also be applied to the reinforced concrete pile cap if some conditions were added.
