Report of investigation, first floor slab in ORNL building 9204-1, Y-12 plant

Abstract

The primary objective of the work reported here was to determine safe allowable axle loads for fork trucks using above grade floors in certain ORNL buildings in the Y-12 area. A necessary part of the accomplishment of this objective was the formulation of a method for assessing the flexural capacity of a slab and for determining the bending moment induced by an applied axle load. A decision was made to focus on a particular slab region on the first floor of Building 9204-1. This slab had one of the lowest allowable axle loads, as determined from earlier analyses, and it was located in an area where the use of 4000-lb fork trucks loaded to capacity was crucial to the performance of the large coil fusion project. Also, it was in a location easily accessible for experimental investigation. The procedure followed to attain the desired objectives was as follows. Load tests on a slab in Building 9204-1 were performed. Two fork trucks, 4000 and 6000-lb capacity, were used. The trucks were loaded to different load levels, the axle loads were obtained by weighing, and the trucks were run, singly, over the slab. Both computer (finite element) and hand analyses were made. Criteria were defined, based on the experimental and analytical studies, to determine a reasonable safe axle load. Finally, a procedure was developed for extending the results to other slabs. The results show no visible evidence of any distress of the slab or beams under any of the loadings, and that the dynamic load factor was approximately 1.05, which is considerably lower than that generally used in design.