Area A1a houses a large-scale reaction frame for structural testing. The reaction frame consists of approximately 500 square ft (30 ft long x 17.5 ft wide) strong floor and an L-shaped reaction wall (each side of which is 15 ft wide x 14 ft high). On the strong floor, anchor groups of four holes (for 1 ½ inch bolts at a spacing of 10 inches) are spaced at 3 ft (center-to-center). Each anchor group is capable of resisting a maximum of 100 kips in tension. The strong floor is designed to resist a total of 500 kips tension or compression force. Similarly, anchor groups of the same type are placed on the strong walls at a spacing of 3 ft. Each anchor group on the walls can resist 100 kips in tension or compression with the total reaction force being limited to 250 kips per wall. The walls are designed to resist 250 kips of load (each) simultaneously for biaxial testing of structural elements. A picture of the reaction frame is provided below. The reaction frame is served by a 5-ton overhead crane. The large-scale reaction frame along with the overhead crane is seen on the right.