The study involved a laboratory and a theoretical analysis designed to understand whether the use of short fibers increases the shear strength of fissured clays. The laboratory experiments involved the direct shear testing of reinforced and unreinforced clay samples containing a preexisting crack. The theoretical analysis used the principles of linear elastic fracture mechanics theory to determine the direction of crack propagation in the fissured clays. The investigation revealed that, if short steel fibers are added to the fissured clays, their shear strength increased. For the

case of a clay sample with a preexisting horizontal crack, the addition of short fibers increased its shear strength by 9 percent. For the case of a clay sample with a preexisting crack inclined at 30 degrees with the horizontal, the shear strength increased by 25 percent with the addition of the fibers. Thus, the use of short fibers appears to be a viable technique for increasing the strength of fissured clays. However, many questions remain about how to effectively reinforce fissured clays in the field, the interaction mechanisms of the fibers with multiple cracks of different lengths and orientations, and the durability of the steel fibers in clay