Effect of Floor Surface Topography on Human Stepping Tribology in Slope Walkway

Slips and falls usually happen during human walking, and slope is a typical walkway. There are many researches about the improving of stepping friction coefficient through changing the materials and surface morphology of sole and floor in level walkway, but only a few are in slope walkway, especially under different surface topography condition. This paper prepared three floors of different surface topography with same surface waviness on 45 steel, studied their stepping friction coefficient in slope walkway by gait friction tester. Results showed that the effect of slope on available coefficient of friction was higher than that of surface roughness. With the increasing of slope, required coefficient of friction increased and available coefficient of friction decreased, and stride frequency first increased then decreased. The effective area that forefoot contacted with walkway decreased with the increasing slope during uphill, as well as the heel contacted with walkway during downhill, that reduced the available coefficient of friction and increased the risk of slip and fall. Human gait shorten the step length to reduce required coefficient of friction in order to maintain body balance.