Observation of the floor surface topography changes in pedestrian slip resistance measurements

Research on Slip Resistance Measurements<br>—A New Challenge

“…They showed that variations in the surface geometry of the shoe heels had a major effect on the slip resistance properties. Kim and Smith 4,5) also analysed the topography changes of floor surfaces before and after the slip resistance measurements. They found that embedding of the polymeric materials from shoe heels into the valley areas of floor surfaces was a major cause of the changes of floor surface geometry.…”

“…There have thus been prolonged efforts to understand the vital causes of such accidents throughout the world. It has been found that the most common precipitating event leading to a fall is a loss of traction between the shoe sole/heel and floor surface and its slip resistance property is measured as a form of coefficient of friction (COF) [3][4][5][6][7] . Hence, knowledge about friction demand and the friction available has been recognized as a primary key factor for the slip safety evaluation.…”

“…Although the concept of friction is relatively simple and straightforward, its measurement, analysis, and interpretation for solving real-world problems on slips and falls are a quite challenging task. However, one of the most important aspects to address is that the COF measure is not a constant value because friction properties are intrinsically noisy and continuously changed as a function of a complex array of tribological phenomena between the shoes and floors 4,5) . As a result, initial surface features and material characteristics of both the shoes and floors are frequently and significantly modified from a first moment of contact by surface failures and wear evolutions.…”

“…Surprisingly, however, there has been little analysis on how friction induced wear developments of the shoe heels and/or floor surfaces affect the slip resistance properties. In addition, slip resistance properties observed at the sliding interfaces between the shoe heels and floor surfaces are diverse and combine various sub-mechanisms of friction and wear events 4,5,8) . Hence, it becomes clear that a simple format of friction measurement does not provide an accurate determination of intrinsic properties of slip resistance between the shoes and floors and accordingly has obvious difficulty as an indicator for the fall safety estimate.…”

“…New conceptual foundations for characterizing the slip resistance properties should be based on thorough understanding of fundamental mechanics and mechanisms of tribological characteristics between the shoes and floors. Because surface topographies of the shoes and floors are largely modified throughout the course of repetitive contact-sliding friction processes, this may considerably affect overall friction and wear behaviours and be one of the most important factors on the slip resistance properties [4][5][6][8][9][10][11][12][13][14][15][16][17] . While controversies around the friction measurement for slipperiness assessment still remain 25) , a tribological classification may provide an objective alternative to overcome the current problems of slip resistance evaluations.…”