Planning safe distances between workers on construction sites

a r t i c l e i n f o A planning methodology is introduced to ensure that workers on construction sites remain at a safe distance from each other. The methodology is based on the assumption that hazardous conditions, which occur on sites due to the proximity of different workers, depend on the interaction between both reinforcing and counteracting characteristics of the workers. The methodology includes a matrix-based method for the definition of minimum safe distances between workers, and the use of 3D time–space diagrams to represent and analyze the dynamic movements of workers on site. The methodology is implemented in a real case study in order to verify its feasibility. According to conservative estimates, at least 60,000 people are fatally injured on building sites around the world every year [7]. Many hundreds of thousands more suffer serious injuries and ill-health. Worldwide , construction workers are three times more likely to be killed and twice as likely to be injured as workers in other occupations [3]. While fatal work injuries in the private construction sector in the US increased by 5 percent in 2012, this followed five consecutive years of declining fatal injury counts [14]. In the UK, the number of worker deaths in 2012/13 was 18% lower than the average for the past five years [6]. Although the statistics may show some improvement, they also clearly indicate that safety on construction sites remains a major problem. Workers on construction sites are exposed to hazards that have three main sources: a) the work technology (e.g. the tools and equipment used to carry out the activity), b) the physical conditions (e.g. high elevations) and c) surrounding activities that are simultaneously carried out by other workers nearby [13]. This research focuses on the prevention of hazards of the third type: i.e. those created by surrounding activities. While there are many methods and models available to assess the risks that workers' own activities pose to themselves, few studies have dealt with the hazards derived from the activities of other workers on site to which workers are also frequently exposed [24]. The problem of accidents on construction sites that are caused by an excessive proximity between workers carrying out different activities is exacerbated by the fact that construction sites are dynamic: the location of workers is transient, and the physical structure and activities often change. Such accidents could be prevented by carefully …