Estimating The Frequency Of Exposure To Uncertain Hazards: Impact Of Wind Conditions On Concrete Dam Construction

Due to the narrow construction site, intensive construction, and constant strong winds, some concurrent activities during concrete dam construction are proven to lead to space conflicts and increase the frequency of exposure to hazards. Despite some valuable contributions, the current methods for quantifying exposure frequency are still subjective and inadequate for reliable safety evaluation. Therefore, this study provides a formal approach to identify exposure under dynamic wind loads and to estimate exposure frequency to scrutinize dynamic interactions at construction sites. In this study, first, the force of hazard with wind loads is analyzed to identify the impact of potential hazards from vertical concrete transport in an undesirable event. Second, combined with the concrete dam construction cycle process and the operating time characteristics, the probability of hazards and victims concurrently appearing in an overlapping space is calculated to measure the possibility of disastrous events from the perspective of spatial and temporal attributes. Then, the exposure frequency is expressed using statistical information on wind conditions, location information on the site layout, and mechanical motion parameters. In contrast to traditional risk-assessment methods, the proposed model combines the uncertainty of wind and the probability of hazards and victims simultaneously appearing in an overlap into a more rigorous safety perspective. Finally, the model's capability of hazard exposure assessment is demonstrated and tested by applying it to a case study of a major real-world construction project. The results show that the novel methodology is able not only to quantify the exposure frequency with the contribution of the influence of strong winds but also to assess the risk of dam construction projects. Furthermore, this method will provide an important objective and precise evaluation tool for hazard exposure. (c) 2020 American Society of Civil Engineers.