Health and safety challenges in deep trench excavations for pipe laying sites in Sri Lankan context

Abstract

Recent developments in Sri Lanka have accelerated the construction, and deep trench excavation is one of the main construction activities. Health and safety in construction includes safe work sites while addressing cost, quality, productivity, and customer satisfaction. Health and safety reduce project risk, an important parameter in construction project management. This research aims to identify and analyze health and safety challenges in deep trench excavations and to determine mitigating measures. Data for the study was collected through personal interviews and a questionnaire survey, covering project managers, engineers and safety officers with experiences in trench excavations. The respondents were selected using simple random sampling technique and based on Cochran's formula for an infinite population, the sample size was 96. SPSS software was employed to analyze the data and the conclusion were made considering descriptive statistics. The results elaborate that the most common hazards associated with deep trench excavations are side wall collapse and earth work support failures, while the most common causative factors for accidents are the absence of adequate shoring systems and the negligence of the workers. The most commonly encountered limitations for implementing health and safety measures in shoring arrangements are financial constraints, followed by time constraints. Hence, it is recommended to include separate billing items for shoring arrangements when creating tender documents and to allocate sufficient funds in the engineer's estimates to mitigate the risks associated with health and safety in deep trench excavations. Furthermore, during the bid evaluation phase, special consideration should be given to determine adequacy of the bidders' allocations for safety and shoring arrangements. Since, cost is the most significant impediment for implementing protective systems, it is recommended further studies on the cost and time constraints of proper shoring arrangements in deep trench excavations, as well as an economic analysis of various shoring types.