Confined Site Construction: A qualitative investigation of critical issues affecting management of Health and Safety

The construction industry is inherently risky, with a significant number of accidents and disasters occurring, particularly on confined construction sites. This research investigates and identifies the various issues affecting successful management of health and safety in confined construction sites. The rationale is that identifying the issues would assist the management of health and safety particularly in inner city centres which are mostly confined sites. Using empiricism epistemology, the methodology was based on qualitative research approach by means of multiple case studies in three different geographical locations of Ireland, UK and USA. Data on each case study were collected through individual interviews and focus group discussion with project participants. The findings suggest that three core issues are the underlying factors affecting management of health and safety on confined construction sites. It include, (i) lack of space, (ii) problem of co-ordination and management of site personnel, and (iii) overcrowding of workplace. The implication of this is that project teams and their organisations should see project processes from a holistic point of view, as a unified single system, where quick intervention in solving a particular issue should be the norm, so as not to adversely affect interrelated sequence of events in project operations. Proactive strategies should be devised to mitigate these issues and may include detail project programming, space management, effective constructability review and efficient co-ordination of personnel, plant and materials among others. The value of this research is to aid management and operation of brownfield sites by identifying issues impacting on health and safety management in project process.

Strategies for Effective Management of Health and Safety in Confined Site Construction

The overall aim of this research is to identify and catalogue the numerous managerial strategies for effective management of health and safety on a confined, urban, construction site. A mixed methods methodology was adopted using interviews and focus group discussions on three selected case studies of confined construction sites. In addition to these, a questionnaire survey was used based on the findings from the interviews and the focus group discussions. The top five key strategies include (1) Employ safe system of work plans to mitigate personnel health and safety issues; (2) Inform personnel, before starting on-site, of the potential issues using site inductions; (3) Effective communication among site personnel; (4) Draft and implement an effective design site layout prior to starting on-site; and (5) Use of banksman (traffic co-ordinator) to segregate personnel from vehicular traffic. The construction sector is one of the leading industries in accident causation and with the continued development and regeneration of our urban centres, confined site construction is quickly becoming the norm - an environment which only fuels accident creation within the construction sector. This research aids on-site management that requires direction and assistance in the identification and implementation of key strategies for the management of health and safety, particularly in confined construction site environments.

Process simulation of co-firing torrefied biomass in a 220 MWe coal-fired power plant

Torrefaction based co-firing in a pulverized coal boiler has been proposed for large percentage of biomass co-firing. A 220 MWe pulverized coal-power plant is simulated using Aspen Plus for full understanding the impacts of an additional torrefaction unit on the efficiency of the whole power plant, the studied process includes biomass drying, biomass torrefaction, mill systems, biomass/coal devolatilization and combustion, heat exchanges and power generation. Palm kernel shells (PKS) were torrefied at same residence time but 4 different temperatures, to prepare 4 torrefied biomasses with different degrees of torrefaction. During biomass torrefaction processes, the mass loss properties and released gaseous components have been studied. In addition, process simulations at varying torrefaction degrees and biomass co-firing ratios have been carried out to understand the properties of CO<sub>2 emission and electricity efficiency in the studied torrefaction based co-firing power plant. According to the experimental results, the mole fractions of CO ₂ and CO account for 69-91% and 4-27% in torrefied gases. The predicted results also showed that the electrical efficiency reduced when increasing either torrefaction temperature or substitution ratio of biomass. A deep torrefaction may not be recommended, because the power saved from biomass grinding is less than the heat consumed by the extra torrefaction process, depending on the heat sources.