Comparison of Design Risk Factors of Multistory Commercial Office Buildings

The risk associated with constructing multistory commercial buildings can take many forms, with significant risk associated with construction site safety hazards. The type and magnitude of risk present on construction sites depends to a great extent on the permanent design features. A project's design forms the basis for the means and methods used during construction. If the risk factors associated with design features are known, risk management can take place during the design stage to select design alternatives which minimize construction safety risk. As part of a recent research study, design risk factors were quantified for all of the construction activities and equipment necessary to construct the shell of a multistory commercial office building. The risk factors were developed through detailed input from general contractor superintendents, general contractor safety managers, and trade contractor personnel. For cast-in-place concrete, for example, the research results indicate that there is no evidence of a difference in risk perception between general contractor superintendents and general contractor safety managers in terms of risk ratings for the activity risk, severity, and total risk. The construction and removal of formwork and pouring of concrete show moderate to suggestive evidence of a difference in the sample mean risk perceptions for the three group comparisons. There is moderate to suggestive evidence of a difference for medium severity, high severity, and total risk for the three group comparisons. There is no evidence of a difference in the way the groups perceive near miss risks. The research results allow for comparison between different design alternatives as well. For example, for steel stud versus concrete masonry unit (CMU) block partition walls, there is moderate evidence that on an average, the construction of CMU block wall has a larger cumulative risk of medium severity and high severity injuries. This paper presents comparisons of risk perception between the three sample groups for different design alternatives, along with comparisons of the perceived risk between different design alternatives, to illustrate the differences in construction safety risk expected during construction.