Challenges in predicting and managing construction noise impacts in urban environments. Case studies from Sydney, Australia

Approval of major infrastructure projects in Australia is contingent on a vigorous environmental assessment process demonstrating that the impacts from such proposals are acceptable and can be satisfactorily managed. As part of this process, an assessment of construction noise is undertaken by predicting the level and duration of impact. Given the scale, complexity and programs for delivery of major infrastructure projects such as the Sydney Metro, the approach to assessment of environmental impacts is typically undertaken based on early concept designs, and assumptions which enable potential worst-case impacts to be considered. Ongoing design development and construction methodologies continue to occur, and are finalised by the contractor responsible for delivering the package of works for the project. Layers of conservatism could therefore be built into the process to ensure that environmental impacts are understood, and appropriate mitigation measures are considered. Moreover, common predictive noise modelling tools are believed to under-estimate the level of barrier insertion loss provided by residential buildings in urban scenarios, further exacerbating the over-prediction of construction noise impacts. By use of case studies, the present paper examines the challenges of assessing and managing construction noise associated with a major infrastructure project in Sydney, Australia.