Temporary Works Toolkit. Part 19: An introduction to the demolition of large stuctures

Many modern office towers are of steel-composite constructione. However, the lightweight nature of steel means a lower modal mass – and vibrations from active sources (e.g. footfall) need be considered carefully during the design stage. This article discusses vibration performance and mitigation based on recent experience in Singapore.

The permanent works designer (PWD) has a major influence on the temporary works and can, for example: eliminate temporary works, e.g. through the use of steel decking rather than timber falsework minimise the use of temporary works, e.g. by using the permanent capping beam as a waling in basement construction design the permanent works so that simple temporary works solutions can be used.

This article explains the theory and background to backpropping and gives advice on the methods recommended to be adopted for backpropping calculations. It looks at the physics involved and how engineers and designers can mitigate damage to concrete slabs during construction.