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

Steel is gaining popularity in metropolitan Asian cities. Many modern office towers are of steel-composite construction, as they are lightweight and achieve faster construction cycles than concrete. However, the lightweight nature of steel also 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.

Current highway bridge designs in the UK tend to favour either composite steel girders with a precast or in situ concrete deck for long spans, or precast concrete beams with an in situ concrete deck for spans of less than 40m. This article considers temporary works, in particular the use of temporary supports, to precast concrete bridge beams during deck construction.

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.