VALUE ENGINEERING

VALUE ENGINEERING

Structural Optimisation

Our approach to Value Engineering is summarized in the quote by the CEO of Jaguar, Dr Ralf Speth who once said that…

“if you think a good design is expensive, you should look at the cost of a bad design”.

Essentially, we do not try to Value Engineer a structural design by simply reducing material marginally, even if it can be justified by code compliant calculations, as this would simply reduce the factor of safety of the building structure. Instead, we Value Engineer a structural design by changing the structural scheme completely (indeed only if it is feasible) for e.g.: –

• by altering the vertical and lateral load paths (and architectural grids if possible) to a more efficient system in high-rise structures

• by converting an RC construction to a longer span post-tensioned (PT) construction in high-rise structures

• by converting an RC / PT construction to a longer span composite steel construction with integrated services in high-rise structures

• by converting a beam and slab construction to a flat slab construction

• by converting an RC transfer floor into a dual-cast post-tensioned (PT) transfer plate in high-rise structures

• by performing automated structural optimization for complex designs such as on a 50-pile pile group pile cap design

• by performing an integrated pile cap and (stiffening) core wall analysis and design

• by performing a more bespoke or customized design considering the actual spans and applied loadings, etc.

whilst maintaining or in fact increasing the structural factor of safety.

Apart from the obvious financial gains associated with a value engineering exercise, perhaps an even more beneficial side-effect is the savings onto the environment. Climate change is caused by a number of different greenhouse gases. Some greenhouse gases have a greater impact whilst some others have a lesser impact on the climate. In order to measure the global warming potential of greenhouse gases, a single unit of measurement is often used, i.e. the “carbon dioxide equivalents” or CO2e. Other synonyms used to describe this global warming potential include ‘embodied carbon’ or ‘carbon footprint’.

Global yearly CO2 emissions have increased from 2 billion tonnes in 1900 to about 36 billion tonnes in 2019.

In building construction, the CO2e refers to the lifecycle greenhouse gas emissions that occur during the manufacture and transport of construction materials and components, as well as the construction process itself and end of life aspects of the building.

Concrete has a large footprint because of the carbon-emitting process used to make one of its most important ingredients i.e. the binder Portland Cement. By some estimates, production of Portland Cement is responsible for 5% of total global CO2 emissions. Further, according to the World Steel Association, steel production is responsible for 6.6% of greenhouse gas emissions globally.

It is estimated that a tonne (i.e. 1,000kg) of concrete produces approximately 150kg of CO2 whilst a tonne (i.e. 1,000kg) of steel produces approximately 1,900kg of CO2.

Thus our approach to climate change is to simply reduce the usage of concrete and steel as raw materials by value engineering the building and bridge structural designs of engineers to make them leaner by introducing more structurally efficient designs.