Construction firms need to be digitally smart to drive quality and alleviate industry pressures
In 2016 we saw the construction industry slip into recession for the first time in four years, with building material prices rising post the EU referendum. Now there is even talk about putting a levy on skilled EU employees working in British companies. With such pressures weighing heavy, it has never been more important for construction firms to work as efficiently as possible.
The deficit of skilled construction workers is often called out as a large contributor to this, with many pointing to the last recession as a catalyst. While this factor cannot be ignored, a more likely drain on construction skillsets is the raft of major projects underway throughout the UK.
When you think about the current projects in the pipeline, such as HS2, Hinkley Point and Heathrow, which will take years, if not decades, to complete, this is easy to understand. As we usher in Industry 4.0, it is not just traditional skillsets that companies are calling on. Modern teams need to understand how to work with 4D/5D BIM software, become data scientists and be experts in the Internet of Things (IoT), which puts even more pressure on the industry.
Is BIM Level 2 enough?
The government is tackling the issue of quality head on with the introduction of the BIM Level 2 legislation in April last year. This requires all government-owned programmes to adhere to new standards, creating an environment where low quality is more traceable and addressed more quickly, resulting in reduced wastage of time and material thanks to more efficient processes.
For example, the integration of Building Information Modelling (BIM) into cost planning and procurement systems can help cut down waste because all stakeholders, including contractors, can collaborate and get real-time visualisations of the project, updating plans along the way.
A wider digital strategy will help lead to quality
Companies leading the way in the industry, though, are those that are thinking more widely about how digital technologies can help improve quality, with the most forward thinking engineering firms collecting performance data from the assets they design which is then fed back in future projects.
Data gathering and analysis is fast becoming a norm across this industry. Many of our clients today want to explore the power of IoT and analytics on their brown field assets. In the future, most components and materials that are used in bridges, railways, sewage works or tunnels will be monitored using advance sensor technology. This data will be stored in data lakes, collated and evaluated with external information such as weather and usage data, to allow engineers to make informed design decisions for the future, besides making better maintenance decisions for the present.
While the technology to deliver this type of ‘closed loop’ design is available now, adoption is still low. One of the barriers is that this requires collaboration between the engineers and operations companies to share the data, something that is not commonplace at present.
Do not be complacent
While poor workmanship is certainly a contributor to waste and poor quality within the industry, the design and scheduling of materials has a big part to play. In my mind, better data driven governance, planning and control will lead to better quality in construction, resulting in less wastage and rework. Those firms just complying with the BIM legislation may find themselves struggling to keep up with the leaders. While those with imagination around the use of digitally-gathered data will be able to work more efficiently and to a higher quality to deliver added value to clients and steal market share.
Read the January 2017 issue of Construction Global here
Why engineers must always consider human-induced vibration
Human induced vibration, or more accurately vibrations caused by human footfall, often conjures images of Millennium Bridge-style swaying or collapsing buildings.
But in reality, the ‘damage’ caused by human-induced vibrations is less likely to ruin a structure and more likely to cause discomfort in people. Though not as dramatic as a structural failure, any good engineer wants to make sure the people using their structures, be it bridges or buildings or anything in between, can do so safely and comfortably. This is why human-induced vibration must be considered within the design process.
Resonance v Impulse
There are two ways that human-induced vibrations affect structures: resonant, and impulse or transient response. Put simply, resonance occurs when Object A vibrates at the same natural frequency as Object B.
Object B resonates and begins to vibrate too. Think singing to break a wine glass! Although the person singing isn’t touching the glass, the vibrations of their voice are resonating with the glass’s natural frequency, causing this vibration to get stronger and stronger and eventually, break the glass. In the case of a structure, resonance occurs when the pedestrian’s feet land in time with the vibration.
On the other hand, impulse or transient vibration responses can be a problem on structures where its natural frequencies are too high for resonance to occur, such as where the structure is light or stiff. Here the discomfort is caused by the initial “bounce” of the structure caused by the footstep and is a concern on light or stiff structures.
Engineers must, of course, design to reduce the vibration effects caused by either impulse or resonance.
Potential impacts from human induced vibration
Human induced vibration can lead to a number of effects upon the structure and its users. These include:
- Interfering with sensitive equipment Depending on the building’s purpose, what it houses can be affected by the vibrations of people using the building. Universities and laboratories, for example, may have sensitive equipment whose accuracy and performance could be damaged by vibrations. Even in ordinary offices the footfall vibration can wobble computer screens, upsetting the workers.
- Swaying bridges One of the most famous examples of human-induced resonance impacting a structure occurred with the Millennium Bridge. As people walked across the bridge, the footsteps caused the bridge to sway, and everybody had to walk in time with the sway because it was difficult not to. Thankfully, this feedback can only occur with horizontal vibrations so building floors are safe from it, but footbridges need careful checking to prevent it.
- Human discomfort According to research, vibrations in buildings and structures can cause depression and even motion sickness in inhabitants. Tall buildings sway in the wind and footsteps can be felt, even subconsciously by the occupants. It has been argued that modern efficient designs featuring thinner floor slabs and wider spacing in column design mean that these new builds are not as effective at dampening vibrations as older buildings are.
- Jeopardising structural integrity The build-up of constant vibrations on a structure can, eventually, lead to structural integrity being compromised. A worse-case scenario would be the complete collapse of the structure and is the reason some bridges insist that marching troops break step before crossing. Crowds jumping in time to music or in response to a goal in a stadium are also dynamic loads that might damage an under-designed structure.
How to avoid it
As mentioned, modern designs that favour thinner slabs and wider column spacing are particularly susceptible to all forms of vibration, human-induced or otherwise, but short spans can also suffer due to their low mass. Using sophisticated structural engineering software is an effective method for engineers to test for and mitigate footfall and other vibrations at the design stage.