Architect’s Follow Up on the Cathedral of Notre-Dame de Paris and Creating Safer Work Environments #UnderConstruction #Safety #Design #Architecture #LessonsLearned #SafetyFirst #Design #Build #Architect #ilmaBlog

Follow Up on the Cathedral of Notre-Dame de Paris and Creating Safer Work Environments

A few weeks ago on April 15th, 2019, a fire destroyed the roof and wooden spire of the Notre-Dame de Paris.

One of the most famous timber frame fires started just after midnight on the 2nd September 1666 in Pudding Lane. After burning for three days it destroyed nearly 90 percent of the inhabitants of London’s homes.

Getty Images

Possible Causes For Blaze

Although officials say that the investigation could last several weeks and nothing can be ruled out at this time, there is much suspicion that the blaze may have been started by a short-circuit near the spire.

The short circuit may have been possibly caused by electrified bells, or negligence by construction workers carrying out the ongoing renovations, a theory fueled by the discovery of cigarette butts.

Typical Sources of Ignition

Not related to the fire, but for a matter of reference, sources of ignition during construction may generally include: (1) Hot works – cutting, grinding, soldering, hot pitching; (2) Faulty electrical equipment – damaged sockets and equipment, service strikes, temporary supplies and halogen lighting; (3) Arson – works in high crime rate areas, protests and objections to the scheme, disgruntled employees or contractors; (4) Reactive chemicals; (5) Fire Loading; (6) Fire Spread – The Offsite Risks; (7) and Constrained sites.   It will be interesting to see what the investigators are able to uncover in the following weeks.

André Finot, the cathedral’s spokesman, pointed out traces of damage. “Everywhere the stone is eroded, and the more the wind blows, the more all of these little pieces keep falling,” he said. (Photo Credit: Dmitry Kostyukov for The New York Times)

Ongoing Renovations

Fallen stones on the cathedral’s roof. Experts say that the building has reached a tipping point and that routine maintenance is no longer enough to prevent rain, wind and pollution from causing lasting damage. (Photo Credit: Dmitry Kostyukov for The New York Times)
Masonry that has broken away or that was taken down as a precautionary measure has been piled up on a small lawn at the back of the cathedral. (Photo Credit: Dmitry Kostyukov for The New York Times)

According to the New York Times, the biggest renovation at the cathedral took place between 1844 and 1864 when the spire and the flying buttresses were rebuilt.  The most recent overhaul, however, was meant to be understated. “The idea isn’t to replace every single stone. I don’t want to give this cathedral a face-lift,” said Philippe Villeneuve, the chief architect behind the project.  The renovations, which are estimated to cost $150 million euro ($169 million) were still ongoing when the cathedral caught fire.  Most likely something to do with the renovations of the cathedral led to its temporary demise.

Design Input

The event, which occurred during holy week sparked an intense national debate on how the 856-year-old cathedral should be rebuilt.  The French public will get a say on how the fire-ravaged Notre Dame cathedral will be rebuilt, officials say. 

FYI: In a separate blog post, ILMA plans to do a write up on the current designs that are being suggested by Architects and designers around the world.

Construction Workers – Risk Management

As a matter of course, this heartbreaking occurrence give us pause to consider the threats that can occur during construction.  Some risks to workers that need to be managed during construction and renovations include the following: (1) Working at Height; (2) Slips, Trips and Falls; (3) Moving Objects; (4) Noise; (5) Manual Handling; (6) Vibrations; (7) Collapses; (8) Asbestos; (9) Electricity; (9) Respiratory diseases. (Sources: Top 10 construction health and safety risks) and OSHA’s Top Four Construction Hazards); From the perspective of keeping the building safe during renovations and/or construction and saving lives, the following should be considered:

Building Safety – Risk Management

  1. Installation of sprinkler systems and fire detection systems early on in construction
  2. Availability of standpipes
  3. Commissioning the sprinkler system
  4. Access to fire extinguishers
  5. Make sure your fire detection and warning systems work
  6. Maintaining means of egress; Building compartmentation and protected fire routes in as the building is constructed
  7. Protect emergency escape routes
  8. Secure the site against arson
  9. Protect temporary buildings and accommodation
  10. Store equipment safely
  11. Design out hot works
  12. Keep the site tidy
  13. Keep project site and equipment safe
  14. No smoking
  15. Increase security for the site – CCTV, Full height hoarding, signage
  16. Engagement of local fire departments – to assess water pressure and accessibility
  17. Proper fire risk assessment that considers fire loading and fire separation distances

Learning From the Tragedy of the Cathedral of Notre-Dame de Paris

As timber is becoming increasingly more popular in high rises it is important to consider the past when managing the risks of projects utilizing wood framing.  Although there are many studies and test on modern day timber/wood designs, it is still important to consider the risks that are present on any jobsite.  Spending the money to do construction the right way will help reduce the inherent risks with construction – both to safeguard people as well as the buildings that we cherish.

For more information on my take on what happened at Notre Dame, please consider checking out the original articles: Personal Reflection on the Tragedy of April 15, 2019 at Notre Dame Cathedral in Paris and What Makes Notre Dame Cathedral So Important as a Work of Architecture?.

Additional Reading:

We would love to hear from you about what you think about this post. We sincerely appreciate all your comments – and – if you like this post please share it with friends. And feel free to contact us if you would like to discuss ideas for your next project!

Sincerely,

FRANK CUNHA III
I Love My Architect – Facebook


Benefits of Using Digital Twins for Construction

Technologies like augmented reality in construction are emerging to digitalize the construction industry, making it significantly more effective.

What if we could have instant access to all the information about a construction site, down to smallest details about every person, tool, and bolt? What if we could always be sure about the final measurements of a beam or that soil volumes in the cuts are close to those of the fills? What if we could always track how fast the supply of materials runs out, and re-order supplies automatically?

All this is achievable with a digital twin — a concept of having a real-time digital representation of a physical object.

The following are some real-time digital twins applications on construction sites.

3d-model

Automated Progress Monitoring

Progress monitoring verifies that the completed work is consistent with plans and specifications. A physical site observation is needed in order to verify the reported percentage of work done and determine the stage of the project.

By reconstructing an as-built state of a building or structure we can compare it with an as-planned execution in BIM and take corresponding actions to correct any deviations. This is usually done by reconstructing geometry of a building and registering it to the model coordinate systems, which is later compared to an as-planned model on a shape and object level.

Often data for progress monitoring is collected through the field personnel and can be hugely subjective. For example, the reported percentage of work done can be faster in the beginning and much slower close to the end of the project. People are often initially more optimistic about their progress and the time needed to finish the job.

Hence, having automated means of data collection and comparison means that the resulting model to as-designed BIM models is less liable to human error. Digital twins solve the common construction process problems.

As-Built vs As-Designed Models

With a real-time digital twins, it is possible to track changes in an as-built model — daily and hourly. Early detection of any discrepancies can lead to a detailed analysis of historical modeling data, which adds an additional layer of information for any further decision-making processes.

The project manager can then reconstruct the steps that led to the error and make changes in the future work schedule in order to prevent any similar mistakes from occurring. They can also detect under-performers and try to fix the cause of the problem earlier in the project or plan the necessary changes to the budget and timescale of the whole project.

Resource Planning and Logistics

According to the Construction Industry Institute, about 25% of productive time is wasted on unnecessary movement and handling of materials.

Digital twin technology provides automatic resource allocation monitoring and waste tracking, allowing for a predictive and lean approach to resource management. With digital twin technology companies would avoid over-allocation and dynamically predict resource requirements on construction sites, thus avoiding the need to move resources over long distances and improving time management.

Safety Monitoring

The construction industry is one of the most dangerous sectors in the world. According to the Bureau of Labor Statistics in the United States, more than four thousand construction workers died on-site between 2008 and 2012.

The real-time site reconstruction feature digital twins allows the industry’s companies to track people and hazardous places on a site, so as to prevent inappropriate behavior, usage of unsafe materials, and activity in hazardous zones. A company can develop a system of early notification, letting a construction manager know when a field worker is located in dangerous proximity to working equipment and sending a notification about nearby danger to a worker’s wearable device.

Microsoft recently shared a great vision of how AI combined with video cameras and mobile devices can be used to build an extensive safety net for the workplace.

Quality Assessment

Image-processing algorithms make it possible to check the condition of concrete through a video or photographic image. It is also possible to check for cracks on columns or any material displacement at a construction site. This would trigger additional inspections and thus help to detect possible problems early on.

See an example of how 2D images using 3D scene reconstruction can be used for concrete crack assessments.

Optimization of Equipment Usage

Equipment utilization is an important metric that construction firms always want to maximize. Unused machines should be released earlier to the pool so others can use them on other sites where they are needed. With advanced imaging and automatic tracking, it is possible to know how many times each piece of machinery has been used, at what part of the construction site, and on what type of the job.

Monitoring and Tracking of Workers

Some countries impose tough regulations on how to monitor people presence on a construction site. This includes having a digital record of all personnel and their location within the site, so that this information could be used by rescue teams in case of emergency. This monitoring is another digital twins application. Still, it is better to integrate digital twin-based monitoring with an automatic entry and exit registration system, to have a multi-modal data fused into a single analytics system.

Getting Data for Digital Twins

Some ways to gather data to be used for digital twins includes the following:

  1. Smartphone Cameras
  2. Time-Lapse Cameras
  3. Autonomous UAV and Robots
  4. Video Surveillance Cameras
  5. Head-mounted Cameras and Body Cameras

Image data processing algorithms for digital twins can be created with the following methods:

  1. 3D Reconstruction: Conventional Photogrammetry
  2. 3D Reconstruction: Structure from Motion
  3. Object Detection and Recognition
  4. Localization
  5. Object Tracking

(Source: https://www.intellectsoft.net/blog/advanced-imaging-algorithms-for-digital-twin-reconstruction)

From an Investor’s Viewpoint

On projects to date, this approach has proven to save time, reduce waste and increase efficiencies.

From a Standardization Proponent’s Viewpoint

Open, sharable information unlocks more efficient, transparent and collaborative ways of working throughout the entire life-cycle of buildings and infrastructure.

From a Solution Provider’s Viewpoint 

While the digital twin is needed initially for planning and construction, it’s also intended to provide the basis for building operations moving forward.

(Source: https://www.siemens.com/customer-magazine/en/home/buildings/three-perspectives-on-digital-twins.html)

The vision of “construction 4.0” refers to the 4th industrial revolution and is a fundamental challenge for the construction industry. In terms of automated production and level of digitalization, the construction industry is still significantly behind other industries. Nevertheless, the mega-trends like Big Data or the Internet of Things offer great opportunities for the future development of the construction sector. Prerequisite for the successful Construction 4.0 is the creation of a digital twin of a building. Building Information Modeling (BIM) with a consistent and structured data management is the key to generate such a digital building whose dynamic performance can be studied by building simulation tools for a variety of different boundary conditions.

Along the total life cycle from design to construction, operation and maintenance towards remodeling or demolition, the digital twin follows all modifications of the real building and dynamically readjusts itself in case of recorded performance differences.

Thus, for the whole life span of the real building, performance predictions generated with the virtual twin represent an accurate basis for well-informed decisions. This helps to develop cost-effective operation modes, e.g. by introducing new cyber-controlled HVAC systems. The digital twin may also analyze the building’s dynamic response to changes in occupation or energy supply; it also indicates the need for building maintenance or upgrades.

The digital twin follows all modifications of the real building and dynamically readjusts itself in case of recorded performance differences.

(Source: https://www.bau.fraunhofer.de/en/fieldsofresearch/smartbuilding/digital-twin.html)

Gartner-digital-twin-best-practices-to-tackle-challenges

We would love to hear from you on what you think about this post. We sincerely appreciate all your comments – and – if you like this post please share it with friends. And feel free to contact us if you would like to discuss ideas for your next project!

Sincerely,
FRANK CUNHA III
I Love My Architect – Facebook