BIM based approach addressing evacuation in fire

Complex building designs, new construction materials and ever-changing building lay-outs all stress the difficulty to properly address evacuation in modern buildings. Even though the number of fire deaths/ injuries show a great decline compared to 19s, the rate has reduced from around 50% to 10%. One of the reasons is known to be lack of adapting safety measures based on the risk in complex buildings.

FESG is starting a comprehensive research program to set forward a methodology that will check the safety level of the building using real time evacuation data and simulation results of how fire and smoke would spread throughout the building. This high-end approach is made possible thanks to integration into a corresponding BIM model. Such a combination between fire evacuation and BIM is rather unique, and comes timely noticing an increased use of BIM models in AEC industry.

The outcome of the research will not only provide useful information for the scientific community and regulators about well adapted building evacuation processes; it will allow FESG to respond to contractors and architects which demand for more integrated fire safety and evacuation from the start of the building process.

Role of BIM in Fire engineering firm: Why BIM?

BIM (Building Information Modeling/ Management) is marked as one of the technological series in the 4th industrial revolution. It is regarded as the future of the AEC (architecture, engineering, and construction) industry. In recent years there has been a global shift towards a holistic design approach with a tendency to extend the applicability of BIM models in the architectural design and engineering of (complex) buildings. The BIM model incorporates different aspects (HVAC, MEP, structural information, etc.) of the building in one aggregate model allowing a streamlined design process. Fire safety and evacuation is however often overlooked and only enters the design process in the final stages.

The information is heart of the BIM and most of the required information by fire safety engineers are already available or can be easily added to the BIM models. Therefore, a lot of time can be saved by having the models. Moreover, the possibility to collaborate with different parties through BIM makes it an ideal tool for fire safety engineers.

                                                              Visualization of the Building Information Modeling (BIM) concept @ https://visual.ly/  

                                                               Visualization of the Building Information Modeling (BIM) concept © https://visual.ly/

Future Services

Automated Code Compliance Checker

The rules addressing fire safety in Flanders are almost entirely based upon a set of prescriptive regulations. This assumes that when a building complies with this set of rules the building is supposed to attain an acceptable safety level. Checking whether a building fulfils all these rules is a tedious job, now performed by architects and for more complex buildings FESG professionals are asked for help. There are a lot of interpretations to be done, which leads to a large variation of quality in compliance checks. On top of that, the architectural design is often an iterative process, which means it can be time consuming to do the compliance checks for every modification.

We target the incorporation of the prescriptive regulations for fire safety in an integrated design approach applying BIM. Fire and life safety can then enter the design process in a much earlier stage of the design, allowing architects and developers to detect clashes between architectural freedom and the prescriptive rules in every stage of the design and building process (as well as in the later maintenance of the building).

Performance Based Evacuation Framework

Why do we need performance based design? 

The built environment has become so complicated that in many cases none of the prescriptive rules give a clear strategy for risk reduction, but also with the advent of new technologies and new materials unknown risks emerge which prescriptive codes are unable to tackle. That’s why Performance based design (PBD) is gaining more and more momentum among designers and fire safety engineers. The legislative regulations in Belgium allow for application of PBD only if the equivalent safety level to a prescriptive design is achieved. Therefore, FESG aims to develop a new methodology for PBD approach for assessing building evacuation strategy.

What is the methodology?

The following explains the envisioned strategy to obtain the performance based evacuation framework.

        1. Continuously Monitored Evacuation Strategy

Tracking of occupants will be performed during yearly evacuation drills using the most suitable tracking technology which is aimed to be the best and possibly most available tracking system for occupant tracking in the buildings.

Most of the evacuation drills are often only judged by a crude check whether everybody got out of the building in a certain pre-defined time span. However, much more detailed data could be gathered during the exercise. By adding a tracking component to evacuation exercises, details about queue formation, usage of exits and emergency route choices becomes visible. When coupled to a dynamic BIM model, indoor tracking of the occupants gives a clear vision on the real-time presence of occupants and to have an insight in the progressive evacuation status. This way FESG can offer a powerful tool in the analysis of evacuation procedures.

The possible technologies for indoor tracking include: WIFI tracking, RFID embedded cards, BLE (Bluetooth Low Energy) Beacons, Infrared system, Radio technology, etc. Even if the tracking system is not available, the methodology will use theoretical concepts or principals derived from previous buildings to form the basis for the design of the new buildings.

FESG ensures to be compliant to the GDPR (The General Data Protection Regulation 2016/679) in EU law for indoor tracking of the building occupants.

      2. Modeling fire and smoke spread through the building

FESG has expertise to conduct CFD simulations to provide the designer with an enormous amount of information which makes it possible to visualize and quantify information concerning smoke and fire spread. This information is nearly impossible to obtain even if experiments were to be conducted. Temperatures, concentrations of toxic and irritant gases, smoke spread, radiation levels and many other fire related data can be derived from a CFD simulation.

       CFD simulation with FDS

Knowing the consequences of a fire scenario is crucial for an evacuation analysis. CFD simulations can be conducted using the real-time geometrical characteristics of the building obtained from the BIM model.

      3.  Coupling of BIM, evacuation and fire modelling

One of the major causes of casualties in case of fire is a delayed evacuation in which a lack of knowledge about the fire situation results in the wrong selection of safe evacuation routes. In case fire safety management systems could receive real-life information on the evacuation status of occupants, it is possible to significantly enhance the evacuation by an intelligent real-time guidance system.

By coupling the BIM model data, smoke and fire spread information obtained from CFD simulations and evacuation data obtained from evacuation exercises and real-time tracking, a complete performance-based framework towards evacuation can be adopted and deployed.

The following figure shows a schematic description of the whole methodology.

Are you thinking about Smart Buildings?
The information obtained via the CFD simulations and real-time tracking of the building’s occupants can then also be used for active dynamic evacuation signage. This enables users of the building to follow the safest path out of the building based on real-time data and previously analyzed fire scenarios in CFD. This active steering can then be further enhanced by addition of information of other sensors such as smoke opacity sensors.

To obtain the best results, sensors will need to be placed in the right position. The methodology will also help designers and installers on location specification of the sensors.

Can the methodology be applied to both old and new buildings?

The methodology will be applied on existing buildings which will allow gathering data about evacuation processes, and then theoretical concepts or principals will be derived to form the basis for design of the new buildings. OF course, the final developed performance-based evacuation framework can be used for already available buildings as well. The building owners or designers can revise/ change their evacuation strategy based on the most recent changes in their buildings.

Who can benefit from our future services?

  • Architects and Designers: Building designers and architects can use the automated Code Compliance checker to identify any non-compliances in their model any time from the earlier stage of their design. Upon request, this can be done by FESG performing iterative design check without asking for extra costs.
  • Fire brigade Department: There will be a version of the automated Code Compliance checker tool for fire brigades who need to check the code compliancy of the buildings.
  • Authorities: The methodology will also be able to help the legislator in receiving regular input on how building usage/evacuation strategies evolve. The FOD internal affairs will benefit from evacuation data to review, adjust or apply regulations (e.g. the process of phased evacuation, etc.). The collected data also allows to monitor the way derogations, granted during construction of the building, affect the evacuation. With the specific tool provided to the authorities, they will be able to speed up the building conformity assessments as well.

 

 

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