Ensuring the safety of crowds

The design of sports stadia has been front of mind with the general public again with projects like Tottenham Hotspurs’ new Stadium due to open for the 2018-19 season and, on a more sombre note, the UK’s Hillsborough inquiry having reminded us what can go wrong.

For architects and designers, it is a fast-evolving topic of constant interest, as the traditional stadium concept evolves into multi-functional sports and cultural complexes. One thing doesn’t change: the overarching need to ensure the safety of crowds using the venues and, as we are reminded by crowd safety and risk analysis expert Prof. Keith Still , disasters are not caused by stampedes but are design and management issues.

Dynamic Modelling

There is no comfort in simple code compliance, as that does not guarantee that a building will function well during either normal use or an emergency. So dynamic  crowd modelling and analysis is now routinely part of the design process and increasingly part of the ongoing management of a facility to visualise how people will behave in response to triggers such as fire and congestion.

With 50,000 a fairly average capacity, and seating now often exceeding six figures, that is a tall order for simulation software, but one that is being met by Oasys MassMotion.

Dynamic modelling enables designers to factor in and visualise the key causes of problems described in the Green Guide to Safety at Sports Grounds that is used by professionals to inform the design and management of sports grounds around the world. These are:

• Crowd Force
• The Information on which the crowd acts
• The physical Space that the crowd inhabits
• Time effects

Speaking at the last MassMotion User group meeting in London, Dr Elisabetta Carattin of Arup Fire described a number of scenarios where dynamic crowd modelling had been used, and had revealed behaviours that differed from hand calculations that had led directly to informed design modifications.

While the priority is emergency egress and getting people to a place of safety, the MassMotion model, once built, has much wider use and will continue to deliver a return on investment throughout the life of the building.  Crowd simulation also helps to improve the quality of visitor experiences:  at half time there is an inevitable rush for facilities to cope with, and on arrival and normal departure crowds need to get to and from car parks and transport stations with ease.  Underlying all this is the owners’ need to optimise footfall and revenues for associated retail outlets.  All of this can be analysed and visualised, with design changes tested in the model before expensive implementation on the ground.

You can see Dr Carattin’s full presentation below