HOW 4D MODELING AND SENSING MAY ELIMINATE THE LEADING CAUSES OF INJURY
By Fernanda Leite, PhD, PE
Since the Occupational Safety and Health Act of 1970 placed the responsibility of construction safety on the employer, newly developed injury prevention strategies have led to dramatically decreased fatality and disability rates in the construction industry. Despite these improvements, however, construction remains the second most hazardous industry, representing 21.4 percent of U.S. workplace fatalities in 2015.
The Bureau of Labor statistics estimates that eliminating the “fatal four” leading causes of construction death — falling, being struck by an object, electrocution, and being caught in or between objects and machinery — could save 602 workers’ lives in America every year.
The key to eliminating these fatalities will be in innovative injury prevention practices such as virtual modeling and sensing to improve safety planning and management.
With the wide adoption of mobile computing in the architecture, engineering and construction (AEC) industries, we have entered an era rife with information and data, and where sensors and computers are playing increasingly important roles in project development. New technology in data management, sensing and visualization has changed much of how engineers design, build and maintain our infrastructure. Take Virtual Design and Construction (VDC) as an example: we can now build virtual models to enable better client communication, identification of potential design and construction issues and more effective quality control.
All of these technological advancements can be applied to improving safety protocols and, in many cases, the industry has made great strides. However, we’ve still got a long way to go.
Obstacles To Fully Integrated Safety Planning & Autonomous Monitoring
Lack of integration between construction and safety planning: Current safety planning approaches do not take temporal or spatial information into account. That is, they don’t consider when and where construction activities may increase hazards and require elevated safety controls. For example, low risk activities such as painting, landscaping or bricklaying may suddenly increase in risk if they occur at the same time and adjacent to an activity using heavy equipment such as earth movement with a bulldozer. To create more effective site-specific safety plans, it is important to integrate safety planning and project scheduling functions.
Insufficient sources for site-specific safety planning: While information technology-based approaches such as 3D Building Information Modeling (BIM) are widely used for project planning and monitoring, construction safety planning is still highly dependent on traditional sources such as 2D drawings, paper-based regulations and tacit information. Because these traditional methods yield more generalized renderings, current safety planning approaches limit the capability to identify and analyze hazards prior to construction, and could be improved with the integration of information technology.
Imperfections inherent in real-world sensor data: Autonomous jobsite safety monitoring applications are built on the assumption that the collected location data represent the exact situation, which might not be true due to erroneous data. For example, a sensor error of three feet on an open edge could mean the difference between falling or not. While we could correct for this by broadening the range of the sensor (so it alerts workers when they are farther away from the edge), it is important that these systems not sound too many false alarms, as that risks desensitizing workers. Therefore, the data in autonomous jobsite safety monitoring systems should be further perfected before it can be trusted for decision making.
The Future Of Automated Safety Planning
Moving forward, construction safety planning can be systematically formalized through a 4-dimensional (4D) environment that integrates space and time to address site-specific temporal and spatial safety information.
Safety personnel would be able to devise a preliminary plan in the early stages of the project, prioritizing risky activities and preparing proper responses without site-specific information. Then, the safety schedule would be integrated with a 3D project model in order to extract site-specific spatial information. Finally, a 4D simulation integrating general safety data with site-specific temporal and spatial information would allow safety personnel to identify the hazards of concurrent activities and the dangerous zones in any given time period.
After the planning phase, autonomous jobsite safety monitoring applications would represent an extra pair of eyes on construction workers. Actuators connected to safety monitoring systems could function similarly to collision avoidance systems in passenger vehicles by automatically stopping equipment in dangerous situations, such as when a piece of heavy machinery is about to back up over a worker.
With dedicated planning and development, information technologies such as modeling and sensing can have a dramatic impact on construction safety by preventing “fatal four” accidents in construction sites. While there are still challenges to overcome, automated construction safety is an active research area with many prototypes under development and testing. In the coming years, the technology that is now confined to research laboratories may be commonplace in construction sites. The future of construction safety looks bright.
Fernanda Leite, Ph.D., a Public Voices Fellow, is an Associate Professor in Construction Engineering and Project Management in the Civil, Architectural and Environmental Engineering Department at the University of Texas at Austin. She teaches courses on Project Management and Economics, Building Information Modeling and Construction Safety. She currently serves as Chair of the American Society of Civil Engineers (ASCE) Visualization, Information Modeling and Simulation (VIMS) Committee.