On May 26, workers at a mixed-use development in Oakland, California, were pouring concrete into elevated formwork when the shoring system supporting the formwork collapsed. The workers fell some 20 feet along with freshly poured concrete, reinforcing steel, timber framework, and tools and equipment. Thirteen workers ended up in the hospital; one worker’s injuries required surgery. The workers were fortunate: their landing was softened by the freshly-poured concrete.
On December 14, Cal/OSHA cited three contractors $147,315 for safety violations. The agency’s investigation found that the formwork and vertical shoring system that collapsed were not properly designed, installed or inspected. Serious and serious accident-related citations were issued to Largo Concrete, Inc. and N.M.N. Construction, Inc., who were cited $73,365 and $70,320, respectively, for:
- failure to ensure that the formwork and vertical shoring were designed to safely withstand all intended loads
- failure to have calculations and drawings approved by a California registered civil engineer as required for vertical shoring over 14 feet tall
- failure to ensure the shoring supports were erected on a level and stable base
General contractor Johnstone Moyer, Inc., was also cited for general violations carrying $3,630 in proposed penalties.
Who’s Behind Your Falsework?
Concrete forms are considered falsework, which is covered by Construction Safety Orders section 1717. The definition of falsework also includes support systems for forms, newly completed floors, bridge spans, and similar structures that provide support until appropriate curing or stressing processes have been completed. In order to ensure the safety of falsework, Cal/OSHA’s rules require review by qualified professionals at each step in the process.
With respect to the design and erection of falsework, the standard requires that:
- Concrete formwork and falsework be designed, supported, and braced to safely withstand the intended load. To that end, falsework design, detailed calculations, and drawings be signed and approved by a professional engineer if the falsework height exceeds 14 ft; the individual horizontal span length exceeds 16 ft; or if vehicle or railroad traffic goes through the falsework. Designs for other falsework may be approved by a manufacturer’s representative or a licensed contractor’s qualified representative.
- Falsework plans must be available at the jobsite.
- Falsework must be erected on a stable, level, compacted base and supported by adequate pads, plates, or sills.
- Shore clamps (metal) must be installed in compliance with manufacturer’s instructions.
Additional requirements that must be met before a contractor can pour concrete on falsework include:
- A professional engineer or the engineer’s representative must inspect for and certify compliance with the approved plans, for falsework requiring design approval.
- For falsework not requiring a professional engineer’s approval, the inspection and certification may be provided by a manufacturer’s representative or a licensed contractor’s qualified representative.
Cal/OSHA provides summary guidance to these and other construction safety requirements in its Cal/OSHA Pocket Guide for the Construction Industry.