Multi Crane Lifts and the New Tappan Zee Bridge
In July 2015, Vincent Siefert presented a webinar to 225 people set up by the Industrial Training International (ITI). In this webinar he presented The Six Most Important Issues when executing a 2-crane lift.
Safe Lifting and Handling of Rebar Cages – Deep Foundations
In January 2016, Vincent Siefert presented a webinar set up by Industrial Training International (ITI).
Rebar cages for Drilled Shafts and Slurry Walls are notoriously difficult to work with. As the popularity of these deep foundation elements increases, so do the challenges to safely lift and handle the prefabricated reinforcing steel and associated embedded items. The fabrication and erection of these cages are generally based on experience and rule of thumb practices of the suppliers, fabricators and contractors. However several recent collapses have exposed the shortcomings of these techniques and have demonstrated the need to establish scientific methods to safely lift and handle rebar cages. This presentation will introduce the audience to the recommended principles and best practices for fabrication with internal bracing and added bars, lift planning and rigging, temporary support systems and installation procedures, as well as analysis and design methods for these structural elements that best resemble “wet noodles.” Especially critical is the tilting up process that subjects the cage to asymmetrical loading and represents the most serious loading condition on the cage stability. Any interruption in the load path or sudden loss of stiffness in the cage during the erection process will result in failure and most likely have a detrimental effect on project cost, quality, schedule and may unfortunately cause cause injuries or death. Construction engineers will learn valuable lessons from this talk for immediate field use. The Geotechnical and Structural engineers involved in the permanent design and fields will also benefit from this presentation by understanding how simplified and uniform details for rebar, embeds and instrumentation will improve the safety and efficiency on the jobsite with the result of a quality foundation element.