Experimental research has shown that the use of well-confined diagonal reinforcement cages, designed to resist the total shear demand, ensures a stable behavior under displacement reversals such as those induced during a strong earthquake. The reliance on diagonal reinforcement to resist the entire coupling beam shear demand, however, often translates into the use of large diameter diagonal bars. In recent years, the use of relatively slender coupling beams has become popular due to limitations in story heights. This article presents the results from two large-scale tests that show that the addition of randomly oriented steel fibers to the concrete will allow significant simplifications in the design and construction of slender coupling beams, including complete elimination of diagonal bars and substantial reductions in confinement reinforcement.

The Omnilife Stadium in Guadalajara, Mexico, evokes the image of a “volcano with a cloud” rising from the countryside. The revised design for the project maintained the overall architectural concept and incorporated significant changes that allowed dramatic cost reductions. Sloped slabs were used in place of berms for the volcano and eliminated the need for massive retaining walls. Footings were used throughout the structure. Macrocolumns supporting the roof are incorporated into the supporting structure for the sloped slabs and provide support for the upper seating areas. The sloped walls form a cone that resists seismic effects. The sloped walls and raker beams and columns work together with the macro-columns to resist overturning moments from the large roof cantilever.

Now in its 20th consecutive year, the Achievement Awards program of the Tilt-Up Concrete Association (TCA) was established to honor projects that use site-cast tilt-up concrete to introduce new building types, advance industry technology, and provide unique solutions to building programs.