OPAC Consulting Engineers

Sixteenth Street Pedestrian Bridge


Denver, Colorado

Client:

KL&A Consulting Structural Engineers

Date:

Study completed 2002

Scope of work:

Dynamic Assessment

Construction Cost:

N/A

Services Performed:

  • Wind analysis
  • Evaluation of dynamic effects

Issues:

  • Dynamic self-induced pedestrian load and aerodynamic evaluation
  • Design of vibration damping systems

The Sixteenth Street Pedestrian Bridge was designed by a Denver-based Architect and Engineer to provide pedestrian, bicycle, and disabled access across the South Platte River near a major new mixed-use commercial development. The design made use of a single span flared truss, and abutments remaining from a previous bridge, to cross the river in a single innovative span.

The design engineer recognized the potential of the design for self-induced oscillation due to wind loads and foot traffic. OPAC and West Wind Laboratory were engaged to study the response of the bridge to these effects and prepare designs for mitigating measures if required.

The studies concluded that the bridge design is very sensitive to wind excitation, and would be subjected to excessive pedestrian-induced oscillations at about one fifth of its design occupancy. Mitigating measures consisting of Tuned Mass Dampers and Viscous Dampers were subsequently designed to the extent necessary to demonstrate effectiveness and estimate costs.

The bridge design was subsequently abandoned in favor of a more inherently stable structure.