Pedestrian Bridge B in LaGuardia Airport connects the Head House and the new Concourse B. It has a span of about 450ft and is made of steel trusses and plate girders. Heavily built-up or rolled W-shape sections were used for the truss chords and the braced frames at the north end of the bridge.
 

CHI conducted a peer review of the bridge design. The purpose of the review was twofold: 1. To verify pedestrian - induced vibrations were within allowable limits; 2. Checking the stresses at truss connections.

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An evaluation of pedestrian-induced vibrations was conducted using two types of empirical equations and a 3D finite element model, which operated under the assumption of different densities of pedestrians and various levels of damping.

Two truss connections were modeled using a 3D finite element program: Midas FEA. One was at the top chord level and the other was at the bottom chord level, and both had relatively high out-of-plane bending moments. Detailed stress contours were obtained for assessing the adequacy of the connection design.

In addition, the connection details of trusses and braced frames were reviewed. Recommended changes were proposed to the original design for consideration and incorporation.