InTrans / Aug 14, 2018

Fatigue design criteria of MPC wood trusses for bridge applications

Lightweight metal plate connected (MPC) wood
trusses are commonly used in residential and
commercial roof construction. These trusses also
offer advantages for low-volume rural bridges such
as ease of construction, high stiffness and wide
availability. MPC trusses can be used in bridge
applications provided that proper consideration for
fatigue, corrosion protection, and detailing to
prevent connector plate ‰Û÷back-out‰Ûª are incorporated
into the MPC joint design. Using fatigue test results
of 172 individual MPC joints and 34 fill-scale
trusses, recommendations for fatigue design are
given. Two MPC truss bridges, 46 ft and 39 ft long,
built in Maine in 1993 and 1994 are described