2013’s rapid spring snowmelt caused havoc to several Upper Peninsula County Road Commissions. Not the least was Baraga County, where numerous already marginal culverts and bridges failed or were further compromised. The complete failure and resulting road closure of a large corroded metal culvert at Beaufort Lake Road over the Spurr River proved especially troublesome. The available detour route was inconvenient for residents and time consuming for emergency vehicles but, the low ADT count limited available funding as those funding agencies considered the cost-benefit analysis of a bridge. A permit necessitated a much larger structure hydraulically than the existing undersized culvert while mandating a much higher low bridge elevation than the current culvert. Existing road elevations required a maximum top of structure elevation or incur a significantly costly lift of the entire roadway and approach. Compounding these challenges was a loading design that met the new MDOT HL 93 MOD criteria (see scope) due to heavy logging in the vicinity.
All these geometric and hydraulic factors eliminated the consideration of a conventional arch or three-sided box culvert. Installation and maintenance costs of a conventional bridge beam structure was also considered prohibitive. LowSpan was selected as the most suitable structure for the location.
Location: Baraga County Michigan, Beaufort Lake Rd. over the Spurr River (24’ span x 4.5’ rise x 33’ length)
Date: Fall/early Winter of 2015
Owner/Engineer: Baraga County Road Commission (additional funding provided by the U.S. Department of Interior Bureau of Indian Affairs)
Precast Producer: Upper Peninsula Concrete Pipe Co., Inc. (UPCPC)
Contractor: MJO Contracting, Inc.