An access road winds down a steep forested hillside to a valley below. At the valley floor is a stream and its broad flood plain. At the narrowest point of the streambed, we placed a bridge to carry construction vehicles and maintenance machinery across this delicate wetland.
Three pairs of 10 ¾” thick curved planks of glue-laminated southern yellow pine, placed by crane from the lower bank of the stream, structure the bridge’s 75’ by 11’ deck. Each pair of planks spans 25’ between board-formed concrete piers and abutments. The piers taper to reduce the surface area of their upstream edges so that, like the narrow but dense profile of the bridge deck, they resist the scouring effects of rushing high water and deflect the blows of waterborne debris during the annual floods that engorge the stream each spring.
Two bolt-laminated wooden rails form flexible and shock absorbent wheel curbs that trace the deck’s curved edge and harness the bridge to stone anchors at each abutment.