Bridge Barrier Rail Height Study

SC Solutions was engaged to perform a first of its kind set of computer simulations of the impact of a bicyclist into the ST-10 bridge barrier rail to determine the safe rail height for a wide range of impact conditions. The optimal solution was defined to be the lowest overall rail height that can effectively prevent a bicycle rider from falling off the bridge in a near-worst-case impact scenario as it pertains to the Ten Mile River Bridge Replacement along Route 1 in Mendocino County.

The approach used in this task included incorporating models of the rider, bicycle, bridge deck and barrier rail in the impact simulation, and the use of the LS-DYNA finite element program. These models were then analyzed dynamically using the defined project parameters that included two different rider models, speeds of 15 and 30 mph, impact angles of 10° and 25°, and super-elevations of 0° and 9°. Failure criteria were established and an optimization procedure developed to determine the optimum height of the barrier.