Boardwalk Wharf Replacement:
Riggs Engineering undertook a condition survey of the popular timber boardwalk wharf in Tobermory (which is located at the northern tip of the Bruce Peninsula) in 2007-08. The timber wharf suffered from deterioration of the crib timbers, basal instability related to inadequate bearing capacity and possibly scouring at the lakebed. As well, the timber deck had numerous trip hazards due to the deterioration of the timber stringers.
The solution involved demolition of the timber work to the low water line and reconstruction with precast concrete elements. The stability of the cribs as well as the precast concrete elements was analyzed using classical limit equilibrium methods. The precast concrete elements were simulated using finite element software as shell elements and both the shape and reinforcing steel were optimized. The stability of the cribs was enhanced by employing helical pier anchors in 2010.