LIMITIATIONS OF GOLD’S FORMULA FOR PREDICTING ICE THICKNESS REQUIREMENTS FOR HEAVY EQUIPMENT

ABSTRACT Common practice for determining the required ice thickness for vehicles and equipment relies on Gold’s Formula as outlined in Provincial and Territorial publications relating to ice safety [e.g. 1-4]. This practice persists despite recent advances in ice engineering knowledge that provide more comprehensive design methods utilizing limit states design approaches (Masterson 2009, Kerr, 1996). The authors have identified that the use of Gold’s Formula for determining required ice thickness may lead to unsafe practices when utilized in the context of heavy construction equipment, increasing the risk of ice breakthrough to personnel and equipment. The authors use recent design examples to demonstrate instances in which the use of Gold’s Formula results in predicted flexural tensile stresses in the ice cover that exceed the maximum design stress recommended in contemporary literature (Masterson 2009, Hayley and Proskin 2008, US Army Corps of Engineers 2002, Gold 1981). In the case of large excavators (53 metric tonnes), and heavy dozers (40 metric tonnes), as examples, the use of Gold’s Formula for determining the required ice thickness will result in predicted flexural tensile stresses that exceed the recommended maximum design stress by 56%-71%.