Place cursor over title to read an overview of the article, or click to download document in Adobe Acrobat format.

Seismic Guidelines for Cranes

July 2009

by Erik Soderberg, Jonathan Hsieh, and Anna Dix

Presented by Erik Soderberg at TCLEE 2009 conference

Current large cranes with 100 foot rail gages are much heavier, which results in significantly larger seismic forces in the crane structure. Our studies indicate that many jumbo cranes will be extensively damaged in moderate earthquakes, and many jumbo cranes will be severely damaged, or collapse, in the contingency level design earthquake.

Our presentation suggests some approaches to evaluate what seismic risk is tolerable to existing cranes and some guidelines on what structural characteristics increase or decrease the seismic risk, along with suggested practical retrofit options including strengthening, stiffening, and adding a base isolation mechanism that can limit the seismic forces.

Wind Damage to Dockside Cranes: Recent Failures and Recommendations

July 2009

by Patrick McCarthy

Presented by Patrick McCarthy at TCLEE 2009 conference

Wind-related damage is a threat to most dockside cranes. Typically, damage is localized, but occasionally cranes collapse. Recent crane collapses have been caused by hurricane winds, usually when tie-downs fail, and by lesser winds under operating conditions.

We propose incorporating “ductile link” equalization into tie-down systems as a retrofit method for existing cranes in high-wind areas. We use an economy vs. risk approach to evaluate the need to retrofit existing cranes.