Cranes: Seismic Issues

Seismic Considerations for Existing Quay Cranes

by Michael Jordan, Yoshi Oritatsu, and Erik Soderberg.
Published in Port Technology International, Fifty Seventh Edition, March 2013.
This article presents several seismic retrofit options for existing quay cranes.

Seismic Considerations for New Quay Cranes

by Michael Jordan, Yoshi Oritatsu, and Erik Soderberg.
Published in Port Technology International, Fifty Fifth Edition, Summer 2012.
This article focuses on seismic design considerations for new cranes.

Seismic Protection of Quay Cranes

by Michael Jordan, Yoshi Oritatsu, and Erik Soderberg.
Published in Port Technology International, Fifty Fourth Edition, Summer 2012.

Container cranes have evolved to serve ever increasing ship sizes. Today’s typical container cranes are about triple the size of the first cranes, much heavier, and more vulnerable to damage from seismic events. This article discusses how the Liftech Friction Damper offers seismic protection of quay cranes.

Seismic Design of Container Cranes

by Erik Soderberg, Michael Jordan, Jonathan Hsieh, and Yoshi Oritatsu.
Presented at the Port and Terminal Technology 2010 Conference in Long Beach, California.

Container cranes have evolved to serve ever increasing ship sizes. Today’s typical container cranes are about triple the size of the first cranes, much heavier, and more vulnerable to damage from seismic events. This presentation shows the changes over time that have caused the vulnerability, revisions to design criteria that reduce the vulnerability, the effect of the criteria changes to crane cost and weight, and considerations for existing cranes including some retrofit options and cost estimates.

M 8.8 Chile Earthquake Port Damage Assessment

by Arun Bhimani (contributor: Alberto A. Saez Geraldo of SyS Ingenieros Consultores).
Presented by Arun Bhimani at the TOC Asia 2010 Conference in Shanghai, China.

This presentation provides an update on the damage to the Chilean port facilities from the February 27, 2010, M 8.8 earthquake.

Seismic Guidelines for Cranes

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.

EQ Response – Cement Unloader

Video of linear elastic response of cement unloader on typical West Coast wharf subjected to ground motions transverse to wharf from Port of Los Angeles design earthquake with 475 year mean return interval. Analysis based on no damage to unloader structure.

Seismic Response of Jumbo Container Cranes and Design Recommendations to Limit Damage and Prevent Collapse

by Erik Soderberg and Michael Jordan.
Presented by Erik Soderberg at the Ports 2007 Conference.

Container cranes have evolved to serve ever increasing ship sizes. Today’s typical container cranes are about triple the size of the first cranes, much heavier, and more vulnerable to damage from seismic events. The seismic vulnerability of these large cranes was only recently recognized as a result of detailed time history analysis.

This presentation discusses what changed to cause the vulnerability, the results of the time history analysis, a physical explanation of the crane-wharf interaction, the inconsistency of seismic design criteria for wharves and cranes, recommended design criteria, and some base isolation and modification concepts.