Evaluation of Building with Severe Impact Damage: The Banker's Trust Building

Structural engineers are often called upon to evaluate a structure after a failure or collapse. The evaluation may range from simply a qualitative judgment call to an advanced analysis of the structure. The various types of assessment required by a building could not be more evident than those conducted following the events of September 11, 2001. In the hours, days, weeks, and months that followed, structural engineers were called upon to evaluate the safety of several damaged buildings. One such building, which suffered significant structural damage, was the 39-story 130 Liberty Street, Manhattan or The Bankers Trust Building, also known as Deutsche Bank. The first assessment was provided only hours after debris scarred a large portion of the building and was based on superficial and partial information. Over the following weeks and months more additional evaluations were performed which included simple two-dimensional frame models and, finally, a complete three-dimensional push-over analysis. This paper illustrates the process undertaken to evaluate the safety of the Bankers Trust Building after the events of September, 2001.