JPMorgan Chase Tower (Houston) - Hurricane Ike

Hurricane Ike

On September 13, 2008, many of the tower's windows were blown out as Hurricane Ike moved through the area leaving desks exposed, metal blinds hanging in a twisted heap and smoky black glass covering the streets below. Police were forced to cordon off the area due to the amount of debris lying in the streets.

At first, it was speculated that the glass came off the building due to impact from debris or due to high-speed winds in the confined spaces. However, flying glass debris must be entirely governed by drag and lift forces that overcome gravity for a considerable time period. Also, the high speed in confined spaces theory is not entirely justified since the height of damage seen in the tower exceed too significantly the height of the Chase Center parking garage next to the tower. This theory was proposed because an increase in wind speed produce a drop in external pressure in the side and leeward walls and the pressure inside the building remained normal (high) thus resulting in a force that would overcome design pressures. Other interesting observations include those of ABS Consulting engineers who suggest that glazing damage may have been produced by "organized" vortices produced by the upwind Calpine Center and steady vortices between the Tower and the Chase Center parking garage. The NatHaz Modeling Laboratory at the University of Notre Dame is currently conducting an investigation of the flow field around the structure, modeling the tower and the immediate area surrounding it using Computational fluid dynamics (CFD). Preliminary findings suggest that the localized damage is the result of a confluence of multiple mechanisms arising from the arrangement of nearby buildings, critical flow directionality and the possible entrapment of debris within evolving flow structures.