Figure 5 - Matagorda Balanced Cantilever one month prior to landfall of Hurricane Ike. Figure 6 - Cables securing bottom slab of segmental box girder to approach bent.

On September 13, 2008, Hurricane Ike, a strong category 2 storm, made landfall in southeast Texas. Five Balanced Cantilever and two Cable-Stayed bridges were in its path. Two of the bridges, Trinity (450' main span) and Matagorda (320') (Fig. 5), were in full cantilever, but lacked the last few approach span segments that would have secured them to the approach bents. In the days just prior to landfall, contractors for both bridges lashed the back span to the approach bent via diagonal cabling (Fig. 6).

In spite of the fact that the bridges were in their most vulnerable construction state and one of them (Trinity) experienced a near-direct hit, neither of the two bridges demonstrated any sign of damage. The most significant problems were work stoppage, flooded job trailers, and submerged construction materials.

Similarly, the completed bridges survived the storm without any ill effects. This includes the 1250' Fred Hartmann Bridge with superstructure height of nearly 200 feet that was directly in the path of the hurricane.

Figure 7 shows the locations of segmental bridges near the storm, their orientation, construction type and main span length. The Maximum Sustained 1-Minute Wind Speeds are also provided. These speeds were obtained from the Atlantic Oceanographic and Meteorological Laboratory NOAA Hurricane Research Division utilizing their unique HRD Surface Wind Analysis System. This system relies on data gathered from various locations (ships, buoys, land-based stations and reconnaissance aircraft) which are processed to create a contour map of wind speeds at a level of 33 feet. The exposure condition is open terrain with adjustment made only for marine or land location. Inland wind speeds have not been fully synthesized as of this writing and are estimates only. Given that the shortest of these bridges (Trinity) has a vertical clearance of 50' and a maximum structure depth of 25', it is likely that the wind speeds at the level of the superstructures were even greater than those indentified here.