As if building the world’s tallest skyscraper weren’t enough, Dubai will soon add the tallest, longest, widest arch bridge on earth to its list of superlatives. Slated to open in 2015, the Sheikh Rashid bin Saeed Crossing will encompass a 12-lane highway, a light rail line and a pedestrian walkway, all while being anchored in shifting desert sands. Here’s how they’ll do it.
Author JACQUELINE DETWILER
1 The architects FXFowle initially conceived the bridge with the taller of the two arches off-center, mirroring Arabic calligraphy, but engineers were concerned that the shape would put undue stress on the arch (and an already unstable junction of bridge and sand). To fix it, they moved the taller arch slightly back toward the center and added large foundations at each end.
2 “You typically build arch bridges where there’s rock,” notes Parsons Corp. manager Ken Serzan, “because there’s a huge force at both ends that has to be transferred to the ground.” But in Dubai there is only sand, and under that, crumbly sandstone. To build a bridge on such precarious terrain, Parsons’ engineers plan to sink a series of 2-meter-wide concrete pylons along the length of the span.
3 Around the time of the bridge proposal, another firm was designing an iconic opera house (think Sydney) on a nearby island. Early plans for the bridge would have resulted in its blocking views of this structure, so FXFowle proposed a solution: Why not build the bridge so that it would frame, even accentuate, the opera house? Problem solved.