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The city of Lone Tree in Colorado, at the south edge of Denver’s metropolitan area, is the proud owner of an iconic new pedestrian bridge – which we are equally proud to have equipped with RESTON®SPHERICAL bearings
The Leaf Pedestrian Bridge, a cable-stayed pedestrian bridge over a highway to the south of Denver’s downtown area, opened to traffic this summer with one particularly striking feature: it’s leaf-shaped pylon.
Despite its elegant, light-as-a-leaf appearance, the pylon is subjected to significant forces from the stay cables that support the deck – forces that must be countered at the deck’s support points by suitably designed bearings, which must also accommodate deck movements in most cases. The bearings at one end of the structure had to be designed to resist uplift forces in some circumstances, and all bearings are subject to substantial rotations. Considering all design requirements, and the benefit of making the bearings as small and unobtrusive as possible for aesthetic reasons, bearings of the RESTON®SPHERICAL type were selected for use. This type of bearing is made almost entirely of steel, except for its sliding interfaces which consist of stainless steel and ROBO®SLIDE, mageba’s far superior alternative to PTFE. Since ROBO®SLIDE is not only many times more resistant to wear and abrasion than PTFE, but also able to resist much higher pressures, the RESTON®SPHERICAL bearing can resist very high pressures when loaded, resulting in a smaller bearing size than would arise with other bearing types.
This characteristic of the RESTON®SPHERICAL bearing makes it the ideal solution in many situations – including for extremely large forces, as demonstrated in the 2011 supply of bearings for the Tran Thi Ly Bridge in Da Nang, Vietnam. The RESTON®SPHERICAL bearings for that bridge were designed with an incredible loadbearing capacity of up to 56,000 kips [250,000 kN] each – approximately three times the weight of the Eiffel Tower on a single bearing! Thanks to RESTON®SPHERICAL’s exceptional strength for a sliding, rotating bearing, these bearings could be designed with a manageable size considering fabrication, transportation and installation needs – a great example of this bearing type’s advantages.
Bridge designer: Thornton Tomasetti
Architect: Fentress Architects
Contractor: Hamon Infrastructure