Building Skywalks foundation
Having in mind the rock’s hardness and the necessity of limiting the natures elements the engineers consider possibilities for the foundations of the structure. At that time Bill Karren from Lochsa Engineering thought it would be very easy to attach the structure to the rock. His team decides to nail the foundations into the rock by using caisson and DYWIDAG (acronym pronounced Doo-Wee-Dag) high strength steel threaded rod rock anchors. A caisson is a concrete footing placed under a building column or wall and extending down to hardpan or rock. It is also known as pier foundation. Each DYWIDAG has a diameter of 6.5 centimeters (2 and a half inches) and length of 14 meters (46 feet). This method for strengthening the foundation is very effective.
On 1 October 2004 Hualapai Nation representatives perform a ancient ritual on the future building site. One month later the building works begin. Percussion rotary air blast drilling and Diamond core drilling were used. Drilling is difficult as the rock is very hard. The construction manager at that time says that this rock is one of the most hard materials that he has ever seen.
During the drilling a serious problem occurs. One of the drills reaches an intersection of 2 of the main cracks in the rock. This caused part of the compressed air of the drill has found a way out through the crack. The whole project was endangered at that time as that crack could become bigger and a new place for Skywak may need to be found. The engineers decide to stabilize and consolidate the crack by inserting a metal cage of horizontal and vertical steel bars. This decision happens to be effective and the crisis was overcame. Drilling works continued.
After the caissons were located at their places they were filled with concrete. The connecting points were now ready. A year and a half after the drilling works, the construction workers are done with pouring the concrete. The foundation’s ability to hold the provided load was tested. The results are amazing – it can hold up to 32 million kilograms which is equal to the weight of 71 fully loaded Jumbo jets. The construction workers have done their job perfectly by following the recommendations of the geologist and the engineers.