Hurricane Georges blew through the Caribbean in September 1998 with 120 mph winds that ripped apart buildings, tossed trees, and caused billions of dollars in damage to the islands of Puerto Rico and the Dominican Republic. The building protecting limestone storage at Essroc San Juan's sole Puerto Rican facility was one of thousands damaged by Mother Nature's fury. Fortunately for Essroc San Juan, a hurricane-resistant enclosure to prevent another such incident was available.

Essroc San Juan, a unit of the Italcementi Group, contracted Geometrica in February 1999 for the supply and installation of a longitudinal enclosure for limestone storage at its plant in Dorado, 15 miles west of San Juan. As the second Geometrica dome purchased by Essroc, the new structure will replace the previous storage building.

The dome represents Essroc's commitment to environmental protection by preventing the possibility of runoff and dust pollution. The economical construction system offered by Geometrica provides an alternative for covering stockpiles that would otherwise have been left unprotected and exposed to the elements. The dome interface with the foundation is fixed to the edge beam to provide a more stable and strong building.

The time frame for construction was short. Construction began on site in October 1999 (Photo 1), with the assembly and erection of 27 separate arches, partially assembled and shipped from the fabrication facility in Monterrey, Mexico.

The arches make up the central barrel shape of the dome and are constructed of standard structural steel elements. Two 50-meter-diam semi-domes of patented design will enclose the ends of the barrel (Figure 1). The cladding of the barrel section began in February 2000, so a covered area was available for additional foundation work for the conveyors. One of the design advantages is that it is possible to construct a dome enclosure during other equipment installation or civil works.

The completed longitudinal structure will measure 175 meters long Yen 50 meters wide Yen 18.5 meters high. Two vehicle-access doors, three conveyor openings, and two personnel doors are incorporated into the structure. Approximately 15,000 work hours will result in the dome's scheduled completion in April 2000. The skeletal structure has over 337 tons of steel incorporated into the finished dome; 254 tons of steel structure and 83 tons of steel cladding. The new dome is designed to handle a wind load of 145 mph, or a Category 4 hurricane strength. This coming hurricane season promises to be an excellent test.