...service and the location of the cooling plant. “It was like building a high-rise from the top down,” says Bernard L. Grove, Clark’s vice president.

The building, which sits on precast piles and caissons, has no basement. That saved money, especially considering the poor soil quality and a high water table.

TREE COLUMNS Vertical erection column (left) of tree columns (right) eliminated shoring towers. (Photo left courtesy of Lemessurier, right courtesy of Abbott Boyle Construction)

Steel erection began in July 2001 and ended in November 2002. The sequence called for first constructing the side buildings to serve as anchors for the exhibit hall. The low-roof bays followed, with the high roof going up last.

The low-roof erection sequence was developed in collaboration with steel fabricator Canam Steel Corp., Point of Rocks, Md., and its steel erector, a joint venture led by Capco Steel Corp., Providence, including Dorel Steel Erection Corp., Quincy, Mass.; James F. Sterns Co. Inc., Hingham, Mass.; and Prime Steel Erecting Inc., N. Billerica, Mass.

Work proceeded in 90-ft-square bays using a temporary vertical column rising from each of the tree column pedestals. This eliminated the need for shoring towers to stabilize the branches during construction. After four bays were complete, workers placed the concrete slab. Crews then removed temporary vertical columns for reuse on the next section.

The sloping roof may have kept the height of the south end to 75 ft, but it created another issue. Residents to the south did not want the high-roof rainwater draining into their neighborhood. Instead of pumping the water “uphill” to the storm sewer, the team made use of a siphoning system that sucks water off the roof to a trough on the flat, low roof. Water moves from the trough to a collection tank connected to the sewer. The system is new to the U.S., though it has been used in Canada and Europe.

Though no date has been set, MCCA has long-term plans to lengthen the convention center southward and fill the remaining 20 acres of the 60-acre site. Their hope is that, based on their first experience, the convention center’s neighbors will put out the welcome mat for the expansion.