Mega Brace Shoring Provides Unique Solution For Water Project

By Jeff Griffin, Senior Editor | December 2010 Vol. 65 No. 12

“Beam and plate,” said Graham, “would require counter sinking the beams below the bottom grade, but the soil reports indicated extremely hard materials that would have been very slow for the required caisson drilling. We had the same issues with the sheet pile options, but were able to engineer it without the toe in.”

Graham said slide rail was an option that could have been made to work, but would have required multiple sets of cross struts running both north/south and east/west. Not only would the installation have been longer due to the excavator needing to work around the cross struts, it would have required the concrete crew to work around these cross struts and then have an excavator on stand-by to pull them up as the concrete structure progressed.

Sheet pile with conventional I-beams welded to sheet pile would have achieved the same results, Graham continued, but would have required certified welders to cut and weld the rings/levels of I-beam and cut and grind them from the sheet pile at the time of removal. This would have required an estimated one-day per ring/level and downtime of crew and equipment to swing the I-beam to welders.

“Instead, the Mega Brace system was installed with the same size crew and equipment in an average of two hours per ring/level, saving close to one week on the installation and the cost of the certified welders,” Graham said.

Manufactured by Ground Force Engineering, Harrogate, North Yorkshire, England, the Mega Brace takes the place of conventional I-beams for use as a waler system in a sheet pile/beam and plate installation, said Graham.

“Mega Brace,” he said, “has pre-manufactured lengths of I-beam and cross struts that have the ability to quickly pin together to fit the length or width required for the construction project. What makes the Mega Brace system unique compared to I-beam walers is that a six-inch telescoping hydraulic ram is pinned to the ends of the I-beam extensions or struts. This allows the system to pump in or out to fit the excavation and hold the system in place without the required welding to the sheet pile required of a conventional application.”

Installation
When the project was bid, said Graham, United Rentals had 90 percent of the Mega Brace equipment required on hand. By the time work was ready to begin, equipment was committed to other projects, and United Rentals transferred equipment from Florida and Georgia for the Colorado project.