by Katherine Marr
Shoring system on the basement level
Isaac Blair and Co., Inc., Marr’s specialty shoring company, is working for Columbia Construction to install a shoring system on the basement level of a 10-story building at 9 Channel Center on A Street in South Boston.
Historically a mill building constructed in the late 1800s, the structure was built with large wooden columns to support it, as big as 24-inch x 24-inch, starting on the basement level and decreasing a few inches in circumference on the above floors. With a plan for a restaurant to occupy the basement space by winter of 2016, the decision was made to replace the existing wood columns with narrower steel columns (8-inch x 8-inch) to allow for greater visibility and functionality.
Bolts, steel channels, wood cribbing, and 1950s style simplex 50-ton house screwjacks are being used to support columns on the first floor.
Isaac Blair designed a shoring system to allow the general contractor to replace 11 of the 25 wood columns. Working with four columns at a time in a tic-tac-toe pattern, Isaac Blair installed shoring towers on the basement level around each column to the underside of the floor directly above, while steel bolts and jacks were installed to sandwich the floor and grab the columns on the first floor. The shoring system provides support to the nine upper floors while the wooden basement level columns are replaced by steel. The work is being done in three phases, with a completion time expected before the new year.
Katherine Marr is the communications coordinator for The Marr Companies of South Boston.
