Seattle— DBM Contractors Inc. recently completed installing 224 soldier piles as part of a shoring system for a segment of the Downtown Seattle Transit Tunnel (DSTT) Retrofit and Expansion along both sides of Pine Street between Eight and Ninth Avenues.

This $1.14 million portion of the project involved installing the soldier piles in 30-inch and 36-inch diameter shafts, ranging from 53 feet to 92 feet in depth. The project was challenging due to the logistics of maintaining Pine Street open to traffic during construction, and the amount of coring required through abandoned concrete ducts, vaults, areaways and shoring systems from adjacent buildings.

Work areas and shoring wall alignments were located in very close proximity to existing and operating businesses, including the historic Paramount Theater. Throughout the summer, DBM will install 67 tieback anchors on the east shoring wall. The remaining soldier piles are internally braced from the opposing wall. Balfour Beatty, the general contractor, furnished the steel piles used in the shoring system.