Top Down In The North-West

Centre 425 – Bellevue, Washington

We have recently completed shoring and basement wall construction work on this 16-story high-rise building located in downtown Bellevue. The project involved installing temporary earth retention shoring and top-down constructed reinforced basement walls with an average excavation depth of 83-ft. Due to a lack of soil nail easements on the North and West walls Malcolm installed interior columns to brace the walls during construction. The North and West walls were supported by a soldier beam lagging system, the East and South walls received 58 vertical elements, 744 soil nails and shotcrete. As part of the building’s foundation and for lateral support of the North and West walls, 4-ft diameter interior steel-cased concrete columns were installed to an average depth of 177-ft.

The very wet and soft soil ground conditions posed challenges during the installation of the soldier piles, vertical elements and interior columns. Twelve interior dewatering wells were installed and able to draw down the 50-ft deep water table. Malcolm’s team self-performed the majority of the work and participated in constructability reviews and support scheme refinement by working closely with the General Contractor. Foundation and parking garage construction was just completed, with the building tower expected to be completed in 2019.

For more information, please contact John Schneider at