Q21 Mixed Use Project Approaching CompletionJan 11 2017 · 0 comments · Mixed-Use, NISHKIAN DEAN ·0
By Robert A. Aman, PE, SE
This 7-Story, 202,200 square feet project with 162 living units located adjacent to the Conway District at NW 21st & Quimby in downtown Portland will be ready to rent out units starting next month. Nishkian Dean proudly worked with YBA Architects and Andersen Construction Company on this unique and challenging project. The project is highlighted by three-story tapered steel columns at the main entrance that form an “XXI” shape to symbolize the project name and street number location. These specialty columns were constructed with two tapered 12-sided steel sections welded together at the column midpoint to form a double-tapered member. A cantilevered post-tensioned concrete beam spans across the tops of the tapered steel columns to support four stories of structure above.
This mixed-use building project consists of a two-level post-tensioned concrete parking structure with two, 3-Story wood framed residential buildings above separated by a courtyard. These buildings connect directly to a seven-story post-tensioned concrete structure that includes residential units at the upper levels, an office floor level, and retail spaces at the ground floor level. There is also a one-story retail space that extends off the north side of this multi-story structure. Two-story townhomes also occupy the ground level along the south side of the building. Canopy structures and sunshades also highlight the building exterior. The foundation system also provided challenges with the adjacent existing structures, where a micro pile foundation system was utilized to avoid a costly shoring wall and support new building columns located near the property line edge.
At the request of the owner, one of the unique aspects of the project included preserving and modifying the 35-foot tall existing concrete tilt-up wall panels from the warehouse building that was on the original site, and then incorporating the panels into the architectural and structural design. Panels were required to be cut, reinforced, and braced during construction. Some of the panels were lowered and transported to off-site storage to allow for site access during construction. Nishkian Dean provided engineering support for this entire process during the initial phase of construction.
This was a particularly exciting and rewarding project for us to be a part of and we are proud to have played a role in shaping it and the neighborhood that is in.
Robert A. Aman, PE, SE is Associate at Nishkian Dean a structural engineering consulting firm in Portland, Oregon and is the Project Manager for the structural design of the Q21 project.