The U.S. Army Corps of Engineers AIT Barracks facility in Monterey, Ca is a four story, load-bearing, cold-formed steel structure that required a number of outside the box solutions to keep the project on time and on budget. From high seismic loading, antiterrorism requirements and a mix of cold-formed steel, masonry and structural steel, the project encompassed several very difficult design challenges.
What makes this structure unique are the numerous lateral and vertical design considerations in addition to a massive coordination effort between trades through BIM and panelization. From a design perspective, the masonry wall was required to meet United Facilities Criteria (UFC) antiterrorism requirements where cold-formed steel wall studs could not resist the prescribed design loads. Adding to the complexity, the structure is located in a high seismic region which required a large number of shear walls and holdowns.
ClarkDietrich served as both the specialty cold-formed engineer as well as the project Engineer of Record. To resist seismic loading, sheet steel was used to provide overall stability to a majority of the structure with the exception of the masonry wall along the access road. Proprietary shear wall posts were connected with prefabricated holdowns between floors. At the foundation, tension loads on the shear wall posts exceeded the capacity of post-installed concrete anchors, requiring structural steel plates which were precast into the foundation. These structural steel plates were designed by McClure Engineering to resist the seismic tension forces at the shear wall posts. Small structural plates were welded to each shear wall post and then down to the embed plates, allowing for field adjustment.
To meet the progressive collapse requirement for the exterior walls required running the joist framing from demising wall to demising wall. The end joists at the exterior wall were then designed to support the wall and roof loading above. This allowed for large sections of exterior wall framing to be removed, while still providing vertical support to the structure above, which satisfied the progressive collapse requirements.