Architect: BJG Architecture & Engineering, Reno, NV
Engineer: BJG Architecture & Engineering, Reno, NV
General Contractor: Clark & Sullivan Construction, Sparks, NV
Reinforcing Bar Fabricator: Northern Nevada Rebar, Reno, NV
Total Project Size: 24,500 sq ft
Floor System: Reinforced concrete
Framing System: Cast-in-place concrete test floor area and shear walls
Award: 2016 CRSI Award Winner – Educational Facility Category
Photography: BJG Architecture & Engineering, Reno, NV
The Earthquake Engineering Laboratory, University of Nevada, Reno includes 24,500 square feet of new laboratory, office, and auditorium space. It houses the University’s four earthquake simulators and is home to state-of-the art control and instrumentation rooms. A 140-seat auditorium equipped with a video wall and broadband Internet technologies serves as a virtual window to the nation and world.
Sustainability was a secondary issue as there was only one material that could meet the requirements. However, fly ash was used in the concrete and there is a high-recycled steel content in rebar. Concrete aggregate and sand were locally sourced.
STRUCTURAL FRAMING SYSTEM
The building test floor sits approximately 15 feet below the adjacent street that could not be disturbed during or after construction. The end wall of the building at the street side is a reinforced two foot thick wall, is designed as both a retaining wall as well as a reaction wall to mount hydraulic cylinders for some test configurations. An additional reaction wall was built to provide a reaction wall for outdoor experiments, providing as much flexibility in experiment design as possible. These walls had not design criteria other than to make them as strong as possible with conventional rebar. These walls also had to be structurally compatable and integrated with the steel braces for the upper portion of the structure.
The test floor has unknown design criteria. The floor has a grid of sleeves on two foot centers that allow anchorage of concrete reaction blocks, the shake tables or other components to be anchored to the test floor as “fixed”. This anchorage is accomplished by using high-strength steel reinforcing (DWYIDAG) bars to post tension the connection to the slab. The slab has short main spans of only 14 feet and is three feet thick with #14 bars @ 12 top and bottom. Many different experiments have been run in this lab and its older sister of similar design and no damage has occurred to the test floor structure.
Due to funding issues, the laboratory floor was constructed in two parts; the first half of the laboratory floor was constructed first and used for one summer as an outdoor test facility for static loading tests. When funding was secured for the remainder of the building, the remainder of the lab and the building to cover and support the testing was constructed.
REASONS FOR CHOOSING REINFORCED CONCRETE
- Reinforced concrete was the only way to achieve the massive and strong base for the shake tables. The experiment reaction mass needed to be about two orders of magnitude more than the experiment itself for dynamic testing, (otherwise you might be testing the building rather than the experiment). Reinforced concrete was the only way to get the durability, mass and strength needed for this test floor.
- BJG Architecture & Engineering used a complete Building Information Modeling model of both phases of the project. Reinforcing steel (rebar) was to be extended from Phase 1 into Phase 2 using connectors. The 3-foot thick main floor also had to be level and relatively smooth; thus the upper four inches were placed as a second pour. Only minor touch up grinding was needed to bring the floor into specification. Ordinary flatness criteria did not apply because of the large number of sleeves through the slab.
- Reinforcing steel (rebar) layout was carefully designed to allow for the precise placement of the vertical sleeves through the main test floor slab. Dowels were selected based on available development length to insure the best connection possible, as there were no explicit design criteria or the load on the floor system. For example, #9 dowels connect the #14 bar to the walls because #9 dowels were the largest that could be reasonably developed in the supporting walls.