North glass wall with tube steel columns.
The Performing Arts Center at Soka University in Aliso Viejo, Calif. is part of a $73 million project that began in December 2008, with the official groundbreaking taking place on Jan. 13, 2009. The project included construction of a three level 47,836-square-foot Performing Arts Center, which houses a reception lobby, various support spaces and a 1,200-seat auditorium.
The ambitious performing arts program is viewed as a key element in the culmination of Daniel Habuki's tenure as Soka University president. The University is committed to having the Performing Arts Center as a touch point for its community outreach objectives and to foster community involvement and serve as a community resource.
Throughout the project, flexibility has been of the utmost importance to the University and helped drive the overall design of the structure. The Performing Arts Center is intended to host a variety of performance types – from natural voice presentations to theatrical to full musical performances. Due to the diversity required, the shape of the structure had to be an integral part of the acoustical design, while being efficient to accommodate flexible seating and stage configurations.
Owner: Soka University of America
The Performing Arts Center is served by lobbies totaling 7,300 square feet and a 2,100-square-foot mezzanine. Natural acoustics are featured in the main performance hall, designed by noted acoustician Yasuhisa Toyota of Nagata Acoustics. The main hall was designed to be used in three different configurations: a 960-seat concert mode, a 1,034-seat theater mode, and a 1,200-seat convocation mode. The performance platform can be changed for the various needs, with a 3,059-square-foot platform for concerts and a 1,856- square-foot thrust stage for the theater mode.
One unique challenge to the project team, for both design and construction, was the sloping site. The foundations consist of continuous footings and spread footings, which are founded at various elevations. Detailing and construction of the site walls was complicated by the need to maintain pedestrian access all around the building. With the extreme elevation changes, the site took on the look of a wedding cake. The slabs on grade provided the base framing for the seating and the columns and walls are all reinforced concrete.
The overall structural geometry of the main hall was dictated by the acoustical needs of the space. The seating was elevated from the slab on grade to allow for under floor air distribution. The floor framing in the multipurpose hall was unique because it had to be raised to allow for airflow below. An underground air plenum was built below the seats in order to provide air distribution. Low velocity airflow to each seat was used in order to minimize noise.
Cast-in-place raker seating and partially completed wood stage.
With the extreme elevation changes, the site took on the look of a wedding cake. The slabs on grade provided the base framing for the seating and the columns and walls are all reinforced concrete.
Seismic loads were resisted by the massive curved concrete shear walls that form the envelope of the multipurpose hall. In order to maintain the tight tolerances of the architectural curves, the formwork was fabricated off site in large panels to speed up the process. Bar savers and couplers were used extensively to avoid drilling holes into the formwork. One benefit to these massive concrete walls was the ability to resist the majority of the seismic forces within the interior of the footprint. Having the lateral system concentrated within the interior allowed for the majority of the framing outside of the theater to be light, open and airy. This architectural design allows for the structure to blend in with the overall campus architecture.
The mezzanine concourse also required considerable coordination between the design team and general contractor McCarthy Building Companies. In order to achieve the desired sight lines, a series of cantilevered slabs, supported by cantilevered beams, were required to frame the mezzanine levels. McCarthy had to coordinate subsequent construction activities around the shoring, which had to remain in place for an extended period of time in order to allow the concrete time to cure. This multi-cantilevered structure deflected exactly as the design team had anticipated.
Completed view from the northeast lobby corner with a view of the canopy.
In order to maintain the required open space and flexible design, the roof structure was constructed of structural steel. A double roof slab structure was developed in order to provide adequate isolation from exterior noise, while maintaining structural efficiency and cost. The long-span roof structure required the use of four major structural steel trusses, which all span over 100 ft. Due to the depth of these trusses, each over 16 ft., a special escort from the California Highway Patrol was required in order to deliver the trusses at night.
The four large trusses were each shipped in two pieces and then spliced on the ground with welded connections. The erection of these trusses, and the construction of the roof framing, was performed simultaneously along with the stepped floor system construction. When the roof trusses were being erected, the whole project site had to be vacated. In order to lift these trusses into place, two massive cranes had to be used. Quick release of these trusses, after temporarily securing them, was required in order to limit the overall disruption to the site.
Main Hall with the front portion of the stage lowered and seating extended.
Simultaneous construction in different areas of the project by various trades required close coordination between the trades. In order to maintain the projected schedule for all of the trades, rapid resolution of construction queries was required. In many cases, verbal communication was required and the written RFIs or change orders would follow at a later date.
The stage area, designed to meet the owner's needs, required close coordination among members of the design team. The stage composition required large volumes of air below the heavy stage floor, with minimal structural supports, in order to maintain the high acoustical quality. After several rounds of coordination, the design team agreed on an isolated raised steel and concrete platform. Multiple layers of wood flooring and sleepers were stacked on top of the isolated raised slab, utilizing oversized holes with rubber snubbers to dampen the transfer of structural-borne vibrations.
A dual overhead grid system services the performance platform area. An overhead rigging and tension grid is hung from the primary structural grid. The rigging and tension grid is used to support lighting and speaker systems. This two-grid configuration provides for greater flexibility in rigging and lighting for the various types of performances and productions.
Shade detail of the north-facing glass canopy with PV cells.
Even with all of the design and construction challenges that were so much a part of this project, the design and construction team never lost sight of the client's goal to provide a structure to serve not only the university's need for a performing arts center, but to serve as a resource to the community as well.
In addition to its commitment to the community, Soka University is also dedicated to environmentally sustainable design. It was only natural for the University to set a goal of LEED Gold certification through the U.S. Green Building Council for this state-of-the-art building. The design and construction team achieved this goal using carefully planned-out strategies and sustainable construction methods. Green roofs were used to reduce storm water run-off and to reduce the heat-island effect. In addition, photo-voltaic panels were placed on the roof to generate 15 percent of the building's energy requirements.
Soka University's Performing Arts Center stands as a tribute not only to a forward looking University, but also to the design and construction professionals who made it possible.
Kurtis Clandening, S.E., is a principal and senior project manager with John A. Martin & Associates in Los Angeles. Contact him at firstname.lastname@example.org. Kimberly Pacheco, P.E., is a project engineer with John A. Martin & Associates. Contact her at email@example.com.