PHYSICAL EDUCATION ADDITION CALIFORNIA STATE UNIVERSITY LONG BEACH

Significant Aspects of the Project:

This building was the world’s largest space-frame pyramid on its completion in 1994. Soaring to 17 stories tall at its apex, this 45 degree pyramid is 345 feet square at the base and has no interior columns. The interior has only two levels, one for the concourse and the other for the lower court level. Convertible seating accommodates 6,500 spectators. The frame is a multiple-layer space grid assembled with individual tubular steel struts bolted at their ends to a plate node. The assembled space frame behaves as a three-dimensional truss system with axial loads carried primarily by the individual struts. There are 57 different strut types and 22 different node types for a total of 14,400 struts and 3,150 nodes; and the frame is supported at 80 anchor locations.

Relationship to the Judging Criteria:

Creativity of Structural Design: This multiple-layer space grid embodies a very modern structural solution for one of the oldest forms of architecture: a pyramid. The structural design complexities could be only managed with state-of-the-art structural analysis, design, and drafting software systems. Some of these tools were custom-made by research and development staff at JAMA and ASI for the specific purpose of design and drafting of multi-layered space grid systems.

Design Efficiency of Materials or Labor Utilization: The final space frame design incorporates 351 tons of steel, as compared to the 620 tons of steel that would have been required for a traditional box-truss design. To minimize fabrication costs, the frame was designed with as few modular sub-assemblies as practical. The non-patented structural framing system took advantage of common materials and manufacturing processes to open fabrication to steel job shops, resulting in per-pound fabrication costs competitive with conventional structural steel.

How the Design or Construction Methodology Provides for Cost and/or Time Savings: Cost was the major factor in the design of this space frame. In addition to the overall lower cost of steel required for construction, the lightness of the space frame also saved 1/2 million dollars on the cost of the foundation. As well, square tubing was utilized where required in the outer chordal planes of the structure to facilitate the direct connection of a custom steel roof deck. This strategy saved the expense of a support system, usually required in conventional linear truss structures and ball-node type space frames. In total, the design lowered the construction cost by $1 .935 million, or 12% of the total construction budget.

Technical Innovations and Their Influence on Design: Space frame designs represent a highly optimized information-based building approach, as opposed to the traditional material-based building approach utilized in conventional one-way truss designs. Cost savings on materials realized through space frame designs were usually offset by the higher cost information generation and management. While in today’s marketplace materials are still relatively cheap and information is expensive, the balance is beginning to shift. The conservation of materials effected by the use of materials-effective space frame design will soon outweigh the simplicity of standard construction methodologies.

The space frame was analyzed with SPACE-Il, a proprietary special purpose finite element computer program developed solely for 3-D analysis and design of space frames.

Impact on the Public’s Perception of Structural Engineering: The space frame construction is exposed to spectators on the building’s interior, clearly making its structural design the most striking and defining element of the building.