2018 IDEAS2 Awards Brochure - 28

The United States Air Force Academy's Center for Character and
Leadership Development (CCLD) supports the school's mission
to integrate character and leadership development into all aspects
of the Cadet experience-while also serving as a think tank for
leadership and character development initiatives nationwide.
The Skidmore, Owings and Merrill-designed CCLD represents
an important and symbolic addition to the Academy's campus, also
designed by SOM, in 1954, and designated a National Historic
Landmark District in 2004. As the first building constructed in the
Cadet Area since the 1990s, the CCLD creates a significant architectural counterpoint to the Academy's iconic Cadet Chapel.
The CCLD features a dramatic cantilevering 105-ft-long skylight, a design element that establishes a bold presence on the campus while bringing ample natural light into the building. With its
complete integration of architecture and structural engineering, dynamic form and machine-like precision, the skylight is fluid yet disciplined. Its structure consists of diagonal steel plates composed in
a triangular grid and precisely calibrated to resist lateral forces due
to wind loading. The architecturally exposed structural steel (AESS)
is devoid of embellishment or ornamentation, and its sleek connections are cohesive with the aesthetics of the structure. This glassenclosed structure, shaped like a plane's tail fin, aligns precisely with
the North Star, Polaris, signifying the Academy's mission to develop
leaders of character. By aligning this new center for community and
collaboration under Polaris, the design creates a meaningful architectural interpretation of the Academy's aspirations.
The skylight structure simultaneously reflects and responds
to its context. At the Court of Honor Level, marble pavers mark
the 28-ft grid of the campus, and the CCLD continues this pattern to the base of the skylight where the square grid of the
campus transforms to its triangular geometry. The well-defined,
crisp edges of the form are a hallmark of structural steel, requiring no additional cladding, and the structural design sought to
maximize the material characteristics of steel: weldability, ductility, durability and constructability. While the rigidity of the
campus layout is reflected in the skylight, it does not entirely
define it. Like the Cadet Chapel before it, the skylight respects
the right-angle geometry of the Academy but distinguishes itself as a campus landmark with its own character. Below the
Court of Honor, AESS braced frames carrying the skylight are
spaced 14 ft apart. The buttressed forum is afforded an exceptional amount of open, column-free space, allowing a variety
of configurations for programming and audience layout. The
compact shape of the built-up steel frames further enhances the
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transparency of the forum space and visually extends it into the
adjacent breakout rooms.
The skylight's structure consists of horizontal and diagonal
structural steel plates, intentionally landing every 7 ft, composed in
a triangular grid and calibrated to resist the lateral forces produced
by the wind. This calibration was achieved by considering the deflected shape of the skylight geometry under an inward pressure.
When combined with the original geometry, this deflected shape
became the inner boundary of the skylight's steel plates, providing a
varying depth across each face. The product is a triangulated system
using plates of varying depth and creates a normalized stiffness profile across each face to provide a stable base for attaching the glazed
cladding units. The system forms the outer skin of the skylight and
allows for the optimized glass joint dimension. Through the use of
an iterative analysis and design method, structural steel was added
only at locations where it was required by the performance of the
structure, resulting in maximized material efficiency. Analysis of the
skylight also included consideration of both global and local buckling analyses for geometric and material non-linearity, as well as a
check of stresses in the plate members to highlight the flow of loads
through the structure and areas of stress concentration.
Constructability played a central role in the design and detailing
of the skylight. As such, a number of decisions were made throughout the design process to rationalize the geometry to ensure the
building could be constructed easily. Because the skylight is composed of AESS, the design team sought to minimize the number of
connections that must be made in the field. To accomplish this, the
assembly was designed as a series of "stacked trusses." Each truss
was constructed on the ground, where the required level of finish
was more easily attained, before being lifted into place as a whole.
The design of the considered the visual impact of the connections
to preserve the seamless design aesthetic while maintaining bolted
connections for easy erection in the field. Through the use of planar structural steel plate elements, the stacked truss system and
standard connection types, the resulting design was a completely
unique form, yet one that required no proprietary connections or
specialty fabrication.
Having earned LEED-NC Gold certification, the CCLD sets
a new standard for green technology and building practices on the
Academy's campus. Integrated building systems influenced all aspects
of the building's design, construction and operation, which allowed
SOM's design for the CCLD to create a distinct and contemporary
icon for the U.S. Air Force Academy in the 21st century, while also
respecting the discipline and rigor of the original campus plan.

2018 IDEAS2 Awards Brochure

Table of Contents for the Digital Edition of 2018 IDEAS2 Awards Brochure