In 1992, Johnson Leifield Structural Engineers was charged with the development of a curtain wall for the proposed Walt Disney Concert Hall. If you will, visualize the convoluted shape of this iconic structure. Now imagine that instead of the exterior walls composed of titanium sheets as was finally built, but that French limestone enveloped the building. This was the original vision of architect Frank Gehry.
It is recognized that limestone, installed on a wall, can be a very stiff element. At this time, the Concert Hall was being developed using ductile steel moment frames to resist seismic forces. Lateral motions were expected to be on the magnitude of 2½% of the element height. Because of the complex wall shapes, no orthogonal behavior could be expected from the wall. We recognized that the curvilinear walls could not be developed with typical slip type joints at each structural level. Binding would occur elsewhere as the wall tried to slip at any tangent point on the wall. Also, the stone joints were not oriented in any logical horizontal nor vertical plane. We determined that the wall needed to be built and the stone anchored, in such a manner that any non-orthogonal movement could be achieved.
Johnson Leifield Structural Engineers developed a Universal-Movement Connector that could allow lateral movement in any possible direction, vertical movement, and rotations both normal and parallel to the tangent wall surfaces. This enabled the individual stone pieces to move and rotate as it “rides along” with any movements that the wall might experience. The connector was composed of conventional steel shapes that could be easily obtained from any steel supplier. Properly sized stone joint widths utilizing silicone caulking completed the system and insured suitable performance of the curtain wall.
Sadly, the French limestone was deemed too expensive a finish material and was eliminated from the final version of the project. The Universal-Movement Connector, however, was used 11 years later on a new Mansion in Los Altos Hills, CA.
It is recognized that limestone, installed on a wall, can be a very stiff element. At this time, the Concert Hall was being developed using ductile steel moment frames to resist seismic forces. Lateral motions were expected to be on the magnitude of 2½% of the element height. Because of the complex wall shapes, no orthogonal behavior could be expected from the wall. We recognized that the curvilinear walls could not be developed with typical slip type joints at each structural level. Binding would occur elsewhere as the wall tried to slip at any tangent point on the wall. Also, the stone joints were not oriented in any logical horizontal nor vertical plane. We determined that the wall needed to be built and the stone anchored, in such a manner that any non-orthogonal movement could be achieved.
Johnson Leifield Structural Engineers developed a Universal-Movement Connector that could allow lateral movement in any possible direction, vertical movement, and rotations both normal and parallel to the tangent wall surfaces. This enabled the individual stone pieces to move and rotate as it “rides along” with any movements that the wall might experience. The connector was composed of conventional steel shapes that could be easily obtained from any steel supplier. Properly sized stone joint widths utilizing silicone caulking completed the system and insured suitable performance of the curtain wall.
Sadly, the French limestone was deemed too expensive a finish material and was eliminated from the final version of the project. The Universal-Movement Connector, however, was used 11 years later on a new Mansion in Los Altos Hills, CA.