Tunnel Concept

Part of the program that became a necessity was a long circulation tunnel in which materials and constructed sections could be moved quickly and safely across the site, as well as over the flood plain. The development of the tunnel became a real challenge throughout the project. 

During the schematic design, the tunnel began with a form of arbitrary structure copied from a previous bridge design. The next step was to push the design into a rib and skin design, which would  function similarly to aircraft bodies, with a rigid primary structure and a semi-monocoque skin.

I then moved into trying to make a scheme that would require less structure. I learned Grasshopper for Rhinoceros 3D in an effort to be able to parametrically adjust my design variables and the tunnel geometry. The first renditions were extremely bulky and unrefined. I then developed a torqued tunnel idea where structural members rotated around the outside of the tunnel, creating a screw-like mesh.  This significantly reduced the size and number of structural members, as well as provided for all the structural needs of the tunnel. It also allowed for the tunnel to be supported by the buildings rather than pylons driven out of the ground.

The space between the structural members was then adjusted based on structural need. Where more structure was needed, such as the openings to the buildings, the structure was compacted. Where less structure was needed, the geometry of the structural members was expanded to allow for more space between each member.

The circular geometry required by this type of tunnel made another series of problems arise. The next big leap forward was to connect the tunnel via large openings to the buildings and laboratories. With the torqued structure bending around the tunnel, the ribs would spin into the building on a repetitive 20-foot grid as they came to the apex of the top and bottom of the tunnel.