Rift is at a much larger scale than earlier projects but continues to utilize the spatial and structural potential which folding, bending or shaping can give to thin planes of material. In this case, as the reinforced concrete retaining walls cut more deeply into the ground they undulate with increasing amplitude.  Not only does this result in a powerfully evocative spatial envelope, the increase in ‘effective’ cross-sectional depth which is a consequence of the increasing amplitude of the undulations results in a proportional increase in the inherent structural capacity of the walls.

The two retaining walls are constructed utilizing ‘shotcrete’, an application where concrete is conveyed through a hose and pneumatically projected at high velocity onto a forming surface. The great efficiency of this technique lies in the fact that only a single-sided form is required to construct each wall (as only one side of each wall is exposed to view, this is all that is required for the project); and as the two walls are adjacent to one another across the space of the rift, the two single-sided forms can be trussed together periodically to support and counterbalance one another during construction.

 

The undulating plan geometry of the walls is achieved, first, by progressively adjusting the geometry of the periodic trusses in relation to each other to describe the outline of the future rift. Then, a set of CNC machine cut horizontal guides is added at vertical intervals to direct the placement of the forming surfaces themselves.

Within the rugged natural context of the landscape, the architectural space of the rift provides a powerful alternate experience; a somewhat ambiguous juxtaposition of architectural form and land form. Here the forest drops away, the air cools, sound becomes intimate, and only the sky remains: captured within the narrow interval between the at once rock-like, but also abstract, constructed surface of the retaining walls.