Communicating the stability of steep slope infrastructure through landscape architecture: Re-stabilising and re-occupying the steep slope of Clifton, Canterbury, New Zealand

Abstract

The 2010-2011 Canterbury New Zealand Earthquake sequence resulted in the unforeseen regression of some major steep slopes in the Port Hill suburbs. The regression of these slopes has resulted in the abandonment of over 600 properties in high value suburbs, making up approximately 12% of the total red-zoned properties in Christchurch.⁸ People were evidently drawn to occupy these steep slopes pre-earthquakes, however; the precarious nature of the slopes now prevents people from doing so. The main objective of this thesis research is to redefine the inherent approaches architecture and engineering have towards steep slope design, in light of this recent earthquake activity and its dramatic alteration of topography. The design research uses the Port Hill suburbs of Clifton and Sumner as a design case study for resolving the tension between regression and re-occupation of steep slopes post-disaster. The re-stabilisation of the 80-120m high Clifton slope requires major geo-technical engineering design, however, this research argues that this should not be undertaken in isolation. The slope needs to be reoccupied and be designed in collaboration with architectural disciplines. The research reconciles the current disparate relationship between these disciplines and their approaches to steep slope design. Instead of stabilising the slope and preventing re-occupation, the infrastructure used to stabilise Clifton slope is projected out from within the slope and is used as a key design tool. The result is the stability of the slope being communicated to the Port Hill communities. By deriving space and form from the internal infrastructure, people can understand their safety and reoccupy the socially and economically significant Clifton slope. Overall, the research suggests that a holistic, multi-disciplinary approach to post-disaster steep slope design can be achieved. By designing with this approach, a pre-emptive landscape can evolve, which positively engages occupants with the complex natural processes defining their topography.