Tensegrity-Based Structural Systems for Ecologically-Regenerative Urban Development Along Tropical Coastlines

ORGANIZATION NAME: Center for Architecture, Science and Ecology

LOCATION: New York City, USA

SUMMARY: The exponential increase in global population density concentrated along tropical coastlines has inflicted negative impacts on the world’s mangrove ecologies, leading to critical losses in biodiversity and rendering coastal communities vulnerable to environmental catastrophe [Figure 1]. Contemporary methods of shoreline development permanently compromise the fragile networked connectivity of mangrove structures that is necessary for their subsistence; the rhizomatic structure of the their root system is critical to retaining the integrity of the shoreline during severe tropical storms and acts as wave break through the drag forces of its tangled roots and branches. The decline in mangrove forests due to human intervention also carries with it highly unfavorable implications for biologically-dependent ecosystems, such as coral reef and seagrass. The loss of native shoreline structures accelerates erosion and augments the threat of inundation from sea level rise, eliminating the possibility of natural ecosystem migration. The loss of mangrove ecosystems (estimated 35% globally) as critical shoreline thresholds eliminates primary fish habitat and reduces the landscape’s ability to slowly release surface water runoff and filter pollutants such as nitrogen and mercury prior to reaching coastal waters which then disseminates the heavy toxins throughout the marine food chain. Our research focuses on the innovation of radically different structural and architectural systems which allow for large scale development to coexist with a range of native biological systems within a constructed landscape.

The research will test the potential for implementing tensegrity-based compliant structural landscape systems for urban development and pro-active land reclamation that would secure coastal development from destructive weather events, while promoting the regeneration of native mangrove ecosystems and sedimentation processes.

As a landscape, the structure would provide key services to human habitat, and recreate environmental conditions conducive to mangrove ecosystem regeneration [Figures 3 and 4]. The structural matrix acts as shelter for species associated with mangrove forests, promoting local food supply and game fish, while simultaneously providing vegetative substrate to encourage the colonization.

Additionally, the flexible structure approach may offer an opportunity for distributed power generation through the use of piezoelectric materials detailed at flexible connections. The movement within the system would instigate power generation as benefit to urban development while enhancing dual ecosystem regeneration as a partner system to strategies for regenerative coral reef technologies.

PROBLEM SPACE: The shoreline acts as a critical threshold between saltwater and freshwater environments and is therefore linked in a complex ecological relationship directly and indirectly to many additional systems. The interconnected structure of this systemic research and development is diagrammatic of the multiple scales of performance in nature, and will transfer to the shoreline application as a biomimetic landscape. In consideration to future generations, long-term planning for coastal regions must accommodate not only population growth and additional ancillary land use required to support urban centers. Land reclamation utilizing the natural patterns of mangrove forests may retain the integrity of native ecologies while responding to growing global pressures for development. Structural testing is carried out to determine the performance capability of a lightweight structural solution to withstand impact from turbulent weather patterns. The demonstration of space frames and similar structural applications in flexible situations offers insight to the ability of a compliant structure to respond to the environment. Installation of the prototypes at multiple scales will determine and verify the biological colonization capacity of the system, already supported by initial research.

SOLUTION: Current Endeavors: We are currently investigating the structural integrity of a tensegrity-based compliant landscape system and its ability to transfer forces through distribution under gravitational loading (defined by programmatic criteria) and lateral loading (defined by wave energy). In parallel to physical testing, computational modeling of structural performance is carried out through use of parametric software and through the investigation of multiple geometries. We are currently working to develop material logics and system details for energy generation through parametric explorations of environmental and human development criteria. In order to validate the experiment, the system has been reviewed by professional consultants in coastal engineering, biology, and hydrology. Consultation in these areas has provided important insight to the system’s multiple interfaces, and these relationships will continue to expand with the development of the research.

Future Endeavors: Through research and development, the system is undergoing computational simulation and physical modeling in multiple iterations, each increasing in scale and complexity. The two primary testing streams will be structural (through wave testing) and biological response (through shoreline installation).

The results of wave testing at a large-scale facility would identify the system’s ability to successfully slow wave impact and thus reduce energy of incoming storm surge, generate electrical current, and gage material resilience. Implementation of the system as protective feature would be tested through presence of structural and material models. The ability of the system to cyclically deflect and long term material resilience is critical to the development of an economically feasible model for implementation. The installation of a prototype on a shoreline development test site, monitoring the actual colonization of structural elements will begin to test the ecological implications of the system. We are investigating the possibility of prototype deployment in a shoreline development of educational / institutional projects, located in South Florida and South Asia, acting as test-bed to display the principles of the project to potential user groups.