Theoretical framework for sustainability design of engineering structures
Xiao Jianzhuang1,2 Xia Bing1 Xiao Xuwen1
1. College of Civil Engineering, Tongji University, Shanghai 200092, China；
2. State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China
Abstract：Engineering design has taken structural safety and reliability as the basic attributes, and has constantly been progressing to meet human needs. However, the ignorance of environmental impacts induced by engineering structures has made the construction boom become a major cause of environmental degradation.The life cycle assessment (LCA) research is dedicated to improving this situation, based on which, the environmental adaptability design of engineering structures can be conducted, and then the environmental impacts of structural life cycles can be controlled, which guide the engineering progress in an environmental-friendly way. In fact, for a long time, the research progress of structural design and environmental impact design has been on two nearly parallel tracks, so the two types of one-way design often restrict each other in practice. To achieve the sustainable development of civil engineering, the simultaneous sustainable development of engineering structures and the environmental system is an inevitable requirement. Therefore, it is urgent to construct a theoretical system to achieve the compatible symbiosis between structures and environment. To meet this demand, sustainability is proposed as the control attribute of structural design, which characterizes the affordability of the environmental impacts induced by engineering structures in the environmental system, under the premise that the reliability of the structure satisfies the requirements. By establishing a basic coupling relationship and a dynamic compatible coupling relationship to correlate reliability and adaptability, the dynamic feedback influence mechanism of the structure-environment symbiosis can be reflected. Based on that, a two-way design is proposed as the basic design path. Furthermore, the concepts of carbon strength and carbon tolerance are defined as recommended indicators, specific advice is provided on the selection of sustainability goal and the simplified implementation of sustainability design, and the multi-level operational points are put forward, which provide theoretical foundation for green construction.
