工程结构可持续性设计理论架构

Theoretical framework for sustainability design of engineering structures

工程结构设计以安全和可靠性为基本属性,在人本化关切层面不断进步,但对工程结构造成环境影响的忽视致使工程建设热潮成为环境退化诱因之一。近年兴起的生命周期评价研究致力改善这一现状,依此可建立工程结构的环境可适应性设计,实现生命周期环境影响调控,引导环境友好的工程进步。然而长期以来,工程结构设计与环境影响设计的研究进展处于两条近乎平行的轨道,两类单向设计在实践中常相互制约。工程结构与环境系统的同步可持续是土木工程可持续发展的必然要求,因而亟需构建结构与环境相容共生理论体系。基于此,提出可持续性作为结构设计的控制属性,给出可靠性满足的前提下,工程结构对环境影响在环境系统中的可承受程度。通过建立基本耦合关系和动态相容耦合关系,关联可靠性与可适应性,反映结构-环境共生体的动态反馈影响机制,构建双向设计的基本路径。进一步,定义碳强度和碳容度,提出可持续性目标选取与简化实现建议,列出多层次操作要点,为绿色建造提供理论基础。

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.