设置结构的安全储备应该考虑维修策略

Decision of the Structural Safety Margin Considering——Maintenance Strategy

有关“结构的设计安全储备是否应该大幅度提高”的争论作为工程建设界的热点 ,已经持续了五年 ,各方意见不尽相同 ,有的甚至针锋相对。这对国内在工程领域开展学术讨论 ,是一件好事。作者认为 ,争论的各方在讨论结构安全储备的设置时都忽略了对结构的维修策略 ,这是应该统一考虑的。为说明这个问题的重要性 ,本文首先建立了一个比较完善的分析模型 ,在模型中增加了描述混凝土构件功能退化的最新研究成果。通过具体的工程算例 ,看到最优安全设置水平对结构总收益并不敏感 ,这与国际上近期普遍接受的观点一致。这说明 ,“结构的设计安全储备是否应该大幅度提高”的争论的各方实质上可以相互沟通。我国半个多世纪以来设计安全储备偏低是一个事实 ,但不是没有解决的办法 ,今后适当地提高设计安全储备也不是一劳永逸 。

In China, a big argument has lasted for five years in the field of civil engineering, which is that according to the economic development in the past twenty years, is it necessary to increase the safety margin for structural design to a great extent? Some points are different. Even so, it is good for the domestic field of civil engineering to discuss some academic problem. The authors think that the both sides of this argument have ignored the structural maintenance strategy, which should be considered when we decide the safety margin. To show its importance, a complete programming model to analyze the strategy is presented, in which some advanced contributions such as functional deterioration of reinforced concrete elements are integrated. By a practical example, the results show that the safety margin is not sensitive to the overall income, which is identical to the standpoints generally accepted by the structural engineers in the world recently. In fact, the both sides of this argument should be able to understand and communicate with each other. The safety margin of our country for structural design is some low in the past fifty more years, but we do not need feel quite helpless. Even if the safety margin for structural design is increased properly some day, the problem of the structural safety has still not been solved yet. The key of the problem is nothing but we should attach importance to making the maintenance strategy for the structures.