Reliability-Based Simulation for Performance-Based Design

在过去的十年中，建筑设计和施工发生了重大变化：向极限状态设计的转变；在结构设计中使用先进计算工具的革命；在结构设计中使用先进计算工具的革命：以及创新高性能材料的引入。与此同时，许多采用传统方法和标准设计的结构在极端自然灾害下的性能越来越不理想。问题是，在目前的设计规范中，防止结构倒塌已被用作可接受性能的主要标准。然而，人们发现，自然灾害造成的不太剧烈的结构破坏以及功能破坏可能导致接近结构本身成本的经济损失。当前的设计实践侧重于新设施的特征和行为。然而，业主和住户的持续满意度取决于建筑物在较长一段时间内的表现。在过去，材料的耐久性通常在设计和施工阶段通过选材、细部和精加工来解决。这种方法并不总是在服务中取得令人满意的结果，而且随着创新材料被引入建筑施工中，这种方法甚至可能更不成功。为了在基于性能的工程中获得更好的解决方案，材料选择和耐久性问题必须更好地融入设计过程。这样做的方法还处于初级发展阶段。为了使基于性能的工程充分发挥其潜力，必须具备以下要素：评估集成系统性能的计算工具；根据结构响应量定义性能的关系，工程师可以使用可用的方法计算；数据库测量工程参数的不确定性；系统可靠性分析程序为管理这些不确定性和定量风险目标提供了框架。

During the past decade, significant changes have occurred in building design and construction: the move toward limit states design; revolution in the use of advanced computation as a tool in structural design; revolution in the use of advanced computation as a tool in structural design: and the introduction of innovative high-performance materials. At the same, time, the performance of many structures designed by traditional methods and criteria and subjected to extreme natural hazards has been judged increasingly inadequate. The problem is that in current design codes the prevention of structural collapse has been used as the primary criterion of acceptable performance. It has been found, however, that less drastic forms of structural damage as well ass the functional disruptions resulting from natural hazards can lead to economic losses that approach the cost of the structure itself.Current design practice focuses on the characteristics and behavior of a new facility. However, the continued satisfaction of the building owner and occupants depends on the performance of the building over an extended period. In the past, durability of materials usually has been addressed through material selection, detailing and finishing at the design and construction stage. This approach has not always led to satisfactory results in service, and is likely to even less successful as innovative materials are introduced into building construction. To achieve better solutions in performance-based engineering, material selection and durability issues must be better integrated into the design process. Methods to do this are only in a rudimentary stage of development. For performance-based engineering to achieve its full potential, the following ingredients must be available: computational tools to evaluate the performance of integrated systems; relations that define performance in terms of structural response quantities that engineers can compute using available methods; databases to measure uncertainties in the engineering parameters of interest; system reliability analysis procedures to provide the framework for managing these uncertainties and quantitative risk targets.