Abstract Ambient temperature changes may cause considerable and complicated global deformation in long-span bridges. This study investigates the mechanisms of temperature-induced mid-span vertical displacement of symmetrical twin-pylon cable-stayed bridges through geometric models. General formulas are presented to separately quantify the sensitivity of the concerned displacement with respect to the cable, girder, and pylon temperature variations. The applicability of the proposed formulas is verified using numerical models of 15 bridges. The subsequent parametric analysis reveals the relationships among the temperature sensitivity, material property (linear expansion coefficients), and structural geometries (main span L 0 , side-to-main span ratio γ 0 , pylon height-to-span ratio ξ , and pylon height ratio λ 0 ). Furthermore, the relative impacts of the temperature changes of different structural components are compared. This study focuses on the calculation of thermal deformation of a general category of cable-stayed bridges rather than a specific one. The formulas provided show the advantages of conceptual clarity, calculation simplicity, and general applicability. They also have far-reaching implications on the design of structural health monitoring systems and the establishment of the load–response baseline models.

中文翻译：

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斜拉桥温度引起的跨中竖向位移估算通用公式

摘要 环境温度的变化会引起大跨度桥梁相当复杂的整体变形。本研究通过几何模型研究了对称双塔斜拉桥温度引起的跨中竖向位移机制。提供了通用公式来分别量化相关位移相对于缆索、梁和塔架温度变化的敏感性。使用15座桥梁的数值模型验证了所提出公式的适用性。随后的参数分析揭示了温度敏感性、材料特性（线膨胀系数）和结构几何形状（主跨 L 0 、边主跨比 γ 0 、塔高跨比 ξ 和塔高度比λ 0 )。此外，比较了不同结构部件温度变化的相对影响。本研究侧重于计算一般类型斜拉桥的热变形，而不是特定类型的斜拉桥。提供的公式显示了概念清晰、计算简单和普遍适用的优点。它们对结构健康监测系统的设计和负载响应基线模型的建立也具有深远的影响。