Analytical formulas of thermal deformation of suspension bridges

Yi Zhou, Yong Xia, Yozo Fujino, Kazunori Yamaguchi

Research output: Journal article publicationJournal articleAcademic researchpeer-review

7 Citations (Scopus)


Deformation of a long-span suspension bridge is mainly caused by ambient temperature changes. The temperature-induced deformation of a bridge is usually calculated using complex three-dimensional finite element analysis, the mechanism of which is often unclear. In this study, we derive general, succinct analytical formulas of the thermal deformation of three-span suspension bridges. The deformation of different components is unified into a one-dimensional thermal expansion formula (δL=LEθ·δT) by introducing an equivalent length LE. The sag effect of side-span cables is characterized by the modification coefficients, which demonstrate that the neglect of the sag effect overestimates the thermal deformation. Furthermore, the thermal deformation of the main- and side-span cables and towers is found to interact with each other as a result of the cable tension changes with varying temperature. The analytical formulas are validated using eight long-span suspension bridges including the Akashi Kaikyo bridge, the longest main-span suspension bridge in the world. The closed-form solutions herein also apply to the self-anchored suspension bridges.

Original languageEnglish
Article number112228
JournalEngineering Structures
Publication statusPublished - 1 Jul 2021


  • Analytical solution
  • Sag effect
  • Structural health monitoring
  • Suspension bridge
  • Thermal deformation

ASJC Scopus subject areas

  • Civil and Structural Engineering


Dive into the research topics of 'Analytical formulas of thermal deformation of suspension bridges'. Together they form a unique fingerprint.

Cite this