Experimental Investigations On Aerodynamic Interference Effects Of Twin Arch Ribs Of Long Span Bridges

China is a large world-recognized bridge-construction country dating back to ancient times and many original types of bridge can be traced back to the Chinese construction history. Arch bridge has a long history about more than3000years. Today, a lots of long-span arch bridges have appeared with the development of design theory and construction technology as well as constant renewal of the building material.Long span makes bridges much more beautiful and practical, but it also brings unprecedented challenges at the same time. Bridges become longer than before so that their stiffness are getting smaller, therefore they may be destroyed if meet with dangerous external loads such as strong wind or earthquake. The thesis will do a research on wind-resistant performance of the main bridge’s main arch ribs based on the Puwan New-zone Road16#Sea-crossing Bridge and the Hutan Bridge of Dalian City, Liaoning Province.The work of this thesis mainly includes the several parts as follows:(1) It gives a simple introduction about the bridge engineering developing state of both domestic and foreign focusing on the long span arch bridge. It gradually elaborates the developments in research on wind-resistant performance of long span arch bridge which starts with basic concepts of wind-induced vibration.(2) It tells how wind forms in order to introduce the fundamental theories of aerodynamic interference. It describes the interaction as well as static effect and dynamic effect between wind and bridge. It introduces some knowledge of aerodynamic interference numerical simulation which basic idea, formation, development and simulation process included.(3) It begins with fhree components of wind load, the static force coefficients and characteristics of arch bridge wind load so as to get a better understanding of arch rib section model wind tunnel test. It gives some information about the test including testing aim, testing site, testing design and model work.(4) It does some filtering and smoothing work on data which offered by section model wind tunnel test handling with Origin and get the drag coefficients together with their standard deviations. It does several analysis and comparison between them by means of changing some parameters. It summarizes what we get from the test.