Effect Of Climate Change On Highway Bridge Reliability Under Wind Load

ABSTRACT:The wind is an important factor of climate change, and the wind load of structure is an important load. The bridge damage caused by climate change will be increasingly prominent, which makes the safety effect from the wind changes to bridge important. The IPCC report meeting proposed global climate change aggravating,and the wind velocity changes over time, which makes the uncertainty study of bridge reliability necessary.The wind changes in Beijing obeys with actual extremum I (Gumbel)distributions.Using Unified standard for reliability design of highway engineering structures (GB 50153-92), we makes the wind load model by wind load composed of uncertain parameters failure model, using bridge reliability theory for the actual maximum speed nearly 59 years in Beijing and that assumpted by 10% and 20% increased. With the situation by 100 years benchmark period from bridge bearing Angle and Bridges reliability analysis, the relationship between bending capacity of wind and the reliability of the bridge is built with reliable indicators.Wind velocity and discrete has also decreased. According to the structural reliability changes of every 30 years, it has declined.By MATLAB, wind data of 30 years in future has been estimated with a smaller discreteness. According to bridge reliability analysis of every 30 years, change is not only present increasing. That bridge wind loads, reliability and wind speed change is not only related with the wind velocity, but with value of discrete. Namely, it is related with the distribution of velocity variation. In this process, the basic value of wind decreases at 0.21 KN/m2 at the period of 1981-2009. But the existing provisions of the code set the wind reference pressure at 0.5 KN/m2 of 100 years in Beijing. This paper gives suggestions that the reference vaule for the basic wind at the benchmark stage is 0.25KN/m2.