A Study About Overall Safety Evaluationn In Cold Zone Of Prefabricated Bridges

In recent years,with the rapid development of the transport sector,the actual traffic load of the vehicle of some bridges is far more than the bridge designed loads.The phenomenon is very serious,especially on overloaded passenger buses,over width and overweight of trucks,etc.To ensure traffic safety,it is necessary to conduct regularly the detailed and comprehensive security assessments of highway bridges.HulunBuir Yakeshi has a special geographical location,most of this region is a typical cold zone,and the natural environment is extremely bad.It raised a higher requirement to the safe operation of the highway bridge.At present,China conducted more research in the field of bridge assessments,having got great achievements.However,the comprehensive assessment studies of bridge are still deficient in cold area of systematic.This paper will take example of Wollongong Overpass Bridge which is across the railway in cold region,and make evaluation of bridge safety by three-pronged approach :theoretical analysis,modeling analysis and field test analysis.The main work is following three aspects:1,Considering environmental factors in cold area and the presence of frozen rain and snow weather throughout the year in a long time,this paper elaborated the impact of such environments on the bridge deck system,bearing,piers,etc.And the mechanism of the development of corrosion of steel bars and concrete failure and other diseases is also introduced in this paper.2,This paper discussed the method of field load test.The experimental results were compared with the simulation results of MIDAS,and pointed out the analysis results,made a classification evaluation of the bridge.3,Simulated the reinforcement scheme of the bridge,and analyzed the seismic performance of the bridge,provides an important reference for the similar bridge reinforcement in the future.Meanwhile,it established a carbonation service life prediction model thawing in cold regions environment,which provides a useful reference for the durability of bridges cold region.