The Research Of Crack Of The0#Block Of Yutang Cun Bridge

Along with china’s the infrastructure construction is developing rapidly in recentyears, with the unique advantage of continuous rigid frame bridge, it is used more andmore widely in transportation construction. But the problem of crack attracts moreand more attention of the construction workers in the construction or service phase.As the0block is a complex structure, and the usage amount of concrete is large, thehydration heat’s temperature influence is the main cause of temperature crack. So thecracking of0#block become key problem of this kind of bridge’s construction, thecontrol measure of crack become a heavy task in the construction.This paper’s main work and achievement are followed:Based on reading a plenty of references home and aboard, this paper introducedthe classifications and causes of cracks in concrete structure, and analyzed thetemperature crake’s causes and damages. At the same time, the basic theory of thehydration heat’ s temperature field and the calculation method were introduced in thispaper.Based on the background of a main span of100m4-span continuous rigid framebridge-Yu Tang Cun bridge, which was a part of the highway through Baotou toMaoMing in HuaiHua city in HuNan province, the position where the cracksdeveloped, the width of the cracks were analyzed about the0#block. The generalfinite element analysis program midas FEA was used to analyze the0#block of themajor bridge. Analyzing the temperature field and temperature stress characteristicsof the0#block under the influence of hydration heat in the construction phase. Tosummarize the temperature field distribution and the stress values. And get thehydration heat’s influence to the structure temperature cracks. And the dangerouspositions are simulated with the actual situation. According to the results, we knowthat the hydration heat is a main cause of the concrete’s cracks. If the temperaturegradient is too large, it may leads to cracking. And then, simulating the0#blockwhich is layer pouring in two parts. After observing the result, we know that layerpouring is helpful to temperature control of the concrete’s hydration heat, it can prevent the cracks efficiently.To take a part of the0#block structure to simulate, with the sensitive factorsanalysis, we get the sensitive factors’ influences to the hydration heat.Finally, according to the results above, we know that the hydration heat is a maincause of the concrete’s cracks. If the temperature gradient is too large, it may leads tocracking. And a reasonable construction scheme was made out and to put outcontrolling measures to cracks’ producing and developing and treatment measures tocracks which were developed, for the similar bridge construction.