Monitoring Analysis On Temperature Stress Of Large Diameter Reinforced Concrete Silos In Serve Cold Regions

Based on the monitoring experiment on temperature stress of reinforced concrete silos inserve cold regions, the distribution of temperature field and the rule of thermal stresschanging are analyzed. It mainly focused on the vertical and ring to the stress of steel bar inthe silo wall under the effect of temperature. The stress behaviors along the height and ringare summarized and the relations between temperature and stress of steel bar are disucussed.The main results are given as following:(1) It is a short of time when temperature of concrete hydration heat impacts on themeasure point near surface of silo wall during the construction. The stress of hoop steel barhad been obviously compressed during hydration heat process, and it’s influenced by curingconditions. Surface crack would be caused by large temperature difference between thesurface and the interior.(2) Affected by the backfill soil, the structure temperature field along the elevation isobviously different: the upper has a large seasonal temperature gradient while the lower has alittle one. Impacted by the sun and the air temperature, the temperature between inside andoutside the structure is slightly different. In general, temperature is higher on the sun side.Temperature outside the structure is much lower in winter;(3) Seasonal temperature difference would be considered as a permanent load in servecold region. There was a temperature gradient which reached58.5℃during the monitoring.As the local tensile stress in steel bar reached90MPa, it’s far greater than the referencespecified by current silo design specification. So the further research and calculation of silodesigning should be taken in the future.(4) Without internal loading, temperature gradient is the mainly load case. There is alinear relationship between the stress and the temperature of the structure. And surface crackis caused by sharply temperature dropping.