Study On Combined Effect Of Temperature Changes To Over-long Concrete Frame Structures

Previous studies on the temperature effect appeared in the bridges and massive concrete structures. With the development of large-scale structures,over-long concrete structures emerging and frequent temperature anomaly in recent years . Maximum unit length of the concrete frame structures sometimes exceed the current specification permit in practical application and structural measures can not meet the design requirements. The impact of temperature effect is becoming increasingly important. Details for calculation and analysis of the temperature effect of over-long concrete frame structures were scarce in China. Domestic and foreign scholars have also launched a number of studies on this,but still in the exploratory stage.In order to perfect the research system of the temperature effect of over-long concrete frame structures and deeply analyze the adverse influce of temperature effect,the following aspects were worked mainly in this paper:(1)Analyzed the types and characteristics of temperature effect,method for determining the integrated temperature of over-long concrete frame structures was proposed;(2)On the basis of the elastic analysis of considering temperature reduction coefficients,analyzed effect of the concrete creep,plastic nature and cracks on the temperature effect,method for determining the temperature reduction coefficient and calculated temperature was studied;(3)Based on structural probability limit state design method and loads(action)combination rules,the probabilistic model of the temperature effect and combination coefficients of temperature effect were studied. the recommended value of combination coefficients of temperature effect of over-long concrete frame structures was proposed;(4)Taking typical Thermal Power Plant concrete structure as an research subject,it`s combined effect of temperature changes was analyzed according to conclusions of this study and determine the influence degree of temperature effect;(5)Taking into account the design and construction,integrated control measures against over-long concrete frame structural temperature shrinkage cracks was proposed.Conclusions of this Paper will be used as important references for the calculation of temperature effect on the related over-long concrete frame structures.