混凝土核安全壳干缩应力的计算

提出内约束干缩应力和外约束干缩应力的概念,利用混凝土的蠕变理论,建立了考虑施工过程的有限元计算模型,编制了电算程序,计算了秦山核安全壳在施工过程中的干缩应力。

Computation of Shrinkage Stresses in Prestressed Concrete Nuclear Containments

According to a survey, surface cracking on PCRVs and PCCs investigated is found to be confined to drying shrinkage and/or temperature effects and not caused by loading. For PCCs, shrinkage stresses play the major role in surface cracking and their computation is important and useful. In this paper, we first put forward the concepts of shrinkage stresses by internal restraint and by external restraint. Then we compute shrinkage stresses by internal restraint with the integral-type constitutive model for long-term deformation of concrete we developed in 4]. For large in-situ concrete structures like PCCs, previous research indicates that results would be quite different whether the effects of construction sequence is considered or not. Thus we present a computational model with construction effects and calculate long-term shrinkage stresses by external restraint with it. The total shrinkage stresses are the combination of the afore-mentioned two kinds of shrinkage stresses. Finally Qinshan PCC of China is analyzed as a numerical example and certain useful conclusions are drawn about it.