平面形状为圆环形的混凝土框架结构温度应力研究

STUDY ON THERMAL STRESS OF CONCRETE FRAME STRUCTURES WITH PLANE RINGS

对平面形状为圆环形的混凝土框架结构在季节温差作用下构件的温度应力进行了研究。从理论上分析了圆环形混凝土框架结构在温度作用下结构变形、梁板中径向应力、环向应力、柱中应力特点,并通过算例进行了计算验证。研究结果表明:圆环形混凝土框架结构裂缝控制的重点为梁板中的环向应力和柱中应力。梁板中环向应力大小与径向位移约束系数成正比,环向应力自外环至内环逐渐增加,可能引起自内环开始的径向放射状通缝;柱根尤其是边柱柱根承受较大弯矩,可能产生严重的弯曲裂缝甚至破坏,需加强配筋满足裂缝控制要求。

The thermal stress of concrete frame structures with plane rings under a seasonal temperature difference is studied.The paper analyzes the theoretically structure deformation,radial stress and circumferential stress of beams and slabs,and the column stress of ring-shaped concrete frame structures.An example was given to verify the analysis.The results show that the focus of crack control on a ring-shaped concrete frame structure is the circumferential tensile stress of beams and slabs as well as the stress in columns.The value of the circumferential tensile stress is proportional to a constraint coefficient of a radial displacement.The circumferential stress gradually increases from the outer ring to inner ring so that a radioactive penetrating crack may arise starting from the inner ring.The moment of columns,particularly side columns,is considerable and a serious flexural crack or failure may occur.The reinforcement must be strengthened to meet crack control requirements.