摘要
针对超长混凝土结构的特点,给出结构温度效应计算时最大正、负温差取值方法建议,分别对施工阶段与正常使用阶段进行验算。建立了多层框架结构温度计算简化模型,研究温度内力沿结构竖向的变化规律。将桩基础作为具有水平刚度与转动刚度的弹簧,考虑基础刚度对结构底层抗侧刚度的影响。结合多层超长框架结构算例,分析了基础刚度与设防烈度对结构变形、楼板应力、框架梁和框架柱内力的影响。计算结果表明：在温度作用下,结构中部楼板应力分布较为均匀,端部楼板应力变化较大,楼板最大应力发生在框架柱周边;框架梁轴力分布中间大、两端小,框架柱内力由外向内逐渐减小;对于多层超长框架结构,首层结构由温度作用引起的变形与内力最大,2层及以上各层结构的温度效应迅速减小;柱底嵌固条件对温度效应影响显著,随着基础刚度增大,对框架柱的约束程度逐渐提高,温度作用产生的内力增大,层间位移角减小;随着抗震设防烈度提高,竖向构件截面尺寸与结构侧向刚度随之增大,温度效应逐渐增强。
According to the characteristics of super long concrete structures, a method determining the maximum positive and negative temperature differentials was proposed in this paper for calculating temperature effect of structures. The construction stage and the normal service stage were checked respectively. A simplified multi-story structural model for calculating temperature effect was established, and the variation of the temperature internal forces along building height was studied. The pile foundation was regarded as a spring with horizontal stiffness and rotation stiffness, and the influence of foundation stiffness on lateral stiffness of the ground floor was considered. Based on a super long multi-story frame structure example, the influence of foundation stiffness and fortification intensity on the structural deformation, stresses of floor slabs, internal forces of beams and columns were analyzed. The results show that under the action of temperature, the stress distribution at the middle zone of the floor is relatively uniform, but varies obviously at the end of floor. The maximum stress of the floor slab is around the columns. The axial forces of beams are large in the middle and small at both ends, and the internal forces of the columns are gradually reduced from outside to inside. For the multi-story frame structure, the deformation and internal forces at ground floor caused by temperature differential are the largest, and the temperature effect on 2nd floor and above is reduced rapidly. The effect of structural embedding conditions on the temperature effect is significant. With the increase of the foundation stiffness, the restraint degree for the frame columns is increased, the internal forces increase but the inter-story drift ratios decrease subjected to temperature differential. With the increase of seismic fortification intensity, the dimensions of vertical components as well as the lateral stiffness of structures increase accordingly, the temperature effect is enhanced gradually.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2018年第1期136-145,共10页
Journal of Building Structures
基金
中国建设科技集团科技创新基金项目(Z2016J05)
关键词
超长混凝土结构
多层房屋
温差
基础刚度
设防烈度
super long concrete structure
multi-story building
temperature differential
foundation stiffness
seismic fortification intensity
