考虑空间整体效应的温度自应力计算

针对在计算混凝土桥梁结构的温度自应力时,按现行的计算方法得到的结果与实测的数据有较大差别的问题,根据温度作用下的应力-应变关系及结构内力特点,并运用三维平面假设,改变温度荷载的加载方式和多余约束力的状态,推导出考虑空间整体效应的温度自应力计算方法。对箱梁的实例分析表明：在计算桥梁结构的温度自约束应力时,应考虑纵横向温度应力-应变之间的互相影响,采用与实际情况相符合的温度荷载加载方式,这样使计算结果更接近实际值。

Calculation of Thermal Self-restraint Stress by Considering the Global Properties

When calculating the thermal stress in a concrete bridge, large differences are found between the resuits calculated by the current method and the data gotten by actual measurement. Based on stress-strain relation and internal force characteristics affected by temperature, the method for calculation of the thermal self-restraint stress is put forward where the global property is considered. During the course, the three-dimensional assumption of plane is used; the mode of thermal loading and restraining force state are changed. An example of a box beam is analyzed. The results show that when the thermal self-restraint stress in a bridge is calculated, the stress-strain interaction between transverse and longitudinal should be considered and the mode of thermal loading should conform to practice. Consequently the calculated result will be closer to the real value.