预应力混凝土箱梁桥温度场的研究

Study on Temperature Field of Pre-stressed Concrete

连续刚构箱梁桥横截面的非线性温度变化,使其产生纵向应力,这些应力可能达到,甚至超过由活荷载引起的应力,从而使结构构件出现温度裂缝。需要提出一种实用的计算方法,用于模拟预应力混凝土梁桥横截面的温度分布,建立其与结构几何形状、所处地理位置、桥梁走向、材料特性和当地气候条件之间的关系,并提出适合广州地区的气候参数的计算公式。该方法可作为使用有限元法分析桥梁温度应力的边界条件。

It is known that nonlinear temperature variation over a cross section of continuous rigid-frame boxgirder bridges can cause longitudinal stresses and that in some cases such kind of stresses may reach or even exceed those induced by the live loads and that temperature cracking may occur in the structure component. Therefore, a practical computation method is presented to simulate the temperature distribution over cross sections of a prestressed concrete boxgirder bridge. The relative factors are considered including the bridge geometry, the geographical location, the bridge orientation, the material properties and ambient climatic conditions. Then the equations of climatic parameters are presented based on the climate of Guangzhou area. This method can be used to generate the thermal loads for finite element analysis.