混凝土箱形渡槽日照温度场及纵向温度应力研究

根据混凝土箱形渡槽的温度边界特点，给出了箱形渡槽日照温差二次曲线分布形式；针对该日照温度梯度模式，按照温度自约束应力的平衡特点和等效线性化的原则，导出了混凝土箱形渡槽的温度应力的计算公式．对某渡槽的计算表明：日照作用下混凝土连续梁葙形渡槽沿槽身高度方向会产生较大的温差，在非线性温度梯度作用下中跨截面下缘和腹板区域将产生较大的拉应力，会降低截面抗裂性，应加强纵向预应力钢筋，提高其抗裂能力．

The Solar Radiation Temperature Field and Lengthways Thermal Stress Analysis of Concrete Box Aqueduct

According to the characteristic of concrete box aqueduct thermal boundary, the temperature conic distribution is given by solar radiation. Based on the balance characteristic of self-restrict stress and the principle of equivalent linearization,the calculation formula is derived about thermal stress of concrete box aqueduct. The calculation on the aqueduct shows that the difference in temperature will be brought along box aqueduct height direction by solar radiation, and the lower part of the middle span cross-section and abdomen board part will produce large tensile stress, which can reduce the performance of anti-cracking. Therefore,the ability of resisting crack can be improved by the application of the lengthways prestressed reinforcement.