【摘要】 阐述了箱形渡槽横向温度应力产生的原因,根据箱形渡槽的温度边界特点,给出了箱形渡槽骤然降温的温差分布形式,并将箱身横向温度应力分成板厚范围内非线性温差自约束应力和箱身横向框架约束应力两部分,按照温度自约束应力的平衡特点和等效线性化的原则,导出了横向自约束应力和非线性温差分布修正系数的计算公式。对深圳水库渡槽的计算表明:骤然降温作用下混凝土箱形渡槽槽身外表面将产生可观的横向温度应力,会导致槽身混凝土出现纵向裂缝,应通过施加横向预应力,提高其抗裂能力。更多还原

【Abstract】 The causation of transverse thermal stress of concrete box aqueduct is expatiated, and then the distribution of the difference in temperature caused by the sudden drop in temperature of box aqueduct is given according to the characteristics of temperature boundary concerned. Moreover, the transverse thermal stress is divided into two parts, i.e. nonlinear self-restrictive stress of temperature difference within the wall thickness of aqueduct and restrictive thermal stress of the transverse frame. Base on the balance characteristics of the self-restrictive stress and the principle of equivalent linearization, the calculation formula for the correction factor for the transverse self-restrictive stress and the nonlinear temperature distribution is educed. The calculation on the aqueduct of Shenzhen Reservoir shows that the significant transverse thermal temperature will be created on the outside surface of the aqueduct body under the sudden drop in temperature, which will lead to creation of longitudinal cracking on the concrete of the body. Therefore, the anti-cracking performance of the concrete can be improved through the application of the transverse pre-stress therein.更多还原