不同温降下渡槽温度应力模拟及保温层厚度设计

以大型输水工程U型渡槽为例,利用有限元软件计算分析了渡槽在不同降温幅度下的温度应力。为考察玻化微珠保温层的保温性能,模拟计算了不同保温层厚度下三维渡槽的瞬态温度应力。根据数值模拟结果,对比分析了有无保温措施渡槽外表面温度主应力。分析结果表明:当降温幅度大于10℃时将在渡槽外表面产生不可忽略的温度拉应力。根据计算结果,综合考虑保温效果与经济性,实际工程中玻化微珠保温涂层的涂覆厚度以0.5~1 cm为宜,该厚度的保温层能有效控制渡槽混凝土外表面温度裂缝。

Numerical simulation of aqueducts thermal stress during different temperature drop rate and insulation layer thickness design

Aiming at a large aqueduct, we use finite element analysis to research the aqueduct thermal stress under different temperature drop rates in winter. In order to study the thermal insulation performance of the layer of vitrified micro bubbles, the transient principal thermal stress of the large aqueduct with different thickness insulation paint are simulated and calculated. Based on the result, we compare the surface thermal stress of the aqueduct with and without insulation layer. The results show that notable thermal stress will occur on the aqueduct surface when the temperature drop rate is larger than 10 degree. By considering the insulation effect and economy, the rational layer thickness should be in 0.5~1.0cm, which could effectively control the thermal crack of the aqueduct.