3排管冻结梯形-抛物弓叠合等效温度场模型和平均温度

由于3排管冻结温度场的复杂性，不便于对冻土帷幕温度场进行简便描述。故以现有的3排管冻结温度场的势函数叠加法解析解为理论基础，根据温度场的周期性，选择主面与界面之间的合适位置作为等效截面，以等效截面的温度场等效整体温度场。以平均温度为检验标准，简化等效截面的温度场曲线，得出方便应用的梯形抛物弓叠合等效温度场模型。基于等效温度场模型确定平均温度计算方法，得出免于积分运算的平均温度简便计算公式。该公式计算精度满足工程要求，表明等效温度场及其平均温度计算方法具有良好的实用性。

A trapezoidal-parabolic arch superimposed equivalent temperature field model and its average temperature formula for triple-row-pipe freezing

The temperature field of triple-row-pipe freezing is difficult and inconvenient to be described simply due to its complexity.Based on the existing analytical solution of triple-row-pipe frozen temperature field，according to the periodicity of the temperature field，an appropriate position between the main section and the intersection was chosen to be the equivalent section，so that the true temperature field could be replaced by the temperature field of the equivalent section.Using the average temperature as equivalence criteria，a trapezoidal-parabolic arch superimposed equivalent temperature field model was proposed by simplifying the temperature field curve of the equivalent section.In addition，asimplified average temperature formula，which was noneintegral operation，was deduced from the equivalent temperature field model.The calculation results show that the equivalent temperature field and its average temperature formula are accurate enough.