河流穿越管道的抗弯刚度及弯曲应力

Bending Rigidity and Flexuosity Stress of Pipeline for Underwater Cross-ing.

河流穿越管道和海底管道一般采用组合结构,以保证其安全运行。前者常采用组装式混凝土加重块或套管,后者常采用混凝土连续覆盖层,与管道一起构成复合结构。然而在设计阶段,对于这种组合结构的强度设计,由于其复杂性和出于技术、经济方面的考虑,工程上大多不考虑混凝土(水泥)与管道的相互作用。为此,将穿越管道结构看成由不同材料构成的组合梁,并认为混凝土(水泥)与钢管之间没有相对运动,也不计防腐绝缘层的影响,分别导出了穿越管道的抗弯刚度和弯曲应力的计算公式。该公式除可用于水下穿越管道强度的计算之外,还可直接用于穿越管道的弹性敷设弯曲半径计算,以及共振悬空长度确定等的设计计算。另外,公式对研究穿越管道的纵向稳定性也有实际意义。

River crossing pipelines and subsea pipelines usually involve composed structure in order to ensure safe operation. The former is often protected with packaged concrete weights or casing pipes, while the latter with continuous concrete coating, altogether forming composite structure. For the strength calculation with such structure in the design stage, however, the interaction between concrete (cement) and pipeline generally have not been taken into account due to the complexity and technical-economic factor. For this reason, taking the structure of crossing pipeline as a composed beam consisting of different materials , supposing no interaction exists between concrete and steel pipes, and ignoring the influence of insulation coating, the equations calculating the bending rigidity and flexousity stress have been derived. Besides the strength of underwater crossing pipeline, these equations can also be directly used to calculate the curvity radius of elastic laying for crossing pipeline, as well as the resonant suspension length. Also,the equations can be used to study the longitudinal stability of the crossing pipelines.