Establishment and verification of the limit state design of the thin wall pipeline considering environmental and earthquake resistance

在设计中，根据弯环刚度Ei/D^3进行结构分析，计算出管道的挠度和应力。具有相同弯环刚度的管道在设计中具有相同的性能。然而，不难理解的是，管道的性能不仅受Ei/D^3的影响，而且还受E与I的关系的影响。本研究通过埋地软管的坑洞试验、30g下的离心机试验和800伽输入波的大型振动台试验，评价了管道厚度对静力和动力性能的影响。结果表明，管壁越薄，管子的弯曲应变和径向应力越大。这一结果表明，较薄的管道发生屈曲的概率较高。显然，灌溉管道的设计应考虑到这一事实。

In designing, deflection and stress of the pipe are calculated through structural analysis based on bending ring stiffness EI/D^3. The pipes with equivalent bending ring stiffness would have the same behavior in design. However, it is easily understandable that the behavior of pipe may be influenced not only by EI/D^3, but also by the relationships between E and I. In this research, pit tests, centrifuge tests under 30G and large shaking table tests with 800gal input wave for buried flexible pipes were conducted to evaluate the effects of pipe thickness on the static and dynamic behavior. As a result, it was found that the larger bending strain and radial stress of the pipe occurred with the thinner wall. This result suggests that the probability of the buckling of the pipe is higher on thinner pipes. It is evident that the pipelines for irrigation should be designed in consideration of this fact.