燃气埋地聚乙烯管道修补的应力研究

Study on the Stress in Repair of Buried Polyethylene Gas Pipes

为了有助于判断城镇燃气聚乙烯管道工作能力和使用年限,对埋地聚乙烯管道修复的应力分布进行了分析。考虑了管道温度变化、荷载和土壤-管道相互作用等因素,选择了4种修补方式来修复圆形和缝隙型缺陷的管道。基于有限元模拟分析表明,管道峰值应力随管道圆形缺陷范围的增加而增大,30℃时管道缺陷直径高于12.5mm时,峰值应力超出许用应力;不同形状的修补中,鞍形修补对管道和修补处应力的效果最佳;管道裂缝缺陷的形状对管道应力影响较大,当a/b比率低于0.3时,4种修复方式均无法达到修补效果。

In order to help judge the working capacity and service life of urban gas polyethylene pipelines,the stress distribution of buried polyethylene pipeline repair was analyzed.Considering the factors of pipeline temperature change,load and soil and pipeline interaction,four repair methods were selected to repair the circular and gap type defects.Based on the finite element simulation analysis,it is shown that the peak stress increases with the increase of the circular defect scale.When the diameter of pipe defect is higher than 12.5 mm at 30℃,the peak stress exceeds the allowable value.In repair of different shapes,the saddle repair has the best effect on the stress of pipeline and repaired part,and the shape of the crack has a great influence on the stress of the pipeline.When a/b ratio is lower than 0.3,all four repair methods can not achieve the repair effect.