通过山区和丘陵地带的长输管道,纵向拐弯很多,弯头有朝上的也有朝下的,土壤性质各地段也不一样,故分析弯头的温度内力较为复杂。在摩擦很小,几乎可以略而不计的地段,当管道升温膨胀时,这一地段内的各直管的变形将互相发生牵制,每个弯头的温度内力不能单独算出,必须和其它弯头联解才能算出,这是一种类型。这种类型本文暂不考虑。 在土质较干,回填较密实的地段,摩擦并非很小,这种情况下当管道升温时,弯头两侧 Through the long-distance pipelines in the mountains and hilly areas, the vertical turning is quite a lot, the elbows are facing upwards and downwards, and the soil properties are also different in different locations. Therefore, analyzing the temperature internal force of the elbow is more complicated. In the friction is very small, almost negligible lot, when the pipe temperature expansion, the deformation of the straight pipe within this lot will occur mutual restraint, the internal temperature of each elbow can not be calculated separately, and must be the other elbow United solution can be calculated, this is a type. This type of paper is not considered. In the soil is dry, backfill more dense lot, the friction is not very small, in this case when the pipe heating, the elbows on both sides