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There is a general rule of laying precast concrete pipes: the precast concrete pipes should be laid from downstream end to upstream end. Moreover, precast concrete pipes should preferably be laid with spigot end pointing downstream direction when fitted into sockets.
The reason of laying pipes from downstream to upstream is that any rainfall occurs during construction can be drained off the site without flooding the pipe trench. Moreover, gravity and other forces applied to the pipes during installation of pipe joints help tighten the joint and eliminate any remaining joint gap. On the other hand, for pipe laying with spigot point downstream direction, this prevents the joints from opening up arising from pipeline movement. The concrete pipe joints are also protected from the entry of foreign materials.
This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.