How to repair water main after break
PVC pipe is actually welded together by the glue. The two mating surfaces softened by the glue actually intermingle and fuse. When the glue cures the pipe and fitting become a single PVC piece.   Temperature, among other factors, effect the time it takes for the bond to reach full strength. If I remember correctly the glue directions state (paraphrase): "let the joint cure undisturbed for 12(?) hours. Reaches full strength in 24 hours".   I've found the joints hold best when using a PVC primer with the glue. Also use a "full bodied-type" glue also labeled as a "hot" glue. It preforms better when the pipe is leaking water and in cooler climates.  As far as your joint being under stress due to a wrong trench angle shave the trench wall to allow the pipe and fitting to un-bend. This isn't as important as ensuring that the mating pieces are clean, that a full coating of glue is applied to the entire mating surfaces of both parts and that the pieces are pushed together fully and then held tightly for several seconds.