you dont really even need to fill the pipe with flowable fill. Concrete brick and nonshrink grout bulkhead/plug would do it. How large is the line? i assum this is a gravity sewer line? The hardest part is getting in/stoping flow. If you are trying to kill a line comming out of a manhole...
as far as the grouting question goes, if you are using restrained joint pipe it would not be neccessary to grout the anulis. If you do make sure the pipe is tied down so it does not float. if you pump to much grout to fast you may float the pipe. 4000' is alot of twin 60's to thread into a...
