I've been trying to eliminate anchor blocks ever since pipe stress programs requiring anchors to do their analysis have been in existance and became popular with some mideast pipeline operators. Before than, nobody used them very much. I'd recommend that you call yourself a "flexibility engineer", then learn how to develop flexible connections to pipelines and get out of the anchor block business. No future in pipeline anchor blocks as long as I'm around.
Once pipelines are buried, they don't move much as you've already discovered. We hardly ever use anchor blocks in the western hemispheres and in Europe. I'm cleaning up their use in the mideast. Saudi Aramco has finally admitted that since the 80's their anchor blocks have increased in size, even more than doubling in size for the same pipeline loads. That was reported in thier Technology mag, in 2011, I think it was.
Download US Army Corps Of Engineers publication TM 1110 and you'll find out that the American Lifelines and ASCE methods for calculating soil friction assuming it is the result of treating soil as a hydrostatic load based on the weight of soil x friction factor yields about about 1/2 of the real values. That method does not take into consideration the wedging effect of soil particles near the pipeline moving into the particles ahead of it as the pipe moves. That causes a wedging and constricting effect which increases the net friction factor as each ring of soil particles behind wedge into those ahead of them. That method is also popular in concrete pipe design manuals. Those guys have been burying pipe in the ground for over 200 years. I think they know what they're talking about, because I see the same thing every time I see a pipe exiting the gound... not much movement, if any at all. 5 mm to 10 mm maximum, then no further movement; complete lock-up, is typical of most installations.
Similar effects have been observed by recent full scale testing and research conducted at the U. BC in Canada. I made a presentation at the Abu Dhabi Pipeline Transmission Conference discussing the same subject in Sept 2012. We even have one operator here where their pipeline division prefers to usse anchor blocks, but their refinery division does not. Usually the opposite of what is seen in the US and Europe. We will bring up that illogical policy with them very soon.
Independent events are seldomly independent.
