Looking for information/procedures/references for installing municipal sanitary sewer mains and facilities across deep muskeg/peat. (other than excavation to sound subgrade materials)
I think you have at least two design "issues", 1: designing and building a suitable foundation, and 2: the problem of having the pipe float upward under the hydrostatic pressure if it is below groundwater level. one refernce is "Buried Pipe Design", Moser A. P., McGraw Hill, 1990.
Youy may want to consider use of flexible, lightweight, plastic pipe (such as Spirolite) in this application. The use of lightweight bedding materials (such as Solite gravel) is also suggested to reduce the net stress increase felt by the peats. Geosynthetics may also be of benefit in limiting differential settlements.