Inventors:
Francis H. Sayles - Lebanon NH
William T. Black - Irvine CA
Earl P. Ellis - Eagle River AK
Assignee:
The United States of America as represented by the Secretary of the Army - Washington DC
International Classification:
F16L 5700
E03B 710
Abstract:
A system and method for relieving frost-heaving stresses in a pipeline for ransporting a product at a temperature less than 32. degree. F. where said pipeline passes through frost-susceptible ground in a trench beneath the ground surface. Bedding supports the pipeline in the trench with its top substantially below the surface of the ground. A pair of relatively thin, elongated soil separators are installed in the trench, one along each side of the pipeline in parallel relation to the longitudinal axis of the pipeline. Each separator has a transverse width extending vertically upward substantially beyond the top of the pipeline and into backfill soil above the pipeline. Padding supports a lower edge of the shear separators adjacent to the pipeline and the separators each have an upper edge located substantially beyond this padding and beyond the top of the pipeline. A mass of the backfill is between upper portions of the shear separators and the shear separators are positioned so as to separate this backfill mass from laterally adjacent soil in response to upward movement of the pipeline due to the formation of a body of ice beneath the pipeline.