The effect of compaction on pipe-soil interaction

Abstract

The friction forces between the pipe and the surrounding soil are required in pipeline design. Presently there is insufficient information available regarding pipe-soil interaction. This information is needed to determine the horizontal forces acting on the pipe when the pipe is expanded under the action of temperature and pressure differences. Although there is available information on the static coefficient of friction for many materials, there is a lack of data on friction between soils and various coatings used in the pipeline industry. The effect of compaction is known very little on the pipe-soil interaction. In the past, coefficient of friction information was taken from the literature that was believed to have a similarity to the external pipe coating to soil interfare. With the development of tapes and plastic coatings and the increase use of these systems in the pipeline industry, a change from conventional coatings to tapes and plastic coatings would indicate a significiant change in the coefficient of friction design criteria. An experimental model was prepared in the laboratory in order to determine the coefficient of friction and horizontal forces acting on the pipelines. Influences of the degree of compaction, soil density, water content, the size of pipe diameter and the use of different types of coatings were investigated in this laboratory test system.