Pipe-soil interaction during pipe jacking

The purpose of this paper is to introduce some simple theoretical models of pipe-soil interaction during pipe jacking, and relate these to observation s made in the field. Ground conditions, construction techniques and the deg ree of site control all influence the resistance to jacking of pipes, but i f an me resistance to jacking of pipes, but if an appropriate model is chos en it should be possible to predict jacking forces with a reasonable degree of accuracy. Deviations of the pipeline from a straight line increase the jacking resistance. A new analysis, based on observations from the field mo nitoring, provides an explanation for the measured increases in pipeline re sistance for pipes jacked through a stable bore; it highlights the importan t factors and emphasizes the need for careful control of pipeline alignment . Explanations are also sought for the apparently frictional behaviour in t erms of total stress at the pipe-soil interface in firm and stiff cohesive soils. Time effects are shown to be important in high plasticity clays.