Abstract: The vertical buried pipelines will be damaged by soil movements around pipe induced by tunnelling, but the relationship between soil movement and pipeline displacement has not been understood deeply. Three sets of model tests are established to simulate the effects of tunnel excavation on buried pipeline, in which different embodiments, caliber and bending rigidity are considered, the research is carried out about the displacement of soil and vertical pipelines during tunnelling. The results show that the modified Gaussian curves can describe accurately the Greenfield settlement trough due to tunnelling in sand, and the parameter ? varies between 0.2 and 1.0, which is proportional to the depth of soil in sand; The width coefficient of Greenfield soil has great influence on pipeline displacement, and the displacement of pipeline varies inversely to its bending rigidity for the same buried depth; The bigger the caliber is, the more obvious positive downdrag which dominates the behaviour of deep pipelines, however, negative downdrag greatly affect the displacement of pipelines for shallow case; Smax /i is one of the key influence factors for relative pipe-soil settlement, on this basis, a modified formula to calculate the relative pipe-soil rigidity is presented in this paper.

Key words: pipeline, tunnelling, model test, displacement