Abstract: Theoretical and experimental analyses are conducted for the pipe jacking force of the great depth pipeline in pipe roof pre-construction method. The pipe jacking force is closely related to the vertical soil pressure. Reference to the calculation method of vertical earth pressure in tunnel excavation, there are two kinds of frequently-used theories to calculate vertical earth pressure in pipe jacking, i.e. M. M. Promojiyfakonov theory and Terzaghi theory. After analyzing the adaptability and defects of the two kinds of theories, new modified theoretical formula based on M. M. Promojiyfakonov theory and Terzaghi theory is got to calculate vertical earth pressure; and MATLAB program is written to calculate the numerical solution of new modified theoretical formula. Both the soil arching effect and the holding force under the arching of soil are considered in modified theory, which is more consistent with the actual soil deformation. M. M. Promojiyfakonov theory, Terzaghi theory and modified theory are used to calculate jacking force of two pipelines at different depths in pipe roof pre-construction method of Xinle Ruins Station of Shenyang Metro; the calculated results are compared to the measured results. It is shown that the results of M. M. Promojiyfakonov theory and Terzaghi theory are much larger than the measured values; the results of modified theory are slightly larger than the measured results. So that the results of modified theory are more suitable for estimating pipe jacking force of great depth pipelines.

Key words: pipe roof pre-construction method, pipe jacking force, vertical earth pressure, M. M. Promojiyfakonov theory, Terzaghi theory, modified theory, measured jacking force