Abstract: According to a lot of field tests and numerical efforts, the spatial deformation mode of the top beam and pile is deduced for the cantilever soldier pile retaining structure in rectangular excavation; and the expression of the potential energy is derived for the total supporting system. Based on the principle of minimum potential energy, a new analytic solution to determine the maximum displacement of the pile head is derived; and the effects of the retaining structural parameters on the maximum displacement are discussed. Results show that the maximum displacement of the pile head increases with the increase of the surcharge and the spacing of the pile linearly. When the excavation length increases to a critical length, the maximum displacement will be a constant. In addition, the coefficient of the embedded depth of the pile has an dramatic effect on the maximum displacement. Finally, the result obtained from the proposed approach is compared with field tests and elastic resistance method.

Key words: deep foundation pit, cantilever soldier pile retaining structure, principle of minimum potential energy, spatial deformation analysis, maximum displacement of pile head