The influence of partial pile cutting on the pile-anchor supporting system of deep foundation pit in loess area.

Pile cutting behavior has been frequently applied in complex underground space development projects; however, few studies have paid attention to the influence of cutting partial pile on the load transfer trend of supporting structure. In this study, considering a deep foundation pit in Xi'an as an example, a three-dimensional numerical model was established to analyze the redistribution of soil pressure in the foundation pit and the variation of the stress of supporting structure under the condition of partial pile cutting, and the qualitative verification was made by using the field measured data. The results show that the earth pressure redistribution behind the pile is caused by the cutting pile, and the redistribution range and trend of the earth pressure are different at different depths. After the supporting pile is cut, the stress modes of the upper and lower parts of the broken pile are different and the axial force of the anchor decreases. Moreover, the anchor and supporting pile in the adjacent cut pile area exhibit an obvious loading effect, and the bending moment and shear force of the crown beam increase significantly. Notably, the greater the excavation depth, the lower the ability of the foundation pit supporting structures to resist damage. The research results may provide a theoretical basis and practical experience for the construction of similar projects in the future. [ABSTRACT FROM AUTHOR]