The effect of arching pressure on a vertical circular shaft

• This study focuses on the lateral earth pressure acting on a vertical circular shaft.
• The centrifuge model test and full-scale field test were performed.
• The comparison of theoretical calculation and field measurement was also carried out.
• This paper has clearly demonstrated the important arching effect of vertical circular shaft.

The lateral earth pressure of vertical circular shaft is investigated by using experimental tests and a theoretical analysis. The emphasis was quantifying on the magnitude and distribution of a lateral earth pressure measured by three-dimensional arching effect. A framework for determining the earth pressure distribution on the basis of both centrifuge model and full-scale field test results is introduced. Through these studies, it is found that the lateral earth pressure decreases within active displacement (δh/H: 0.2 × 10−2, δh: horizontal displacement, H: Height of vertical shaft) of wall at deep excavation and the arching effect is more significant for deep excavation than for shallow excavation. It is also found that the lateral earth pressure acting on a vertical circular shaft considering arching effect is 80% smaller than that calculated by Rankine theory, and thus represents a significant improvement in the prediction of realistic earth pressure for vertical circular shaft subjected to arching pressure.