A Methodology to Evaluate the Horizontal Earth Pressure Acting on Circular Shafts Based on Its Lateral Displacements

One of the most common solutions to access the underground is through the construction of circular shafts. At a preliminary design stage, analytical expressions are often used to estimate the horizontal earth pressure acting on the lining. However, most of these solutions are based on active state conditions and do not consider the restrictions imposed on the shaft lateral displacements by the rigidity of its lining or by the construction method employed. To overcome this limitation, a new methodology to account for the shaft lateral displacements in the determination of the horizontal earth pressure acting on circular shafts is developed and validated against the results of relevant physical scale models. The obtained results show good agreement with the measured data, adequately reproducing the reduction in the horizontal earth pressure from its initial value to an active state condition with an increase in the shaft lateral displacement. Following this approach, more realistic predictions of the earth pressure acting on the lining of circular shafts can be performed.