Rigid Shaft Structure
Shaft supported using secant pile walls is a typical example of the shaft with rigid construction. In the first construction stage the own shaft construction is built and therefore the soil is excavated. The load on the shaft due to earth pressure is equal to the at rest earth pressure because the rigid construction has minimal deformations. This construction behavior is well described by Y. M. and Y. Y. Hu theory (2005).
Load on rigid shaft is defined using this formula:
depth of cross-section
magnitude of a surcharge
shear strength of soil
radius of shaft
angle of internal friction of soil
ratio of the depth of cut h to the radius of the shaft r0
Cheng, Y. M.; Hu, Y. Y.: Active earth pressure on circular shaft lining obtained by simplified slip line solution with general tangential stress coefficient. Chinese Journal of Geotechnical Engineering, 27 (1), 110-115, 2005.