Soldier Pile Wall (Braced Sheeting)
When analyzing braced sheeting (pile curtain, steel I-section or user input of A, I, E, G) the following approach is adopted to determine the earth pressures:
Up to the depth of ditch the pressures are determined with respect to 1 rm of the structure width. Below the ditch bottom the earth pressures are multiplied by the coefficient of reduction k (the "Coefficient of pressure reduction below ditch bottom"). This coefficient can be input (in the frame "Geometry" as a parameter of the section of a structure) or automatically calculated.
If "Landfill of soil" above the ditch (frame "Excavation") is input, then the pressures within this section are computed with respect to the entire width of wall (k = 1).
The coefficient of pressure reduction below ditch bottom k can be approximately determined (for very conservative design) according to:
where: | a | - | longitudinal spacing of soldier beams, or spacing between piles |
d | - | width of soldier beam, or diameter of pile |
Real value of the coefficient k also depends on the soil type and space effect of earth pressure. Real values of this coefficient (based on experiments) are two to three-times higher than values calculated with the help of the previous formula.
Braced sheeting - schematic view of retaining structure