A 5 inch (inside diameter) well is to be placed to a total depth of 60 m in an unconfined sand aquifer. The saturated unit weight (γsat) of the sand is 20.0 kN/m3 and the anticipated depth to water in the well during pumping is 20 m below ground surface. Would a #30 slot stainless steel screen (2.0 m long; located at the bottom of the well) have sufficient collapse strength for this application?
Notes:
- assume that the water level inside the well will be the same as the water level immediately outside the well
- to obtain a horizontal soil pressure, the vertical soil pressure (stress) at a given depth must be multiplied by a coefficient of earth pressure, Ko (recall basic soil mechanics ...). Assume this coefficient has a value of 0.50
- use a factor of safety of 1.5