I have a site where I need to calculate settlement of a pad (17' x 12') on clay layer over a sand layer.
Clay extends to 15' with sand to 40' plus.
I am calculating settlement down to 24' which is 2B. I have used boussinesq stress distribution to calculate delta P.
I have consolidation data and calculated the settlement of the clay layer using Mv of 0.046 (calculated from consolidation testing). I have calculated settlement in the sand layer using the following formulae based on elastic theory - Layer thickness * Delta P / modulas of elasticity of sand for each layer.
Is the above approach reasonable. Any geotech book i find only details settlement of a clay layer or settlement of sand layer. Never a combination of the two.
I welcome your advice. Thank you very much