... methodsof exploration, such as SPT, CPT, etc. to establishstratification of the subsurface materials, the profileof the top of bedrock and bedrock quality, depth togroundwater, limits of types of ... effective angle of internal friction of clays (°) (10.4.6.2.3)i= instantaneous friction angle of the rock mass (°) (10.4.6.4)1= effective stress angle of internal friction of the top layer of soil ... (DIM); number of soil layers within zone of stress influence of the footing (DIM)(10.4.6.2.4) (10.6.2.4.2)nh= rate of increase of soil modulus with depth (KSI/ft) (10.4.6.3)Pf= probability of failure...