Clay Material 1. Input for calculating axial resistance Initial shear modulus of soil \(F/L^2\) For normally consolidated clays, the initial shear modulus of the soil to be used for generation of t-z curves can be taken as: \[G_0=\frac{300}{I_p}\cdot s_u\] \(I_p\) denotes the plasticity index of the clay and is to be given as a unitless absolute number, not as a percentage. As an alternative, which is valid for both normally consolidated clays and overconsolidated clays, the following expression may be used which includes a dependency on the overconsolidation ratio: \[G_0=600\cdot s_u-170\cdot s_u\sqrt{OCR-1}\] Geotechnical model Sand Material