Analysis of numerical model parameters for dry-mixed soil-cement composite with high content of organic matter

Numerical modelling of geotechnical issues requires basic subgrade parameters which need to be introduced into the program. The best way of collecting such information is to commission a series of tests. Defining the parameters of the material gained when admixtures are introduced into existing soil becomes problematic. Basic strength parameters can be found from trial batches of quasi-concrete composite, however they do not ensure the full spectrum of necessary data. Numerical programs often require more parameters from the user and these data are dependent on the strength hypothesis assumed. In this situation, one of possible solution is to run a inverse analysis. The paper provides exemplary procedure of iterative determination of cohesion, internal friction angle and Poisson’s ratio for a soil-cement sample obtained in dry mixing procedure. The original soil contained relatively high content of organic parts in dry mass. The analysis was made for hypothesis of Coulomb-Mohr and Drucker-Prager. The conclusions drawn from performed studies give some recommendations, but, due to possible soil heterogeneity, emphasise the need for further studies.