Good day. I am Looking for some references on SPT and CPT modeling, which can help studying or verifying the effect of some geotechnical parameters of sands on these tests results.
I can't point out a specific paper, but you could search for studies where machine learning techniques have been used (regression trees, k-nearest neighbors, lasso, etc.). The scikit-learn Python (open source) library provides a wide range of ML techniques and an amazingly useful website to start with ML.
I am also wondering for some reasons about PFC software, it is good to represent discrete elements, but is it good to represent the particles shape ( sphericity-elongation, roundness-angularity, and surface roughness-smoothness)?