in universities of cambridge(critical state soil mechanics) used for over consolidated (dilate and increase in volume when sheared) and normally consolidated or loose soil(decreae in volume when sheared) , and steady state theory(Harvard) used for soil liquefacton due to earthquake.This theory integrate both under one framework. Steady state theory included addtional criteria like constant velocity which is insignificant.
Unified soil theory
Unified soil theory: There have been two schools of research on shear strength of soils advanced independently 5 decades ago
Unified soil theory:soil liquefaction using critical state approach