From which laboratory of field test can we reliably derive Poisson's ratio values?
Salahudeen A. Bunyamin
During triaxial compression, you can estimate Poisson's ratio by measuring lateral expansion of the specimen (while measuring vertical compression of course). You can also measure Poisson's ratio from pressuremeter measurements or dilatometer measurements in the field, as well as by measuring both p-wave and s-wave velocity.
it is diffical to get reliable poisnes ratio from field but you can get in laboratory in triaxial test