Abstract: Method and investigation device associated therewith, for measuring stresses in an agglomerate structure including a binder and a bonded substance, comprising the steps of providing, at one or more points on said structure, at least one investigation device able to measure at least three deformations of said investigation device that are oriented relative to one another on three axes, detecting the corresponding at least three deformation measurements, and calculating a stress that is proportional to a combination of said at least three deformation measurements at the corresponding point.