A modified one-dimensional testing apparatus that incorporates a bender–extender element system and tactile pressure sensors was developed for the monitoring of particle crushing. The apparatus was tested using five types of glass beads with different particle sizes. The compressional shear wave velocities and their ratio were evaluated with respect to the porosity to establish the microstructural evolution of the granular material. The results showed that the bender–extender element system functioned excellently under high-pressure one-dimensional compression, with the shear wave velocity ratio increasing with increasing loading stress up to 7 MPa and thereafter decreasing. The loading stress of 7 MPa was thus considered the breakage stress of the glass beads, as also reflected by a sharp increase in strain. The glass beads subsequently entered Stage 2 of the crushing process, characterized by significant crushing. Arching of the particle assembly was also clearly observed, and this was enhanced by an increase in the roughness of the side plates of the container. An empirical equation for evaluating the arching was derived. The microstructural evolution and macro behavior of the glass beads under the constrained boundary condition and high compression pressure were found to be analogous to those of the crushing of high-porosity sandstone.