Numerous experimental studies indicate that particle breakage alters the grain size distribution curve of calcareous sand

thereby affecting its mechanical behaviors. Consequently

investigating the particle breakage characteristics of calcareous sand and establishing a corresponding breakage evolution model are of critical importance. First

a series of isotropic consolidation and triaxial compression tests were conducted under various loading paths

confining pressures

and axial strains to systematically explore the influence of these factors on particle breakage in calcareous sand. Next

the intrinsic relationships among particle breakage

mean effective stress

and stress ratio were analyzed to quantitatively assess their combined influence on particle breakage within a unified theoretical framework. Finally

a novel particle breakage evolution model was proposed by integrating the experimental findings with an analysis of the Hardin model’s strengths and limitations. The model includes the derivation of the breakage equipotential surface. The model comprises only three parameters

facilitating straightforward calibration and ensuring clear physical interpretations. Furthermore

the model's validity and robustness were rigorously validated through triaxial tests on calcareous sand and other crushable granular materials.