Shear Strength Silumation Test Method Of Graded Broken Stone And Its Appliance

Graded broken stone was typical granular material and its physical and mechanicalproperties were complicated, so it was difficult to reveal the mechanical properties and thefailure mechanism essentially through theory of continuum mechanics and general laboratorytest methods. Hence, shear performance of graded broken stone simulation test wasconstructed by PFC2D, on the basis of its reliability validation, the influence ofmicro-mechanical parameter, test condition, maximum particle size and the differentgradation on shear performance simulation test.Shear performance of graded broken stone simulation test was constructed by PFC2D,on the basis of its reliability validation. Analysis of influence of test conditions on shearperformance numerical test, results show that, the standard test conditions of shearperformance numerical test of graded broken stone is proposed: On direct shear test, loadingrate for5mm/min, specimen size for b50cm×h30cm. On static three triaxial test, loadingrate for0.5%/min, specimen size for Φ30cm×h60cm. Analysis of the influence ofmicro-mechanical parameters on shear performence numerical test, a new and fastmicro-mechanical parameters calibration method is put forward. Analysis grading macadamshear performance numerical meso mechanism, results show that on direct shear test, As theshearing, inside the test piece can form obvious stress concentration region. On static threetriaxial test, large granular component to form a large contact force. Based on static threetriaxial test，Optimization gradation of the gradated crushed stone, strong skeleton-densitygradation was put forward.. Analysis of influence of maximum particle size on shearperformance, results show that with the increase of maximum particle size, shear valueincrease first, when the maximum particle size reach37.5mm, continue to increase themaximum particle size, shear value decrease. Analysis of influence of gradation on shearvalue, proved skeleton dense gradation have better shear performance than dense gradationand the skeleton void type gradation., which proves that the strong skeleton-density gradationhas better mechanical properties.