Numerical And Experimental Studies For Strength Of Refuse Dump Granular Media

The security refuse dump attracts more and more attention with the tunnel excavation and minemining. Refuse dump is a giant artificial deposit comprised of surface soil and rock, whichwill trigger geological disasters such as landslides and debris flows. Reasonableaggregates strength parameters should be selected in order to study the dump slopestability. The on-site investigation of grain size and sieve analysis, laboratory test,numerical simulation is used to study the coarse aggregates strength properties. Theinfluence of some mesoscopic parameters on coarse aggregate strength are analyzed fromthe view of microscopic scale, some systematic rule is obtained. This offer a new way forresearching dump aggregates mechanics properties. The main contents are as follows:1. Particle size distribution of dump slope is obtained by field measurement; grainsize distribution curve is obtained from sieve analysis.2. Stress and strain curve of coarse aggregate is obtained throughconsolidated-drained triaxial test, strength envelope is drawn by Mohr’s circle of stress,and Duncan-Chang model parameters are calculated from test results.3. The numerical model of triaxial test for coarse aggregate is conducted byprogramming embedded fish language and redevelopment PFC^3D. The particle shape isconsidered by introducing clump particles comprised of two or three particles. Model isloaded to destroy by the servo control function. The numerical results are agreed withexperimental results.4. The stress and strain mesoscopic mechanism is studied in the view of microscopicscale. The influence of the mesoscopic parameters such as particle size and theircombination way, particle shape, contact friction, bond strength and contact stiffness ratioon coarse aggregate strength properties are studied quantificationally.