Introduction State and local transportation agencies frequently use opengraded aggregates for wall, roadway, and bridge construction. The primary advantages of using this type of material in wall and abutment applications are ease of constructability, lighter in-place density than well-graded materials, very low fine content, free-draining characteristics, and simpler quality assurance testing,...

One of the most common methods to measure soil mechanical properties (namely cohesion and internal friction angle) is direct shear box test. In this paper the development of a three-dimensional (3D) discrete element soil model for simulation of a cohesive soil’s direct shear test is presented. The aim was to calibrate the properties of the Hertz-Mindlin with bonding contact model available in E...

There exist in Europe, Korea, and elsewhere ammunition magazines under the control of the United States Armed Forces that cannot be utilized to their full capacity because of encroachment of public facilities within the full capacity quantity distance arc. This has led to interest in barriers which could be placed in magazines to prevent the simultaneous detonation of all of the contents. The U...

In this paper, a newly developed 3-dimentional discrete element model (DEM) for gravel-rubber mixtures (GRMs), namely DEM4GRM, that is capable of accurately describing the macro-scale shear response (from small to large deformation) GRMs in direct box apparatus presented. Rigid gravel grains are modelled as simple multi-shape clumps, while soft rubber particles modeled by using deformable 35-ba...

equating test scores is an important issue in large scale testing. almost all standardized tests have several forms which vary in difficulty. new forms are written and added every year. when the items in different forms of a test vary in difficulty, direct comparison of test-takers who have taken different forms and are at the same ability level is not possible; hence, the issue of test fairnes...