نوع مقاله: پژوهشی
نویسندگان
1 دانشیار دانشکده مهندسی عمران، دانشگاه شهید بهشتی
2 دانشکده عمران، دانشگاه علم و فرهنگ، تهران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Abstract: Rockfill dams which are made by dumping and compacting rockfill materials are known as one of the most economical as well as safe dams. The main mechanical characteristics of rockfill depend on particle breakage. Particle breakage occurs when the stress levels are enough high or when the size of the particles are enough high as the rockfill particles. Particle breakage causes a change in grain size distribution of the media and causes a change in mechanical properties of the granular media. Particle breakage is widely studied experimentally by classical laboratory tests which need the large and expensive equipment that are rarely available. Although numerical methods which are based on the continuum mechanics, such as finite element method have been developed to be able to account for discontinuities, nevertheless, the internal discrete structure of the rockfill cannot be considered and physically modeled in this way. In addition the fact that these methods are not capable to simulate particle breakage to predict the mechanical properties of the rockfill materials. Discrete Element Method (DEM) can overcome these problems. In this research, discrete tri-dimensional modeling of rockfill behavior considering the particle breakage, using DEM is studied. Particle breakage is modeled by a bonded particle model and to consider a particle breakage, a mechanical threshold criterion combined with a contact density of particles and a probabilistic criterion is used. PFC3D code and programming in FISH language was performed by investigating the resistance and deformation behavior. In addition, the effects of particle breakage during the tests were considered by providing a failure criterion. The model is compared with the experimental tests on Purulia rockfill dam materials and the obtained results show a good concordance with the obtained experimental results.Finally, the model and the presented failure criteria, whilst it has simple computational procedure and high accuracy, were validated.
کلیدواژهها [English]
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