نوع مقاله : پژوهشی
نویسندگان
1 دانشکده ی مهندسی عمران، دانشگاه علم و فرهنگ، تهران
2 دانشکدهی مهندسی عمران، آب و محیط زیست، دانشگاه شهید بهشتی
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Rockfill dams that are made by dumping and compacting rockfill materials are
known as one of the most economical and safe dams. The main mechanical
characteristics of rockfill depend on particle breakage. Particle breakage
occurs when the stress levels are high enough or when the size of the particles
is high enough as the rockfill particles. Particle breakage causes a change in
grain size distribution of the media and causes a change in the mechanical
properties of the granular media. Particle breakage is widely studied experimentally by classical laboratory tests, which need large and expensive
equipment that is rarely available. Although numerical methods that 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 is 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 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
were 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 good
concordance with the obtained experimental results. Finally, the model and the
presented failure criteria, whilst it has a simple computational procedure and
high accuracy, were validated.
کلیدواژهها [English]
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