One of the most important issues in geotechnical studies is bearing capacity. It is also defined as the resistance when the maximum pressure is exerted from the footing to the foundation without creating shear failure therein. Since earing capacity is highly correlated with the stability of surface and subsurface structures, researchers have become interested in this subject. The area and geometry impacts on the footing are considered as the two important issues in this regard. In this research, a numerical model based on Particle flow code was used in PFC3D software. To do experiments in numerical models, two triple-facet footings were utilized in square, rectangular and circular geometric shapes. Furthermore, these footings held a total area of 64 cm2 and other series included a full area of 49 cm2. In the modeling, the mechanical properties of granite were put into practice and the results of the numerical tests were scrutinized, as well. As a result, it was ascertained that the bearing capacity depends on both the footing geometry and the footing area.

Recently researchers and engineers have been in favour of optimized and efficient designs of all different types of structures, by directing their attention to non-destructive testing and most importantly computer simulations. Thus avoiding time consuming testing, and understanding the true behavior of materials within structures under different loading setups. One of the newly used computer aided analysis methods employed today is the discrete element method (DEM) embedded in PFC computer software. The main purpose of the DEM modeling conducted for this study was to supplement previous research conducted into the area of hot mix asphalt and rock fracture evaluation. The models created for this study demonstrated that PFC software is a powerful analysis tool that can be adapted to a variety of scientific and engineering applications, and has proved to be a very useful tool for modeling several HMA laboratory tests, and with proper modification it can also be adapted to modeling many other materials.

The domestic plasma modeling framework AZERAP is introduced and its capabilities in simulating the plasma based accelerators and intense beam-plasma interaction are discussed. The current first beta-release of AZERAP exploits the fully kinetic, electromagnetic relativistic PIC algorithm as its numerical engine. It is implemented in the object oriented language C++ and utilizes the Message Passing Interface (MPI) for parallelization. The main idea behind the development of AZERAP has been establishing a software platform for virtual plasma laboratory for plasma based Particle beam sources and high power electromagnetic generators. Achieving this goal has implied attaining high functionality in introducing the input problem, supporting abstraction of the field and plasma structures/modules, and supporting high flexibility for future developments. The present first beta-release of AZERAP paws the way toward these objectives. Moreover, it offers a very comfortable user experience with code compile, debugging, execution, data accusation and data animation, simulating plasma based accelerators.

In this work, the interaction between the semi-circular space and the neighboring joint with and without the presence of rock bolts was investigated using the Particle flow code (PFC) approach. For this purpose, firstly, the calibration of PFC was performed using both the Brazilian experimental test and the uniaxial compression test. Secondly, a numerical model with the dimension of 100 mm * 100 mm was prepared. A semi-circular space with a radius of 25 mm was situated below the model. A joint with a length of 40 mm was situated above the space. The joint opening was 2 mm. The joint angles related to the horizontal direction were 0° , 15° , 30° , 45° , 60° , and 75° . Totally, 6 different configurations of the semi-circular space and neighboring joint were prepared. These models were tested with and without the presence of vertical rock bolts by the biaxial test. The rock bolt length was 50 mm. The value of the lateral force was fixed at 2 MPa. An axial force was applied to the model till the final failure occurred. The results obtained showed that the presence of rock bolts changed the failure pattern of the numerical model. In the absence of rock bolts, two tensile wing cracks initiated from the joint tip and propagated diagonally till coalescence from the model boundary. Also several shear bands were initiated in the left and right sides of the tunnel. In the presence of rock bolts, several shear bands were initiated in the left and right sides of the tunnel. The compressive strength with the presence of rock bolts was more than that without the presence of rock bolts. The failure stress had a minimum value when the joint angle was 45° .

In this paper, the effect of the ratio of tensile strength to confining pressure on the penetration of U Shape disc has been investigated using Discrete Element Method. For this purpose, three numerical models with different tensile strength of 5 MPa, 15 MPa and 25 MPa were built. From each model two similar samples were prepared and compressed by two different confining pressures of 5 MPa and 25 MPa, respectively. The U shape cutter penetrates in the model by the rate of 0.02 m/s till 4 mm of disc is penetrated. In total, 6 simulations have been done. The rock materials, below the cutters, show three different mechanical behavior including failure, plastic and elastic behavior. The failure zone is fully fractured while the plastic zone is consisted of partially micro crack with several major fractures. The elastic zone has remained undamaged. The effect of the ratio of tensile strength to confining pressure has substantial effect on the extension of three introduced zones. When tensile strength is 5 MPa, the initiation force and failure stress is increased by increasing the tensile strength but the extension of failure zone and chipping thickness is decreased. When tensile strength is 25 MPa, the initiation force, failure stress, extension of failure zone and thickness of chipping is constant by increasing the tensile strength.