Particle Flow Code
PFC is a Distinct Element Method based software which uses spherical or disk elements to represent particles. The DEM method was introduced by Cundall (1971) and developed for granular material by Cundall and Strack (1979). In this method particles are assumed as rigid and Newton's second law controls the interactions between the particles. Particles can have contact with adjacent particles or walls and force-displacement law acts at contacts.

PFC is a command and code base software. Thus for each test or each model specific codes should be written. In order to simplify this condition ITASCA prepares FISHtank to support some common rock mechanics tests and makes an easier way to calibrate the micro properties that should be defined to get the appropriate macro properties. However these supporting codes are not comprehensive. Therefore in this part I would like to share some of my codes which I think could be useful for other researchers. I should mention that these codes are based on the FISHtank and I developed them for other tests or models.
Direct Shear and Uniaxial Compression tests on a Joint (2D/3D)
Introducing the Synthetic Rock Mass (SRM) approach in PFC has increased the power of this software to model the mechanical behavior of jointed rock masses. In this approach intact rock is modeled by the Bonded Particle Models (BPMs), and discontinuities are modeled by the Smooth-Joint Contact Model (SJCM). Therefore, block breakage as well as joint sliding can be considered. In SRM, discontinuities are generated by the Discrete Fracture Network (DFN) method. So far, limited efforts have been made on the calibration, and modeling of the SJCM. One reason can be the shortcoming of the FISHtank in proposing the direct shear test and the uniaxial compression test on a joint plane. In the following link you can find the developed FISHtank to model these tests in which more than 3,000 fish code lines are added or changed. This pack is named 'Joint' and in the following version you can find the direct shear test and the uniaxial compression test for two dimensional modeling. I also added a feature to model nonliner behavior of joint closure which is explained in detail in Mehranpour and Kulatilake (2017). The three dimensional modeling will be released soon and more feature will be added soon. Please do not forget to reference my papers if you are using these codes and let me know if you find any problem.

In the following version I have added two new methods of applying joint (Joint Side Checking and Joint Plane Checking) which are explained in the Mehranpour and Kulatilake (2017) paper. With these two methods interlocking problem is solved and better results is obtained. It should be mentioned that in the examples in this file joint has variable joint normal stiffness. If you like to run an example with constant joint normal stiffness please read the "Readme.pdf" file to use appropriate values for variations or you can use the previous version.

In this new version the three dimensional analysis is added. Thus you can make rectangular or cylindrical sample to model the direct shear test and the uniaxial compression test on a joint plane. In this file, examples have variable joint normal stiffness and Joint Side Checking (JSC) approach is used to apply a joint. To use different methods for applying a joint or to have constant joint normal stiffness please read the "Readme.pdf" file or you can use previous versions in the top.
Polyaxial and Biaxial compression tests
The uniaxial, triaxial, biaxial, and polyaxial (true-triaxial) compression tests are 4 common compression tests on rock mechanics. In the FISHtank the first 2 tests are provided and in order to do the last 2 tests some modifications should be applied on the FISHtank codes. In the following link you can download the modified FISHtank. You can just copy and replace the files ct.fis and ctParams.p3dat from this folder to your FISHtank folder or use the whole directory. You can find the ReadMe.pdf file containing the complimentary information in the folder. If you use these files please do not forget to cite Mehranpour and Kulatilake (2016).