Investigation of the effect of holes interaction on the concrete structure under high stress using PFC2D

The presence of openings in concrete structure has destructive effect on the lifetime. In this paper, the interaction between two openings has been investigated using particle flow code. For this purpose, after calibration of model, one small opening has been situated in various distances and various angularities from big pore opening. The radius of smaller opening is 0.2 of radios of big opening.  This complex is situated in a concrete slab with uniaxial strength of 7 MPa. This slab is under principal stress of 2MPa and 6 MPa. The results show that spacing and angularity of small opening has important effect on the stress distribution and failure pattern around the big opening. The critical position for small opening is when it situated at 0.0 degree. Also the spacing between two openings is less, the failure volume is more.