Numerical Simulation of Pile Group Behavior by Proposed Optimum Mix Design of Plastic Concrete

Plastic concrete is a type of concrete that usually has high ductility and low permeability and it can be used in the construction of tangential piles in the excavations that have a high groundwater level. In many cases, the project conditions for using plastic concrete with proper mixing plan are not considered. The aim of this research is to present the optimal mixing plan in terms of mechanical and economic characteristics for plastic concrete piles. For this purpose, five different mix designs were considered for plastic concrete and the properties were evaluated. Finally, the group of tangential piles, including structural and plastic concrete piles with strut, was simulated in the vicinity of the deep excavation and the deformation and flow rate passing through the excavation wall were investigated. In two-dimensional simulation, it is not possible to consider the characteristics of the plastic concrete pile in the modeling plane and check the deformation of the pit wall between struts. For this reason, the simulation was done three-dimensionally. Results showed that if the groundwater level is kept constant, water infiltration into the project area is very low due to the very low permeability of plastic concrete piles and the subsidence and deformation created at the top of the piles as well as the swelling of the excavation bed is less than when the groundwater level is lowered. Also by increasing the permeability of plastic concrete piles and soil, the flow rate through the excavation wall increases.