Optimization of bearing capacity and unsymmetrical settlement of vertical pile group using genetic algorithm

Document Type : Original Article


1 Assistant Professor, Department of Civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran

2 MSc of Geotechnical Engineering, Department of Civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran


Capacity of pile group is the summation of the individual piles capacity with influence of spacing between the piles. Pile groups usually have the same length, so if the spacing between piles is too close, the zones of stress around the pile will overlap and the ultimate load of the group is less than the sum of the individual pile capacities especially in the case of friction piles, where the efficiency of pile group is much less. In this research the optimization of bearing capacity and unsymmetrical settlement of cap in the vertical pile group using genetic algorithm were studied. Friction pile in granular soil, with different length and arrangement were investigated to find the best performance of the group for the axial stiffness, bearing capacity and unsymmetrical settlement. The criterion of optimization is the volume of concrete needs for piles and cap. Two patterns of 5×5 pile groups (row variation and squared variation) are studied in this research. The analysis of pile group to find bearing capacity was conducted using the finite element software (Fb-pier) and for optimization used evolutionary genetic algorithm method.


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