Design optimization for asymmetrical gravity retaining walls

The structures that keep the soil at two different levels are called retaning walls. The retaning walls are under the effect of the lateral earth pressures. Internal and external stability checks are carried out for the purpose that the retaning walls can perform its functions safely. The design optimization of asymmetric gravity retaining walls was examined in this study by using a program written in MATLAB programming language and with the interior point method . For this purpose, an optimization problem of continuous functions is developed. The objective function is defined as the cross-sectional area of the wall in order to minimize the cost. The constraint functions derived from external stability and internal stability verifications. The verifications external stability are listed as the overturning, the sliding, the total vertical forces within the middle third of the base, the bearing capacity. The verifications internal stability are listed as the bendings in the stem and the shears in the stem. The heights of the walls are selected as 2.0, 3.0, and 4.0 m in order to investigate the outline of the optimum cross-section and the effect of the wall height on the outline. In addition, in order to investigate the effect of the change in the internal friction angle on the optimum cross-sectional area, the internal friction angle was chosen as 15, 25 and 35 degrees and used in the calculations. The physical and mechanical properties of the soil are kept constant in order to compare only the effect of the height of walls and internal friction angle of soil on the geometry. The minimum dimensions suggested for the gravity retaining walls are not taken into account. As a result, it has been found that the optimum cross-sectional area changes linearly depending on the height of the wall and the main parameter affecting the cross-section geometry of concrete gravity walls is the internal friction angle.