The paper investigates the possibility of applying the genetic algorithm NSGA-II to optimize a reinforced concrete retaining wall embedded in saturated silty sand. Multi-objective constrained optimization was performed to minimize the cost, while maximizing the overdesign factors (ODF) against sliding, overturning, and soil bearing resistance. For a given change in ground elevation of 5.0 m, the width of the foundation and the embedment depth were optimized. Comparing the algorithm's performance in the cases of two-objective and three objective optimizations showed that the number of objectives significantly affects its convergence rate. It was also found that the verification of the wall against the sliding yields a lower ODF value than verifications against overturning and soil bearing capacity. Because of that, it is possible to exclude them from the definition of optimization problem. The application of the NSGA-II algorithm has been demonstrated to be an effective tool for determining the set of optimal retaining wall designs.

The paper presents the design of deep excavation support system in an urban environment. Excavation is carried out in the vicinity of surrounding buildings whose structural stability must be ensured during the execution of the construction works. The 60 cm thick diaphragm wall supported by the two rows (17.00 m and 18.25) of geotechnical anchors was selected as an excavation support system. The approximate floor plan dimensions of the diaphragm wall are 81x118 m, and the maximum excavation depth is 10.5 m. An additional challenge in designing the diaphragm wall is the presence of groundwater, whose maximum level is observed at a depth of approximately 5.8 m. In order to ensure the execution of construction works in dry conditions, a system of drainage trenches and wells is designed at the bottom of the pit. The diaphragm wall is designed in accordance with Eurocode 7.