Examination of console retaining walls according to 2018 TBER

Within the scope of the thesis, first of all, general information about retaining structures is given, and calculation methods in static and dynamic situations are explained. Lateral earth pressures acting on the wall in static condition Rankine and Coulomb pressure theories and Mononobe-Okabe and Seed-Whitman methods, which are dynamic earth pressures acting in dynamic condition, are included in the thesis. Within the scope of the study, in which the news of the collapse of retaining walls in a static condition, which has recently come to the fore in various regions of Turkey, is investigated, the estimated causes of collapse were investigated by examining these walls from photographs. In the photographs, it was observed that the walls collapsed after a rain. It is estimated that the retaining walls collapsed as a result of the use of granular and impermeable fillings that do not have good drainage. The points to be considered in the construction of retaining walls are explained on the faults seen in the collapsed walls. In order to reveal the differences between the new earthquake code and the changing dynamic calculation method, a manual solution was made and the results were compared with the old earthquake code. Studies on cantilever retaining walls in the literature are included in the thesis. The interface presentation of the two software used in the study was supported by visuals. The walls were modeled in two different retaining wall modeling programs and the results were examined comparatively. With the Turkish-made istCAD software, wall height (H) 6.50 m, foundation burial depth (Df) 1.50 m, ground slope (α) 15°, back-ground surcharge load (q) 10 kPa and groundwater level modeling were made. The results were compared with the old and new regulation results solved manually. In the IstCAD program, the effects of groundwater level, wall height, infill material, position of the wall body and ground slope on the cross-sectional effects of the reinforced concrete cantilever retaining wall were investigated in static and dynamic conditions. The dimensions of the retaining structure have been updated and the variation of the cross-section effects in cases where the stability has deteriorated due to the effects of the parameters has been examined. Static and dynamic analysis of the main model (H: 6.50 m, Df: 1.50 m, α: 15°, q: 10 kPa, U.W.L: none) was done with Plaxis 2D, another geotechnical software. In Plaxis, a total of 64 combinations were created for the main model, and the variation of the deformation and cross-section effects on the wall was investigated. The effects of frost level (basic burial depth), surcharge load, groundwater level and ground surface slope on these combinations were investigated. The approximate total cost of the walls has been calculated with the unit prices of the Ministry of Environment, Urbanization and Climate dated 07/2022, by taking the quantity data of 5 reinforced concrete cantilever retaining structures from 4.50 meters to 8.50 meters from the istCAD program. It has been observed that the cost increases as the wall dimensions increase. According to the data obtained, it was revealed by the comparisons that the dynamic account values increased with the new arrangement. It is thought that this increase is due to the fact that the ground effects are included in the calculation with the new earthquake code and the SDS (short period design acceleration spectral coefficient) is taken into account. As a result of the wall analyzes made with istCAD, it has been found that the destructive effect of the groundwater level, that the wall can collapse when an impermeable filling is used, and that the slope of the ground imposes excessive loads on the wall. It has been observed that the cross-sectional effects on the wall body increase more than twice as the lateral pressures acting on the wall increase when used in clay filling material with low shear strength angle, which is an undrained material. The main model was modeled in the Plaxis 2D program and by increasing the ground slope from 0° to 15°, the overall deformation, horizontal deformation rate decreased significantly, while the section effects increased significantly. It was observed that the deformation data decreased in all cases as the foundation depth increased in Plaxis. It has been observed that the surcharge load can collapse the retaining wall in cases where the foundation depth is insufficient. Since the heel of the retaining wall is modeled as 1 meter, the models collapsed in all cases where the groundwater level was at the height of the wall. With Plaxis 2D printing pseudostatic analysis, 0.25g, -0.25g, 0.40g and -0.40g accelerations were applied to the main model and at 0.40g acceleration, the model collapsed due to settlements.