Design of horizontal supported permanent retaining structures in accordance with the excavation support structures code

Approximately twenty years after the international reulations on deep excavations, the Excavation Support Structures Regulation (KDYY) came into forceby considering the soil profile, machinery-equipment and technical personnel in Türkiye. In the first part of this thesis, a deep excavation project, which was designed and implemented before the regulation was published, was re-analysed in accordance with the KDYY in order to compare the KDYY with other similar codes. When the results of the re-analysis of the existing design in accordance with the KDYY were evaluated, it was seen that the designed system exceeded the allowable limits in both the Serviceability Limit State (SLS) and the Collapse Limit State (ULS) analyses and the system safety was not ensured in the evaluation based on the new regulation, although no unexpected displacement etc. situations were encountered in the project. In the first part of the thesis, which consists of two parts, the results obtained after the re-analysis of an existing project show that the KDYY gives conservative results and leads to more costly designs compared to the designs made according to international regulations. In the second part of the thesis, the displacement-safety-cost evaluation of cantilever and horizontally supported permanent supporting systems with heights of 5, 6 and 7 m in coarse-grained soil profiles was carried out. For cantilever systems, eighteen models were designed for six different socket lengths of bored piles with three different diameters for each height and a total of fifty-four different cantilever systems were analyzed. In the systems where ground anchors were used as horizontal support, twelve different models with three different diameters of bored piles, two different socket lengths, two different anchor horizontal spacing were designed for each depth, and a total of thirty-six horizontally supported systems were analyzed. For the 6 and 7 meters high excavations, the lowest cost system was found to be the ground anchored system, while for the 5 meter high excavations, the cantilever bored pile support system was found to be suitable.