Geostatic analysis of the Zeleni park construction pit in Koper considering small-strain soil stiffness

摘要

The subject of diploma thesis is a geostatic analysis for the protection of a deep construction pit for the facility Zeleni park in Koper. This demanding construction pit was dug in sea sediments. Demanding geotechnical conditions required the use of “top-down” method to protect the construction pit with progressive opening of a reinforced concrete diaphragm wall using basement facility plates. Suchudconstruction requires a geotechnical calculation of the construction pit considering excavation phases. The main goal of diploma paper is to evaluate the geotechnical research and to make geostatic analyses for construction pit protection observing different material models for soil in undrained, partially drained and drained conditions, followed by a comparison of results.udDiploma paper begins with information about the location and soil structure. Geotechnical researches are resumed and implementation technology in relation to construction pit protection is explained. In continuation, comparative calculations of construction pit protection with the diaphragm wall are presented using two material models for soil with isotropic hardening: the Hardening Soil Model (HS)udand the Hardening Soil Model with Small-Strain Stiffness (HSS) which also observes small-strain stiffness of the ground. A calculation of maximum axial forces in bracing plates is made for each model with maximum values of transverse forces, bending moments in diaphragm wall and diaphragm wall shifts. Diaphragm wall was dimensioned for all analyses. Results of geotechnical analyses confirmedudthe reasonable use of the HSS model which observes small-strain stiffness of the ground. Calculation shifts of protection construction and the background are more realistic when the ground is considered for small strain, with less force impact on the diaphragm wall and on bracing plates.