Justification of vaulted structures of the Kyiv underground station as design in terms of shallow foundation

Abstract

Purpose. Analysis of the effectiveness and competitiveness of single-span vaulted structures for shallow-depth underground stations. The following objectives were set to achieve the aim: 1. Technical and economic comparison of the proposed designs for shallow-depth underground stations. 2. Calculation of the load-bearing capacity of the structure. The methods. The following methods were employed to address the stated objectives: Calculation of volumes and costs of major construction works for station construction using different designs (at a depth of 0.75 meters). Determination of normal forces and bending moments at the joints of the structure. Findings. During the research, the stress state of the vault blocks was determined by solving a system of 11 linear equations, taking into account vertical and horizontal loads, as well as stress at the rock interface at the joint level. A technical and economic analysis was also conducted using aggregated indicators, indicating the competitive advantages of the proposed designs among single-span structures for shallow-depth underground stations. The originality. Correlations found lies in substantiating the effectiveness of the designs and implementing various configurations of single-span vaulted stations for shallow-depth metro construction. Practical implementation. Based on the technical and economic analysis of the options presented in Tables 2 and 3, it can be observed that compared to the first variant, the third variant incurs reduced costs of monolithic concrete. Additionally, there is no need to deviate from the planned track route during the construction of support tunnels and, consequently, manipulate the rings of the structure. Furthermore, the structural features of the third variant allow for the passage of a larger-sized mechanized tunneling complex compared to the first and second variants. The obtained results from the calculations, in combination with the conducted technical and economic comparison and justification of the proposed designs, indicate that the proposed single-span vaulted station designs with an island platform type fully satisfy the engineering and geological conditions, possess sufficient load-bearing capacity, and are competitive among single-span structures for shallow-depth underground stations.