IMPROVEMENT OF STRUCTURAL-TECHNOLOGICAL SOLUTIONS AND METHODS OF ANALYSIS OF ROOFS OF UNDERGROUND STRUCTURES

In this article, methods of analysis of the improved designs of roofs of shallow underground structures are considered. Alternative methods to improve structural and technological solutions for covering underground structures arranged in an open manner are proposed. The developed design solutions are characterized by increased manufacturability due to reduction of labor costs owing to the use of low thermal conductivity concrete as a heat-insulating layer, which is monolithically connected during the manufacturing process with external layers of structural concrete because of the successive laying of these layers. To analyze the stress-strain state of roof’s structure and soil massif, a finite element method was used implemented in finite-element software packages. Subject: stress-strain state of structures of roofs of underground constructions built by an open method from different types of concrete with a monolithic bonding of layers. Research objectives: verification of finite element software packages used for analysis of the stress-strain state of soil massifs, as applied to multi-layer structures of roofs with a monolithic bonding of layers. Materials and methods: in our research, we used the methods of computer simulation of the stress-strain state of multi-layer bending structures of roofs from different types of concrete with a monolithic bonding of layers used in shallow underground structures. As for numerical software, the finite element software package ZSOIL was used. Results: in the article, we determine the rational areas of application of roof’s structures for shallow underground structures that are capable of sustaining vertical force loads and pressure from the ground massif. Structural and technological design solutions for roofs of underground structures, including the roofs of underground parking lots attached to the erected building, are characterized by low material consumption and increased manufacturability. Conclusions: for underground structures built in open excavation pits over which there are no aboveground floors, it is recommended to use multi-layer roof with a heat-insulating layer of concrete of low thermal conductivity as an alternative to traditional design solutions. Competitive structural and technological solutions of roofs and floors of shallow underground structures are obtained on the basis of computer simulation of stress-strain state using state-of-the-art finite element software.