Sabitov L.S.

Candidate of Engineering Sciences (Ph.D.), Associate Professor, Kazan (Volga region) Federal University, Russia

TECHNOLOGICAL AND DESIGN FEATURES OF DESIGNING A MODULAR REINFORCED CONCRETE FOUNDATION FOR A HIGH-RISE BUILDING OF VARIOUS TYPES

https://doi.org/10.34031/2618-7183-2019-2-6-5-11
Abstract
The paper proposes a new type of modular collapsible reinforced concrete foundation for steel support for various types of structures: power lines, wind power plants, billboards, traffic lights, etc.The foundation has the shape of a cross-hammer in the plan and consists of separate modules manufactured at the factory and connected to each other by concrete dowels and tie bolts on the construction site. At the same time, this technological approach makes it possible to obtain more stable (uniform) strength and deformation properties of both the individual module and the assembled foundation as a whole. Reducing the material consumption is achieved by creating a cavity in each typical module and filling it with local inert material (soil). The central module has an anchor device for joining with the support according to the type of flange connection. This device, along with the use of conventional anchor bolts, involves filling the central module with non-shrinkable fast-hardening steel-fiber concrete. Thus, the positive result of the proposed solution is to increase the bearing capacity of the foundation as a whole, increase the strength and stiffness of its main joints, and simplify installation in comparison with traditional approaches to construction. A comparative calculation of the foundations of the proposed and standard known solutions showed the effectiveness of the first one by at least 17.2%.
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STRESS-STRAIN STATE OF THE SYSTEM “COMBINED TOWER-REINFORCED CONCRETE FOUNDATION-FOUNDATION SOIL” OF HIGH-RISE STRUCTURES

https://doi.org/10.34031/2618-7183-2019-2-6-29-37
Abstract
The aim of the work was to evaluate the effectiveness of the system "combined tower-reinforced concrete foundation-foundation soil" for high-rise structures on the example of a wind power plant (wind turbine) with a capacity of 1.5-2.0 MW using computer modeling in the PC "Ansys". Thus, under the combined tower the article refers to high-rise building, consisting of two parts: the lower composite, the upper – in the form of a thin-walled core-shell closed profile. In both cases, the shell is a pipe with a weak taper. As an analogue, the WPP considered in foreign literature is adopted: the radius of the rotor is R=41 m, the height to the axis of the wind wheel is zhub=80 m. The shell is made of high-strength C355 steel and, unlike the analog in this work, the cavity of the lower part of the tower to a height of 20 m was filled with B60 class concrete. The modeling took into account the spatial work of the elements of the structural system and the physical nonlinearity of the materials from which they are made. At the same time, the Mises strength theory was used for steel, the Williams – Varnake theory for concrete, and the Drukker – Prager theory for the foundation soil. Comparison of the calculation results with the analog showed that the destructive load of the tower increased by 37% due to filling the lower part of it with concrete, which indicates the effectiveness of the proposed solution. In this case, the destruction of the tower with a concrete core and without it occurred from the loss of local stability of the steel shell at the level of the junction of the tower with the foundation (with a compressed zone).
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