Network from the circles of the same radius for sustainable energy-efficient roof structures

In this research paper, we investigated one of the methods of formation of geometric networks of arches of the same radius using regular spherical polyhedra. The variants of cutting sustainable energy-efficient coatings of buildings in the form of spherical domes are proposed. The task conditions of placing the specified network on the sphere are set. The criterion for evaluating the effectiveness of solving the problem is the minimum number of standard sizes of segments of the dome arches, the possibility of using pre-assembly technologies. The solution of one variant of the problem as placing the network on a spherical icosahedron and, accordingly, on a sphere is given. The placement of arches of one radius on the sphere, different from the location in the form of meridians, has an effective solution in the form of a network with minimal dimensions of arch segments and with nodes of paired arches comprised on the basis of circles of the same radii formed on the ground of regular spherical polyhedra. The problem is solved by constructing and combining in a system of regular spherical polyhedral with independent frameworks of arches of the same radius on the basis of paired circles of equal radius

DYNAMIC EFFECTS IN THE BEAM ON AN ELASTIC FOUNDATION CAUSED BY THE SUDDEN TRANSFORMATION OF SUPPORTING CONDITIONS

A mathematical model of a dynamic process in a loaded beam on an elastic Winkler base with the sudden formation of a defect in the form of a change in the boundary conditions is constructed. The solution of the static problem of bending of the beam fixed at the ends serves as the initial condition for the process of forced vibrations hinged supported at the ends of the beam, which arose after a sudden break in the bonds that prevented the rotation of the end sections. Dynamic increments of stresses in the beam for various combinations of beam and foundation parameters are determined. determined

Lakhta Center: Automated Structural and Geotechnical Health Monitoring

"Lakhta Center" became a large scale public and office project in Primorskiy district of Saint-Petersburg, Russia. The Complex is comprised of supertall Tower, Multifunctional Building and the Arch with long span structures integrated with stylobate part. A number of innovation technologies and design solutions have been applied during the construction of the project. According to the Building Codes and Regulations, to improve structural safety during the construction and maintenance periods, permanent structural health monitoring (SHM) program has been developed. The main objective of SHM is to minimize structural failure risks due to uncertainties in soil and structural materials behavior. General information about design and organizational arrangements for deploying automated structural and geotechnical health monitoring system of the "Lakhta Tower" is provided in the following paper. SHM architecture and topology, applied instrumentation, measurement methodology, software and monitoring parameters of the structure are described. The article presents the results of the Tower structural behavior monitoring during the construction period. The correlation between the measured and the predicted Tower structure performance was analyzed and found in good agreement. A few anomalies were identified and investigated. The focus is made to the informational value of the monitoring data for the increasing of soil, foundation and structure FE-modelling quality for construction accompaniment purposes

STATIC BEARING CAPACITY OF STEEL-PLATE COMPOSITE WALLS

The features of the behavior of steel-plate composite walls for static loads are considered. Based on the analysis of modern technical and regulatory documentation, the rationale for the chosen research topic is given. A review of the literature is performed, and the features of development are noted. A detailed description and features of the experimental structures under study and the materials used are presented. The features of the test are considered, and the test equipment is described. Analytical and numerical calculations of structures for eccentric compression have been performed. The description of the calculation complex and the used models of materials is presented; the description of numerical models, the features of their construction and calculation are given, the results of calculations are presented – stress distributions, deformations, features of cracking. The general types of experimental eccentric compression wall models are presented, the nature of the loss of bearing capacity of experimental structures is described, and a picture of destruction is presented. The analysis of the experimental data obtained and their comparison with analytical and numerical calculations are performed

LONG-PERIOD SEISMIC IMPACTS AND IT AFFECTING ON THE STRENGTH OF HIGH-RISE BUILDINGS CONSTRUCTIONS

Currently, in all building codes, the diagrams of dynamics coefficient are limited to a maximum natural oscillation period of 1.8 s. However, this range is clearly not enough for the calculation of constructions of high-rise structures with characteristic basic periods of about 4-5 s and more. This article analyzes the available seis-mological data presented in the Center for Engineering Strong Motion Data (CESMD) database. The spectra of Tolioku earthquakes (Tohoku earthquake. Japan. March 11. 2011) and Emberley (New Zealand Earthquake. New Zealand. November 13, 2016) were studied, and dynamic factors for periods of natural oscillations of structures 4-5 s are calculated. The results of the study allow to establish reasonable values of dynamic coefficients in the field of high periods

Building reguliarities: compulsive or optional? The project of the list of reguliariries, application of which on compulsory basis ensures fullfillment of the requirements of technical regulations: ”On the security of buildings and structures”

A complex of problems is not solved in technical regulation of construction. This includes the list of regulatory documents of compulsory application is not revised yet. The issue of developing high-quality regulative documents for the construction field is of great importance, because their fulfillment guarantees the safety of the population. The project of this list consists of 76 documents; that’s 15 less, than in the existing list. The reasons for reducing the number of documents are doubtful. In the list project there are no standards for building materials. All the documents concerning the rules of work execution are also out of this list, though the documents affecting the building safety should be included it the compulsory list. It is offered not to make a list of documents. It is enough to enumerate all the reference documents in project documentation, which is subject to inspection by the building supervision agencies as compulsory. There will be no need for the additional list of documents for optional application

To the problem 6 of emplacement of triangular geometric net on the sphere

Thesphere creates the minimal surface of enclosing structures and has unique resource saving qualities which makes it indispensable in the construction of “smart buildings». One of the methods of formation of triangular networks in the sphere was investigated. Conditions of the problem of locating a triangular network in the area were established. The evaluation criterion of solution effectiveness of the problem is the minimum number of type-sizes of dome panels, the possibility of pre-assembly and pre-stressing. The solution of the problem of the triangular network emplacement in a compatible spherical triangle on the sphere variant was provided. The problem of the emplacement of regular and irregular hexagons on the sphere, inscribed in a circles, i.e., flat figures or composed ones of spherical triangles with minimum dimensions of the ribs, has an effective solution in the form of a network, formed on the basis of minimum radii circles, i.e., circles on a sphere obtained by the touch of three adjacent circles whose centers are at the shortest distance from each other. The optimization of triangular geometric network on a sphere on the criterion of minimum sizes of elements can be solved by emplacementin the system the irregular hexagons inscribed in circles of minimal sizes, the maximum of regular hexagons

The problem 4 of placement triangular geometric line field

One of the a method of formation of triangular networks in the field is investigated. Conditions the problem of locating a triangular network in the area are delivered. The criterion for assessing the effectiveness of the solution of the problem is the minimum number of sizes of the dome elements, the possibility of pre-assembly and pre-stressing. The solution of the problem of one embodiment of a triangular network of accommodation in a compatible spherical triangle and, accordingly, on the sphere. Optimization of triangular geometric network on a sphere on the criterion of minimum sizes of elements can be solved by placing the system in an irregular hexagon inscribed in a circle of minimal size, maximum regular hexagons

The problem 7 forming triangular geometric line field

Investigated a method of formation of triangular networks in the field. Delivered conditions the problem of locating a triangular network in the area. The criterion for assessing the effectiveness of the solution of the problem is the minimum number of sizes of the dome elements, the possibility of pre-assembly and pre-stressing. The solution of the problem of one embodiment of a triangular network of accommodation in a compatible spherical triangle and, accordingly, on the sphere. Optimization of triangular geometric network on a sphere on the criterion of minimum sizes of elements can be solved by placing the system in an irregular hexagon inscribed in a circle of minimal size, maximum regular hexagons

To the problem 6 of emplacement of triangular geometric net on the sphere

Thesphere creates the minimal surface of enclosing structures and has unique resource saving qualities which makes it indispensable in the construction of “smart buildings». One of the methods of formation of triangular networks in the sphere was investigated. Conditions of the problem of locating a triangular network in the area were established. The evaluation criterion of solution effectiveness of the problem is the minimum number of type-sizes of dome panels, the possibility of pre-assembly and pre-stressing. The solution of the problem of the triangular network emplacement in a compatible spherical triangle on the sphere variant was provided. The problem of the emplacement of regular and irregular hexagons on the sphere, inscribed in a circles, i.e., flat figures or composed ones of spherical triangles with minimum dimensions of the ribs, has an effective solution in the form of a network, formed on the basis of minimum radii circles, i.e., circles on a sphere obtained by the touch of three adjacent circles whose centers are at the shortest distance from each other. The optimization of triangular geometric network on a sphere on the criterion of minimum sizes of elements can be solved by emplacementin the system the irregular hexagons inscribed in circles of minimal sizes, the maximum of regular hexagons