THE INVESTIGATION OF STIFFNESS OF HYBRID BISTEEL I-SECTION BEAMS

The stiffness analysis of the simple supported hybrid bisteel I-section beam subjected by uniformly distributed load is considered in this paper. The hybrid bisteel I-section beam presents a composition of high-strength steel inclusions for the flanges in the region of maximum stresses and of low-strength steel for remaining volume of the beam. The explicit analytical model for evaluation of stiffness of the beams mentioned is presented. The geometrical linear approach and elastic plastic material model have been assumed. The application of high-strength steel inclusion in case perfectly elastic state of the hybrid bisteel I-section beam, increase the deflection insignificantly (up to 10%). While strain hardening effect reduces the deflection by about 4 times compared to the perfect plasticity. The verification of the theoretical analysis has been performed by the FEM. After simple transformations, the proposed model can be easily applied to the evaluation of stiffness of otherwise loaded and supported hybrid bisteel I-section beams.

THE SIMPLIFIED ANALYSIS OF THE ASYMMETRIC SINGLE-PYLON SUSPENSION BRIDGE WITH RIGID CABLES

Suspension bridges are characterized by exceptional architectural expressions and excellent technical and economic properties. However, despite all advantages, suspension bridges have a few negative features. Suspension bridges with flexible cables share excessive deformation caused by the displacement of kinematic origin. In order to increase the stiffness of suspension bridges, an innovative structural solution refers to rigid cables used instead of the flexible ones. The paper describes a methodology for calculating an asymmetric single-pylon suspension bridge with rigid cables considering installation features. Also, the article presents the numerical simulation of the bridge and determines the accuracy of the proposed methodology.

SUSTAINABILITY ASSESSMENT OF THE RESIDENTIAL CONSTRUCTION PROJECTS IN LITHUANIA

Development of real estate has the potential to advance sustainability. This is particularly important in residential sector as it plays a crucial role in the lives of habitats and directly influences their welfare. As populations grow and cities expand, the demand for real estate increases and construction volumes rise. Assurance of sustainability in the residential projects becomes a new concern of real estate developers and construction companies. This article aims to analyse in more detail the concept of a sustainable residential construction and the evaluation criteria. In the first part the concept of sustainable development and its dimensions in residential construction are analysed. The second part describes the research methodology. In the third part, the research methodology is applied to the evaluation of five residential construction projects in Vilnius, Lithuania. The fourth part describes the possibilities of using wooden construction to improve the sustainability of residential construction projects.

THE ENGINEERING METHOD FOR UNIFYING GROUND FLOOR SLAB SETTLEMENTS

For industrial buildings and logistics centres truck lifts are usually used. Therefore, there are special requirements for flatness tolerance of ground floor. The ground floor settlements differences in selected distances are limited. The article reviews the behaviour of soils and the importance of the actual behaviour assessment of soils during the design of floor slab on elastic subgrade. Particular attention is given to the behaviour of floor slab areas above pile foundations that support the building’s columns. Calculation results show the impact of subgrade stiffness on the behaviour of the floor slab, especially in areas above pile foundations, where the stiffness of subgrade is much higher. The article presents a solution for achieving the required level of settlements’ differences in areas where pile foundations for the building’s columns under the ground slab are used. The paper proposes an efficient engineering method to reduce ground slab settlements differences. The results of performed calculations confirm the efficiency of presented method.

ANALYSIS OF BEHAVIOUR OF CALCIUM SILICATE HOLLOW BLOCKS MASONRY SUBJECTED TO THE CONCENTRATED LOAD

Loading of masonry with concentrated load is a sufficiently common case of loading which occurs due to structures of various purposes and sizes which lean against masonry wall, column or partition wall. Reinforced concrete or metal beams, reinforced beams, wooden structures of roof or span are leaned against masonry structures most usually. Investigations show that masonry structures under concentrated load withstand higher loads than structures of which the whole surface area is compressed. In most cases traditional bricks’ masonry under concentrated load was investigated. Its head joints are filled with mortar. This paper describes the experimental and numerical modeling results of investigation of calcium silicate hollow blocks masonry with thin layered mortar and unfilled head joints compressed by concentrated load. The more dangerous case when the edge of masonry unit (wall) is affected by concentrated load was chosen for analysis. Preliminary investigations have shown that the bed joints transmiss horizontal stresses. The stress distribution angle is close to 60°, i.e. close to stress distribution in masonry with filled head joints.

THE PROPERTIES OF GEOMETRICALLY MODELLING COMPUTATIONAL SCHEMES FOR BUILDING STRUCTURES

For launching a project on a structural object, the calculation of building structures stands as one of the most important stages of project development. In order to correctly analyse structural behaviour, determine the stress-strain state and solve design or inspection problems, the designer is forced to adequately formalize the actual structure turning it into a faultless computational scheme. Virtual testing is one of the main features of the single graphical-information model. Interoperable systems for three-dimensional modelling and analysis, calculation and design ensure smooth data transfer between the physical and computational model. Modern object-modelling techniques and integrated analysis systems allow achieving the defined goal. The article deals with the forms of data exchange, the developmental features of the designed and computational (analysis) BIM model, the integrated design process of CAD/CAE as well as the conversion problems of the physical and computational model.

BEHAVIOUR OF MINERAL WOOL SANDWICH PANELS UNDER BENDING LOAD AT ROOM AND ELEVATED TEMPERATURES

This paper presents a parametric study for the bending stiffness of mineral wool (MW) sandwich panels subjected to a bending load. The MW panels are commonly used as wall panels for industrial buildings. They provide excellent insulation in the case of fire. In this research, the performance of sandwich panels is investigated at both ambient and elevated temperatures. To reach that goal, a finite element (FE) model is developed to verify simulations with experimental results in normal conditions and fire case. The experimental investigation in the current paper is a part of STABFI project financed by Research Fund for Coal and Steel (RFCS). The numerical study is conducted using ABAQUS software. Employing simulations for analysis and design is an alternative to costly tests. However, in order to rely on numerical results, simulations must be verified with the experimental results. In this paper, after the verification of FE results, a parametric study is conducted to observe the effects of the panel thickness, length and width, as well as the facing thickness on the bending stiffness of MW sandwich panels at normal conditions. The results indicate that the panel thickness has the most significant effect on the bending stiffness of sandwich panels.

POSSIBILITIES OF NEUROSCIENCE APPLICATION IN HOUSING DEVELOPMENT

The identification of the best housing alternatives is influenced by a wide variety of factors, including supply, demand, social, cultural, psychological, personal factors. All of these factors have an effect on the behavior and emotional state of a home buyer. What are the most effective ways to choose a home when there is a plethora of complex choices? To determine the most effective choice, neuroscience techniques can be used. These techniques are classified in the following main groups in the article: 1) momentary techniques for measuring changes in electronic neuronal activity, 2) techniques for measuring changes in metabolic neuronal activity, 3) techniques for measuring changes in psychological response to a stimulus. Article’s analysis, its identification of advantages and disadvantages of the techniques, representing these groups: electroencephalography, functional magnetic resonance imaging, functional semi-infrared spectroscopy, eye capture, and galvanic skin reactions, has revealed the potential of using latter techniques in making marketing decisions, while working with target audiences of different ages, life experiences, character traits who want to live where they feel best.

ANALYSIS OF TURKISH RESIDENTIAL CONSTRUCTION MARKET DYNAMICS FOR THE PERIODS OF 2010–2015, 2015–2019, AND PROJECTIONS FOR THE FUTURE

The Turkish residential market supported by macro-economic developments is of great importance for the country's economy and the construction industry. The main purpose of this study is to analyze the Turkish residential construction market dynamics, especially in terms of price-cost and supply-demand regimes and conduct future projections. For this purpose, analysis of construction cost and residential price indexes, total and mortgaged residential sales, and construction and occupancy permits were evaluated utilizing institutional data. In addition, positive and negative effects of the changes in the residential prices in the macro scale were examined. After, conducting the residential price and cost change analysis for between 2010-2023, future stock volume and residential market projections were carried out. As a result of the analysis, we can divide the residential market into 3 periods: positive development period between 2010 and 2015, the recession period from 2015 to 2019, and the period after 2020. In the projection, depending on the supply contraction and the results of demand changes, price and cost increases, the current residential stock volume will reach its lowest level by 2023. Following this, the last period is expected to reach a more balanced residential market shaped by need-based purchases rather than individual investments.

ANALYSIS OF SECOND-ORDER EFFECTS EVALUATION OF STEEL FRAMES BEHAVIOUR

The evaluation of second-order effects of steel framed structures can provide different analysis results than using linear analysis methods. In various structural engineering literature were distinguished different methods of analysis: taking or without taking into account second-order effects. It depends on the sensitivity to the horizontal actions. The slenderer the structure, the more sensitive it is to horizontal actions. Using nonlinear methods, the sensitivity of steel frame to second-order impact is considered. This paper shows the importance of evaluations of the second-order effects in behaviour of steel frame structures. Performed investigations reveal the influence of the rotational stiffness of the joints to the behaviour of whole framed structure. Calculation results show that decreased flexibility of the semi-rigid joints increase sensitivity of the framed structure to the second-order effects and vice versa. The identified interdependence between the sensitivity to the second-order effects and the flexibility of the semi-rigid joints highlights the importance of evaluation of such dependencies.