Vertical Elements Research Articles

Regional features of the formation of sustainable tourist buildings of the Russian-Kazakhstan border

The purpose of this research is to study climatic and landscape characteristics of the Russian-Kazakh border region on the example of the Astrakhan region, affecting the formation of sustainable "green" buildings of ethno-cultural tourist clusters. In the course of the study, it was concluded that in order to reduce the influence of severe climatic factors of the region, to create comfortable environmental conditions and the microclimate of the premises, it is necessary to use landscaping of horizontal and vertical structural elements of the cluster building complex. The work carefully examined various types of vertical and horizontal landscaping (extensive and intensive). Based on the analysis of scientific research and expeditions to the region, the condition of existing green spaces in Astrakhan was carefully studied. Thus, as a result of the study, certain types of plants were identified and recommended for the technology of horizontal gardening of ethno-cultural tourist clusters in the Astrakhan region.

Connection Performance of Mass Plywood Panels

Abstract Tall wood buildings have become more prevalent in North America in the past 10 years. Tall wood-frame buildings implement both mass timber construction and products. Mass timber products are wood-based products that can withstand and hold large loads for long durations of time. Mass timber has allowed for large buildings, which consist mainly of wood, to be erected comprising multiple stories. One new mass timber product that has been fashioned is Mass Plywood Panels (MPP). MPP is a veneer-based engineered wood product, which is a massive, large-scale, structural composite lumber–based panel designed for use in building applications as both a vertical and horizontal element. For any new product to be used in the industry with confidence, a thorough investigation of its physical, mechanical, and connection properties is needed. A series of connection tests, such as fastener withdrawal resistance, dowel-bearing strength, lateral resistance, and a component test on a wall-to-floor system were conducted. The lateral resistance test indicated that the current European Yield Models can be used to calculate the yield loads and yield mode of the MPP by using the dowel-bearing strength of plywood. Three different connection configurations were tested in two distinct loading directions—shear and withdrawal. Their performances are evaluated and compared using two existing engineering models—namely, the American Society of Civil Engineers 41-13 tri-linear model and the seismic analysis of wood-frame structures 10-parameter connection model.

Perforated TWCF steel beam-columns: European design alternatives

Steel storage racks are lightweight structures, made of thin-walled cold-formed members, whose behaviour is remarkably influenced by local, distortional and overall buckling phenomena, frequently mutually combined. In addition, the need of an easy and rapid erection and reconfiguration of the skeleton frame usually entails the presence of regular perforations along the length of the vertical elements (uprights). Holes and slots strongly influence their behaviour, whose prediction is however of paramount importance to guarantee an efficient design and a safe use of racks. This paper focuses on the behaviour of isolated uprights subjected to both axial load and bending moments, differing for the cross-section geometry and for the regular perforation systems. According to the European standards for routine design, four alternatives to evaluate the bending moment–axial load resisting domains are shortly discussed and critically compared in terms of member load carrying capacity.

상업공간에서 실시간 시선추적에 나타난 성별 시지각 특성

This study analyzed eye information acquisition characteristics of males and females by investigating what to watch (selection), how often they watch (interest) and how long they watch (immersion) during eye observations (eye tracking) of males and females in commercial spaces. In the existing still picture (image) experiment, visual information of diverse experiment space domains was acquired, but when it comes to acquiring spatial information from videos, visual information was acquired focusing on shops with vertical elements (Ⅱ-1). Especially, female subjects only showed a strong frequency of gaze at R/L domain(stores). This means they are more likely to acquire information of products. Male subjects showed a strong frequency of gaze at relatively various space domains than female ones. This is because most of the experimental images displayed were female products and male subjects showed a relatively lower interest than female ones. This study got over the limitation of the existing studies and examined a space search process, which is approximate to reality. Furthermore, it is considered that this study can serve as basic data of commercial space design by suggesting merchandise display characteristics and spatial characteristics to draw consumers’ attention.

Monitoring system of high-rise buildings, determined from the nature of the curvature of the elastic line of vertical elements

Introduction. Issues arising from the automatic monitoring of high-rise buildings are considered. One of such issues is the necessity of minimizing the number of sensors when taking the operational patterns of such load-bearing systems. The method of sensor placement in high-rise buildings is described. Materials and methods. Different structural systems of high-rise buildings have common dependencies of longitudinal axis deformation on rigidity of vertical and horizontal load-bearing elements. Calculation of deformations from static wind load, comparison of data obtained by manual and computer calculation, and also comparison of static wind load with the wind load pulsation component are performed. Results. From the analysis of the extrema of the deformation function of the building vertical axis with the horizontal plane of the floor structure preserved, the main typical monitoring points necessary to minimize the number of sensors in high-rise buildings were determined. Based on the typical breaking points, the required number of sensors located 1/4 of the building height away from each other and the range of measured values of deformations that occur during operation were determined. Conclusions. For automatic (constant) monitoring of high-rise buildings, it is advisable to use a complex integrated method of measuring deformations of vertical load-bearing structures, frequencies and amplitudes of oscillations, and rotation angles. According to the general design theory of high-rise buildings and computer calculation models, the most efficient placement of engineering structure monitoring sensors is when they are evenly covering the perimeter of each floor and the entire height of the building. Measurements should be carried out following the outlines of the floor structures on stories located 1/4 of the building height away from each other, as well as on the stiffening core to control the integrity of floor structures and their connection to the stiffness core.

RACING CIRCUITS AND THEIR GEOMETRIC DESIGN CHARACTERISTICS

Existing race circuits were created using one of the two methods - intuition or engineering. Under the intuitive approach, the track was completely built by adapting to the terrain and environment in which it is located. The engineering approach to racing circuit development involves planning, designing, and building a car park at a specific location to accommodate all the users. Racing circuit design is based on recommendations depending on the type of race to be held. In Croatia, Croatian Car and Karting Federation issued the Circular Motor Racing Track Ordinance that defines the minimum requirements for organization and equipment of racing circuits. This paper presents a conceptual design of a racing circuit that is designed as per international requirements (FIA and FIM regulations) to host international sports events. This conceptual circuit is planned to be located in Osijek, which is the largest city in Eastern Croatia. It has a great location potential for becoming a motor sport center. The selected location has a possibility of venue extension for additional content, such as a test vehicle polygon, training center, and karting racing circuit. The conceptual design includes all the criteria, such as horizontal and vertical alignments, water drainage, pavement design, safety measures, and construction elements.

A SIMPLIFIED ANALYTICAL PROCEDURE FOR SEISMIC ANALYSIS OF TIMBER LIGHT-FRAME SHEAR WALLS

The seismic performance of timber light-frame shear walls is investigated in this paper with a focus on energy dissipation and ductility ensured by sheathing-to-framing connections. An original parametric finite element model has been developed in order to perform sensitivity analyses. The model considers the design variables affecting the racking load-carrying capacity of the wall. These variables include aspect ratio (height-to-width ratio), fastener spacing, number of vertical studs and framing elements cross-section size. A failure criterion has been defined based on the observation of both the global behaviour of the wall and local behaviour of fasteners in order to identify the ultimate displacement of the wall. The equivalent viscous damping has been numerically assessed by estimating the damping factor which is in use in the capacity spectrum method. Finally, an in-depth analysis of the results obtained from the sensitivity analyses led to the development of a simplified analytical procedure which is able to predict the capacity curve of a timber light-frame shear wall.

Rocking effect on seismic response of a multi-story traditional timber pagoda model

Characterized by discontinuous vertical elements and high aspect ratios, multi-story traditional timber pagodas in Southeast Asia have been of interest to many researchers. Combined with shake table tests on a one-fifth scaled seven-story traditional timber pagoda, this paper investigates the effect of rocking on the seismic behavior of multi-story traditional timber pagodas. Firstly, to describe the rocking behavior of timber columns, a modified empirical formula is proposed and verified by experiments. Secondly, considering discontinuous columns in multi-story traditional timber pagodas as rocking elements, mechanical properties of such columns under lateral loading are determined by use of the proposed formula. Thirdly, a simplified numerical model is developed in OpenSees, with which time history analyses are conducted to simulate the dynamic responses of the scaled timber pagoda subjected to earthquake excitations of various intensities (0.2 g, 0.44 g and 0.8 g). Finally, the numerical and shake-table experimental results are compared and discussed. It is found that the numerical simulation captures efficiently and with high accuracy most of the dynamic response characteristics along the structural height under each excitation intensity, including acceleration responses, displacement peaks and major natural frequencies. Major conclusion of this study is that the rocking-based numerical simulation can effectively predict the dynamic responses of the pagoda model under high intensity earthquakes. The proposed simulation method can be conveniently utilized to provide reasonable references for design or strengthening similar structures.

The operation analysis of the stanchion as an open column element

One-story buildings with steel frames are used in many cases for the output production for various purposes. The main vertical bearing element of such frames are the steel columns. With the presence of the technological lifting mechanisms in the building in the form of bridge supporting cranes in such columns, the crane part is designed lattice, and a special step (ledge, beam) is provided in the column design for supporting the crane girders. The columns are determined for a significant proportion of the metal consumed on the steel frame. Reducing the metal columns is an urgent task. Improving the efficiency of the design solutions is possible based on the study of the structures’ actual operation factors, in particular – the columns stability, and the accumulation of data to clarify the standard design methods for sustainability.

An Investigation of the Fundamental Period of Vibration for Moment Resisting Concrete Frames

The determination of fundamental period of vibration for structures is essential to earthquake design. The current codes provide empirical formulas to estimate the approximated fundamental period and these formulas are dependent on building material, height of structure or number of stories. Such a formulation is excessively conservative and unable to account for other parameters such as: length to width ratios, vertical element size and floors area. This study investigated the fundamental periods of mid-rise reinforced concrete moment resisting frames. A total of 13 moment resisting frames were analyzed by ETABS 15.2.2, for gross and cracked eigenvalue analysis and Extreme Loading for Structures Software® or ELS, for non-linear dynamic analysis. The estimated periods of vibration were compared with empirical equations, including current code equations. As expected, the results show that building periods estimated based on simple equations provided by earthquake design codes in Europe (EC8) and America (UBC97 and ASCE 7-10) are significantly smaller than the periods computed using nonlinear dynamic analysis. Based on the results obtained from the analyzed models, equations for calculating period of vibration are proposed. These proposed equations will allow design engineers to quickly and accurately estimate the fundamental period of moment resisting frames with taking different length to width ratios, vertical element size, floors area and building height into account. The interaction between reduction factor and the reduced period of vibration is studied, and it is found that values of maximum period of vibration can be used as an alternative method to calculate the inelastic base shear value without taking reduction factors in consideration.

All-Around Beam Switched Antenna With Dual Polarization for Drone Communications

This communication presents a drone-to-drone adaptive beam switched antenna with 360° beam coverage and dual polarizations. The proposed antenna maintains the all-around beam coverage with high directivity based on 16 concentric planar Yagi-Uda dipole array. The high gain dipole array beams are configured by eight vertical polarization elements and eight horizontal polarization elements with directors and reflectors. Depending on various communication environments, a single beam, multiple beams with identical polarization, or multiple beams with different polarizations can be adaptively controlled for highly reliable drone-to-drone communication. To ensure the compactness in the antenna array, 16 concentric planar antenna elements are arranged in an orthogonally crossed manner with optimized vertical and horizontal transition matching circuits. Each Yagi-Uda dipole element for vertical or horizontal polarization showed a measured peak gain of 6.35 and 6.40 dBi at 5.5 GHz, respectively. The proposed antenna was integrated with sub-6 GHz transceiver and microcontroller unit (MCU) to verify the switched beam performance with dual polarization. Also, the Tx and Rx operation at random beam conditions was tested by using two proposed antennas and showed an excellent performance from 5 to 6 GHz.

Students' landscaping preferences for open spaces for their campus environment

This study seeks to find appropriate landscape patterns of campus based on students’ preferences. A photo questionnaire containing scenes of different types of campus landscapes was distributed among 200 students in University of Tabriz, Iran. The results emphasized the importance of vegetation, seating areas and water features of campuses. Also, students prefer open spaces consisting of lawn and grass (M = 3.31, S.D. = 1.00). Students also prefer a campus, which has a natural base, landscape elements and seating places, while the least preferred (M = 2.96, S.D. = 0.89) scenes comprise a large amount of hardscape. Students had a different preference for landscaping of open study area and leisure time place where the studying area should be designed with vertical natural elements. Shading trees and benches were also highlighted as very important furniture for these places. In terms of spatial organization, the content analysis revealed that these areas should be open and spacious. Places for leisure time need to be decorated with informal landscape design for creating a pleasant view. Designing a landscape with various forms will make these places more pleasant. Scenes of curved paths and colourful plants for these places showed a positive association with student socialization activities.

Progressive collapse assessment of post-tensioned reinforced concrete flat slab structures using AEM

Progressive collapse is defined as the failure of a primary vertical element of a structure, which may result in the failure of adjoining elements, consequently, leads to a partial or total collapse of the structure. Unified Facilities Criteria (UFC) and General Services Administration (GSA) guidelines used to assess the behavior of structures subjected to progressive collapse as a result of the loss of primary vertical support. For the current case study, numerical analysis is carried out for a typical ten-story reinforced concrete post-tensioned flat slab structure subjected to primary vertical element loss (corner column, edge column, internal column, edge shear wall & internal shear wall). The structure is designed according to (ACI 318-14) and its progressive collapse is assessed according to UFC guidelines. Non-linear dynamic analysis for the structure is carried out using Extreme Loading for Structures (ELS) software. The Applied Element Method (AEM) is used to create a 3D model to assess the structure’s progressive collapse behavior as a result of primary support removal. Evolution of axial forces in columns, principal stress contour for slabs and tendon’s prestressing losses are the parameters used to investigate the post-tensioned flat slab progressive collapse as a result of support removal.

The role of geometry on stability of large domes: Roman Pantheon as cultural emblem and constructive reference

This paper focuses on large domes’ building techniques and use of geometric rules in the design and construction of religious structures. A quick excursus on the cultural heritage in Italy and abroad highlights how domes have been used almost exclusively in sacred architecture, rather than in civic buildings, for most of history. Born of the need to cover large spaces without facing with the encumbrance of vertical elements, the domed cover, ideal for places of worship crowded by hundreds of faithful, has assumed, over the centuries, a symbolic meaning to every religion. In fact, identifying the shape of a large dome in the urban landscape immediately means to recognize the sacredness of that place. The ancient Romans who believed in the gods, Christians, Hindus and Muslims, all used this very peculiar architectural element in churches or mosques to express a kind of spiritual symbolism and, as mentioned, the fact that the shape of the dome arises from a functional reason, it has over time got pushed aside. Furthermore, the circle is a geometric form that possesses a great symbolic force, generated by the idea that, having no beginning and no end, reflected perfection, the eternal, and also the heavens. In this perspective, drawing a circle both in the horizontal and vertical section, the ultimate paradigm for all monumental domes was the Roman Pantheon which, with its centrally placed "oculus" or “eye of heaven” proved to be a model for all other domes after it, retaining its position as the most ancient and well preserved dome in the world. Therefore, this article concentrates on the study of the Pantheon as an emblem and reference model for all monumental domes. By analyzing the “meaning” of its architectural design and its structural and geometric characteristics, the research dissects a comparison between similar large domes, similar to each other, such as that of St. Francesco di Paola in Naples and the Mosta Dome in Malta. The comprehension of these valuable architectural artifacts lies between the search for their original geometry and the identification of structural models through which their shape was defined, namely the geometric and proportional rules of the past.

A perceptual bias for man-made objects in humans.

Ambiguous images are widely recognized as a valuable tool for probing human perception. Perceptual biases that arise when people make judgements about ambiguous images reveal their expectations about the environment. While perceptual biases in early visual processing have been well established, their existence in higher-level vision has been explored only for faces, which may be processed differently from other objects. Here we developed a new, highly versatile method of creating ambiguous hybrid images comprising two component objects belonging to distinct categories. We used these hybrids to measure perceptual biases in object classification and found that images of man-made (manufactured) objects dominated those of naturally occurring (non-man-made) ones in hybrids. This dominance generalized to a broad range of object categories, persisted when the horizontal and vertical elements that dominate man-made objects were removed and increased with the real-world size of the manufactured object. Our findings show for the first time that people have perceptual biases to see man-made objects and suggest that extended exposure to manufactured environments in our urban-living participants has changed the way that they see the world.

Axial Compressive Behavior of Steel-Damping-Concrete Composite Wall

This paper presents a novel steel-damping-concrete (SDC) composite wall as a vertical element for high-rise buildings and nuclear power plants etc. In an SDC composite wall, a damping layer is sandwiched between the concrete core and steel plates to reduce structural response based on its damping characteristics under axial and seismic loads. To ensure that an SDC composite wall exhibits a comparable compressive resistance as a steel-concrete-steel (SCS) composite wall, two types of reinforcing approaches including steel sheets and sleeves are utilized to enhance the weakness of the damping layer on the concrete core. The compressive performance of the reinforced SDC composite wall is numerically and analytically investigated using finite element (FE) simulations by ABAQUS. The influences of several key parameters including the type of reinforcement, the thickness of the damping layer, steel plates, and concrete core, the binding bar spacing as well as the diameter of steel sheets on the compressive performance of the composite walls are investigated through numerical analyses. The results show that while only embedding the rubber interlayer in the composite wall leads to the decrease of compressive resistance of the composite wall, the steel sheets and sleeves can provide the confinement effect on concrete core efficiently and improve the compressive resistance and ductility of walls. Based on the available methods in the current design codes such as Eurocode 4, AISC-360, a theoretical model is developed to predict the ultimate compressive resistance of SDC walls. The predictions show a reasonable correlation when compared with the numerical results.

TRAY RESEARCH OF THE STRAIN STATE OF SOIL BASES REINFORCED BY SOIL-CEMENT ELEMENTS UNDER THE STRIP STAMP

Experimental research of weak bases reinforced by vertical soil-cement elements are discribed in this article. Tray research ofweak clay bases and bases with percent of reinforcement from 2,1% to 7,1% under strip stamp were conduct. As a result ofthe experiment settlements for each of soil base models were obtained. Characteristic curves of the influence of the reinforcement percentage on the bearing capacity, deformability are given, character of settlements of the investigated soil massin time at step-increasing loading are shown. It was found that depending on the percentage of reinforcement the critical pressures increased linearly and the values of settlement at critical pressures were determined increased with the base reinforcement percentage. Empirical dependencies were obtained to determine the critical pressures depending on the percentage ofreinforcement for the investigated soil conditions. In conclusion, the effectiveness of reinforcing the base of the strip foundations by vertical soil-cement elements was proved.

Miniaturised MIMO antenna array of two vertical monopoles embedded inside a planar decoupling network for the 2.4 GHz ISM band

This study introduces a fundamentally new approach to suppress mutual coupling among two closely-spaced vertical monopole elements of a multiple-input multiple-output antenna array. The 40 × 40 × 1.27 mm decoupling and matching element consists of a single planar ring resonator acting as a stop-band filter along with two tuning strips printed on an ungrounded substrate surrounding a two-element co-planar waveguide-fed monopoles separated by 8 mm ( λ 0 /16) at 2.45 GHz. Measurements reveal 14.2% bandwidth centred at 2.395 GHz over which the decoupling is below 20 dB, and -10-dB impedance bandwidth of 19.5% centred at 2.36 GHz. An improvement of 43 dB in isolation is observed at a frequency of 2.38 GHz. It is shown that the decoupled array provides a total realised gain of 1.69 dBi with excellent diversity performance as demonstrated by the low envelope correlation coefficient and improved link efficiency in highly-correlated channel environments due to the spatially orthogonal 3D radiation patterns. The capacity offered by the decoupled array is enhanced by 50, 22, 18 and 12% at signal-to-noise ratios of 5, 20, 30, and 50 dB, respectively, as compared to the coupled array in an urban micro-channel spatial model.

Collapse and damage to vernacular buildings induced by 2012 Emilia earthquakes

In May 2012, two seismic events hit the Emilia-Romagna Region, in Northern Italy. The earthquakes caused collapses and damage to traditional vernacular building heritage, highlighting its seismic high vulnerability. The paper presents a wide collection of damage and collapses observed in the aftermath field inspections on 22 historical vernacular buildings. It was noted that few recurring structural typologies are present in the area hit by earthquake and buildings of the same typology show similar damage mechanisms. Then, with the main goal to identify the most typical damage affecting similar structures, the building stock has been subdivided in different categories based on building plan distribution and intended use. The principal collapse causes, based both on in-field observations and analyses, performed on local and global finite element models, can be ascribed to poor connections between orthogonal walls, lack of effective connections between floor elements and walls, excessive flexibility of floor diaphragms and high slenderness of vertical elements. The outcomes in the present paper allow identifying the vernacular building typologies most vulnerable to earthquake and can help to plan the future retrofitting strategies for vernacular heritage.

Reinforcement methods for compression perpendicular to grain in top/bottom plates of light timber frames

Relatively low load-bearing capacity of top and bottom plates in light timber framed structures under compression perpendicular to grain and the consequential shortening of vertical elements have resulted in their limited applications in construction of mid-rise buildings. Solutions for the enhancement of the compression perpendicular to grain need to be further developed to tackle this problem. This paper investigates the contribution of excessive deflection of horizontal members to the vertical shortening of light timber frames due to compression perpendicular to the grain and evaluates the effectiveness of some different reinforcement techniques for improving the bearing strength of these members. A comprehensive experimental investigation of light timber framed members under compression perpendicular to the grain, provides information on different mechanical properties, different types of reinforcement methods and their effects on the load carrying capacity of a range of structural timber elements. For this purpose, 750 practical tests are carried out to evaluate the effectiveness of the solutions. The techniques include applying timber on timber and steel on timber connections, use of additional reinforcing materials and mechanical fasteners. The results indicate that the bearing capacity under compression perpendicular to grain can be considerably improved by applying some of these solutions; the level of improvement varies for each solution though.