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Introduction: Artificial islands for new construction and works in a dry environment are created in water areas by installing enclosures, which allow buildings to remain rigid and stable and withstand the influence of climatic factors. Purpose of the study: We aim to develop a method for the construction of low-rise buildings in the coastland and water areas with the least labor effort required to erect buildings and ensure their safe operation. Methods: In the course of the research, we have performed theoretical studies in the field of experimental construction and analyzed the results of Russian and foreign scientific research related to the construction of buildings in water areas. Results: We have examined methods for the construction of waterproof enclosures in water areas that make it possible to erect buildings in a dry environment in open water areas with unstable wave conditions. Such methods reduce labor efforts, decrease the term of construction, and improve performance indicators.

The article considers some options of integration of small wind power plants (hereinafter SWPP) into the architectural design of low-rise residential buildings using the effect of strengthening wind flows («draught»). The influence of the architectural form on the creation of this effect emerging near the SWPP location is investigated, the SWPP being regarded as an architectural element of the building. The classification of SWPPs is presented applying the principles of allocation and operation in the most suitable places in the structure of low-rise residential buildings. The «draught» effect emerging in various forms of low-rise buildings is analyzed graphically and on the basis of a software research method envisaging a testing in the form of experimental design. As a hypothesis and goal setting, the authors propose a new architectural morphogenesis of low-rise residential buildings using small wind power plants.

Earthquakes are natural disasters causing havoc to life and property since several centuries. Indian subcontinent has a history of devastating earthquakes in its recent past. One way to tackle an earthquake is to equip the building with a proper seismic resistant system. One of the most popular and effective technique for low and midrise buildings is base isolation. However, existing base isolation systems are very expensive for non-commercial buildings. Hence, this study mainly concentrates on fibre reinforced elastomeric isolators which are cost efficient without a marginal compromise in its performance. A comparison between the performance of unbonded and bonded fibre reinforced elastomeric isolators has been carried out. The unbonded fibre reinforced elastomeric isolators have better performance in terms of stresses, horizontal flexibility, and damping. A low rise reinforced concrete residential building’s response is studied with and without fibre reinforced elastomeric isolators. The results show significant reduction in storey drift, story shear, storey level acceleration in both equivalent static method and time history analysis, along with increase in the time period of building’s fundamental mode.

The article deals with the key issues related to overcoming the complex of social, environmental and economic problems in urban planning, connected, firstly, with providing citizens of Ukraine with comfortable and economically affordable housing, and secondly, creation of life-sustaining living environment, environmentally safe, conserving natural resources. Foreign experience has shown the possibility of using low-rise energy-efficient housing to create a comfortable environment for people. The interaction of the system of principles of the organization of ecological low-rise residential development is the theoretical basis of the integrity of the organization of suburbanized settlement. This is aimed at the development of low-rise life-sustaining housing development in Ukraine's airspace. The problem is to conduct research on the creation of an environmentally safe, comfortable living environment in urban settlements and housing entities, taking into account the specificity of the location, the use of new engineering technologies of life support for use in design practice. Requires architectural and planning organization of low-rise residential development based on the consideration of environmental laws and in accordance with the interests of man. Three basic principles must be put first: 1) conservation of natural resources and the environment; 2) human factor - the quality of life support of the living environment for increasing the birth rate and life expectancy of the population; 3) the natural value of the territory. The purpose of this work is to develop systemic principles for the organization of low-rise residential development in the space of Ukraine's settlement, to create conditions for human life, improve the quality and environmental safety of the living environment. This is necessary for the stable social structure of society and the preservation of the surrounding nature.

Considering the cubic nature of the most frequent geometries among the urban elements and their configurations, the manipulation of the free stream wind flow around the enormous objects, as well as within relatively narrow corridors, such as street canyons is significant in many regards. One of its instances could be mentioned as pedestrian comfort. In this case study, the implementation of an Oblique Streamlining Membrane (OSM) has been studied on a sub-branch of a low rise, but bulky, building, over which a roof-top outdoor food court area has been primarily designed. The OSM serves as the streamlining mechanism, preventing the roof-top area from the intense fluctuations of the wind flow after the flow is separated from the inlet corner side of the building in question. The optimization of sub-geometries and the proof of the concept for the OSM flow controlling mechanism were the subject of the current manuscript, for which a 3D numerical Reynolds Average Navier-Stokes (RANS) scheme has been used. An unstructured computational grid has been applied around the 3D geometry of the entire building and its sub-branching details, which is in contrast with most studies on full-scale geometries, tending to have simplifications on the body to reach a more generalized set of results. All cases have been numerically tested with and without the presence of the OSM. This comparison has been the grounds for proving the effectivity of the said flow controlling mechanism to eliminate high gradient fluctuations of the separated flow off the roof corners. This has led to pedestrian/resident comfort on the roof-top food court area located on top of the building.

Because output accelerographs always contain noise, to use data in analysis and design of structures, there is a need for rational correction of raw data. These corrections include baseline...

Cool roofs with higher solar reflectance and emittance can effectively reduce building energy consumption. However, it is still limited to use at night on account of the development of roof materials during the past decades. The newly proposed metamaterial-based cool roof (MCR) greatly improves the possibility of the radiative cooling in the daytime. To study the influence of MCR on the energy consumption for the office building, a small single-floor office was adopted to analyse the cooling performance of MCR by using EnergyPlus. In this study, the optimization analysis was conducted based on the proposed dimensionless thermal resistance ( θRTR) and roof pitch (Δ). Then the annual electricity saving potential of the office building with MCR was evaluated in details based on the selected cities from all five climate zones in China. The results show that more annual electricity saving can be achieved under the optimized values of θR7 = 1.53 and Δ = 20°. Furthermore, more than 15.7% of annual cooling electricity saving can be achieved while the optimized θRTR and Δ are applied.

The evaluation of structural collapse capacity is an integral part of the estimation of collapse risk in performance based earthquake engineering. Several methods and procedures have been proposed in the past to quantify collapse capacity. However, there is no clear consensus on which method is most appropriate. Recently physics-based collapse criteria have been proposed, but their effectiveness is yet to be compared with codes of practice. In order to ensure safety and consistency, different code/standard based recommendations enforce the use of thresholds predominantly in terms of the engineering demand parameter (EDP) for the performance level of collapse prevention. These thresholds serve as limit-state criteria to evaluate the collapse capacity of a structure. This paper compares several performance measures that are derived using different criteria to understand their impact on the final collapse risk estimates. Four different criteria are studied, two of which are based on standards, and the other two are physics-based, which use energy formulations. Three different ASCE 7-16 code conforming RC buildings are designed and analysed. The effects of modelling uncertainties and of the ground motion spectral shape have been considered to impart more confidence in the results. The collapse risk estimates are interpreted in terms of different collapse performance measures. The estimates derived from all the four criteria are compared. It was found that the collapse risk is significantly affected by the choice of the criterion. For the same collapse risk, the physics-based criteria allow higher ultimate deformation at collapse. On the other hand, the code/standard based criteria tend to be conservative as they censor the deformation response of the structure using upper bound thresholds. It was also found that the physics-based criteria could underestimate the collapse risk, yet they can still be employed to produce more economical designs.

Introduction. Latakia Governorate, Syria, includes Kesab located in a mountainous area. Plains, that are good for construction purposes, are depleted; therefore, mountain slopes have to accommodate new construction projects. The analysis of space planning solutions, designated for single-family residential houses, was performed with regard for the terrain of Kesab. This analysis underlies the fundamental principles of the architectural solutions that take account of the following factors: the slope type/orientation, the layout of buildings in relation to the slope and access routes, the use of the “bearing floor” design system that reduces construction costs, the use of cantilever solutions for first floors, the availability of summer premises protected from overheating in the Kesab climate, the orientation of the slope towards cardinal points, and traditions of Arabic families. Principles of architectural design of single-family residential houses with account taken of the local terrain constitute the subject of this research. The objective is to develop recommendations designated for architectural solutions for single-family residential houses to be built in the mountainous environment of Kesab, to assure indoor comfort depending on the earth grade and terrain orientation towards cardinal points, and to reduce construction costs. Materials and methods. The research is based on the analysis of the Kesab terrain, the analysis of potential construction work to be performed on the slopes having different orientations, the use of the “bearing floor” structural system, the analysis of effective Syrian and Russian regulations and data sources. Results. As a result of research into a single-family residential house built with regard for the Kesab terrain in Syria, the co-authors developed design principles applicable to single-family residential houses in the areas featuring rough terrain. Conclusions. The recommendations are designated for low-rise single-family houses that have different orientations towards cardinal points in the areas that have varied earth grades like Kesab located in the mountain valley.

The recently proposed scalable-manufactured randomized glass-polymer hybrid metamaterial (i.e. metamaterial film) exhibits good energy-saving potential for building applications. The most convenient way to employ this metamaterial film-based radiative cooling is to integrate it with buildings as cool roofs. However, metamaterial film-based radiative cooling is more suitable for buildings with higher roof area to floor area ratios, as this accounts for its relative lower cooling power of 110 W/m2 on a daily average. The prefabricated buildings in China are commonly less than two floors, which are preferable for the application of this metamaterial film-based radiative cooling. To clearly reveal the cooling performance of the metamaterial film-based cool roof (MFCR), a single-floor prefabricated building is modelled in this study, and the energy-saving potential and economic feasibility of the application of the MFCR on the prefabricated building are discussed in detail. When comparing the model in this study with buildings that have the more commonly used shingle roofs or typical white roofs, the annual cooling electricity consumption is reduced by 28.9%–43.0% and 7.8%–12.9%, respectively, for buildings with MFCRs located in five cities in China, each in a different climate zone. Furthermore, the simple payback period for the buildings with MFCRs located in all five climate zones is less than three years compared to the buildings with shingle roofs. Practical application: A recently proposed metamaterial film exhibits good energy-saving potential for building applications. This paper explores the application of this metamaterial film as a cool roof on a low-rise prefabricated building. The analysis of the cooling performance and economic value of this low-rise prefabricated building located in all five climate zones in China provides guiding significance for the application of MFCR.

The present article considers the possibility of using an unvented underfloor space enclosed with heat-insulated panels for pile-supported, low-rise buildings in permafrost areas. A long-term, in-situ experiment revealed a pattern of changes occurring over time in the ambient air temperature, the temperature in the underfloor space, as well as the depthwise temperature changes of the foundation-bed soils both under and outside the buildings.

A multi-criteria assessment of the choice of a rational option for the construction of low-rise residential buildings, taking into account energy consumption on the construction site, was carried out. The structure of energy consumption in the construction of low-rise and high-rise housing, as well as a comparison of the specific consumption of energy resources in the construction of complex low rise and multi-storey monolithic residential building.

Due to the strike of wind-blown raindrops, the pressure caused by wind and rain on building facades is different from the action of wind-only. The wind–rain induced pressure during Typhoon Haikui (2012) was collected at three taps on the windward side of Tongji University experimental building which was located near the coast of East China Sea. The observed data during the storm was compared with both the data of normal wind events without rains and wind tunnel test. The results show that the presence of driving rains intensifies the wind effects acting on the windward side of the building. More specifically, the mean wind–rain induced pressure coefficients at the three locations of the experimental building are larger than those collected from the strong wind-only events and the wind tunnel test when the wind direction ranges from 110° to 130°. It was also found that the mean wind–rain induced pressure coefficients at each tap increase in magnitude with rainfall intensity and the distance between the pressure tap and the wall corner. Similarly, the fluctuating wind–rain induced pressure coefficients are larger in comparison to the wind-only pressure coefficients from the full-scale measurement and wind tunnel test. However, the coefficients decrease with the distance from the wall corner in the case of 80°–140° wind directions. In addition, it was found that Gamma distribution is a robust model to represent the probability distribution of the wind–rain induced pressure coefficients. High quality of pressure correlation was observed among three taps, regardless of the rainfall intensity. By contrast, the presence of driving rains slightly reduces the correlation of wind–rain induced pressure.

Shading louvers are widely used in buildings to protect the indoor environment from excessive heat gain, especially in hot climatic regions. However, few studies mentioned their influences on wind ...

With the advancements in the analysis tools to estimate the inelastic performance of the buildings, the Pushover Analysis (POA) has been adopted as a reliable procedure for the assessment of the nonlinear performance of the buildings. The pushover analysis has a few advantages over the nonlinear dynamic analysis; (i) it is less time-consuming; (ii) it is easy to implement as it does not require to define specific earthquake time-history data. The one of the governing parameters in the seismic response prediction by the POA is the choice of the load pattern. The present study is performed to evaluate the predictions of a new lateral load pattern (LLP) which is developed to perform the pushover analysis of base-isolated buildings. A LLP is developed by modifying the original uniform load pattern; as an example, a 5-storey building frame, which resembles low rise buildings and a 10-storey building, which resembles midrise buildings are selected for the analysis. The buildings are provided with the base isolation layer at the bottom of the buildings with the lead rubber bearings’ isolators (LRB). The POA is conducted by selecting three target displacements depicting three behavioral states of the building. The three states are such chosen to depict the structural behavior from elastic to plastic range. For the comparison purpose, the conventional LLP which corresponds to the fundamental mode shape is also used. The predictions of the newly proposed LLP are then compared with the accurate results obtained by conducting the Nonlinear Time History Analysis (NTHA). A suite of real far-field earthquake records is used for performing the NTHA. The study concludes that the new LLP provides better results as compared to the conventional LLP when compared to the benchmark estimates obtained by the NTHA.

PurposeThis study investigates the aerodynamics of the airflow over low-rise houses subjected to turbulent cyclonic winds along the South-eastern peninsular India, routinely afflicted by tropical cyclones. The purpose of this paper is to demonstrate how the power of modern computational fluid dynamics (CFD) and its engineering application accentuate decision-making at the planning stage of house designing in vulnerable areas.Design/methodology/approachThe Weather Research and Forecasting (WRF) model was used for first simulating the landfall of cyclone Hudhud, a real storm, and its effect in extant and new house designs. Results from the WRF model were utilized to configure further CFD simulations of airflow around house designs. The analyses yielded deep insights, often non-intuitive, into airflow patterns around these houses with disparate roof forms indicating new possibilities in redesigning houses along Indian coastal areas.FindingsThis study shows that storm-induced high TKE values warranted a fuller CFD-based study. The second major finding showed that for a 90° angle of attack, arguably the most destructive attack angle, a pitched roof (with a pitch angle of 10°) worked best – this is about half the recommended angle sourced from earlier empirical estimates dating back to the British Raj period. There is a thin layer of padded air cushion shielding the roof's vulnerable surface from the storm's most energetic parts.Originality/valueThe originality of this research lies in its discourse to systematically resolve the TKE distribution of a cyclone impacting a standalone house. In particular, the study presents a lucid demonstration of all the probable scenarios connecting cyclonic stresses with a roof response, inferred from a careful combination of results garnered from cyclonic storm modelling coupled with CFD analysis. Additionally, the paper also shows a graphic visual representation of the forces induced on different roof designs, presented as a checklist for the first time. This should serve as a ready reckoner for civic authorities involved in disaster management over cyclone-ravaged areas.

Introduction. Low-rise housing construction is an area that has extensive potential in Russia. One of the top-priority objectives, pursued by public politicians in the Russian Federation, is to improve the energy efficiency of versatile branches of the national economy. Given the fact that the building construction, representing a comparatively short stage in the building’s life cycle, is energy consuming, energy saving in the process of construction turns particularly relevant. Prevailing manual labour and low-capacity construction machinery substantially reduce power consumption at the stage of low-rise housing construction. Widely spread low-rise construction technologies and consequent discrepancies in structural and technological solutions determine the mode of operation, numbers and the engineering performance of construction machines. Hence, energy resources, to be consumed in the process of mechanized work performance on a construction site, is projected, and these projections may differ. As for the rational expenditure of resources, consumption of fuel and energy can be expediently planned at the stage of construction project scheduling. Materials and methods. The co-authors have analyzed scientific publications focused on the subject of research, applied organizational and construction process patterns developed in the form of work performance schedules needed to regulate fuel consumption in the process of mechanized work performance, whenever low-rise construction technologies are used. Results. The co-authors offer a set of instruments, designated for the calculation of fuel consumption in the process of mechanized work performance, whenever low-rise construction technologies are used. Conclusions. At the project planning stage, the fuel consumption rate analysis, applicable to construction machines and mechanisms, enables to (1) project the amount of fuel consumed in the course of specific construction works performed within the framework of the whole process of construction, (2) to identify technologies and mechanized units which are most rational in terms of power consumption.

The focus of this paper is liveable, low-rise high-density urban morphologies of residential architecture and urban planning practices in Tokyo. Over the last several decades, historically established qualities in cities worldwide are increasingly sacrificed in favour of globalization–led ‘universal’ typologies. Tokyo is not an exception: it is gradually changing to a high-rise, high-density built city environment. From a morphological point of view, the paper demonstrates bioclimatic and cultural disadvantages of such developmental paradigm shift in Tokyo. Presented case studies elaborate upon the ways in which low-rise high-density environments and subsequent urban forms better facilitate human interaction and, consequently, can aid in reducing social isolation and contribute to mental well-being. Presented case studies, observed over the period of six years depict how residential environments created by row-houses can be seen as a collection of adjoining private spaces. The emphasis is on the interconnected set of phenomena: low-rise high-density morphologies, climate-responsive semi-exterior spaces, facilitating human and public-private interaction. The conducted morphological and functional analysis shows how design requirements of bioclimatic responsive semi-exterior space fully coincide with those of desirable public-private interface and human interaction. However, site-specific constraints critically affect spatial configurations of low-rise high-density developments in contemporary Tokyo, emphasizing the requirement for case-by-case attention in design and management of such places. Only design processes conscious of spatial management aware of the potential embedded in the design process can enhance socio-cultural interplay and bioclimatic performance.

This study focused on two types of roof spaces: concrete and corrugated zinc. Both green roofs were covered with short-lived productive vegetables throughout dry and rainy seasons, monitored by an ...

The areas of low-rise buildings in Leningrad in the period from 1944 to 1950 are considered. The current state of development is reflected. A detailed analysis of the features of residential blocks is carried out on the example of the Udelnaya district. Graphic diagrams showing the location of low-rise blocks in the modern urban fabric are presented. The process of involving creative teams of architects in the design of low-rise buildings is described. The general characteristics of urban planning and architectural aspects of development are given. The characteristic features of the planning structure formed in each area of low-rise construction are analyzed. The assessment of the preservation of the building ensemble at the present stage is given. The existing urban fabric of the Udelnaya district is presented, indicating the gradual formation of development. The architectural features of low-rise buildings in the Udelnaya district are analyzed using the example of three types of houses. A comparative analysis of three types of houses is presented in tabular form. The comparative analysis provides a graphical representation of the main facades and the three-dimensional composition of buildings. The graphic scheme illustrates the silhouette of Yeletskaya street in the Udelnaya district. A general description of the area improvement environment is given. As a result of the study, the positive and negative sides of low-rise buildings are identified. In conclusion, the operational disadvantages of the analyzed low-rise buildings are indicated. Based on all the materials presented in the article, it is proposed to renovate low-rise areas as a single ensemble.

Reinforced concrete multi-story buildings are commonly used in residential, commercial, and administrative projects; therefore, selecting the optimum structural system with minimum cost is the top priority of the structural designer. Although earlier researches intensively studied this issue, it is still not completely covered. This research aims to introduce recommendations for the optimum gravity and lateral systems for a multi-story reinforced concrete (RC) building from a perspective of direct cost. In order to achieve that goal, a parametric study was carried out using 72 RC buildings with several stories ranged between 5 and 50 floors, and grid spacing ranged between 6.0 and 12.0 m. Four floor systems were considered, solid, 2 ways ribbed, waffle, and flat slabs. Also, three lateral loads resisting systems were considered which are intermediate moment resisting frames, shear walls, and a dual system. The study covered the low, medium and high rise buildings. The results indicated that the dual system is the most suitable system for medium and high rise buildings with combination with solid slabs for short spans and ribbed slabs for medium and long spans. On the other hand, frame with solid slabs is the optimum for low rise with short spans and shear wall with the flat slab is the optimum for low rise with medium and long spans.

A formulation is presented for simplified evaluation of the roof acceleration response for the purpose of assessing non-structural components in unreinforced masonry buildings with flexible diaphragms excluding torsional effects. The method is based on modal calculations that are further studied through nonlinear time-history analysis (NLTHA) of four case study buildings. The NLTHA results for a relatively small level of ground shaking was used to validate the overall ability of the simplified modal method to predict the diaphragm flexibility effects. The NLTHA results were also used to discuss the effects of the building inelastic response in the conservatism of the simplified modal technique. It was found that, in lieu of a comprehensive modal analysis, it is possible to calculate roof accelerations in symmetric low-rise buildings with flexible diaphragms using a simplified two-mode modal method. Based on this study, a predictive method is proposed for conservative estimation of peak roof accelerations in these buildings.

A strong wind would cause roof openings on a low-rise building and bring further structural damage. Previous related studies focused on different shapes of openings on flat roofs. Little study has been done on the sloped roofs with openings in vulnerable roof areas. In this study, wind tunnel tests were carried out to investigate the steady-state and transient internal pressure characteristics due to opening at the vulnerable roof areas of a low-rise building. The tests considered both steady-state and transient openings of roof. The experimental results indicated that the steady-state internal pressure distribution tends to be uniform and that the internal pressure induced by leeward roof ridge opening is obviously lower than that induced by the windward one. The fluctuation effect around the orifice area is apparent with the skewed wind direction and the combined effect of internal and external pressures on the unopened roof side is significantly smaller than that on the opened side. Current design provision of China for internal pressure evaluation is found to be unconservative. The transient overshoot is closely related to the opening location in the vulnerable roof area and is more pronounced when the opening is on the leeward side. Among the internal pressure coefficients commonly adopted in design, the extreme net wind pressure coefficient is most important, which is affected most at the orifice near eaves, roof corners and tails, and leeward roof ridge.

18 páginas Los muros delgados de hormigón armado (RC) con refuerzo de una sola capa se han utilizado para casas y edificios en varios países de América Latina. Aunque algunos códigos de diseño incluyen recomendaciones para paredes delgadas en cuclillas en construcciones de poca altura, su desempeño sísmico no ha sido validado adecuadamente en terremotos pasados. Este artículo presenta los resultados de una campaña experimental de nueve probetas a gran escala realizadas para caracterizar la influencia del tipo de acero, la relación de refuerzo y el espesor de la pared en el comportamiento sísmico de muros delgados RC con refuerzo de una sola capa. Tanto el alambre soldado como las barras deformadas se utilizaron como refuerzo de la red. Los resultados experimentales se utilizan para desarrollar modelos no lineales para evaluar el comportamiento sísmico de un prototipo de casa de dos pisos con refuerzo de alambre soldado y barras deformadas mediante análisis dinámicos incrementales. Los resultados experimentales muestran que el tipo de acero tiene la mayor influencia en el comportamiento sísmico del muro. Los resultados numéricos sugieren que los muros RC con refuerzo de una sola capa son adecuados para aplicaciones de viviendas de hasta dos pisos en regiones de alta sismicidad, particularmente muros detallados con barras deformadas. Thin reinforced concrete (RC) walls with single layer reinforcement have been used for houses and buildings in several Latin American countries. Although some design codes include recommendations for squat thin walls in low-rise constructions, its seismic performance has not been validated adequately in past earthquakes. This article presents the results of an experimental campaign of nine full-scale specimens conducted to characterize the influence of the steel type, the reinforcement ratio, and the wall thickness on the seismic behavior of squat thin RC walls with single layer reinforcement. Both welded wire and deformed bars were used as web reinforcement. Experimental results are used to develop nonlinear models to assess the seismic behavior of a prototype two-story house with welded wire reinforcement and deformed bars by means of incremental dynamic analyses. The experimental results show that the type of steel has the largest influence on wall seismic performance. The numerical results suggest that RC walls with single layer reinforcement are suitable for housing applications up to two stories in high seismicity regions, particularly walls detailed with deformed bars.

The equivalent viscous damping is a key parameter in the prediction of the maximum nonlinear response. Damping constitutes a major source of uncertainty in dynamic analysis. This paper studies the effect of using viscous damping, on the reduction of the seismic responses of reinforced concrete RC frame buildings modeled as three-dimensional multi degree of freedom (MDOF) systems, and the use of nonlinear time history analysis as a method of visualized behavior of buildings in the elastic and inelastic range. This study focuses on the implications of the available modeling options on analysis. This article illustrates the effect of using the initial or tangent stiffness in Rayleigh damping in analysis of structures. Correspondingly, this work is also concerned with the estimation of Rayleigh, mass-proportional or stiffness-proportional damping on engineering demand parameters (EDPs). As a result of a series of considerations, a damping modeling solution for nonlinear time history analysis (NLTHA) was carried out to compute the damage index. The application example is a building designed according to reinforced concrete code BAEL 91 and Algerian seismic code RPA 99/Version 2003 under seven earthquake excitations. The simulations demonstrated the accuracy and effectiveness of the proposed method to account for all of the above effects. RESUMEN El amortiguamiento viscoso equivalente es un parámetro clave en la predicción de la respuesta máxima no lineal. La amortiguación constituye una fuente importante de incertidumbre en el análisis dinámico. Este artículo estudia el efecto del uso de la amortiguación viscosa, en la reducción de las respuestas sísmicas de los edificios de estructuras de concreto reforzado con hormigón reforzado modeladas como sistemas tridimensionales de múltiples grados de libertad, y el uso del análisis de historia de tiempo no lineal como un método de comportamiento visualizado de Construcciones en la gama elástica e inelástica. Este estudio se centra en las implicaciones de las opciones de modelado disponibles en el análisis. Además, este artículo ilustra el efecto del uso de la rigidez inicial o tangente en la amortiguación de Rayleigh en el análisis de estructuras. Este trabajo también se ocupa de la estimación de Rayleigh, la amortiguación proporcional a la masa o la rigidez proporcional en los parámetros de demanda de ingeniería. Como resultado de una serie de consideraciones, se llevó a cabo una solución de modelado de amortiguamiento para el análisis de historial de tiempo no lineal para calcular el índice de daño. El ejemplo de aplicación es un edificio diseñado de acuerdo con el código de hormigón armado BAEL91 y el código sísmico argelino RPA99/2003 bajo siete excitaciones de terremoto. Las simulaciones demostraron la precisión y la eficacia del método propuesto.

In this research an attempt has been made in order to determine the efficiency of different types of structural systems at different heights up to 30 stories (300 feet). The investigation has been carried out on three types of lateral load resisting systems i.e. moment resisting frame, building frame system and outrigger braced frame system for seismic zone 2B as per UBC 1997 considering dead, live, seismic, wind load and their combinations. It was found that up to a 5 story building (50 feet) moment resisting frame was found more cost efficient as moment resisting frame was found stiff enough to resist lateral load and addition of shear wall was not required for further increase in stiffness. From 6 story building up to 20 story building (200 feet) building frame system was found more cost efficient and from 21 story building and beyond outrigger braced frame system was found more cost efficient. Accordingly, from one to five story buildings were categorized as low rise, from six to nineteen story buildings as medium rise and from twenty stories onwards as high rise buildings.

Light-frame low-rise wood dwellings have typically had adequate levels of safety in terms of collapse prevention. Nevertheless, damage to this type of construction due to earthquakes has resulted in large economic losses and thousands of displaced families. This paper evaluates the benefits, on a regional scale, of using a recently developed design and construction method referred to as unibody. This cost-effective method increases the lateral strength and, particularly, the lateral stiffness of walls of wood-frame houses, leading to significant reductions in lateral displacement demands. For houses at a given distance from the seismic source, reduced displacement demands translate into much smaller probabilities of damage. Consequently, for a region affected by a seismic event, this translates into a much smaller area of damaged houses. It is found that, for short-period structures, increasing the lateral stiffness is more efficient than increasing the lateral strength. Thus, when using unibody construction, which greatly increases the lateral stiffness of wood-frame houses, the number of damaged residential units is greatly reduced. It is shown that these relationships are strongly nonlinear and are positively combined resulting in a substantial reduction of seismic risk on a regional scale.

Communities need seismic vulnerability indices to identify which buildings are most susceptible to severe damage during earthquakes. To be of greatest value, these indices should be easy to use and should be vetted against data from previous earthquakes. To date, more than 800 reinforced concrete buildings have been surveyed after earthquakes for the purpose of evaluating a seismic vulnerability index proposed by Hassan and Sozen in 1997. This number includes 130 buildings surveyed after the 6 February 2016 earthquake in Taiwan. The data collected during these surveys consist of descriptions and photographs of damage, structural sketches, and measurements. Analyses of the data indicate that probability of severe damage and failure increases with decreasing column index and wall index (normalized measures of column and wall areas). They also suggest that the exact form of the threshold used to distinguish more vulnerable structures from less vulnerable structures is of little consequence in terms of the probable cost and benefits of the strengthening program this threshold may inform.

It has been commonly recognized by the international research and practice community that the presence of both outer and inner stirrups may significantly enhance the axial load capacity of reinforced concrete (RC) columns. However, there is limited testing evidence to support this conclusion that has been published nationally. This paper reports an experimental programme to study the effectiveness of stirrup detailing on the structural performance of columns having small sectional dimensions that are common in low-rise building structures. Nine column specimens with the same geometrical dimensions of 220 mm x 220 mm x 880 mm in three batches were detailed with different stirrup categories, have been gradually axially loaded to failure. The test data have revealed that although the presence of stirrups can generally enhance the axial load capacity of the column specimens, the enhancing levels are much dependent to the shapes of the stirrups. Selected interesting aspects of the test results have also been discussed, which set a concrete base for recommendations for design and detailing of such vertical structural elements. Keywords: experimental investigation; low-rise building columns; axial load capacity; stirrups.

In this paper, it is proposed to carry out the sustainable design of steel building systems were explained briefly as per codal provisions. Light gauge steel is one of the technologies which have very high potential for low rise residential and commercial buildings. This eliminates the huge reduction in construction time. Finally a comparative study is achieved by designing a industrial steel warehouse using conventional steel as well as cold formed steel by using a design software ETABS.

The biologically active area is one of the most important elements of residential development. Its size is determined by the percentage factor established in local spatial development plans and laws regulations. The publication was set minimum values ​​for this ratio for single-family and multi-family housing, and the outcomes were compared with a new type of housing, currently popular in Poland, low-rise high-density residential development. The studies were done on the example of the city of Bialystok, where there are many buildings of this new type of housing.