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Reliability Index of Tall Buildings in Earthquake Zones  [PDF]
Mohammed S. Al-Ansari
Open Journal of Earthquake Research (OJER) , 2013, DOI: 10.4236/ojer.2013.23005

The paper develops a reliability index approach to assess the reliability of tall buildings subjected to earthquake loading. The reliability index β model measures the level of reliability of tall buildings in earthquake zones based on their response to earthquake loading and according to their design code. The reliability index model is flexible and can be used for: 1) all types of concrete and steel buildings and 2) all local and international codes of design. Each design code has its unique reliability index β as a magnitude and the interaction chart corresponding to it. The interaction chart is a very useful tool in determining the building drift for the desired level of reliability during the preliminary design of the building members. The assessments obtained using the reliability index approach of simulated, tested, and actual buildings in earthquake zones were acceptable as indicators of the buildings reliability.

Shell Roof of Tall Buildings in Earthquake Zones  [PDF]
Mohammed Salem Al-Ansari, Muhammad Shekaib Afzal
Open Journal of Earthquake Research (OJER) , 2019, DOI: 10.4236/ojer.2019.84013
Abstract: This paper studies and analyzes tall buildings with shell and flat roof responses designed for gravity and earthquake loads in different zones having different soil profiles. These tall buildings having two different heights and different configurations are simulated with different load combinations. The responses of the simulated structural models with flat and shell roofs are studied and analyzed. These responses draw recommendations and guidelines for preliminary design of structurally efficient and reliable tall buildings with shell roof in earthquake zones. Five different earthquake zone factors (Z1 - Z5) along with the five different soil profiles (S1 - S5) are selected in this study. The non-linear dynamic response of buildings was obtained using three simulated models of buildings; square/rectangular, circular, and tube-shaped building. Total of 12 building models, four under each category, are analyzed using the finite element software (STAAD pro) subjected to the gravity as well as earthquake loading defined by UBC and IBC codes. Each building model is analyzed with two different story heights; which are 120 meters for 30 stories and 72 meters for 18 stories respectively. Horizontal and vertical displacement comparison is made among the flat roof and shell roof building for 32 and 18 stories building satisfying the ACI code of design requirement and drift index of 1/500 (0.002). The results showed that the drift index value for all the studied buildings is close to 0.002. All the maximum horizontal and vertical deflections occur under the earthquake zone-5 (0.40 gravitational acceleration) with soil profile-5 (Soft soil). The shell roof slab with less thickness than the flat roof slab did satisfy the horizontal and vertical deflection limits, therefore, it is more economical than the flat roof slab.
Review of Conventional and Innovative Technologies for Fire Retrofitting of Existing Buildings  [PDF]
Farshad Zahmatkesh, Ali M. Memari
Open Journal of Civil Engineering (OJCE) , 2017, DOI: 10.4236/ojce.2017.72014
Abstract: Fire effects can be one of the most harmful conditions that any building may experience throughout its service life. Developing practical protection methods and concepts against potential fire disasters in buildings has been an important consideration in design of buildings in recent decades. Rapid developments in technology have heightened the demand for new and innovative fire protection systems in comparison with conventional and traditional methods. Such a need for new technologies is in particular of greater importance when it comes to existing buildings. Retrofitting an existing building for fire safety is a greater challenge compared with designing a new building using materials and components that have more desirable and superior fire rating to begin with. Furthermore, strategies to design a new building that includes state-of-the-art fire safety features are also different from solutions that may be more suitable for retrofitting an existing building. This paper presents a review of the literature concerning conventional and new or innovative retrofitting methods for fire safety of buildings. Advantages and disadvantages of different fire protection devices and methods as available and understood from the literature are mentioned. Study of fire safety systems shows that each has its drawbacks. Comparison of the results shows that disadvantages of a solitary system for retrofitting against fire can be improved by using a combination of several fire safety concepts or methods simultaneously.
Statistical assessment of fire safety in multi-residential buildings in Slovenia  [PDF]
Domen Ku?ar,Vojko Kilar
Urbani Izziv , 2009,
Abstract: Nearly a third of residential units in Slovenia are located in multi-residential buildings. The majority of such buildings were built after WW2, when the need for suitable accommodation buildings was at its peak. They were built using the construction possibilities and requirements of the time. Every year there are over 200 fires in these buildings, resulting in fatalities and vast material damage. Due to the great efforts over the past centuries, which were all mainly aimed at replacing combustible construction materials with non-combustible ones, and with advancements in fire service equipment and techniques, the number of fires and their scope has decreased significantly but they were not entirely put out. New and greater advances in the field of fire safety of multi-residential buildings became obvious within the last few years, when stricter regulations regarding the construction of such objects came into force. Developments in science and within the industry itself brought about several new solutions in improving the situation in this field, which has been confirmed by experiences from abroad. Unfortunately in Slovenia, the establishment of safety principles still depends mainly on an occupants’ perception, financial means, and at the same time, certain implementation procedures that are much more complicated due to new property ownership. With the aid of the statistical results from the 2002 Census and contemporary fire safety requirements, this article attempts to show the present-day situation of the problem at both the state and municipality level and will propose solutions to improve this situation. The authors established that not even one single older, multi-residential building meets complies with modern requirements. Fortunately, the situation is improved by the fact that most buildings in Slovenia are built from non-combustible materials (concrete, brick), which limit the spread of fire.
Structural Performance of Reinforced Concrete Flat Plate Buildings Subjected to Fire
Sara J. George,Ying Tian
International Journal of Concrete Structures and Materials , 2012, DOI: 10.1007/s40069-012-0011-2
Abstract: The research presented in this paper analytically examines the fire performance of flat plate buildings. The modeling parameters for the mechanical and thermal properties of materials are calibrated from relevant test data to minimize the uncertainties involved in analysis. The calibrated models are then adopted to perform a nonlinear finite element simulation on a flat plate building subjected to fire. The analysis examines the characteristics of slab deflection, in-plane deformation, membrane force, bending moment redistribution, and slab rotational deformation near the supporting columns. The numerical simulation enables the understanding of structural performance of flat plate under elevated temperature and, more importantly, identifies the high risk of punching failure at slab-column connections that may trigger large-scale failure in flat plate structures.
On the Establishment of Climatic Zones in Europe with Regard to the Energy Performance of Buildings  [PDF]
Katerina Tsikaloudaki,Kostas Laskos,Dimitrios Bikas
Energies , 2012, DOI: 10.3390/en5010032
Abstract: Nowadays, subjects such as eco-design requirements, product rating or code compliance with regard to energy efficiency are expanding towards a pan-European level. This leads to the necessity of defining zones within the European region, which share common climatic characteristics and will further facilitate the quick estimation of building energy performance. Towards this direction stands the current paper; it presents an approach for defining climatic zones in Europe on the basis of the amount of heating and cooling degree days. It is applied for the climate classification of selected European cities and is compared with the conventional scheme based solely on heating degree days. Since the approach is orientated mainly towards the assessment of building energy performance, its outcomes are evaluated with regard to the actual heating and cooling energy needs of a reference building unit with office use located in representative cities of the proposed climatic zones and facing the four cardinal orientations. The classification of climatic zones on the basis of both heating and cooling degree days leads to more realistic results, since nowadays cooling needs form a substantial part of the energy balance of the building, especially in the Mediterranean regions.
The estimation of enclosing structures edge zones influence on thermal performance and energy efficiency of buildings (rus)  [PDF]
Korniyenko S.V.
Magazine of Civil Engineering , 2011,
Abstract: One of priority directions in modern building is maintenance of energy efficiency of buildings and constructions. This problem can be realized by perfection of architectural, constructive and technical decisions. The particular interest is represented by an influence estimation of temperature and moisture mode of enclosing structures on a thermal performance and energy efficiency of buildings. The analysis of the data available in the literature has shown absence of effective calculation methods of temperature and moisture mode in edge zones of enclosing structures that complicates the decision of this problem.The purpose of the given work is an estimation of edge zones influence on a thermal performance and energy efficiency of buildings. The design procedure of energy parameters of a building for the heating period, realized in the computer program is developed. The given technique allows settling an invoice power inputs on heating, hot water supply, an electrical supply. Power inputs on heating include conduction heat-losses through an envelope of a building taking into account edge zones, ventilation heat-losses and leakage air (infiltration), internal household thermal emissions, heat-receipt from solar radiation. On an example it is shown that the account of edge zones raises conduction heat-losses through an envelope of a building on 37 %, the expense of thermal energy on building heating on 32 %, and the expense thermal and electric energy on 13 %. Consequently, thermal and moisture mode in edge zones of enclosing structures makes essential impact on building power consumption. Perfection of the constructive decision leads to decrease of transmission heat-losses through an envelope of a building on 29 %, the expense of thermal energy on building heating on 25 %, the expense of thermal and electric energy on 10 %. Thus, perfection of edge zones of enclosing structures has high potential of energy efficiency.
On utilization of seismic resistance of masonry infills in design of lowrise mixed r.c. buildings -A case study  [PDF]
Amiya Kumar Samanta
Journal of Engineering and Applied Sciences , 2009,
Abstract: In early stage of civilization, people constructed mostly masonry buildings based on those low-engineered and empirical approaches. In design of new buildings, the structural behaviour of masonry elements is of interest mostly in case of infilled frames or mixed RC frames, where masonry element are also being utilized as participating in structural behaviour of the building. The infilled frames show larger ductility than isolated masonry walls. Very few codes have made provisions on RC frames with brick masonry infill. Euro code (8) and Nepal Building Code (201) make some provisions for ordinary building up to three storey in the low seismic zones, whereas the Indian seismic code IS: 1893 recommends linear elastic analysis for the bare RC frames excluding the effect of brick infill. In the present case study, the author makes an attempt to evaluate contributions of such infill on RC frames using the literature of Aliaari (2005) and effectively utilizes in design of mixed masonry RC frame structures.
Fire risk map for the Serra de S o Domingos Municipal park, Po os de caldas, MG  [PDF]
Henrique Nery Cipriani,José Aldo Alves Pereira,Rossi Allan Silva,Sávio Gouvêa de Freitas
CERNE , 2011,
Abstract: This study constructed a fire risk map for the Serra de S o Domingos Municipal Park (SSDMP), southern Minas Gerais Sate, Brazil, which harbors Atlantic Forest remnants and endangered species. Geo-processing techniques were used for producing a preliminary risk map for altimetry (a), land slope (e), slope orientation (d), land-use/cover (u) and influence of roads and buildings (i). After, the risk maps were overlaid to produce a structural fire index (SFI)-based risk map for the Park. The SFI was calculated by using the formula SFI = 0,35i + 0,30u + 0,15d + 0,10a + 0,10e. The risks classes were classified as low (0.0-0.9), moderate (1.0-1.9), high (2.0-2.9), very high (3.0-3.9) and extreme (4.0-5.0). All data were processed with 2.5 m base spatial resolution by using the ArcView GIS. According to the SFI calculated, the SSMP area can be divided into the following fire risk zones: Low (0.93%), Moderate (61.77%), High (31.32%), Very High (4.79%) and Extreme (1.19%). The main risk factor is due to the influence of roads and buildings and most fires start due to anthropogenic causes. The low and moderate risk classes comprehend most of the rainforest area. Clearings and grasslands fit mainly the High risk class. The most vulnerable area of SSDMP was the Northern area bordering pasture, crops and eucalypt fields. The SFI map can be a valuable tool for elaborating a fire prevention plan in a small conservation unit when few climate and fire occurrence data are available.
The influencing of smoke exhausting on over development buildings under fire in subway vehicle base

, YANG Shun, ZHANG Xin

- , 2017,
Abstract: 地铁车辆基地排烟口设置位置对上盖物业的影响较大,分析地铁车辆基地排烟口可能的开设位置,采用数值模拟方法研究排烟口不同开设位置下烟气蔓延的影响因素及规律。研究结果表明:为避免车辆基地火灾烟气对上盖物业的影响,当排烟口开设在车辆基地顶部时,排烟口与上盖物业之间的水平距离不应小于13 m;当排烟口开设在车辆基地侧墙时,防火挑檐宽度不应小于4 m。
Over development buildings is greatly influenced by the setting exhaust port of subway vehicle base ,The opening position of exhaust port of subway vehicle base is analyzed, the smoke spread rule and influencing factors is studied under the different opening position of the subway vehicle base exhaust port by the numerical simulation, the research results show that, in order to avoid the effect of the subway vehicle base fire smoke to the over development buildings, when the exhaust port is opened at the top of the subway vehicle base, the horizontal distance between the exhaust port and over development building should not be less than 13 m; When the exhaust port is opened at the side wall of the subway vehicle base, the width of the fire overhangs should not be less than 4 m
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