Types Of Building Structures Research Articles

Test Research on Seismic Performance of Beam

Reinforced concrete ( RC) frame structure is one type of building structure which is widely used in China. Damage of some reinforced concrete frame structures under the earthquake is caused by the damage of RC beams, So RC beams are an essential seismic members. The paper introduces the design of RC beam specimen, mechanical properties of materials, production of RC beam specimen, test method, loading device, loading system, the contents of measurement and data acquisition in detail. From the above analysis, it is obvious that the test is the most effective means of studying the seismic performance of beam.

Numerical estimation of fire resistance and a flexible design of fire protection for structures made of reinforced materials

The basic principles of a progressive methodology for calculating the fire resistance of reinforced structures, meant for application to high-rise, multifunctional, and unique buildings, are presented. The methodology is universal with respect to materials, types of building structures with fire protection, and different force and heat loads acting on them under the conditions of fire. It permits one to take into account all particularities of the thermomechanical behavior of structures in the case of joint action of thermal and force loads. The solution procedure is based on using high-level mathematical models and universal methods of numerical analysis, i.e., the finite-element method (FEM) and the finite-difference method (FDM). To simplify and reduce the labor content of computational algorithms, a mathematical model of special beam finite element has been developed, which in a natural way takes into account the complex structure of buildings, spatial nonuniformity of temperature fields, and the nonlinear behavior of materials. This procedure allowed us to determine the limits of applicability of the known approximate approach, which is based on the use of the concept of “critical temperature,” to the estimation of fire resistance and to the design of fire protection of concrete structures. The procedure has been used in designing a number of unique structures built in Moscow.

Finite Element Simulation of RC Beams and Columns

Reinforced concrete (RC) frame structure is one type of building structure which is widely used in China. Damage of some reinforced concrete frame structures under the earthquake is caused by the damage of beams and columns, so beams and columns are essential seismic members. However, the test datum are not enough to study the performance of RC beams and columns , Therefore, Finite element simulation of RC beams and columns is performed by software ABAQUS in the paper. Through comparing with the finite element simulation and the test of load - displacement skeleton curve, failure mode and steel bar strain, the result shows that the finite element simulation can more accurately simulate the situation of the test and verifies the finite element simulation is the most important research tool besides test.

Major Earthquakes of the Past Decade (2000-2010): A Comparative Review of Various Aspects of Management

Objectives:This article sought to review and compare data of major earthquakes of the past decade and their aftermath in order to compare the magnitude, death toll, type of injuries, management procedures, extent of destruction and effectiveness of relief efforts.Materials and Methods:A retrospective study of the various aspects of management and aftermath of 5 major earthquakes of the past decade (2000–2010) was undertaken. This included earthquakes occurring in Bam Iran, Sichuan China, Port-au-Prince Haiti, Kashmir Pakistan and Ica Peru. A literature search was done via computer of published articles (indexed in Pubmed). The issues assessed included: 1)Local magnitude,2)Type of building structure 3)Time of the earthquake (day/time/season), 4)Time to rescue, 5)Triage, Transfer, and Treatment 6) Distribution of casualties (dead/ injured), 7)Degree of city damage, 8)Degree of damage to health facilities, 9)Field hospital availability, 10)International aid, 11)Air transfer, 12) Telecommunication systems availability, 13) PTSD prevalence, 14) Most common injury and 15) Most common disease outbreak.Results:The Bam earthquake had the lowest (6.6 Richter’s) and the Sichuan earthquake had the greatest magnitude (8.0 Richter’s). Mortality in Haiti was 212,000 and it was the deadliest earthquake of the past decade. Collapse of heavy clay roofing structures was a major cause of death in Iran and Pakistan. Earthquakes occurring at night and nonworking days carried a high death toll. The time to rescue and treat was the lengthiest in Haiti (possibly contributing to the death to injured ratio). However, the worst dead to injured ratios were in Bam (51%) and in Pakistan (47%); the best ratio was in China (15%). Iran and Pakistan suffered the highest percentage of damage to the health facilities (90%). Field hospital availability, international aid and air transfer were important issues. Telecommunication systems were best in China and worst in Pakistan. PTSD prevalence was highest in Iran. Respiratory infection was the most common infection following all 5 earthquakes.Conclusions:Earthquake damage, death toll, managerial protocols etc. vary in different countries and are influenced by many factors including the hour the earthquake hits and the day of the week. Additionally, social, structural and geographic factors as well as the medical, governmental and NGO respondents are influential. Engineered residential construction remains to be of importance in reducing mortality in developing countries. It is essential that hospitals, fire departments and police stations, water, telephone and electrical facilities be made earthquake proof.

Optimum parameters of tuned liquid column-gas damper for mitigation of seismic-induced vibrations of offshore jacket platforms

SUMMARY The effectiveness of tuned liquid column–gas damper, TLCGD, on the suppression of seismic-induced vibrations of steel jacket platforms is evaluated in this study. TLCGD is an interesting choice in the case of jacket platforms because it is possible to use the structural elements as the horizontal column of the TLCGD. In this study, optimum parameters of the TLCGD are obtained, considering nonlinear damping of the TLCGD and water–structure interaction between jacket platform and sea water. Equation of motions and other related formulas are derived, and using a SimuLink model, the frequency and the head loss coefficient of the TLCGD are optimized. Results are in general agreement with those obtained in earlier studies for typical building structures. However, effects of period of the structure and ground motion characteristics on the optimum parameters are also evaluated in this study. Results show that until a particular threshold for the mass ratio, the higher the mass ratio, the higher the efficiency of the damper. After that, by increasing the mass ratio, there is no improvement on the damper efficiency. It is also found that PGA and frequency content of a ground motion have no important effect on the optimum frequency ratio, but they have a noticeable effect on the optimum head loss coefficient. Besides, frequency content has some effect on the TLCGD efficiency. It is shown that the optimum frequency of a TLCGD is uncoupled with the area ratio and the head loss coefficient, and they have no effect on the optimum frequency ratio. Copyright © 2011 John Wiley & Sons, Ltd.

Simplified dynamic analysis of eccentric buildings with a setback. 2: the effect of stiffness irregularity

SUMMARYThe effect of stiffness irregularity is investigated in eccentric buildings with a setback. Stiffness irregularity is assumed to be created when some of the lateral load resisting bents are curtailed at the top of the base structure. The methodology suggested in the companion paper for assessing vibration frequencies, base shears and torques is extended to include the effect of curtailed bents. Their contribution is evaluated by an indirect method after the modal stiffness of the symmetrical counterpart structure is determined and the modal contribution of the full height bents is assessed by Southwell's approach. A number of numerical examples, representing common types of building structures, are presented to illustrate the procedure and provide an insight into the response of such setback buildings. The results are compared with more accurate results obtained by three‐dimensional dynamic analyses. Copyright © 2009 John Wiley & Sons, Ltd.

FEM Analysis on the Action of Pile Foundation -Soil- Superstructure in the Earthquake Force

The building sets up reservoir slope, in order to avoid mass of excavation and fill geotechnical Engineering,according to the change of slope angle, pile foundation is generally made into different height. the foundation of building is Considered apart from Superstructure in general design. in the normal loading condition to satisfy coordination between bearing capacity and strain. But accidental loading is acted to the type of construct whether satisfy up,the strain of lower part structure moderate and is then canned not know by force condition. According to this, with some library coast of the 5 F frame stake foundation for instance, adopted FEM software ANSYS to analyze to carry to act in the earthquake force, pile foundation -soil- Superstructure common coupling action and general design, while carry on internal force and strain result under two kinds of conditions of contrast analysis. While analyzing a result to express the type of building structure to design should well in consideration of the stake and soil, lower part structure thus makes design for effecting upside structure more safety reasonable.

Generalization of the statistical moment-based damage detection method

A novel structural damage detection method with a new damage index has been recently proposed by the authors based on the statistical moments of dynamic responses of shear building structures subject to white noise ground motion. The statistical moment-based damage detection (SMBDD) method is theoretically extended in this paper with general application. The generalized SMBDD method is more versatile and can identify damage locations and damage severities of many types of building structures under various external excitations. In particular, the incomplete measurements can be considered by the proposed method without mode shape expansion or model reduction. Various damage scenarios of two general forms of building structures with incomplete measurements are investigated in consideration of different excitations. The effects of measurement noise are also investigated. The damage locations and damage severities are correctly identified even when a high noise level of 15% and incomplete measurements are considered. The effectiveness and versatility of the generalized SMBDD method are demonstrated.

Statistical Analysis of Seismic Vulnerability for Various Types of Building Structures in Wenchuan Earthquake

Based on the nearly 5,000 building samples investigated on site, damage characteristics of different types of building structures which located in different intensities regions are described and the reasons are analyzed in this paper. Three kinds of structural damage characteristics have been summarized as follows: 1) fortified masonry structures and unfortified ones; 2) masonry buildings with bottom frame; 3) reinforced concrete frame structures. The damage ratio of these three kinds of buildings in different intensities is obtained and the vulnerability has been compared. It provides the reference for those people who work for earthquake engineering to know the earthquake damage of different types of structures with fortified or unfortified. Also it provides important reference for revising seismic design code.

Predicting torsion‐induced lateral displacements for pushover analysis: Influence of torsional system characteristics

AbstractThe increasing popularity of simplified nonlinear methods in seismic design has recently led to many proposals for procedures aimed at extending pushover analysis to plan asymmetric structures. In terms of practical applications, one particularly promising approach is based on combining pushover analysis of a 3D structural model with the results of linear (modal) dynamic analysis. The effectiveness of such procedure, however, is contingent on one fundamental requirement: the elastic prediction of the envelope of lateral displacements must be conservative with respect to the actual inelastic one.This paper aims at verifying the above assumption through an extensive parametric analysis conducted with simplified single‐storey models. The main structural parameters influencing torsional response in the elastic and inelastic range of behaviour are varied, while devoting special attention to the system stiffness eccentricity and radius. The analysis clarifies the main features of inelastic torsional response of different types of building structures; in this manner, it is found that the above‐mentioned method is generally suitable for structures characterized by moderate to large torsional stiffness, whereas it cannot be recommended for extremely torsionally stiff structures, as their inelastic torsional response almost always exceeds the elastic one. Copyright © 2010 John Wiley & Sons, Ltd.

Performances of Different Global Positioning System Devices for Time-Location Tracking in Air Pollution Epidemiological Studies

Background:People’s time-location patterns are important in air pollution exposure assessment because pollution levels may vary considerably by location. A growing number of studies are using global positioning systems (GPS) to track people’s time-location patterns. Many portable GPS units that archive location are commercially available at a cost that makes their use feasible for epidemiological studies.Methods:We evaluated the performance of five portable GPS data loggers and two GPS cell phones by examining positional accuracy in typical locations (indoor, outdoor, in-vehicle) and factors that influence satellite reception (building material, building type), acquisition time (cold and warm start), battery life, and adequacy of memory for data storage. We examined stationary locations (eg, indoor, outdoor) and mobile environments (eg, walking, traveling by vehicle or bus) and compared GPS locations to highly-resolved US Geological Survey (USGS) and Digital Orthophoto Quarter Quadrangle (DOQQ) maps.Results:The battery life of our tested instruments ranged from <9 hours to 48 hours. The acquisition of location time after startup ranged from a few seconds to >20 minutes and varied significantly by building structure type and by cold or warm start. No GPS device was found to have consistently superior performance with regard to spatial accuracy and signal loss. At fixed outdoor locations, 65%–95% of GPS points fell within 20-m of the corresponding DOQQ locations for all the devices. At fixed indoor locations, 50%–80% of GPS points fell within 20-m of the corresponding DOQQ locations for all the devices except one. Most of the GPS devices performed well during commuting on a freeway, with >80% of points within 10-m of the DOQQ route, but the performance was significantly impacted by surrounding structures on surface streets in highly urbanized areas.Conclusions:All the tested GPS devices had limitations, but we identified several devices which showed promising performance for tracking subjects’ time location patterns in epidemiological studies.

The assessment of embodied energy in typical reinforced concrete building structures in Ireland

This paper demonstrates that by understanding how energy is consumed in the manufacturing of reinforced concrete, designers can significantly reduce the overall embodied energy of structures. Embodied energy of products can vary from country to country. Therefore, to accurately estimate the embodied energy of reinforced concrete structures, data specific to the country where they are being constructed must be used. This paper presents the assessment of embodied energy in typical RC building structures in Ireland. The most common methods used to calculate EE are evaluated in this paper and the most suitable method was applied to reinforced concrete. The EE of a typical 30 MPa concrete mix in Ireland is calculated to be 1.08 MJ/kg. Notably cement is credited with 68% of the total EE. The major contributors of energy consumption are identified, which should aid to minimise energy consumption and optimise efficiency. A case study is presented which compares the EE of a typical reinforced concrete structure in Ireland using two concrete mix designs. The first uses Ordinary Portland Cement, while the second uses GGBS replacing half of the cement content. As expected, the EE of the GGBS mix is significantly lower (30%) than that of its counterpart.

Probabilistic Assessment of Structural Damage due to Earthquakes for Buildings in Mid-America

This paper provides an approach to conduct a probabilistic assessment of structural damage due to seismic events with an application to typical building structures in mid-America. The developed methodology includes modified damage state classifications based on the Applied Technology Council (ATC)-13 and ATC-38 damage states and the ATC-38 database of building damage. Damage factors are assigned to each damage state to quantify structural damage as a percentage of structural replacement cost. To account for the inherent uncertainties, these factors are expressed as random variables with a Beta distribution. A set of fragility curves, quantifying the structural vulnerability of a building, is mapped onto the developed methodology to determine the expected structural damage. The total structural damage factor for a given seismic intensity is then calculated using a probabilistic approach. Prediction and confidence bands are also constructed to account for the prevailing uncertainties. The expected seismic s...

On the Disaster Harm and Pattern of Chinese Village and Town Housing’s Typical Building Structure and the Countermeasures------ An Analysis of 499 Questionnaires in China

Based on 499 effective questionnaires in China, this paper firstly analyzes and concludes the type characteristics, spatial distribution, and combined characteristics of typical village and town housing’s building structure in China. Secondly, this paper studies the features and sorts of chief disasters in China and the harms on village and town housing. Finally, this paper summarizes the main factors that cause the disasters and the disaster pattern, and puts forward relevant countermeasures.

필로티형 고층 RC건물의 비선형시간이력해석

강한 지진에 대한 필로티형 고층 철근콘크리트 건물의 거동을 묘사하기 위한 해석기법의 개발과 성능평가를 위해, 상부벽식 하부 골조형식인 필로티형 건물에 대한 1/12축소 진동대 실험결과와 OpenSees를 이용하여 실험모델에 대한 비선형 시간이력해석을 수행한 결과를 비교하였다. 하부골조 형식은 모두 골조로 이루어진 형태(BF)와 전단벽이 한쪽 외부골조에 치우쳐 비틀림이 발생하는 형태(ESW)의 실험체에 대해 해석연구를 수행하였다. 철근과 콘크리트의 응력-변형률관계를 정의한 후 이를 단면에 이식시킨 섬유모델을 통해 비선형거동을 나타내도록 하였으며, 벽체는 MVLEM모델을 이용하였다. 해석결과 본 논문에서 제시한 비선형 모델은 필로티층의 거동(예를 들면 필로티층의 항복강도와 강성 상부구조물의 흔들림, 거동, 그리고 축력의 변화에 따른 축강성과 전단강성의 변화)을 비교적 정확하게 묘사하였다. 그러나 MVLEM으로 벽체의 비선형거동을 구성한 결과 거시거동은 실제 모델을 잘 따랐으나, 비틀림이 주된 진동주기일 때 발생하는 벽체 횡강성의 급격한 증가와 Warping현상으로 인해 코너기둥에 발생하는 과도한 인장력은 제대로 반영하지 못하였다. 비선형 해석으로 설계부재력을 구할 경우 실제보다 약 <TEX>$20{\sim}30%$</TEX> 작게 나타났는데, 이는 실험과 해석방법의 차이때문에 발생한 것으로 보이며, 비선형 거동이 과도하게 발생한 수준의 지진에 대해서는 필로티형 건물의 거동특성을 충실히 나타내었다. Two types of piloti-type high-rise RC building structures having irregularity in the lower two stories were selected as prototypes, and nonlinear time history analysis was performed using OpenSees to verify the analysis technique and to investigate the seismic capacity of those buildings. One of the buildings studied had a symmetrical moment-resisting frame (BF), while the other had an infilled shear wall in only one of the exterior frames (ESW). A fiber model, consisting of concrete and reinforcing bar represented from the stress-strain relationship, was adapted and used to simulate the nonlinearity of members, and MVLEM (Multi Vertical Linear Element Model) was used to simulate the behavior of the wall. The analytical results simulate the behavior of piloti-type high-rise RC building structures well, including the stiffness and yield force of piloti stories, the rocking behavior of the upper structure and the variation of the axial stiffness of the column due to variation in loading condition. However, MVLEM has a limitation in simulating the abrupt increasing lateral stiffness of a wall, due to the torsional mode behavior of the building. The design force obtained from a nonlinear time history analysis was shown to be about <TEX>$20{\sim}30%$</TEX> smaller than that obtained in the experiment. For this reason, further research is required to match the analytical results with real structures, in order to use nonlinear time history analysis in designing a piloti-type high-rise RC building.

Gebaute Umwelt als Determinante für Lageattraktivität

Abstract This study aims at assessing external effects of built environment. A hedonic model is employed to assess the percentage impact of area typical building structure on location desirability. We control for location by application of a decentralized approach based on potentiality variables and micro-level data. After controlling for legal building density, location and neighborhood characteristics we find that building structure proves to be a significant determinant for the value of urban land. While areas dominated by Wilhelminian-style attached arrangements generate premiums of up to 7.7%, properties embedded into a post-war modern-style building structure sell at significant discounts of up to 7%. These results not only highlight the role of built environment as determinant for attractiveness of urban location but also allow a considered evaluation of a range of policies for city development. Taking as a basis the market results, it is evident that the policy of careful renewal running since the...

Seismic Screening of Public Facilities in Oregon’s Western Counties

The objective of this study was to use rapid visual screening (RVS) methods to identify potential seismic hazards for Oregon's public facilities, including schools, hospitals, fire stations, police stations, and emergency response centers. There were 1,075 buildings screened in nine western Oregon counties. This study is part of a larger effort under the 2005 Oregon Senate Bill 2 to assess the seismic needs and upgrade public facilities in Oregon. RVS methodology generally followed the Federal Emergency Management Agency's FEMA 154 Rapid Visual Screening of Buildings for Potential Hazards: A Handbook. This method identifies structural type and building characteristics that may indicate poor performance under the maximum considered earthquake (MCE). Each building is given a final score related to the probability of collapse under the MCE. Screening was conducted by four individuals over three months. Quality assurance (QA) testing on nine buildings examined consistency between screeners. QA results showed final scores varied between screeners depending on building size, structure type, and architectural cladding. FEMA 154 was developed using California buildings. Differences between Oregon and California construction and the use of FEMA 154 in Oregon are discussed in this paper, reviewing the Uniform Building Code (UBC) and Oregon Structural Specialty Code (OSSC) amendments. The study provided two important conclusions. First, the average final score for buildings screened fell below the FEMA 154 cut-off score of 2.0 Second, the OSSC had an exception to the UBC that allowed the construction of unreinforced masonry buildings two stories or less in height. With this context, screening results can help in assigning priorities for further analysis and seismic retrofits.

Theory and Practice of New Types of Long-Span Building Structures Developed at Guizhou University

This paper presents the theory and practice of new types of long-span building structures developed at Guizhou University for the recent 25 years. The new structural systems include RC open-web sandwich plate structures, steel/RC composite open-web sandwich plate structures, prestressed RC open-web sandwich plate structures, and cast-in-place concrete round eye hollow plate structures. The mechanical characters and technical indexes of each system are described. The application of the structures is detailed in tables and photos.

Safety analysis on a vibrating prismatic body: A data-mining approach

In this paper, the flow-induced oscillation of a prismatic body, viz., a square section cylinder (test cylinder) under interference conditions is analysed considering it as representing a typical building structure. The analysis is carried out using a data-mining tool called ‘Decision Tree’ mainly in view of assessing the safety of the structure (test cylinder) with respect to the vibratory amplitude. To achieve this aim, wind tunnel studies have been conducted on the vibratory response of the test cylinder when it is vibrating in the vicinity of another square cylinder (interfering cylinder) which is placed at various locations relative to the test cylinder. The amplitude data thus obtained is suitably classified to carry out the safety analysis. All the data gathered pertains to at a single value of reduced velocity (10.0). Experiments have been carried out for various size ratios ( b/ B) of the test cylinder (upstream structure) and the interfering cylinder with values of 0.5, 1.0, 1.5 and 2.0. The results indicate that, for certain combinations of the parameters – relative position ( L/ B, T/ B) and size ratio ( b/ B), the upstream structure could vibrate with high amplitudes making the structural environment ‘critical’ (unsafe). In practical situations (such as in the case of tall buildings), the critical combinations of these parameters could be identified and eliminated for ensuring structural safety. Parametric combinations ensuring safe structural condition are also identified. Decision Tree also brings out the order of importance of various parameters influencing the interference excitation of the structure (test cylinder); L/ B is shown to be the most influencing parameter. The results also show that, for L/ B > 3.0, there is a higher possibility for the structure to become unsafe when compared to the conditions at L/ B ⩽ 3.0.

Status of the indoor air chemical pollution in Japanese houses based on the nationwide field survey from 2000 to 2005

This paper describes the present state and the changes in indoor air pollution levels by Volatile Organic Compounds (VOCs) in houses in Japan, as revealed through measurements of indoor VOC concentrations and investigations on the actual conditions in the residential environment by means of a questionnaire survey covering a total of more than 10,000 newly built houses over six years (from 2000 to 2005). The VOCs initially measured were formaldehyde, toluene, xylene, and ethylbenzene, followed by the subsequent inclusion of styrene and acetaldehyde. The survey in 2000 revealed that the indoor concentrations of formaldehyde and toluene exceeded the guideline values established by the Ministry of Health, Labor and Welfare (MHLW) of Japan in more than 27% and 12% of houses surveyed, respectively. This rapidly led to the development of a variety of countermeasures for improving the indoor air environment, such as the amendment of the Building Standard Law (BSL) to a performance-based regulation and the enactment of the Housing Quality Assurance Act, which provides a housing performance indication system. This study presents the changes in the state of indoor air pollution (including the mitigation of indoor air pollution by VOCs as their concentrations decreased) on a nationwide basis in all the types of building structures during the period from 2000 to 2005, when the regulatory measures mentioned above were instituted, and discusses factors associated with these changes.