scholarly journals Limit States Design—A Probabilistic Study

1975 ◽  
Vol 2 (1) ◽  
pp. 36-49 ◽  
Author(s):  
D. E. Allen
Keyword(s):  
Structural Steel ◽  
Composite Structures ◽  
Human Error ◽  
Residential Buildings ◽  
Building Structures ◽  
Limit States ◽  
Design Rules ◽  
Performance Factors ◽  
Importance Factor ◽  
Probabilistic Study

Canadian structural standards for buildings are moving toward a unified limit states philosophy with common safety and serviceability criteria for all materials and types of construction. Structural steel and cold formed steel will have limit states design rules by 1975 and concrete, masonry, and wood will follow later.This paper compares the new rules with existing NBC/CSA requirements on the basis of probability of failure calculated by simplified theory. The main emphasis is on load combinations of dead, floor, and wind loads for office and residential buildings where failure occurs by yielding of steel. Other aspects of the new limit states design rules—column formula for structural steel, performance factors for composite structures, the importance factor which reflects the seriousness of failure, and safety factors during construction, are also considered.The results indicate that the new rules provide more consistent safety than existing rules for different combinations of loads and materials; and that simple rules are sufficiently accurate, keeping in mind the predominating influence of human error on failures and the simplifications used in analyzing complex building structures.

Influence of Human Error on Structural Reliability

2017 ◽  
Author(s):  
Eric Brehm ◽  
Robert Hertle ◽  
Markus Wetzel
Keyword(s):  
Human Error ◽  
Structural Reliability ◽  
Failure Modes ◽  
Structural Model ◽  
Limit State ◽  
Design Procedure ◽  
Material Strength ◽  
Limit States ◽  
The Impact

In common structural design, random variables, such as material strength or loads, are represented by fixed numbers defined in design codes. This is also referred to as deterministic design. Addressing the random character of these variables directly, the probabilistic design procedure allows the determination of the probability of exceeding a defined limit state. This probability is referred to as failure probability. From there, the structural reliability, representing the survival probability, can be determined. Structural reliability thus is a property of a structure or structural member, depending on the relevant limit states, failure modes and basic variables. This is the basis for the determination of partial safety factors which are, for sake of a simpler design, applied within deterministic design procedures. In addition to the basic variables in terms of material and loads, further basic variables representing the structural model have to be considered. These depend strongly on the experience of the design engineer and the level of detailing of the model. However, in the clear majority of cases [1] failure does not occur due to unexpectedly high or low values of loads or material strength. The most common reasons for failure are human errors in design and execution. This paper will provide practical examples of original designs affected by human error and will assess the impact on structural reliability.

scholarly journals Effective polyurethane compositions filled with industrial wastes

2018 ◽  
Vol 7 (2.13) ◽  
pp. 240
Author(s):  
Goncharova Margarita Alexandrovna ◽  
Korneeva Anastasia Olegovna ◽  
Korneev Oleg Olegovich ◽  
Hameed Ghalib Hussain Al-Surraiwy
Keyword(s):  
Polyurethane Foam ◽  
Residential Buildings ◽  
Converter Slag ◽  
Sandwich Panels ◽  
High Strength ◽  
Average Density ◽  
Polyurethane Foams ◽  
Industrial Wastes ◽  
Building Structures ◽  
Coefficient Of Thermal Conductivity

Formulations are developed and optimized for of rigid polyurethane foams filled with converter slag. The optimum content of the filler is 30%. Polyurethane compositions have the following characteristics: average density – 42.59 kg/m3, compressive strength at 10% deformation – 0.293 MPa, water absorption by volume 1.71%, coefficient of thermal conductivity – 0.028 W/m·0C. Polyurethane foams are applied in sandwich panels, multi-layer roof constructions and for the manufacture of fixing systems for metal rolled.Sandwich panels with polyurethane foam insulation and sheathing of specialized panels are designed for the construction of pre-fabricated residential buildings. The forecasting of polyurethane durability in building structures as thermal insulation in sandwich panels the foam lifespan is about 75 years, which is approximately two times greater than that of the unreinforced foam.Layered roof structures with modified rigid polyurethane foam are used for buildings and structures for various purposes. Their use makes it possible to solve several tasks: creating a complete architectural image, ensuring high strength and deformation characteristics with good noise and heat insulation, minimization when mounting. The use of lightweight, transportable and technologically advanced roofing elements in conditions of mass production creates significant opportunities for industrial construction. The proposed foam fixing systems during shipping rolled metal in containers makes it possible to exclude the possibility of the longitudinal and transverse shift of pallets with rolls, to protect metal from damage, to simplify the design of the foxing elements, reduce the production cost, and minimize the amount of time for fixing metal rolls in the container.  

MODELING THE WEAR PROCESS OF BRICK BUILDINGS

2021 ◽  
Vol 14 (1) ◽  
pp. 44-50
Author(s):  
S. Nikolenko ◽  
Svetlana Sazonova ◽  
N. Akamsina
Keyword(s):  
Residential Buildings ◽  
Subsequent Development ◽  
Residential Building ◽  
Building Structures ◽  
Apartment Building ◽  
Wear Process ◽  
Physical Deterioration ◽  
Technical Examination

The main damages in brick structures of buildings are considered. The purpose of the work is to analyze the results of a technical examination of the building structures of a residential building, with the subsequent development of proposals for their restoration and strengthening. The object of the study is the brick structures of the house. The process of organizing a technical survey of brick residential buildings, which allows to determine the procedure for collecting and storing data, is considered. Modern solutions for the restoration of building structures are proposed. The physical deterioration of the apartment building was determined and recommendations were given for the elimination of brickwork defects.

scholarly journals Research Status on Steel-bamboo Composite Structure

2019 ◽  
Vol 275 ◽  
pp. 01018
Author(s):  
Jialiang Zhang ◽  
Keting Tong ◽  
Pei Wu ◽  
Yushun Li
Keyword(s):  
Composite Structures ◽  
High Capacity ◽  
Building Structures ◽  
Composite Section ◽  
Long Time ◽  
Section Design ◽  
New Type ◽  
Cold Formed Steel ◽  
Composite Wall ◽  
Structural Adhesive

This paper presents a new type of lightweight composite structural system using bamboo-based panel and cold-formed thin-walled steel. The bamboo-based panel and cold-formed steel with C-section and U-section or profiled steel sheet can form various steel-bamboo composite members, including composite slab, composite wall, composite beam and composite column, utilizing structural adhesive or adhesive-screw reinforced joins. The paper summarizes the section design, mechanical experiments of the steel-bamboo composite structures based on the application of bamboo-based panel in modern building structures. Research shows that the two materials can form a perfect composite section and the connection systems are very effective in a long time, composite members have high capacity, ideal stability and ductility. The study shows that steel-bamboo composite components have good prospects in building structures of China.

scholarly journals An Intelligent Model to Predict Energy Performances of Residential Buildings Based on Deep Neural Networks

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 571 ◽  
Author(s):  
Azadeh Sadeghi ◽  
Roohollah Younes Sinaki ◽  
William A. Young ◽  
Gary R. Weckman
Keyword(s):  
Neural Networks ◽  
Sensitivity Analysis ◽  
Goodness Of Fit ◽  
Deep Neural Networks ◽  
Residential Buildings ◽  
Independent Set ◽  
Energy Performance ◽  
Processing Technique ◽  
Building Structures ◽  
Wall Area

As the level of greenhouse gas emissions increases, so does the importance of the energy performance of buildings (EPB). One of the main factors to measure EPB is a structure’s heating load (HL) and cooling load (CL). HLs and CLs depend on several variables, such as relative compactness, surface area, wall area, roof area, overall height, orientation, glazing area, and glazing area distribution. This research uses deep neural networks (DNNs) to forecast HLs and CLs for a variety of structures. The DNNs explored in this research include multi-layer perceptron (MLP) networks, and each of the models in this research was developed through extensive testing with a myriad number of layers, process elements, and other data preprocessing techniques. As a result, a DNN is shown to be an improvement for modeling HLs and CLs compared to traditional artificial neural network (ANN) models. In order to extract knowledge from a trained model, a post-processing technique, called sensitivity analysis (SA), was applied to the model that performed the best with respect to the selected goodness-of-fit metric on an independent set of testing data. There are two forms of SA—local and global methods—but both have the same purpose in terms of determining the significance of independent variables within a model. Local SA assumes inputs are independent of each other, while global SA does not. To further the contribution of the research presented within this article, the results of a global SA, called state-based sensitivity analysis (SBSA), are compared to the results obtained from a traditional local technique, called sensitivity analysis about the mean (SAAM). The results of the research demonstrate an improvement over existing conclusions found in literature, which is of particular interest to decision-makers and designers of building structures.

scholarly journals Behavior of an Advanced Bolted Shear Connector in Prefabricated Steel-Concrete Composite Beams

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2958 ◽  
Author(s):  
Jun Chen ◽  
Wei Wang ◽  
Fa-Xing Ding ◽  
Ping Xiang ◽  
Yu-Jie Yu ◽  
...  
Keyword(s):  
Composite Structures ◽  
Concrete Slab ◽  
Concrete Strength ◽  
High Strength ◽  
Fe Model ◽  
Building Structures ◽  
Shear Connector ◽  
Test Results ◽  
Shear Connectors ◽  
Bolt Pretension

The high-strength bolt shear connector in prefabricated concrete slab has advantages in applications as it reduces time during the construction of steel-concrete composite building structures and bridges. In this research, an innovative and advanced bolt shear connector in steel-concrete composite structures is proposed. To investigate the fundamental mechanical behavior and the damage form, 22 static push-off tests were conducted with consideration of different bolt dimensions, the reserved hole constraint condition, and the dimension of slab holes. A finite element (FE) model was established and verified by using test results, and then the model was utilized to investigate the influence of concrete strength, bolt dimension, yield strength, bolt pretension, as well as length-to-diameter ratio of high strength bolts on the performances of shear connectors. On the basis of FE simulation and test results, new design formulas for the calculation of shear resistance behavior were proposed, and comparisons were made with current standards, including AISC, EN 1994-1-1, GB 50017-2017, and relevant references, to check the calculation efficiency. It is confirmed that the proposed equation is in better agreement with the experimental results.

Safety factors and limit states analysis in geotechnical engineering

1984 ◽  
Vol 21 (1) ◽  
pp. 1-7 ◽  
Author(s):  
G. G. Meyerhof
Keyword(s):  
Geotechnical Engineering ◽  
Stability Conditions ◽  
Safety Factors ◽  
Limit States ◽  
Resistance Factors ◽  
Performance Factors ◽  
Load Factors ◽  
Partial Safety Factors ◽  
And Performance ◽  
Earth Retaining Structures

This paper outlines the ultimate and serviceability limit states in geotechnical engineering analyses. The magnitude of customary total and suggested partial safety factors in earthworks, earth retaining structures, excavations, and foundations is discussed. On the basis of comparisons between these safety factors and using recommended load factors on various types of loading, including water pressures, common resistance factors on cohesion and friction of soils and performance factors can be established together with some additional modification factors for particular stability conditions. The serviceability limit states of foundations and structures are briefly discussed.

Vibro-Acoustic Comfort Assessment Methodology of Residential Buildings in Urban Environment

2014 ◽  
Vol 1041 ◽  
pp. 428-431 ◽  
Author(s):  
Marian Flimel
Keyword(s):  
Urban Environment ◽  
Residential Buildings ◽  
Evaluation Criteria ◽  
Objective Evaluation ◽  
Sound Insulation ◽  
Building Structures ◽  
Assessment Methodology ◽  
Noise Sources ◽  
Acoustic Comfort ◽  
And Performance

Noise in residential buildings should be assessed not only in terms of impact on health, safety and performance of inhabitants, but also for the “value” of the building (apartment) in a certain environment. Building energetic certification implementation is one of the first compulsory legislative evaluation criteria. This paper wants to draw the attention to the need for vibro-accoustic building (apartment) certification. Presented tabular evaluation is an objective evaluation. The reason for that are the tendencies related to noise in environment: increased number and levels of noise sources in buildings’ exterior and interior, increasing demands for sound insulation of building structures and growing number of “noise” complaints.

scholarly journals TECHNOLOGICAL AND SOCIAL RETROFIT STRATEGIES FOR THE PUBLIC RESIDENTIAL BUILDINGS OF THE SECOND POST-WAR

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Michele Di Sivo ◽  
Daniela Ladiana ◽  
Giovanni Santi ◽  
Lediana Rrjolli
Keyword(s):  
World War Ii ◽  
Urban Areas ◽  
Social Inclusion ◽  
Residential Buildings ◽  
Seismic Energy ◽  
Building Structures ◽  
Initial Examination ◽  
Suggested Approach ◽  
The Individual ◽  
The Impact

This experimental study on the renewal of post-World War II suburban areas addresses the theme of the technological retrofitting of buildings, focusing on typological features, construction techniques and, more in general, of all aspects that fail to meet the needs of contemporary living. An initial examination of Italian and international case studies helped to identify possible guidelines for the optimization of urban renewal activities. The guidelines were tested by applying them to a case study: a 1950s-era neighborhood in the city of Pisa. The study undertaken highlights the need to consistently integrate all of the activities that affect the building structures-consolidations and static adjustments, improvement of energy efficiency, functional and spatial adaptation-and that work towards strengthening social integration by taking into account the specific needs of the individual. The work is implemented on individual buildings and urban areas, with the aim of improving the local identity characteristics. The suggested approach is that of a circular economy, which helps to reduce the impact on the environment, mainly through the extensive use of recycled materials. The proposed experiment thus aims to test the resilience of buildings following their seismic, energy and functional updating, including sociological and environmental psychology assessments, with particular attention to vulnerable users, in order to find solutions capable of promoting social inclusion.

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