scholarly journals STATISTICAL SUBSTANTIATION OF SNOW LOAD STANDARDS ON BUILDING STRUCTURES

2021 ◽  
pp. 103-118
Author(s):  
S.F. Pichugin ◽  
Keyword(s):  
Quantitative Description ◽  
Physical Nature ◽  
Building Design ◽  
Building Structures ◽  
Design Standards ◽  
Snow Load ◽  
Urgent Task ◽  
Design Values ◽  
Meteorological Observations ◽  
Scientific Results

Ensuring the reliability and safety of buildings and structures largely depends on a proper understanding of nature and quantitative description and rationing of loads on building structures, including snow loads. These loads on structures have a very complex physical nature and changeable nature, requiring knowledge of thermodynamic processes in the atmosphere and soil, physical properties of snow, methods of meteorological observations and climatological description of the terrain, variability of loads, the nature of snow deposition on buildings and structures. Such features are to some extent reflected in the sections of design standards of building structures that contain standards for snow load. Most parameters of snow load norms are probabilistic in nature and require the use of statistical methods to justify them. These methods are constantly changing and evolving along with the regular review of building design codes. Analysis of the evolution of domestic snow load codes together with their statistical substantiation is an urgent task. Materials on snow load have been published in various scientific and technical journals, collections of articles, conference proceedings. Access to these publications is difficult, and published reviews of the development of snow load rationing are incomplete and do not include the results of research over the past 15 – 20 years. The article contains a systematic review of publications in leading scientific and technical journals on the problem of snow load over the 80-year period from the 40s of the twentieth century to the present. The main attention is paid to the analysis of tendencies of development of designing codes concerning changes of territorial zoning and design coefficients, appointment of normative and design values of snow load and involvement in it of experimental statistical data. There is a high scientific level of domestic code DBN B.1.2-2006 "Loads and loadings", which have a modern probabilistic basis and are associated with the codes of Eurocode. Scientific results that can be included in subsequent editions of snow load standards are highlighted.

scholarly journals DEVELOPMENT OF RANKING OF CRANE LOADS ON BUILDING STRUCTURES

2021 ◽  
Vol 4 (164) ◽  
pp. 82-98
Author(s):  
S. Pichugin
Keyword(s):  
Quantitative Description ◽  
Building Design ◽  
Building Structures ◽  
Design Codes ◽  
Limit States ◽  
Construction Design ◽  
Industrial Buildings ◽  
New States ◽  
European Standards ◽  
Radical Revision

Ensuring the reliability and safety of buildings and structures largely depends on a proper understanding of the nature and quantitative description and rationing of loads on building structures, including crane loads. Loads from cranes can be significant; they have a variable dynamic nature and have a significant force on the structure of industrial buildings. These features are to some extent reflected in the sections of design codes of building structures that contain standards for crane load. Most of the parameters of the crane load codes are probabilistic nature and require the use of statistical methods to substantiate them. These methods are constantly changing and evolving together with the regular revision of building design codes. Analysis of the evolution of domestic codes of crane load together with their statistical substantiation is an urgent task, which is the purpose of this article. The beginning of domestic standardization of crane loads was laid in 1930, when the «Uniform codes of construction design» were introduced. They separately normalized vertical, horizontal longitudinal and horizontal transverse crane loads. This division is preserved in all subsequent versions of the load codes from bridge and overhead cranes. Since the late 1930s, leading construction research institutes and universities have conducted research on crane loads, the results of which have been consistently incorporated into design codes. These studies are time consuming and complex, as they are performed in existing production facilities and require the development of specific methods and equipment for measuring loads from operating bridge cranes. For 90 years, load codes have been constantly changing, taking into account the experience of operation and trends in construction science. The 50s of the last century were marked by the transition of structural calculations from the method of allowable stresses to the method of limit states, which led to a radical revision of the codes of crane loads. In the 60's and 80's, statistical studies of crane loads were intensified, the results of which opened up the possibility of reducing overload coefficients and introducing additional combination coefficients for crane loads. There were constant discussions about the assessment and consideration in the codes of horizontal transverse loads - braking and lateral forces from the skew of the moving cranes. This question still remains open for further research. It is also important to clarify the coefficients of load combination from several bridge cranes. With the collapse of the USSR, the new states had the opportunity to move away from the rough Soviet rationing and develop their own, more adequate codes for crane loads. Further development of crane codes in the CIS was realized in the form of national codes of individual states. Ukrainian specialists, in contrast to Russian standards developers, have prepared the State Standards of Ukraine DBN B.1.2: 2006 «Loads and impacts», conceptually different from SNiP in terms of crane loads. The publication of these codes was preceded by the systematization of the results of many years of work in the field of crane loads. Giving an overall assessment of Ukrainian standards of crane loads, it should be emphasized that they are compiled on a modern methodological basis, close to European standards Eurocode, based on representative statistics, more differentiated and have a scientific probabilistic rationale, more deeply developed than in codes of previous years.

THE EVOLUTION OF BUILDING DESIGN STANDARDS

2020 ◽  
Vol 0 (6) ◽  
pp. 119-134
Author(s):  
Denis Mykhaylovskyi ◽  
Bohdan Bondarchuk
Keyword(s):  
Building Design ◽  
Design Standards

scholarly journals Probabilistic Assessment of Roof Snow Load and the Calibration of Shape Coefficients in the Eurocodes

2021 ◽  
Vol 11 (7) ◽  
pp. 2984
Author(s):  
Pietro Croce ◽  
Paolo Formichi ◽  
Filippo Landi
Keyword(s):  
Conversion Factor ◽  
Reference Value ◽  
Construction Site ◽  
Probability Of Exceedance ◽  
Snow Load ◽  
Shape Coefficient ◽  
Annual Probability ◽  
Wind Exposure ◽  
Design Values ◽  
One Year

In modern structural codes, the reference value of the snow load on roofs is commonly given as the product of the characteristic value of the ground snow load at the construction site multiplied by the shape coefficient. The shape coefficient is a conversion factor which depends on the roof geometry, its wind exposure, and its thermal properties. In the Eurocodes, the characteristic roof snow load is either defined as the value corresponding to an annual probability of exceedance of 0.02 or as a nominal value. In this paper, an improved methodology to evaluate the roof snow load characterized by a given probability of exceedance (e.g., p=0.02 in one year) is presented based on appropriate probability density functions for ground snow loads and shape coefficients, duly taking into account the influence of the roof’s geometry and its exposure to wind. In that context, the curves for the design values of the shape coefficients are provided as a function of the coefficient of variation (COVg) of the yearly maxima of the snow load on the ground expected at a given site, considering three relevant wind exposure conditions: sheltered or non-exposed, semi-sheltered or normal, and windswept or exposed. The design shape coefficients for flat and pitched roofs, obtained considering roof snow load measurements collected in Europe during the European Snow Load Research Project (ESLRP) and in Norway, are finally compared with the roof snow load provisions given in the relevant existing Eurocode EN1991-1-3:2003 and in the new version being developed (prEN1991-1-3:2020) for the “second generation” of the Eurocodes.

Lateral Force Resisting Systems Made of Cold-Formed Steel Material: Proposal of Seismic Design Criteria for 2nd Generation of Eurocode 8

2021 ◽  
Vol 885 ◽  
pp. 127-132
Author(s):  
Sarmad Shakeel ◽  
Alessia Campiche
Keyword(s):  
Seismic Design ◽  
Shear Walls ◽  
Lateral Force ◽  
Background Information ◽  
Design Criteria ◽  
Eurocode 8 ◽  
Building Structures ◽  
Design Standards ◽  
Design Strength ◽  
Cold Formed Steel

The current edition of Eurocode 8 does not cover the design of the Cold-Formed steel (CFS) building structures under the seismic design condition. As part of the revision process of Euro-code 8 to reflect the outcomes of extensive research carried out in the past decade, University of Naples “Federico II” is involved in the validation of existing seismic design criteria and development of new rules for the design of CFS systems. In particular, different types of Lateral Force Resisting System (LFRS) are analyzed that can be listed in the second generation of Eurocode 8. The investigated LFRS’s include CFS strap braced walls and CFS shear walls with steel sheets, wood, or gypsum sheathing. This paper provides the background information on the research works and the reference design standards, already being used in some parts of the world, which formed the basis of design criteria for these LFRS systems. The design criteria for the LFRS-s common to CFS buildings would include rules necessary for ensuring the dissipative behavior, appropriate values of the behavior factor, guidelines to predict the design strength, geometrical and mechanical limitations.

scholarly journals An accurate single descriptor for ion–π interactions

2020 ◽  
Vol 7 (6) ◽  
pp. 1036-1045 ◽  
Author(s):  
Zhangyun Liu ◽  
Zheng Chen ◽  
Jinyang Xi ◽  
Xin Xu
Keyword(s):  
Electrostatic Interactions ◽  
Quantitative Description ◽  
Physical Nature ◽  
Binding Energies ◽  
Electrostatic Energy ◽  
Π Interactions ◽  
Practical Strategy ◽  
Leading Term ◽  
Level Method ◽  
High Level

Abstract Non-covalent interactions between ions and π systems play an important role in molecular recognition, catalysis and biology. To guide the screen and design for artificial hosts, catalysts and drug delivery, understanding the physical nature of ion–π complexes via descriptors is indispensable. However, even with multiple descriptors that contain the leading term of electrostatic and polarized interactions, the quantitative description for the binding energies (BEs) of ion–π complexes is still lacking because of the intrinsic shortcomings of the commonly used descriptors. Here, we have shown that the impartment of orbital details into the electrostatic energy (coined as OEE) makes an excellent single descriptor for BEs of not only spherical, but also multiply-shaped, ion–π systems, highlighting the importance of an accurate description of the electrostatic interactions. Our results have further demonstrated that OEEs from a low-level method could be calibrated to BEs from a high-level method, offering a powerful practical strategy for an accurate prediction of a set of ion–π interactions.

A Probabilistic Approach to the Prediction of Snow Loads

1974 ◽  
Vol 1 (1) ◽  
pp. 28-49 ◽  
Author(s):  
N. Isyumov ◽  
A. G. Davenport
Keyword(s):  
Formation Process ◽  
Extreme Values ◽  
Meteorological Data ◽  
Digital Simulation ◽  
Probabilistic Approach ◽  
Snow Accumulation ◽  
Meteorological Variables ◽  
Snow Load ◽  
Design Values ◽  
Snow Loads

The magnitudes of loads imposed by snow depend upon a number of climatological and meteorological variables and as a result exhibit marked variations geographically, due to local effects within a particular region, and with time. The snowload formation process, which depends both on the macro- and microclimates of such meteorological variables as the depth of the snowfall, the snowfall density, wind speed, air temperature etc., as well as, the size and geometry of particular roofs and the influence of their immediate environment, is discussed.A model of the snow load formation process based on a mass balance approach, which takes into account the deposition of snow by individual snowfalls and the depletion of the snow load by wind action and thermal effects, is introduced. The use of this approach requires the establishment of statistical descriptions of the various meteorological variables, as well as a knowledge of the physical process of snow accumulation and depletion for a particular roof. The statistical properties of some of the more important meteorological variables are discussed. Also presented are some model derived data of snow accumulation and depletion for particular roofs located in different terrain.It is shown that even relatively simple statistical descriptions of the relevant meteorological data and snow accumulation and depletion mechanisms can lead to realistic predictions of roof snow loads. Snow loads on a flat roof are generated by a digital simulation technique and compared with full scale observations. Annual extreme values of the simulated snow load process are presented and compared with currently specified design values. Comments are made regarding the practicability of this approach.

scholarly journals Analysis of the Response of a One-Storey One-Bay Steel Frame to Blast

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Rupert G. Williams ◽  
William A. Wilson ◽  
Reisa Dookeeram
Keyword(s):  
Analytical Study ◽  
Considerable Increase ◽  
Plastic Region ◽  
Blast Loading ◽  
Building Design ◽  
Charge Weight ◽  
Building Structures ◽  
Single Degree Of Freedom ◽  
Blast Design ◽  
Plane Frame

In recent years, there has been a considerable increase in perceived risks of blast loading attacks or similar incidents on structures. Blast design is therefore a necessary aspect of the design for building structures globally and as such building design must adapt accordingly. Presented herein is an attempt to determine the numerical response of a seismically designed single-degree-of-freedom (SDOF) structure to blast loading. The SDOF model in the form of a portal frame was designed to withstand a typical seismic occurrence in Northern Trinidad. Blast loads caused by applying a 500 kg charge weight of TNT at standoff distances of 45 m, 33 m, and 20 m were then applied to the model. The blast loading on the frame was determined using empirical methods. The analytical study showed that the seismically designed SDOF plane frame model entered the plastic region during the application of the blast load occurring up to the critical standoff distance.

scholarly journals Directions of Convergence of the Requirements of the Main Domestic Standard for the Design of Concrete and Reinforced Concrete Structures SP 63.13330.2012 with the Requirements of the International Standard ISO 19338

2019 ◽  
pp. 93-98
Author(s):  
Sergey B. Krylov ◽  
Ravil S. Sharipov ◽  
Sergey A. Zenin ◽  
Yury S. Volkov
Keyword(s):  
Reinforced Concrete ◽  
Prestressed Concrete ◽  
Concrete Structures ◽  
National Standards ◽  
Reinforced Concrete Structures ◽  
Building Structures ◽  
Design Standards ◽  
Structural Concrete ◽  
International Standard ◽  
Assessment Requirements

Design standards on building structures should contain, first of all, the performance and assessment requirements of structures. At the same time, design standards should provide the possibility for design and construction of concrete and reinforced concrete parts of buildings and structures that meet the requirements of the Technical regulations "On the safety of buildings and structures". Taking into account the importance of ensuring the reliability and safety of buildings and structures erected with the use of structural concrete, the technical Committee of the international organization for standardization ISO TC 71 "Concrete, reinforced concrete and prestressed concrete", certifies national standards for compliance with the requirements of the international standard ISO 19338 "Performance and Assessment Requirements for Design Standards on Structural Concrete", developed by the same Committee. The standard describes the issues that should be included in the standards for the design of concrete and reinforced concrete structures (terms and definitions, basic requirements, performance requirements,loads and impacts, design estimates, requirements for manufacturing and construction, as well as quality control). These requirements are common to all standards in the design of concrete and reinforced concrete structures. In this regard, it is relevant and important to establish the possibility of presenting the National Code of rules SP 63.13330.2012 "SNiP 52.01-2003 Plain and Reinforced Concrete Structures. General Provisions" for certification for compliance with the requirements of ISO 19338. To achieve this goal, the relevant work has been done, based on the results of which were made the proposals for the submission of SP 63.13330.2012 for certification for compliance with ISO 19338:2014. These proposals are set out in the text of the article.

scholarly journals THE RELEVANCE OF CHANGING THE DESIGN SOLUTION COVERAGE WITHOUT STRENGTHENING EXISTING FOUNDATIONS

2019 ◽  
Vol 7 (2) ◽  
pp. 42-49
Author(s):  
Ольга Хрянина ◽  
Ol'ga Hryanina ◽  
Мария Колесникова ◽  
Maria Kolesnikova
Keyword(s):  
Raw Materials ◽  
Technical Condition ◽  
Operating Conditions ◽  
Design Solution ◽  
Building Structures ◽  
Construction Site ◽  
Satisfactory Condition ◽  
Geological Conditions ◽  
Design Values ◽  
Instrumental Methods

The authors carried out the study of raw materials and their analysis, which allowed to identify the engineering-geological conditions of the construction site and outline the program of scientific and survey works. Full-scale and instrumental examination of the technical condition of the bearing and enclosing structures of the building. It is established that the building structures during operation have not received deformations that prevent normal operating conditions and are currently in satisfactory condition. The strength of concrete Foundation organoleptic and instrumental methods, which showed compliance with the design values. Analysis of verification calculations of the base, a satisfactory condition of the building structures showed that the structural solution of the coating can be changed and performed in kind without strengthening the existing foundations.

scholarly journals Evaluation of Design Standards of Four-Hour Volume Traffic Signal Warrant

2012 ◽  
Vol 49 (3) ◽  
Author(s):  
Xuesong Zhu ◽  
Albert Gan ◽  
David Shen
Keyword(s):  
Traffic Control ◽  
Traffic Signal ◽  
Microscopic Simulation ◽  
Design Standards ◽  
Control Delay ◽  
Critical Design ◽  
Design Values ◽  
Average Control ◽  
Street Traffic ◽  
Control Devices

Traffic signal warrants set the minimum conditions under which a traffic signal installation may be appropriate. The four-hour volume signal warrant in the current Manual on Uniform Traffic Control Devices (MUTCD) (FHWA 2009) is applied based on a set of critical vehicular volumes for different lane combinations of major and minor streets. This paper describes an effort to apply microscopic simulation to evaluate the critical volumes used in the four-hour warrant. The results show significant differences in average control delay for minor street traffic under different volume combinations, lane configurations, turning volume percentages, heavy vehicle percentages, and the number of major street lanes (four versus six lanes), most of which are not currently considered in the four-hour warrant. This finding provides some evidence of the need to possibly revise the critical design values of the current four-hour volume warrant.

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