Review of NBCC earthquake-resistant design requirements for cladding connectors

1994 ◽  
Vol 21 (3) ◽  
pp. 455-460 ◽  
Author(s):  
Michel Bruneau ◽  
Julie Mark Cohen

As a consequence of recent increases in the severity of seismic design force requirements in Canada, practicing engineers who design cladding connectors should be concerned with their seismic resistance. The current design requirements of the 1990 edition of the National Building Code of Canada for nonstructural components call for unduly high prescribed design forces for the cladding connectors without providing justification, commentary, or substantiation for this constraint, nor guidance on how this is to be achieved. This paper offers some rationalization of these stringent design requirements based on a review of their evolution, outlines some of the shortcomings of the current design approach, recommends possible abatements of the requirements in special cases, and points toward future directions and alternate philosophies for the design of cladding connectors. In particular, the following are recommended: (i) the scope of Part 4 of the National Building Code of Canada should be modified to specifically indicate that cladding connectors are to be designed by a professional engineer, (ii) the latest cladding-connector seismic-resistant design philosophy of the Structural Engineers Association of California should be incorporated into the National Building Code of Canada; (iii) a distinction should be made between out-of-plane and in-plane cladding-connector seismic-resistant design requirements; (iv) a commentary should be written on cladding-related seismic-resistant design issues to clearly state current philosophy, uncertainties, and limits of knowledge be included in the building code, and (v) standardized seismic-resistant cladding connectors be developed with capacities to meet prescribed levels of ductile behavior and interstory drifts and widely distributed to the profession. Key words: cladding, connectors, earthquake, design, code, seismic.

2000 ◽  
Vol 16 (1) ◽  
pp. 115-125 ◽  
Author(s):  
Richard M. Drake ◽  
Leo J. Bragagnolo

With the publication of the 1997 Uniform Building Code ( UBC) and the 1997 NEHRP Recommended Provisions for the Seismic Regulations for New Buildings and Other Structures, there has been a significant change in the earthquake design force provisions for buildings, structures, elements of structures and nonstructural components. Engineers and architects need to become informed regarding a variety of earthquake design force provisions, primarily those published in the UBC and those developed as part of the NEHRP Provisions. Both sources provide design force provisions for the building structural system and separate design force provisions for elements of structures and nonstructural components. This paper describes the development, evolution, and application of the earthquake design force provisions for elements of structures and nonstructural components.


2003 ◽  
Vol 30 (2) ◽  
pp. 279-286 ◽  
Author(s):  
Ronald H DeVall

There are many changes proposed for the Earthquake Design Provisions of the 2005 edition of the National Building Code of Canada (NBCC). Among them are requirements for complete load paths, separation of stiff nonstructural elements, and the introduction of definitions of irregular structures and special design requirements associated with these irregularities. A new requirement for direction of loading is introduced, along with requirements for elements common to more than one lateral load resisting system. The effects of displacements are emphasized throughout the document, and revised provisions for drift limits are proposed. Revisions to the importance factor that integrate it into the proposed revised format for Part 4, Structural design, of the NBCC are given. Background information is presented.Key words: load path importance factor, irregular structures, direction of loading, special requirements, drift limits.


2011 ◽  
Vol 473 ◽  
pp. 209-216
Author(s):  
Eugen Oswald ◽  
Mathias Liewald ◽  
Oliver Stephan

In the automotive industry, current design and dimensioning of forming tools and bearing tool components occurs according to guidelines. Possible interactions between arising loads as well as dimensioning are empirically estimated. Simulative computations, which are based on CAE-methods, are only realized in special cases. Therefore, most often current standards lead to oversized tools. In consequence, new studies based on CAE-analyses are supposed to investigate new possibilities to design forming tools and components optimized in their structure corresponding to the right distribution of forces and stress. This is made in order to increase reliability during the manufacturing process, as well as the tools’ stiffness and contribute to decrease of investment costs.


Author(s):  
Kevin McCue

A recently published seismic zoning map of Papua New Guinea does not correlate particularly well with either presentday seismicity or tectonic models of the region. Several reasons are given and a modified version of the map is presented for discussion and as a replacement in the Building Code.


Author(s):  
Yasser Hassan

Design of vertical alignment is one of the main tasks in highway geometric design. This task requires, among other things, that the designer ensure drivers always have a clear view of the road so they can stop before hitting an unexpected object in the road. Therefore, the ability to determine the required and available stopping sight distance (SSD) at any point of the vertical alignment is essential for the design process. Current design guides in the United States and Canada provide simple analytical models for determining the minimum length of a vertical curve that would satisfy the sight distance requirement. However, these models ignore the effect of grade on the required SSD. Alternative approaches and models have also been suggested but cover only special cases of vertical curves. Two specific models were expanded to determine the required SSD on crest and sag vertical curves. By comparing profiles of available SSD and required SSD on examples of vertical curves, it was shown that current North American design practices might yield segments of the vertical curve where the driver’s view is constrained to a distance shorter than the required SSD. An alternative design procedure based on the models was developed and used to determine the minimum lengths of crest and sag vertical curves. Depending on the approach grade, these new values of minimum curve length might be greater than or less than values obtained through conventional design procedures. Design aids were therefore provided in tabular form for designers’ easy and quick use.


Author(s):  
Bernhard Bettig ◽  
Vikram Bapat ◽  
Balaji Bharadwaj

Computers are being used extensively in the manufacturing industry to design and analyze products. In spite of the power of existing CAD systems and potential power of current Design Automation systems, we believe that they possess an inherent limitation that keeps them from aligning with and fully supporting the design process. Specifically, all of these systems are based on using parametric operators to generate valid designs. This paper examines the limitations of parametric operators for CAD and design automation and shows how “variational” methods could be used. An approach using variational methods is compared with traditional CAD and design automation methods. The paper also proposes a language of objects and relationships to represent design requirements. This work is a step towards realizing an interactive design synthesis system that can represent and satisfy design requirements.


2005 ◽  
Vol 21 (1) ◽  
pp. 213-224 ◽  
Author(s):  
Brian J. Sielaff ◽  
Richard J. Nielsen ◽  
Edwin R. Schmeckpeper

Seismic design requirements for precast concrete cladding panel connections have evolved significantly over the past fifty years. This paper summarizes the pertinent requirements from the Uniform Building Code from 1967 to 1997, and the International Building Code 2000. A hypothetical design illustrates how emphasis in the code has evolved for both lateral force requirements and story drift displacement requirements arriving at a balance of moderate lateral force and displacement requirements. The numerical results are based on a hypothetical case of panel connections for a ten-story moment-resisting steel frame structure built in seismic Zone 4. This historical summary is of value to designers who deal with the seismic rehabilitation of precast panel connections.


2000 ◽  
Vol 16 (1) ◽  
pp. 141-162
Author(s):  
S. K. Ghosh

U.S. seismic codes are undergoing profound changes as of this writing. Changes from the 1994 to the 1997 edition of the Uniform Building Code (UBC) (ICBO 1994, 1997) are many and far-reaching in their impact. The 1997 edition of the National Earthquake Hazards Reduction Program (NEHRP) Recommended Provisions for Seismic Regulations for New Buildings (BSSC 1998) contains further evolutionary changes in seismic design requirements beyond those of the 1997 UBC. The latter document will form the basis of the seismic design provisions of the first edition of the International Building Code (IBC), to be published in the spring of 2000. This paper first discusses the major changes that have been made in the concrete-related provisions from the 1994 to the 1997 edition of the UBC. The paper gives background to these changes, provides essential details on them, and indicates how they have been or how they are going to be incorporated (at times with significant modifications) into the 1997 NEHRP Provisions and the 2000 IBC. The newly published ACI 318-99, Building Code Requirements for Structural Concrete (ACI 1999), is going to be adopted by reference into the 2000 IBC. This entails further changes in concrete-related provisions beyond the 1997 UBC. Some of the more important of these changes are discussed here. A small number of amendments and additions to the ACI 318-99 provisions are going to be included in the 2000 IBC. The more important of these are also outlined in this paper.


2013 ◽  
Vol 275-277 ◽  
pp. 1441-1445
Author(s):  
Jiang Chun Hu ◽  
Hong Fang Wang ◽  
Chen Li

Seismic liquefaction is a major geological hazard of earthquakes. In the paper, the earthquake liquefaction of subway engineering in GUANGZHOU is calculated based on the standard penetration test method according to the rules of code for seismic design of buildings, specifications of earthquake resistant design for highway engineering, code for water resources and hydropower engineering geological investigation as well as the railway engineering anti-earthquake design specification. It is concluded that different code have very different result on sand liquefaction discrimination. And the data selection is a key factor when we discriminate sand liquefaction. The shortage of codes is evaluating the site liquefaction according to the data of points. The conclusions have positive role for engineering seismic liquefaction discrimination and the seismic liquefaction mechanism research.


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