Erratum: “Empirical evidence for site coefficients in building code provisions” [Earthquake Spectra 18, 189–217 (2002)]

2003 ◽  
Vol 19 (2) ◽  
pp. 453-454
Author(s):  
Roger D. Borcherdt
Keyword(s):  
Empirical Evidence ◽  
Building Code ◽  
Site Coefficients ◽  
Code Provisions

Empirical Evidence for Site Coefficients in Building Code Provisions

2002 ◽  
Vol 18 (2) ◽  
pp. 189-217 ◽  
Author(s):  
Roger D. Borcherdt
Keyword(s):  
Confidence Level ◽  
Empirical Data ◽  
Site Response ◽  
Building Code ◽  
Northridge Earthquake ◽  
Empirical Estimates ◽  
Site Coefficients ◽  
Percent Confidence Level ◽  
Lower Confidence Bound ◽  
Code Provisions

Site-response coefficients, Fa and Fv, used in U.S. building code provisions are based on empirical data for motions up to 0.1 g. For larger motions they are based on theoretical and laboratory results. The Northridge earthquake of 17 January 1994 provided a significant new set of empirical data up to 0.5 g. These data together with recent site characterizations based on shear-wave velocity measurements provide empirical estimates of the site coefficients at base accelerations up to 0.5 g for Site Classes C and D. These empirical estimates of Fa and Fv as well as their decrease with increasing base acceleration level are consistent at the 95 percent confidence level with those in present building code provisions, with the exception of estimates for Fa at levels of 0.1 and 0.2 g, which are less than the lower confidence bound by amounts up to 13 percent. The site-coefficient estimates are consistent at the 95 percent confidence level with those of several other investigators for base accelerations greater than 0.3 g. These consistencies and present code procedures indicate that changes in the site coefficients are not warranted. Empirical results for base accelerations greater than 0.2 g confirm the need for both a short- and a mid- or long-period site coefficient to characterize site response for purposes of estimating site-specific design spectra.

PCI Standard Design Practice Ref ACI 318-14

2021 ◽  
Author(s):  
Keyword(s):  
Prestressed Concrete ◽  
Precast Concrete ◽  
Building Code ◽  
Design Practice ◽  
Structural Concrete ◽  
Design Engineers ◽  
Standard Design ◽  
Precast Prestressed Concrete ◽  
Consistent Approach ◽  
Code Provisions

Precast, prestressed concrete design is based on conformance with the provisions of the American Concrete Institute’s (ACI’s) Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14). In most cases, these provisions are followed explicitly. Occasionally, interpretation of some sections of ACI 318 is required to ensure quality is maintained in conjunction with the unique characteristics of precast and prestressed concrete fabrication, shipping, and erection. Members of the PCI Building Code Committee, along with other experienced precast concrete design engineers, have identified code provisions, detailed in this publication, that require clarification or interpretation. These design practices are followed by most precast concrete design engineers to produce safe, economical precast concrete structures and they provide a consistent approach for the designers and contractors.

Eccentricity in irregular multistory buildings

1986 ◽  
Vol 13 (1) ◽  
pp. 46-52 ◽  
Author(s):  
V. W.-T. Cheung ◽  
W. K. Tso
Keyword(s):  
Dynamic Analysis ◽  
Necessary Conditions ◽  
Vertical Axis ◽  
Building Code ◽  
Necessary Condition ◽  
Practical Procedure ◽  
Multistory Buildings ◽  
Plane Frame ◽  
Code Procedure ◽  
Code Provisions

To evaluate the seismic torsional effect on multistory buildings, the concept of eccentricity is extended from single-story buildings to multistory buildings by defining the locations of the centers of rigidity at each floor. A practical procedure to locate the centers of rigidity and hence floor eccentricity is introduced. This procedure depends on the use of plane frame computer programs only and is suitable for use in design offices. The seismic torsional provisions in the National Building Code of Canada 1985 (NBCC 1985) explicitly emphasize that the code provisions apply to buildings where the centres of rigidity lie on a vertical axis only. By means of examples, it verifies the claim of NBCC 1985. Also, it shows that, for buildings with centers of rigidity scattered from a vertical axis, the code procedure may or may not apply. Therefore, one should interpret the condition of centers of rigidity located along a vertical axis to be a sufficient, but not a necessary, condition for the NBCC 85 code provisions to be applicable. Until the necessary conditions are known, dynamic analysis remains the most reliable method to assign the torsional effects to various portions of the building. Key words: building code, center of rigidity, dynamic analysis, eccentricity, irregular, multistory, seismic, torsion.

Design for seismic torsional forces

1984 ◽  
Vol 11 (2) ◽  
pp. 150-163 ◽  
Author(s):  
J. L. Humar
Keyword(s):  
Ground Motion ◽  
Analytical Study ◽  
Critical Evaluation ◽  
Building Code ◽  
Rotational Ground Motion ◽  
Building Model ◽  
Design Basis ◽  
Building Models ◽  
Adequate Design ◽  
Code Provisions

An analytical study of the responses of a single storey and a multistorey building model to a combined translational and rotational ground motion is presented. The models, which are assumed to be elastic, are eccentric about one plan direction but are symmetric about the perpendicular direction. The ground excitations are represented by idealized spectra.A critical evaluation is made of the torsion provisions of the National Building Code of Canada. It is shown that the code provisions, while not necessarily nonconservative, are somewhat difficult to apply for multistorey buildings. An alternative provision for design eccentricity is proposed. The forces obtained by the use of the proposed method are compared with the analytical results of single storey and multistorey building models and are shown to provide an adequate design basis.

scholarly journals Facilities Planning for Safety and Emergency Response: Bridging the Gap between Design Features and Safety Planning

2013 ◽  
Vol 56 (1) ◽  
pp. 17-28
Author(s):  
Steve Schultz ◽  
Jack Paul
Keyword(s):  
Emergency Response ◽  
Building Construction ◽  
Building Code ◽  
Safety Planning ◽  
Design Features ◽  
Safe Operation ◽  
Facilities Planning ◽  
Safety Considerations ◽  
Code Provisions ◽  
Design And Construction

This article describes some of the safety considerations for the design and construction of micro/nano facilities and applicable building code provisions. The two key elements required for safe operation in micro and nanotechnology facilities are: (1) engineered features incorporated into building construction, and (2) administrative features that deal with how people work within the facility.

Updated Port Wave/Flood Load Building Code Provisions

Ports 2010 ◽  
2010 ◽  
Author(s):  
U. Prasad ◽  
S. Fenical ◽  
C. Delp
Keyword(s):  
Building Code ◽  
Code Provisions

A proposal to improve the static torsional provisions for the National Building Code of Canada

1983 ◽  
Vol 10 (4) ◽  
pp. 561-565 ◽  
Author(s):  
W. K. Tso
Keyword(s):  
Building Code ◽  
Torsional Moment ◽  
Moment Estimates ◽  
Modal Coupling ◽  
Code Provisions

A proposal consisting of four recommendations is presented to improve some of the shortcomings of the seismic torsional provisions in the National Building Code of Canada 1980. The first two changes will improve the torsional moment estimates for buildings with small and large ecentricities, taking the effect of modal coupling into account. The second two proposed changes clarify the limitations of the static code provisions.

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