On the dynamic foundation factor for the National Building Code of Canada: low to medium rise buildings

1994 ◽  
Vol 21 (2) ◽  
pp. 353-356
Author(s):  
A. C. Heidebrecht ◽  
A. Rutenberg
Keyword(s):  
Engineering Design ◽  
Seismic Response ◽  
Earthquake Engineering ◽  
Building Codes ◽  
Building Code ◽  
Building Structures ◽  
Response Factors ◽  
Vibration Period ◽  
Site Specific ◽  
Site Investigations

Site-specific seismic response factors for low-period building structures are presented as an alternative to the recently proposed foundation factor F* for inclusion in the seismic provision of the National Building Code of Canada. These factors are not explicit functions of the site vibration period, and, therefore, are more suitable for the design of small to medium rise buildings for which only limited site investigations are routinely carried out. Key words: earthquake engineering, design spectra, site-specific, building codes.

Evaluation of the seismic response factor introduced in the 1985 edition of the National Building Code of Canada

1988 ◽  
Vol 15 (3) ◽  
pp. 382-388 ◽  
Author(s):  
A. C. Heidebrecht ◽  
Chee Yuen Lu
Keyword(s):  
Seismic Response ◽  
Strong Motion ◽  
Building Code ◽  
Response Factor ◽  
Seismic Zone ◽  
Response Factors ◽  
Dynamic Factors ◽  
Wall Structures ◽  
Time Histories ◽  
Velocity Spectra

The seismic loading provisions included in the 1985 edition of the National Building Code of Canada simulate the dynamic response of structures using a seismic response factor, which has three branches depending upon the relationship between the velocity-related seismic zone Zv and the acceleration-related zone Za. This paper utilizes three ensembles of actual seismic strong motion records to evaluate the seismic response factor; each ensemble has acceleration/velocity ratios corresponding to one of the three branches of the seismic response factor. These strong motion time histories are used as input to relatively simple elastic models of frame and wall structures in order to obtain dynamic seismic response factors. The comparison of these dynamic factors with those specified in the NBCC 1985 indicates that the code factors are generally quite satisfactory, with the exception of the case of frame structures with low fundamental periods located such that Za is two zones higher than Zv. The paper references several other investigations that produce similar results. In that instance, it is recommended that the seismic response factor should be increased, particularly if the structure is located on stiff soil rather than on rock. Key words: structures, loading, seismic, code, earthquake, dynamic, elastic, acceleration, velocity, spectra.

Evaluation of site-specific seismic design requirements for three Canadian cities

1988 ◽  
Vol 15 (3) ◽  
pp. 409-423
Author(s):  
A. C. Heidebrecht ◽  
N. Naumoski
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Epicentral Distance ◽  
Response Spectra ◽  
Quebec City ◽  
Response Factors ◽  
Site Specific ◽  
Specific Location ◽  
Tectonic Environment ◽  
Design Requirements

Siesmic design requirements as specified in building codes normally use a generic approach in which the seismic response is independent of the site location, except for a single intensity-related parameter used to define the severity of the expected ground motion. In reality, the characteristics of earthquakes that influence structural response depend on both the level of seismic motion and the seismo-tectonic environment at the specific location. This paper describes a methodology for determining seismic design requirements that uses both magnitude (M) and epicentral distance (R) to define the seismo-tectonic environment. Ensembles of actual seismic strong motion records are selected to match the combinations of M and R that dominate the seismic risk at a specific location. These time histories are used to determine both response spectra and seismic response factors (as used in the 1985 edition of the National Building Code, NBCC 1985) for the location in question. This paper applies this methodology to Vancouver, Ottawa, and Quebec City and compares the results with the response spectra and seismic response factors specified in NBCC 1985. The results indicate that a site-specific investigation of seismic design requirements is important in distinguishing between locations having different seismo-tectonic environments. Key words: structures, design, seismic, code, dynamic, acceleration, velocity, spectra, magnitude, epicentral distance.

Evaluation of base shear provisions in the 1985 edition of the National Building Code of Canada

1989 ◽  
Vol 16 (1) ◽  
pp. 22-35 ◽  
Author(s):  
T. J. Zhu ◽  
W. K. Tso ◽  
A. C. Heidebrecht
Keyword(s):  
Yield Strength ◽  
Seismic Response ◽  
Structural Damage ◽  
Ground Motions ◽  
Response Spectra ◽  
Building Code ◽  
Base Shear ◽  
Response Factors ◽  
Period Range ◽  
Short Period

A statistical analysis is performed to evaluate the base shear provisions in the 1985 edition of the National Building Code of Canada (NBCC 1985). Three sets of real earthquake records are selected to represent seismic ground motions with low, normal, and high peak acceleration to velocity (a/v) ratios. Single degree of freedom stiffness degrading systems are used as structural models; three damage indicators are employed to measure structural damage. The yield strength of the systems is specified in two different ways: (a) a single seismic response factor is used, irrespective of the a/v ratios of the input ground motions; (b) three different seismic response factors are used in the short-period range, depending upon the a/v ratios of the input ground motions, as suggested in NBCC 1985. A comparison of the statistical results of the three damage parameters for the systems designed with these two methods of strength specification indicates that the NBCC 1985 base shear provisions provide consistent control over structural damage when the structural systems are subjected to ground motions with different a/v ratios. Key words: earthquakes, ground motions, response spectra, stiffness degrading systems, seismic design, base shear, yield strength, inelastic response, damage parameters.

Seismic Response Analysis of CFST Arch Bridge Considering Input Earthquake Characteristics

2011 ◽  
Vol 255-260 ◽  
pp. 962-966
Author(s):  
Fan Xing ◽  
Lin Zhao ◽  
Ya Zhe Xing
Keyword(s):  
Seismic Response ◽  
Research Result ◽  
Steel Tube ◽  
Response Analysis ◽  
Vibration Period ◽  
Arch Bridge ◽  
Near Fault ◽  
Long Span ◽  
Cfst Arch Bridge ◽  
Out Of Plane

In view of huge destructibility of the near-fault ground motions, structures with long natural vibration period are liable to fall into nonlinear reaction stage. Based on a full understanding of the near-fault seismic spectrum characteristics, the out-of-plane seismic response of a long span concrete-filled steel tube (CFST) arch bridge was studied in depth, and the research result could offer a reference for near-fault aseismic design.

Casualties and behavior of populations during earthquakes

1970 ◽  
Vol 60 (4) ◽  
pp. 1309-1313
Author(s):  
Cinna Lomnitz
Keyword(s):  
Engineering Design ◽  
Earthquake Engineering ◽  
Time Of Day ◽  
Human Populations ◽  
Positive Correlation ◽  
And Behavior ◽  
Emergency Measures

abstract A positive correlation is established between the time of day and the number of victims in Chilean earthquakes. This correlation is attributed to a 24-hr cycle of dwelling occupancy. The incidence of foreshocks lowers the number of casualties. These observations are of interest to earthquake engineering design and to emergency measures for the protection of human populations in earthquakes.

Effect of differential settlement on seismic response of building structures

2020 ◽  
Vol 173 (3) ◽  
pp. 136-145
Author(s):  
Rajib Sarkar ◽  
Sekhar Chandra Dutta ◽  
Ranjeet Saw ◽  
Jai Prakash Singh
Keyword(s):  
Seismic Response ◽  
Differential Settlement ◽  
Building Structures

Study on Dynamic Characteristic and Seismic Response of Long-Span Suspension Bridge with 1960 MPa Cable Wire

2016 ◽  
Vol 858 ◽  
pp. 157-162 ◽  
Author(s):  
Hao Lei Wang ◽  
Feng Jie Ma ◽  
Chao Zhu
Keyword(s):  
Dynamic Characteristic ◽  
Seismic Response ◽  
Response Spectrum ◽  
Water Channel ◽  
Suspension Bridge ◽  
Viscous Damper ◽  
Vibration Period ◽  
Long Span ◽  
Design Response Spectrum ◽  
Cable Wire

In order to break through the limitation of the width of river, depth of water, channel and etc., it is an optimal choice to construct a long-span suspension bridge. In a suspension bridge, the main cable is the major bearing member; and the use of super high strength cable wire can lighten the dead weight and obtain an economical design. 1960 Mpa cable wire is adopted by an under-construction suspension bridge, namely Ni-Zhou Channel Bridge, for the first time in China. In this paper, taking the Ni-Zhou Channel Bridge as a case-study, comparative analyses on dynamic characteristic and seismic response of long-span suspension bridge with 1960 Mpa cable wire are performed. Firstly, dynamic calculating model for Ni-Zhou Channel Bridge is built and its dynamic characteristics are studied; then by using response spectrum and time history analysis method, seismic response of Ni-Zhou Channel Bridge is investigated on the basis of design response spectrum and artificial seismic ground motions; finally, the energy dissipation performances of a seismic protection devices (viscous damper) are also discussed. The results show that long-span suspension bridge with 1960 Mpa cable wire has a longer natural vibration period; the use of viscous damper can effectively reduce the peak value of bending moment in stiffening girder. This paper can provide references for the project’s construction.

scholarly journals Forensic Engineering Data Collection For Stairway Incidents

2007 ◽  
Vol 24 (2) ◽  
Author(s):  
Wilbur T. Yaxley ◽  
Armstrong Jeffrey D.
Keyword(s):  
Data Collection ◽  
Building Codes ◽  
Building Code ◽  
Engineering Data ◽  
Forensic Engineering ◽  
Riser Height ◽  
Design Construction

Forensic Engineers Are Often Called Upon To Investigate Injury Events On Stairs. A Significant Number Of Injuries And Deaths Occur On Stairways. With A Background In Design, Construction, And Building Codes, Forensic Engineers Can Identify The Appropriate Codes With Which The Stairs Might Be Required To Comply, Can Determine Whether Deficiencies Exist And To What Extent, And Whether Deficiencies Are Related To The Design Or The Construction Of The Facility. Data Collection On Stairways Can Be Difficult And Tedious. Measurements Of Tread Depths And Riser Heights Must Be Measured With Precision To Compare With Allowable Tolerances. This Paper Presents Various Means Of Collecting Data Related To Stairways, Including Documentation Of Tread Depth, Riser Height, Tread Slope, Nosing, Handrails, And Headroom Clearances. The Paper Will Also Introduce A Device That Was Developed And Validated By The Authors For Measuring Treads And Risers. This Paper Focuses Only On Data Collection Methodologies, And Does Not Present Analyses Or Render Opinions With Regard To Building Code Requirements. The Building Code Requirements That Are Presented Herein Are Only For The Purpose Of Illustrating Typical Code Requirements, To Illustrate Why Various Data Must Be Collected, And To Review Proper Methods Of Data Collection.

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