Comparisons among Earthquake Codes

1989 ◽  
Vol 5 (4) ◽  
pp. 767-789 ◽  
Author(s):  
RenéW. Luft
Keyword(s):  
Review Paper ◽  
Construction Materials ◽  
Base Shear ◽  
Limit States ◽  
Hazard Exposure ◽  
Moderate Seismicity ◽  
Strength Based ◽  
Importance Factor ◽  
Seismic Hazard Exposure ◽  
High Seismicity

This review paper compares ANSI, NEHRP, SEAOC, and UBC. A few essential differences among these documents are as follows: (a) The NEHRP document gives force levels corresponding to a strength-based or limit states design, while the other three documents give force levels that correspond to working or service stress design; (b) the importance factor is used as a multiplier of base shear level in all documents except NEHRP, which treats building importance by a seismic hazard exposure group; (c) NEHRP and UBC-1988 contain detailing requirements for all common construction materials and all seismic zones, while UBC-1985 contains detailing requirements for zones of high seismicity but only limited requirements for zones of moderate seismicity; (d) P-delta analysis is specified by NEHRP for all buildings that must be analyzed, by SEAOC for buildings that exceed drift limits, by UBC-1988 for all buildings except those in Zones 3 and 4 meeting drift limits, and is not specified by ANSI.

Impact of Damping Scaling Factors on Direct Displacement-Based Design

2016 ◽  
Vol 32 (2) ◽  
pp. 843-859 ◽  
Author(s):  
Cuiyan Kong ◽  
Mervyn J. Kowalsky
Keyword(s):  
Response Spectra ◽  
Equivalent Linearization ◽  
Base Shear ◽  
Limit States ◽  
Scaling Factors ◽  
Equivalent Viscous Damping ◽  
Direct Displacement Based Design ◽  
Displacement Response Spectra ◽  
Performance Limit States ◽  
Displacement Based

Damping scaling factors (DSFs) play an important role in direct displacement-based design (DDBD) as they provide a means to establish displacement response spectra for damping values beyond 5%. Response spectra for multiple damping values are needed for DDBD as the approach relies on equivalent linearization, expressed in the form of effective stiffness and equivalent viscous damping, to establish design forces for prescribed performance limit states. In the past, DSFs based on the Eurocode have been employed for DDBD; however, recent research has resulted in more robust DSF models. This paper examines the accuracy of the current DSF equation used in DDBD across the parameters that are important for structural design. A nonlinear regression analysis is performed based on the data obtained by the Rezaeian et al. (2014) model, and a base shear adjustment factor (SAF) is proposed for application to the DDBD base shear equation.

A WIRELESS NETWORK SYSTEM FOR AUTOMATED TRACKING OF CONSTRUCTION MATERIALS ON PROJECT SITES

2008 ◽  
Vol 14 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Won-Suk Jang ◽  
Mirosław J. Skibniewski
Keyword(s):  
Tracking System ◽  
Construction Material ◽  
Construction Materials ◽  
Cost Benefit ◽  
Signal Strength ◽  
Industrial Applications ◽  
Network System ◽  
Automated Tracking ◽  
Hybrid Techniques ◽  
Strength Based

This paper presents a new prototype framework of automated tracking and monitoring system for construction materials. Previous technologies such as RFID and GPS deployed in construction material tracking have been reviewed and signal strength‐based localisation has been examined. As an emerging network standard for industrial applications, brief specifications of ZigBee™ protocol have been described. We introduce a ZigBee‐based tracking system architecture using hybrid techniques of RF and ultrasound to improve positioning accuracy and cost benefit. Finally, feasibility analysis and application scenario have been examined to present the possible deployment framework in construction area. Santrauka Straipsnyje aprašomas naujas automatizuotos statybinių medžiagų stebėsenos sistemos modelis. Apžvelgiamos tokios technologijos, kaip RFID ir GPS, anksčiau naudotos stebint statybines medžiagas, ir nagrinėjamas signalo stiprumu pagrįstas lokalizavimas. Aprašoma tinklo standarto ZigBee™ protokolo, naudojamo pramonėje, specifikacija. Pateikiama ZigBee tipo stebėjimo sistema, naudojanti RF ir ultragarso technologiją, skirtą pozicionavimo tikslumui gerinti ir jo kainai mažinti. Be to, pateikiama sistemos galimybių analizė ir taikymo sistema, nagrinėjanti galimą šios sistemos naudojimą statyboje.

scholarly journals Calibrating Partial Factors – Methodology, Input Data and Case Study of Steel Structures

2019 ◽  
Author(s):  
Vitali Nadolski ◽  
Árpád Rózsás ◽  
Miroslav Sýkora
Keyword(s):  
Input Data ◽  
Structural Reliability ◽  
Construction Materials ◽  
Steel Structures ◽  
Structural Performance ◽  
Limit States ◽  
Different Types ◽  
Load Effects ◽  
Previous Design

Partial factors are commonly based on expert judgements and on calibration to previous design formats. This inevitably results in unbalanced structural reliability for different types of construction materials, loads and limit states. Probabilistic calibration makes it possible to account for plentiful requirements on structural performance, environmental conditions, production and execution quality etc. In the light of ongoing revisions of Eurocodes and the development of National Annexes, the study overviews the methodology of probabilistic calibration, provides input data for models of basic variables and illustrates the application by a case study. It appears that the partial factors recommended in the current standards provide for a lower reliability level than that indicated in EN 1990. Different values should be considered for the partial factors for imposed, wind and snow loads, appreciating the distinct nature of uncertainties in their load effects.

Seismic Design Requirements for Regions of Moderate Seismicity

2000 ◽  
Vol 16 (1) ◽  
pp. 205-225 ◽  
Author(s):  
Guy J. P. Nordenson ◽  
Glenn R. Bell
Keyword(s):  
United States ◽  
Seismic Design ◽  
Soft Soil ◽  
The United States ◽  
Mitigation Measures ◽  
Quarter Century ◽  
Seismic Codes ◽  
The Past ◽  
Moderate Seismicity ◽  
High Seismicity

The need for earthquake-resistant construction in areas of low-to-moderate seismicity has been recognized through the adoption of code requirements in the United States and other countries only in the past quarter century. This is largely a result of improved assessment of seismic hazard and examples of recent moderate earthquakes in regions of both moderate and high seismicity, including the San Fernando (1971), Mexico City (1985), Loma Prieta (1989), and Northridge (1994) earthquakes. In addition, improved understanding and estimates of older earthquakes in the eastern United States such as Cape Ann (1755), La Malbaie, Quebec (1925), and Ossippe, New Hampshire (1940), as well as monitoring of micro-activity in source areas such as La Malbaie, have increased awareness of the earthquake potential in areas of low-to-moderate seismicity. Both the hazard and the risk in moderate seismic zones (MSZs) differ in scale and kind from those of the zones of high seismicity. Earthquake hazards mitigation measures for new and existing construction need to be adapted from those prevailing in regions of high seismicity in recognition of these differences. Site effects are likely to dominate the damage patterns from earthquakes, with some sites suffering no damage not far from others, on soft soil, suffering near collapse. A number of new seismic codes have been developed in the past quarter century in response to these differences, including the New York City (1995) and the Massachusetts State (1975) seismic codes. Over the same period, the national model building codes that apply to most areas of low-to-moderate seismicity in the United States, the Building Officials and Code Administrators (BOCA) Code and the Southern Standard Building Code (SSBC), have incorporated up-to-date seismic provisions. The seismic provisions of these codes have been largely inspired by the National Earthquake Hazard Reduction Program (NEHRP) recommendations. Through adoption of these national codes, many state and local authorities in areas of low-to-moderate seismicity now have reasonably comprehensive seismic design provisions. This paper will review the background and history leading up to the MSZ codes, discuss their content, and propose directions for future development.

scholarly journals Ranking soccer teams on the basis of their current strength: A comparison of maximum likelihood approaches

2019 ◽  
Vol 19 (1) ◽  
pp. 55-73 ◽  
Author(s):  
Christophe Ley ◽  
Tom Van de Wiele ◽  
Hans Van Eetvelde
Keyword(s):  
Maximum Likelihood ◽  
Statistical Models ◽  
Predictive Performance ◽  
Current Strength ◽  
Soccer Match ◽  
Poisson Models ◽  
Strength Based ◽  
Long Time ◽  
Importance Factor ◽  
Soccer Teams

We present 10 different strength-based statistical models that we use to model soccer match outcomes with the aim of producing a new ranking. The models are of four main types: Thurstone–Mosteller, Bradley–Terry, independent Poisson and bivariate Poisson, and their common aspect is that the parameters are estimated via weighted maximum likelihood, the weights being a match importance factor and a time depreciation factor giving less weight to matches that are played a long time ago. Since our goal is to build a ranking reflecting the teams’ current strengths, we compare the 10 models on the basis of their predictive performance via the Rank Probability Score at the level of both domestic leagues and national teams. We find that the best models are the bivariate and independent Poisson models. We then illustrate the versatility and usefulness of our new rankings by means of three examples where the existing rankings fail to provide enough information or lead to peculiar results.

Design and Assessment of Cold-Formed Steel Shear Wall Systems Located in Moderate-to-High Seismicity Regions

2018 ◽  
Vol 763 ◽  
pp. 645-652
Author(s):  
Smail Kechidi ◽  
Luís Macedo ◽  
José Miguel Castro ◽  
Nouredine Bourahla
Keyword(s):  
Seismic Performance ◽  
Design Procedure ◽  
Shear Wall ◽  
Assessment Procedure ◽  
Nonlinear Behaviour ◽  
Seismic Performance Assessment ◽  
Behaviour Factor ◽  
Moderate Seismicity ◽  
Cold Formed Steel ◽  
High Seismicity

This paper presents a numerical simulation aimed at analysing the seismic performance of low- and mid-rise cold-formed steel (CFS) framed buildings, employing wood-sheathed shear wall panels (SWPs), designed according to a seismic design procedure compatible with the framework of the Eurocodes. To simulate their nonlinear behaviour, the structures were modelled adopting a recently developed deteriorating hysteresis model. In order to study the seismic performance and determine the seismic performance factors, Incremental Dynamic Analysis of 54 archetype buildings was performed in OpenSees. The seismic performance assessment was evaluated according to the methodology defined in FEMA P695. The results indicate that a behaviour factor q equal to 2 is appropriate for CFS framed structures using wood-sheathed SWPs lateral load resisting system designed for low and moderate seismicity regions. Further, the probabilistic seismic risk assessment of the studied frames, is presented. The importance and usefulness of the risk metrics are highlighted and adopted as an indicator to explore the behavioural features of the CFS-SWP structural system. Overall, the assessment procedure showed an acceptable seismic performance and therefore the CFS-SWP can be seen as a reliable structural solution to achieve performance-based objectives even in moderate-to-high seismicity regions.

scholarly journals Simulation two storey house of masonry wall under the earthquake load

2019 ◽  
Vol 12 (2) ◽  
pp. 1-12
Author(s):  
Maan H. Saeed
Keyword(s):  
Compressive Strength ◽  
Model Simulation ◽  
Construction Materials ◽  
High Sensitivity ◽  
Research Paper ◽  
Masonry Wall ◽  
Base Shear ◽  
Maximum Displacement ◽  
Finite Element Package ◽  
Earthquake Load

The masonry wall building systems have high sensitivity against earthquakes and the fact that this system of construction is widespread in Iraq, especially condominiums. Iraq subjected to many earthquakes in recent years and is expected to be subjected to more intensities of earthquakes in the future engendered an urgent need to investigate the behavior of this type of construction under the influence of earthquakes. The analysis of two-storey house in this research paper was performed by the finite element package program ABAQUS. Model simulation with dimensions (5 * 20 m) from the common one and two-storey house models in Iraq. The compressive strength of bricks (17MPa) type A  and compressive strength of mortar(15MPa) with mixing ratio 1:3 was used to represented of the properties of construction materials in Iraq. The nonlinearity behavior of the materials is considered in this research paper. The model is subjected to PGA(0.5g) from  EL-Centro Earthquake (1940 N-S ) as input ground motion to determine its seismic performance compared the maximum displacement, drift and base shear for models with the seismic demand of Iraq. Through the analysis of the results, the models proved efficient and stable against the effect of earthquakes, especially when the load applied in the Z long direction, more than the load applied in the X short direction for all models

The Mexico Earthquake of September 19, 1985—Response and Design Spectra Obtained from Earthquake-Damaged Buildings

1989 ◽  
Vol 5 (1) ◽  
pp. 113-120 ◽  
Author(s):  
A. Gómez ◽  
R. Ortega ◽  
J. J. Guerrero ◽  
E. González ◽  
J. P. Paniagua ◽  
...  
Keyword(s):  
Mexico City ◽  
Shear Force ◽  
Response Spectrum ◽  
Base Shear ◽  
Natural Period ◽  
Safety Level ◽  
Design Spectrum ◽  
Design Spectra ◽  
Mexico Earthquake ◽  
High Seismicity

The resistant shear force of 13 buildings severely damaged by the 1985 Mexico City earthquake was determined by static and dynamic analyses. The results of the static analysis suggest the advisability of increasing the shear base coefficient of the 1987 Mexico City building code RDF87 from 0.4 to 0.6 in the high seismicity zones of the area. The results of the dynamic analysis show that in order to obtain the same safety level, the maximum ordinate of the design spectrum should be larger than the base shear coefficient used with the static method, leading to a 0.8 maximum ordinate for Mexico City. When the resistant shear force is plotted as a function of the natural period of each building, the response spectrum obtained is very similar to the inelastic spectrum derived from the accelerograms, considering 5% critical damping, a ductility factor of 4 and degradation in resistance from 5% to 10%. Based on these results, new design spectra are proposed for use in the high seismicity zones in Mexico City.

Review of Techniques for Predicting the Fundamental Period of Multi-Storey Buildings: Effects of Nonstructural Components

2015 ◽  
Vol 15 (02) ◽  
pp. 1450039 ◽  
Author(s):  
Massoud Sofi ◽  
Graham Leighton Hutchinson ◽  
Colin Duffield
Keyword(s):  
Tall Buildings ◽  
Lateral Load ◽  
Wind Load ◽  
Lateral Stiffness ◽  
Limit States ◽  
Nonstructural Components ◽  
Lateral Deflection ◽  
Moderate Seismicity ◽  
Drift Limit ◽  
Lateral Deflections

The design of lateral load resisting elements of tall buildings in regions of low to moderate seismicity is normally governed by the requirements to meet inter-storey drift limit under wind load. The key objective of the design of tall buildings is to provide adequate lateral stiffness to the buildings to limit their lateral deflections and inter-storey drifts under the lateral load. The current design practice assumes that only the structural skeleton provides lateral resistance against wind load. Although the effects of nonstructural elements on the lateral stiffness are widely acknowledged, the effects are often ignored in the analysis of the buildings. This paper presents a state-of-the-art of review on the effects of nonstructural elements on the lateral deflections and inter-storey drifts of buildings at serviceability limit states. It was found that ignoring the nonstructural elements could significantly underestimate the lateral deflection for certain types of buildings. However, the shape and form of the lateral deflection in the overall building is not significantly affected by the nonstructural elements.

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