scholarly journals Code Approaches to Seismic Design of Masonry-Infilled Reinforced ConcreteFrames: A State-of-the-Art Review

2006 ◽  
Vol 22 (4) ◽  
pp. 961-983 ◽  
Author(s):  
Hemant B. Kaushik ◽  
Durgesh C. Rai ◽  
Sudhir K. Jain
Keyword(s):  
Seismic Design ◽  
Failure Modes ◽  
Design Procedure ◽  
Point Of View ◽  
Initial Stiffness ◽  
Negative Effects ◽  
Analysis And Design ◽  
Model Code ◽  
Rc Frames ◽  
Performance Point

Masonry infill (MI) walls are remarkable in increasing the initial stiffness of reinforced concrete (RC) frames, and being the stiffer component, attract most of the lateral seismic shear forces on buildings, thereby reducing the demand on the RC frame members. However, behavior of MI is difficult to predict because of significant variations in material properties and because of failure modes that are brittle in nature. As a result, MI walls have often been treated as nonstructural elements in buildings, and their effects are not included in the analysis and design procedure. However, experience shows that MI may have significant positive or negative effects on the global behavior of buildings and, therefore, should be addressed appropriately. Various national codes differ greatly in the manner effects of MI are to be considered in the design process from aseismic performance point of view. This paper reviews and compares analysis and design provisions related to MI-RC frames in seismic design codes of 16 countries and identifies important issues that should be addressed by a typical model code.

Evolution of seismic design codes of highway bridges in Chile

2021 ◽  
pp. 875529302098801
Author(s):  
José Wilches ◽  
Hernán Santa Maria ◽  
Roberto Leon ◽  
Rafael Riddell ◽  
Matías Hube ◽  
...  
Keyword(s):  
Seismic Design ◽  
Failure Modes ◽  
Highway Bridges ◽  
Design Codes ◽  
Seismic Codes ◽  
Analysis And Design ◽  
Residual Displacements ◽  
Shear Keys ◽  
Maule Earthquake ◽  
2010 Maule Earthquake

Chile, as a country with a long history of strong seismicity, has a record of both a constant upgrading of its seismic design codes and structural systems, particularly for bridges, as a result of major earthquakes. Recent earthquakes in Chile have produced extensive damage to highway bridges, such as deck collapses, large transverse residual displacements, yielding and failure of shear keys, and unseating of the main girders, demonstrating that bridges are highly vulnerable structures. Much of this damage can be attributed to construction problems and poor detailing guidelines in design codes. After the 2010 Maule earthquake, new structural design criteria were incorporated for the seismic design of bridges in Chile. The most significant change was that a site coefficient was included for the estimation of the seismic design forces in the shear keys, seismic bars, and diaphragms. This article first traces the historical development of earthquakes and construction systems in Chile to provide a context for the evolution of Chilean seismic codes. It then describes the seismic performance of highway bridges during the 2010 Maule earthquake, including the description of the main failure modes observed in bridges. Finally, this article provides a comparison of the Chilean bridge seismic code against the Japanese and United States codes, considering that these codes have a great influence on the seismic codes for Chilean bridges. The article demonstrates that bridge design and construction practices in Chile have evolved substantially in their requirements for the analysis and design of structural elements, such as in the definition of the seismic hazard to be considered, tending toward more conservative approaches in an effort to improve structural performance and reliability for Chilean bridges.

scholarly journals Direct displacement-based seismic design of concrete buildings

2000 ◽  
Vol 33 (4) ◽  
pp. 421-444 ◽  
Author(s):  
M.J.N. Priestley ◽  
M.J. Kowalsky
Keyword(s):  
Seismic Design ◽  
Design Procedure ◽  
Time History ◽  
Initial Stiffness ◽  
Concrete Buildings ◽  
History Analysis ◽  
Starting Point ◽  
Displacement Profile ◽  
Displacement Based ◽  
Design Earthquake

A seismic design procedure is developed to enable concrete buildings to be designed to achieve a specified acceptable level of damage under the design earthquake. The acceptable limit is defined as a displacement profile related to limit material strains or code specified drift limits. In this procedure, the elastic properties, including initial stiffness, strength and period, are the end product of the design rather than the starting point. It is shown that the procedure is simple to apply, and results in significant differences from the more conventional force-based procedure. Designs for multi-storey frame and wall buildings are presented, and target displacements are compared with results from inelastic time-history analysis.

Portal Frames with a Novel Cold-Formed Tapered Box-Section

2018 ◽  
Vol 763 ◽  
pp. 301-309
Author(s):  
Amir Shahmohammadi ◽  
James B.P. Lim ◽  
George Charles Clifton
Keyword(s):  
Failure Modes ◽  
Numerical Models ◽  
Experimental Testing ◽  
Design Procedure ◽  
Torsional Stiffness ◽  
Food Storage ◽  
Analysis And Design ◽  
Portal Frame ◽  
Frame System ◽  
Lateral Bracing

This paper introduces a novel steel portal frame system, in which cold-formed nested tapered box members are used in the design. The bird and dust proofing features of the system make it useful for applications where clean work areas are required, such as food, storage, and manufacturing industries. The new section used in the portal frames comprises two cold-formed channels welded to each other, forming a box-shaped steel member, either tapered or prismatic along its length. Such sections possess high torsional stiffness compared with the conventional I-sections; therefore, lateral bracing employed for the flexural-torsional buckling suppression of I section portal frames is mostly unnecessary. A comparative study, taking into account the cost of steel, painting, bird proofing and lateral bracing, is conducted between a number of portal frames with the proposed box-sections and the conventional I-sections. An analysis and design code, incorporating the Genetic Algorithm (GA), is developed to optimise the weight of the designed frames. The results indicate that the novel portal frame system is economically viable with additional benefits of bird and dust proofing. To investigate the failure modes and verify design procedure of the new portal frame, an experimental testing program is undertaken in University of Auckland. The test results show excellent behaviour and good agreement with the numerical models but have been completed too recently to be included in this paper.

scholarly journals Optimal Design of RC Frames using a Modified Hybrid PSOGSA Algorithm

2017 ◽  
Vol 63 (4) ◽  
pp. 123-134 ◽  
Author(s):  
Sonia Chutani ◽  
Jagbir Singh
Keyword(s):  
Search Algorithm ◽  
Gravitational Search Algorithm ◽  
Design Procedure ◽  
Optimization Techniques ◽  
Rc Frame ◽  
Local Optima ◽  
Analysis And Design ◽  
Positive Effects ◽  
Rc Frames ◽  
The Cost

AbstractThe present study has been taken up to emphasize the role of the hybridization process for optimizing a given reinforced concrete (RC) frame. Although various primary techniques have been hybrid in the past with varying degree of success, the effect of hybridization of enhanced versions of standard optimization techniques has found little attention. The focus of the current study is to see if it is possible to maintain and carry the positive effects of enhanced versions of two different techniques while using their hybrid algorithms. For this purpose, enhanced versions of standard particle swarm optimization (PSO) and a standard gravitational search algorithm (GSA), were considered for optimizing an RC frame. The enhanced version of PSO involves its democratization by considering all good and bad experiences of the particles, whereas the enhanced version of the GSA is made self-adaptive by considering a specific range for certain parameters, like the gravitational constant and a set of agents with the best fitness values. The optimization process, being iterative in nature, has been coded in C++. The analysis and design procedure is based on the specifications of Indian codes. Two distinct advantages of enhanced versions of standard PSO and GSA, namely, better capability to escape from local optima and a faster convergence rate, have been tested for the hybrid algorithm. The entire formulation for optimal cost design of a frame includes the cost of beams and columns. The variables of each element of structural frame have been considered as continuous and rounded off appropriately to consider practical limitations. An example has also been considered to emphasize the validity of this optimum design procedure.

Study of Seismic Design Method for Slope Supporting Structure of Soil Nailing

2013 ◽  
Vol 353-356 ◽  
pp. 2073-2078
Author(s):  
Tian Zhong Ma ◽  
Yan Peng Zhu ◽  
Chun Jing Lai ◽  
De Ju Meng
Keyword(s):  
Seismic Design ◽  
Calculation Method ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Calculation Model ◽  
Soil Nailing ◽  
Case Record ◽  
Analysis And Design ◽  
Supporting Structure ◽  
Earthquake Action

Slope anchorage structure of soil nail is a kind of economic and effective flexible slope supporting structure. This structure at present is widely used in China. The supporting structure belong to permanent slope anchorage structure, so the design must consider earthquake action. Its methods of dynamical analysis and seismic design can not be found for the time being. The seismic design theory and method of traditional rigidity retaining wall have not competent for this new type of flexible supporting structure analysis and design. Because the acceleration along the slope height has amplification effect under horizontal earthquake action, errors should be induced in calculating earthquake earth pressure using the constant acceleration along the slope height. Considering the linear change of the acceleration along the slope height and unstable soil with the fortification intensity the influence of the peak acceleration, the earthquake earth pressure calculation formula is deduced. The soil nailing slope anchorage structure seismic dynamic calculation model is established and the analytical solutions are obtained. The seismic design and calculation method are given. Finally this method is applied to a case record for illustration of its capability. The results show that soil nailing slope anchorage structure has good aseismic performance, the calculation method of soil nailing slope anchorage structure seismic design is simple, practical, effective. The calculation model provides theory basis for the soil nailing slope anchorage structure of seismic design. Key words: soil nailing; slope; earthquake action; seismic design;

scholarly journals Determinants of Corporate Anti-Corruption Disclosure: The Case of the Emerging Economics

2021 ◽  
Vol 13 (6) ◽  
pp. 3462
Author(s):  
Maider Aldaz Odriozola ◽  
Igor Álvarez Etxeberria
Keyword(s):  
Empirical Studies ◽  
Geographical Area ◽  
Control Variable ◽  
Emerging Countries ◽  
Point Of View ◽  
Press Freedom ◽  
Negative Effects ◽  
Key Factor ◽  
Using Data ◽  
Positive Effect

Corruption is a key factor that affects countries’ development, with emerging countries being a geographical area in which it tends to generate greater negative effects. However, few empirical studies analyze corruption from the point of view of disclosure by companies in this relevant geographical area. Based on a regression analysis using data from the 96 large companies from 15 emerging countries included in the 2016 International Transparency Report, this paper seeks to understand what determinants affect such disclosure. In that context, this paper provides empirical evidence to understand the factors that influence reporting on anti-corruption mechanisms in an area of high economic importance that has been little studied to date, pointing to the positive effect of press freedom in a country where the company is located and with the industry being the unique control variable that strengthens this relationship.

Drift-based seismic design procedure for Buckling Restrained Braced Frames

Structures ◽  
2021 ◽  
Vol 30 ◽  
pp. 62-74
Author(s):  
Seyed Amin Mousavi ◽  
Seyed Mehdi Zahrai ◽  
Ali Akhlagh Pasand
Keyword(s):  
Seismic Design ◽  
Design Procedure ◽  
Braced Frames ◽  
Buckling Restrained Braced Frames

scholarly journals Lower Limb Kinematics in Individuals with Hip Osteoarthritis during Gait: A Focus on Adaptative Strategies and Interlimb Symmetry

2021 ◽  
Vol 8 (4) ◽  
pp. 47
Author(s):  
Micaela Porta ◽  
Massimiliano Pau ◽  
Bruno Leban ◽  
Michela Deidda ◽  
Marco Sorrentino ◽  
...  
Keyword(s):  
Lower Limb ◽  
Functional Limitations ◽  
Hip Osteoarthritis ◽  
Movement Analysis ◽  
Human Movement ◽  
Point Of View ◽  
Negative Effects ◽  
Gait Patterns ◽  
Limb Kinematics

Among the functional limitations associated with hip osteoarthritis (OA), the alteration of gait capabilities represents one of the most invalidating as it may seriously compromise the quality of life of the affected individual. The use of quantitative techniques for human movement analysis has been found valuable in providing accurate and objective measures of kinematics and kinetics of gait in individuals with hip OA, but few studies have reported in-depth analyses of lower limb joint kinematics during gait and, in particular, there is a scarcity of data on interlimb symmetry. Such aspects were investigated in the present study which tested 11 individuals with hip OA (mean age 68.3 years) and 11 healthy controls age- and sex-matched, using 3D computerized gait analysis to perform point-by-point comparisons of the joint angle trends of hip, knee, and ankle. Angle-angle diagrams (cyclograms) were also built to compute several parameters (i.e., cyclogram area and orientation and Trend Symmetry) from which to assess the degree of interlimb symmetry. The results show that individuals with hip OA exhibit peculiar gait patterns characterized by severe modifications of the physiologic trend at hip level even in the unaffected limb (especially during the stance phase), as well as minor (although significant) alterations at knee and ankle level. The symmetry analysis also revealed that the effect of the disease in terms of interlimb coordination is present at knee joint as well as hip, while the ankle joint appears relatively preserved from specific negative effects from this point of view. The availability of data on such kinematic adaptations may be useful in supporting the design of specific rehabilitative strategies during both preoperative and postoperative periods.

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