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.

Structural Performance of Bridges in the Offshore Maule Earthquake of 27 February 2010

2012 ◽  
Vol 28 (1_suppl1) ◽  
pp. 533-552 ◽  
Author(s):  
Ian Buckle ◽  
Matias Hube ◽  
Genda Chen ◽  
Wen-Huei Yen ◽  
Juan Arias
Keyword(s):  
Failure Modes ◽  
Highway Bridges ◽  
Ground Movement ◽  
Structural Performance ◽  
Plane Rotation ◽  
Skewed Bridges ◽  
Historic Masonry ◽  
Shear Keys ◽  
Maule Earthquake ◽  
Low Incidence

Of the nearly 12,000 highway bridges in Chile, approximately 300 were damaged in this earthquake, including 20 with collapsed spans. Typical failure modes include damage to connections between super- and substructures, unseating of spans in skewed bridges due to in-plane rotation, and unseated spans with some column damage due to permanent ground movement. Unusual failure modes include unseating of spans in straight bridges due to in-plane rotation, plate girder rupture due to longitudinal forces, scour and pier damage due to tsunami action, and collapse of a historic masonry bridge. The most common damage mode was the failure of super-to-substructure connections (shear keys, steel stoppers, and seismic bars), which is the most likely reason for the low incidence of column damage. Whereas the fuse-like behavior of these components is believed to have protected the columns, the lack of adequate seat widths led to the collapse, or imminent collapse, of many superstructures.

Problems and Suggestions of Chinese Highway Bridge Seismic Design

2013 ◽  
Vol 574 ◽  
pp. 127-134
Author(s):  
Xiu Yun Gao ◽  
Shao Yi Zhang
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Highway Bridges ◽  
Developed Countries ◽  
The United States ◽  
Highway Bridge ◽  
Design Codes ◽  
New Codes ◽  
Single Standard ◽  
The Developed Countries

The seismic design of Chinese Highway Bridge changed from single standard of fortification and one-step design performed nearly two decades to two-level fortification and two-stage design with the introduction of the new codes in 2008 and 2011. However, there are some shortcomings of the new codes such as the choice of response spectrum type, the determination of reinforced concrete constitutive relation, the discrimination of site-type and the bearing checking items, which leave a large room for improvement. Combined with the design codes of the developed countries like Japan and the United States, some useful suggestions are put forward in this paper for Chinese existing design codes. It is believed that Chinese seismic levels can be significantly increased so long as highway bridges are designed in accordance with the improved codes.

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.

scholarly journals Risk-adjusted Design Basis Earthquake’s Adequacy for use in Seismic Design Codes

2021 ◽  
Author(s):  
Mohammad Zaman ◽  
Mohammad Reza Ghayamghamian
Keyword(s):  
Seismic Design ◽  
Peak Ground Acceleration ◽  
Design Parameters ◽  
Design Codes ◽  
Acceptance Criteria ◽  
Ground Acceleration ◽  
Seismic Codes ◽  
Residual Drift ◽  
Design Basis ◽  
Made In

Abstract In most buildings’ seismic design codes design basis peak ground acceleration (PGADBE) is provided by employing a uniform-hazard approach. However, a new trend in updating seismic codes is to adopt a risk-informed method to estimate the PGADBE so-called risk-adjusted design basis peak ground acceleration (PGARDBE). An attempt is made here to examine the adequacy of the PGARDBE to fulfill the assumptions made in seismic codes for converting the maximum considered earthquake’s (MCE) intensity to PGADBE. To this end, the performance of regular intermediate steel moment frames (IMF) is assessed in terms of collapse margin (CMR) and residual drift ratios in the event of MCE and design basis earthquake (DBE), respectively. The PGARDBEs are computed for Karaj County, Iran. A set of 96 index archetypes of regular IMF are designed considering four design parameters, which include the number of stories (2, 3, 6, 9, 12, and 15), span lengths (4 and 8 meters), occupancies (residential and commercial), and seismic demands (0.15, 0.25, 0.35 and 0.45g). The PGADBE prescribed by Standard No. 2800 for Karaj neither meets the assumed acceptance criteria nor stands on the safe side. Meanwhile, PGARDBE fulfills the acceptance criteria but does not necessarily satisfy the implicit assumption made in codes that the code-conforming buildings have at least a CMR of 1.5 if the MCE occurs. This emphasizes that the PGARDBE should not be used without examining the CMR fulfillment. The results recommend that a lower limit need to be set on PGARDBEs, which is found to be 0.35g for Karaj. Outcomes also reveal that the code-conforming buildings designed with the proposed PGARDBE can fulfill both repairability and life safety performances at the DBE and MCE, respectively. These buildings also have a high chance to be even considered as repairable ones at the seismic demand of MCE. Furthermore, regardless of the employed method for estimating PGADBE, various relationships between design parameters with different performance indicators such as CMR, residual drift ratio, ductility demand, imposed drift ratio, and building’s normalized weight are presented. These relationships can be used to evaluate the buildings’ safety factor against collapse and repairability, justification of using IMF in regions with high seismicity, level of structural and nonstructural damage as well as the economic consequence of changes in PGADBE. The presented relationships provide a multi-criteria decision-making tool to decide on the optimum PGADBE leading to an affordable alternative and tolerable damage.

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 Probabilistic seismic response analysis of coastal highway bridges under scour and liquefaction conditions: does the hydrodynamic effect matter?

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Xiaowei Wang ◽  
Yutao Pang ◽  
Aijun Ye
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Highway Bridges ◽  
Element Model ◽  
Response Analysis ◽  
Hydrodynamic Effect ◽  
Strong Earthquakes ◽  
Influence Of Water ◽  
Scour Hazard ◽  
Ground Motion Records

AbstractCoastal highway bridges are usually supported by pile foundations that are submerged in water and embedded into saturated soils. Such sites have been reported susceptible to scour hazard and probably liquefied under strong earthquakes. Existing studies on seismic response analyses of such bridges often ignore the influence of water-induced hydrodynamic effect. This study assesses quantitative impacts of the hydrodynamic effect on seismic responses of coastal highway bridges under scour and liquefaction potential in a probabilistic manner. A coupled soil-bridge finite element model that represents typical coastal highway bridges is excited by two sets of ground motion records that represent two seismic design levels (i.e., low versus high in terms of 10%-50 years versus 2%-50 years). Modeled by the added mass method, the hydrodynamic effect on responses of bridge key components including the bearing deformation, column curvature, and pile curvature is systematically quantified for scenarios with and without liquefaction across different scour depths. It is found that the influence of hydrodynamic effect becomes more noticeable with the increase of scour depths. Nevertheless, it has minor influence on the bearing deformation and column curvature (i.e., percentage changes of the responses are within 5%), regardless of the liquefiable or nonliquefiable scenario under the low or high seismic design level. As for the pile curvature, the hydrodynamic effect under the low seismic design level may remarkably increase the response by as large as 15%–20%, whereas under the high seismic design level, it has ignorable influence on the pile curvature.

Research Situation on the Performance-Based Seismic Design Method for Reinforced Concrete Structure

2010 ◽  
Vol 163-167 ◽  
pp. 1757-1761
Author(s):  
Yong Le Qi ◽  
Xiao Lei Han ◽  
Xue Ping Peng ◽  
Yu Zhou ◽  
Sheng Yi Lin
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Design Method ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Seismic Evaluation ◽  
Seismic Codes ◽  
Performance Based Seismic Design ◽  
Capacity Calculation ◽  
Seismic Design Method

Various analytical approaches to performance-based seismic design are in development. Based on the current Chinese seismic codes，elastic capacity calculation under frequent earthquake and ductile details of seismic design shall be performed for whether seismic design of new buildings or seismic evaluation of existing buildings to satisfy the seismic fortification criterion “no damage under frequent earthquake, repairable under fortification earthquake, no collapse under severe earthquake”. However, for some special buildings which dissatisfy with the requirements of current building codes, elastic capacity calculation under frequent earthquake is obviously not enough. In this paper, the advanced performance-based seismic theory is introduced to solve the problems of seismic evaluation and strengthening for existing reinforced concrete structures, in which story drift ratio and deformation of components are used as performance targets. By combining the features of Chinese seismic codes, a set of performance-based seismic design method is established for reinforced concrete structures. Different calculation methods relevant to different seismic fortification criterions are adopted in the proposed method, which solve the problems of seismic evaluation for reinforced concrete structures.

Implementing the performance-based seismic design for new reinforced concrete structures: Comparison among ASCE/SEI 41, TBI, and LATBSDC

2021 ◽  
pp. 875529302098196
Author(s):  
Siamak Sattar ◽  
Anne Hulsey ◽  
Garrett Hagen ◽  
Farzad Naeim ◽  
Steven McCabe
Keyword(s):  
Reinforced Concrete ◽  
Los Angeles ◽  
Seismic Design ◽  
Common Ground ◽  
Seismic Analysis ◽  
Tall Buildings ◽  
The United States ◽  
Analysis And Design ◽  
Performance Based Seismic Design ◽  
New Buildings

Performance-based seismic design (PBSD) has been recognized as a framework for designing new buildings in the United States in recent years. Various guidelines and standards have been developed to codify and document the implementation of PBSD, including “ Seismic Evaluation and Retrofit of Existing Buildings” (ASCE 41-17), the Tall Buildings Initiative’s Guidelines for Performance-Based Seismic Design of Tall Buildings (TBI Guidelines), and the Los Angeles Tall Buildings Structural Design Council’s An Alternative Procedure for Seismic Analysis and Design of Tall Buildings Located in the Los Angeles Region (LATBSDC Procedure). The main goal of these documents is to regularize the implementation of PBSD for practicing engineers. These documents were developed independently with experts from varying backgrounds and organizations and consequently have differences in several degrees from basic intent to the details of the implementation. As the main objective of PBSD is to ensure a specified building performance, these documents would be expected to provide similar recommendations for achieving a given performance objective for new buildings. This article provides a detailed comparison among each document’s implementation of PBSD for reinforced concrete buildings, with the goal of highlighting the differences among these documents and identifying provisions in which the designed building may achieve varied performance depending on the chosen standard/guideline. This comparison can help committees developing these documents to be aware of their differences, investigate the sources of their divergence, and bring these documents closer to common ground in future cycles.

Preliminary Parametric Assessment of a Bolted Endplate Joint under Combined Axial Force and Cyclic Bending Moment

2011 ◽  
Vol 255-260 ◽  
pp. 718-721
Author(s):  
Z.Y. Wang ◽  
Q.Y. Wang
Keyword(s):  
Finite Element Analysis ◽  
Axial Force ◽  
Seismic Design ◽  
Axial Load ◽  
Failure Modes ◽  
Bending Moment ◽  
Element Analysis ◽  
Cyclic Behaviour ◽  
Joint Behaviour ◽  
Steel Joints

Problems regarding the combined axial force and bending moment for the behaviour of semi-rigid steel joints under service loading have been recognized in recent studies. As an extended research on the cyclic behaviour of a bolted endplate joint, this study is performed relating to the contribution of column axial force on the cyclic behaviour of the joint. Using finite element analysis, the deteriorations of the joint performance have been evaluated. The preliminary parametric study of the joint is conducted with the consideration of flexibility of the column flange. The column axial force was observed to significantly influence the joint behaviour when the bending of the column flange dominates the failure modes. The reductions of moment resistance predicted by numerical analysis have been compared with codified suggestions. Comments have been made for further consideration of the influence of column axial load in seismic design of bolted endplate joints.

Fuzzy set-theoretic models for interpretation of seismic design codes

1989 ◽  
Vol 29 (3) ◽  
pp. 277-291 ◽  
Author(s):  
Seema Alim ◽  
David Lloyd Smith
Keyword(s):  
Seismic Design ◽  
Fuzzy Set ◽  
Design Codes
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