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Investigation Of Seismic Performance And Design Of Typical Curved And Skewed Bridges In Colorado
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Book Synopsis Investigation of Seismic Performance and Design of Typical Curved and Skewed Bridges in Colorado by : Suren Chen
Download or read book Investigation of Seismic Performance and Design of Typical Curved and Skewed Bridges in Colorado written by Suren Chen and published by . This book was released on 2018 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the analytical studies on the seismic performance of typical Colorado concrete bridges, particularly those with curved and skewed configurations. A set of bridge models with different geometric configurations derived from. a prototype bridge selected in Denver area were studied. Some discussions about the connection modeling are carried out in terms of the interior bent support. For the displacement-based and force-based designs, due to the lack of design details that without detailed analyses of all possible detailing options. Therefore, some general observations of these two design concepts are ummarized in the end of the report. In the appendices, the design examples of 2-span and 3-span bridges are listed to help the engineers to conduct bridge seismic analysis in Colorado.
Book Synopsis Behavior of Typical Skewed and Curved Bridges in Extreme Seismic Events by : Pla-Junca, Pere
Download or read book Behavior of Typical Skewed and Curved Bridges in Extreme Seismic Events written by Pla-Junca, Pere and published by . This book was released on 2010 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study is on evaluation of two GMSM methods for estimation of bridge response parameters during seismic excitation. The main focus is on understanding the behavior and proper modeling of the structures used to conduct such evaluation. A total of six bridges, three skewed and three curved bridges, design by the California Transportation Department, Caltrans, and located in Orange and Los Angeles counties are considered. They are modeled using OpenSees (McKenna et al. 2000) open-source structural analysis platform. The selected GMSM methods are labeled as Sa(T1) scaling (where T1 is the fundamental period of the bridge under consideration) and Conditional Mean Spectrum (CMS) scaling. For each method, several sets of scaled ground motions are generated. These sets of records are applied to the bridges and the respective responses are analyzed. Curved bridges present numerical instabilities when using force-based elements to model their columns. Displacement-based elements are used instead. Pushover analysis of the bridges every 5o. can be used to determine their strongest and weakest directions. For curved bridges, these are those defined by an axis tangent to the arc described by the deck in its middle point and the corresponding perpendicular axis, respectively. For skewed bridges, the transverse is the strongest direction, and the longitudinal the weakest. A method for computing the plastic hinge length of a column is proposed. Finally, the structural responses obtained using Sa(T1) scaling and CMS scaling methods do not show any clear trend.
Book Synopsis Analytical Modeling of Seismic Performance of Curved and Skewed Bridges by : Suren Chen
Download or read book Analytical Modeling of Seismic Performance of Curved and Skewed Bridges written by Suren Chen and published by . This book was released on 2019 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Performance-based Seismic Bridge Design by : M. Lee Marsh
Download or read book Performance-based Seismic Bridge Design written by M. Lee Marsh and published by Transportation Research Board. This book was released on 2013 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 440, Performance-Based Seismic Bridge Design (PBSD) summarizes the current state of knowledge and practice for PBSD. PBSD is the process that links decision making for facility design with seismic input, facility response, and potential facility damage. The goal of PBSD is to provide decision makers and stakeholders with data that will enable them to allocate resources for construction based on levels of desired seismic performance"--Publisher's description.
Author :National Cooperative Highway Research Program Publisher :Transportation Research Board ISBN 13 :0309067537 Total Pages :55 pages Book Rating :4.3/5 (9 download)
Book Synopsis Comprehensive Specification for the Seismic Design of Bridges by : National Cooperative Highway Research Program
Download or read book Comprehensive Specification for the Seismic Design of Bridges written by National Cooperative Highway Research Program and published by Transportation Research Board. This book was released on 2002 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Seismic Design and Assessment of Bridges by : Andreas J Kappos
Download or read book Seismic Design and Assessment of Bridges written by Andreas J Kappos and published by Springer Science & Business Media. This book was released on 2012-04-17 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book focuses on the use of inelastic analysis methods for the seismic assessment and design of bridges, for which the work carried out so far, albeit interesting and useful, is nevertheless clearly less than that for buildings. Although some valuable literature on the subject is currently available, the most advanced inelastic analysis methods that emerged during the last decade are currently found only in the specialised research-oriented literature, such as technical journals and conference proceedings. Hence the key objective of this book is two-fold, first to present all important methods belonging to the aforementioned category in a uniform and sufficient for their understanding and implementation length, and to provide also a critical perspective on them by including selected case-studies wherein more than one methods are applied to a specific bridge and by offering some critical comments on the limitations of the individual methods and on their relative efficiency. The book should be a valuable tool for both researchers and practicing engineers dealing with seismic design and assessment of bridges, by both making the methods and the analytical tools available for their implementation, and by assisting them to select the method that best suits the individual bridge projects that each engineer and/or researcher faces.
Book Synopsis Experimental and Analytical Investigation of Seismic Bridge-abutment Interaction in a Curved Highway Bridge by : Joseph Wieser
Download or read book Experimental and Analytical Investigation of Seismic Bridge-abutment Interaction in a Curved Highway Bridge written by Joseph Wieser and published by . This book was released on 2014 with total page 1040 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seat-type bridge abutments are most commonly used to support the end spans of curved highway bridges. This type of abutment is often selected to eliminate unbalanced stresses in the superstructure under service loads, in particular thermal expansion and contraction. However, depending on the width of the expansion gap, large earthquakes may cause the expansion gap to close which results in bridge-abutment interaction. This phenomenon was studied in a federally-funded research project examining the seismic performance of curved highway bridges at the University of Nevada, Reno. As a part of this research a 2/5 th scale model of a 3-span curved steel girder bridge was constructed on four multi-degree-of-freedom shake tables. Two configurations of the bridge one without bridge-abutment interaction and one with nonlinear bridge-abutment interaction were tested. The purpose of these tests was to: (i) identify the influence of bridge-abutment interaction on the global seismic response of the bridge, (ii) characterize the force-deformation characteristics of dynamic bridge-abutment interaction, and (iii) provide experimental data used to calibrate numerical models of bridges including bridge abutment interaction. Based on the experimental investigation it was concluded that bridge-abutment interaction shortens the effective period of vibration of the bridge, which results in decreased deck displacement and increased total base shear demands. However, the increase in base shear demand is resisted by the abutments which results in a net reduction in column shear demand. Though the deck displacement is reduced at the mid-span of the bridge, the active displacement of the deck at the abutments is increased due to the increased in-plane deck rotation generated as a result of the sudden changes in eccentricity between the center of mass and center of stiffness. The amount of in-plane rotation is shown to depend on the phasing and intensity of the ground motion. Interaction between the bridge and abutment backwall can generate significant radial shear forces through contact friction. These radial forces limit the radial displacement of the bridge while in contact with the backwall particularly after the radial shear keys have failed. However, depending on the details of the abutment backwall local damage may occur. In general, engaging the passive resistance of the backfill soil was able to improve the seismic response of the bridge by reducing damage to the columns and adding an additional form of energy dissipation. Both rigorous 3D finite element and simplified grillage models of the experimental model were validated using available software. Good agreement between the numerical models and the experimental data were obtained using both models however the computational effort was greatly reduced using the simplified grillage model. A grossly simplified 3DOF model of the bridge analyzed using the linear multi-modal response spectrum method was shown to give a prediction of the peak displacement response with minimal complexity. Finally, a parameter study determined that the degree of curvature, size of expansion gap, column diameter, and abutment backfill soil type all influence the response of the bridge. Based on the small scale parameter study conducted herein, bridge designers are encouraged to optimize the combination of expansion gap width with the selection of column diameter to minimize the column and/or abutment soil ductility demands.
Book Synopsis Guidelines for Analyzing Curved and Skewed Bridges and Designing Them for Construction by : Daniel Gattner Linzell
Download or read book Guidelines for Analyzing Curved and Skewed Bridges and Designing Them for Construction written by Daniel Gattner Linzell and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of design, fabrication, and construction on the geometry and load distribution in a curved or skewed bridge system are areas in which further study and understanding are required. This project utilized remote acquisition capabilities for instruments on two structures in the Interstate 99 corridor: a horizontally curved, steel, I-girder bridge, and a skewed, prestressed, concrete bridge. Data obtained from these structures were examined and the numerical model accuracy for curved and skewed, steel, I-girder bridges and select appropriate model types and software was investigated. Parametric studies were undertaken on a group of representative curved and skewed steel bridge structures to numerically examine the influence of specific variables on behavior during construction. Results enabled the identification of preferred erection sequencing approaches.
Book Synopsis Sensitivity of Response of Skewed Bridges to Their Span Length, Number of Bents and Abutment Modeling by : Shayan Sheikhakbari
Download or read book Sensitivity of Response of Skewed Bridges to Their Span Length, Number of Bents and Abutment Modeling written by Shayan Sheikhakbari and published by . This book was released on 2016 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sensitivity of the seismic performance of two typical bridges to the modeling variation of their abutment parameters is investigated and compared through a comparison parameter proposed in this study. One of the bridges is a two-span two-column-bent bridge with seat-type skew abutment and the other is a three-span three-column-bent bridge with seat-type skew abutment. A set of 40 pulse-like ground motions is applied to the bridges for nonlinear time-history analysis.In the transverse direction, two force-deformation models, which are based on strut-and-tie and sliding shear friction mechanisms, are used. The analytical models are based on the extensive experimental research previously conducted.A hyperbolic force-deformation model (General Hyperbolic Force Deformation) is used to represent the passive lateral resistance of the abutment backfill. For considering the possible variation in the backfill geotechnical property, three typical abutment backfill is chosen from the exciting data that was collected from multiple highway bridges in California. Two alternative methods are used to account for the effect of the abutment skew angle on the backfill reaction. The methods include an empirical relationship derived from experimental data, and an analytical method developed based on assumed log-spiral soil failure mechanism.A comparison parameter is proposed in this study, which is a representative of ductility demand of a skewed bridge to the same non-skewed bridge. For each case, the parameter is computed using the data derived from the nonlinear time-history analysis to investigate the seismic performance of bridges and compare the ductility demand of the specimen bridges.The outcome of this research reveals the significance of shear keys and abutment backfill on the global response of bridges. The sensitivity of the comparison parameter to the specimen bridges' geometry is also discussed in detail in this study.
Book Synopsis Guidelines for Analyzing Curved and Skewed Bridges and Designing Them for Construction by : Daniel Gattner Linzell
Download or read book Guidelines for Analyzing Curved and Skewed Bridges and Designing Them for Construction written by Daniel Gattner Linzell and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of design, fabrication, and construction on the geometry and load distribution in a curved or skewed bridge system are areas in which further study and understanding are required. This project utilized remote acquisition capabilities for instruments on two structures in the Interstate 99 corridor: a horizontally curved, steel, I-girder bridge, and a skewed, prestressed, concrete bridge. Data obtained from these structures were examined and the numerical model accuracy for curved and skewed, steel, I-girder bridges and select appropriate model types and software was investigated. Parametric studies were undertaken on a group of representative curved and skewed steel bridge structures to numerically examine the influence of specific variables on behavior during construction. Results enabled the identification of preferred erection sequencing approaches.
Book Synopsis Seismic Performance of Steel Plate Girder Bridges with Integral Abutments by : U. S. Department Transportation
Download or read book Seismic Performance of Steel Plate Girder Bridges with Integral Abutments written by U. S. Department Transportation and published by CreateSpace. This book was released on 2013-04-24 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents the results of a pilot study on the seismic behavior and response of steel bridges with integral abutments. Analytical investigations were conducted on computational models of steel bridges with integral abutments to determine their seismic behavior as a system and to develop seismic design guidelines. The effect of the superstructure flexibility due to inadequate embedment length was investigated using 3D finite element models. This flexibility, modeled as translational and rotational springs, proved to have significant effect on the overall bridge dynamic characteristics in terms of periods and critical mode shapes. Lateral and longitudinal load paths and the seismic response were investigated using modal pushover and nonlinear time history analyses. A limited investigation on the effect of skew was conducted on a single-span integral abutment bridge. A procedure for incorporating the system level damping due to the yielding and inelastic responses of various components was proposed for use in the seismic analysis. Based on the analytical investigations and available experimental research, guidelines for the seismic analysis and design of integral abutment bridges were developed.
Book Synopsis Seismic Performance of New Bridges with Skew and Curvature by : Ryan T. Moore
Download or read book Seismic Performance of New Bridges with Skew and Curvature written by Ryan T. Moore and published by . This book was released on 1998 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Seismic Performance Design Criteria for Bridge Bent Plastic Hinge Regions by : A. K. M. Golam Murtuz
Download or read book Seismic Performance Design Criteria for Bridge Bent Plastic Hinge Regions written by A. K. M. Golam Murtuz and published by . This book was released on 2020 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this research was to quantify the material strain limits for seismic assessment of existing sub-standard reinforced concrete bridge bents considering operational performance design criteria. Limited confidence exists in the current material strain limit state for operational performance criteria due to lack of experimental results considering the typical detailing of Oregon bridges and the cumulative damage effect resulting from an anticipated long-duration Cascadia Subduction Zone (CSZ) event. Component details for bridge bents such as geometry and reinforcing details were determined through a statistical analysis of available bridge drawings built prior to 1990 in the State of Oregon. Three full-scale bridge bent column-footing subassembly specimens were constructed and subjected to reverse cyclic lateral deformations utilizing a traditional loading protocol and a protocol representing the demands expected from a CSZ earthquake. The tests were designed so that variable axial loading could be applied in order to simulate the secondary effects experienced in a column that is part of a multi-column bent during an earthquake event. Material strains along with global and local deformation quantities were measured with a suite of external and internal sensors mounted to and embedded in the specimens. Despite having sub-standard seismic detailing, all three specimens exhibited ductile behavior under reverse cyclic lateral loading, achieving a minimum displacement ductility of 8.0. The obtained results also suggest that the material strain limits currently used for the seismic evaluation of existing bridges in Oregon considering operational performance criteria are conservative, but may still require further experimental validation. Finally, strain limits based on previous research at Portland State University (PSU) were compiled and combined with the results from this study to propose recommended strain limit values.
Book Synopsis An Investigation of the Effectiveness of Existing Bridge Design Methodology in Providing Adequate Structural Resistance to Seismic Disturbances by : Ma-chi Chen
Download or read book An Investigation of the Effectiveness of Existing Bridge Design Methodology in Providing Adequate Structural Resistance to Seismic Disturbances written by Ma-chi Chen and published by . This book was released on 1977 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Four different mathematical model elements are incorporated into the three dimensional computer program which possess the capability of performing linear or nonlinear-time-history dynamic response analysis. Solid finite element modelling is used for the backfill soils and the abutment walls. The bridge deck, pier columns and pier caps are modelled using prismatic beam elements. A frictional element is used to model the discontinuous behavior at the interfaces of the backfill soils and abutments. Boundary elements provide foundation flexibility at the base of columns supported on either piles or spread footings. In the nonlinear mathematical model the effects of separation, impact and slippage at the interfaces between the abutment walls and the backfill soils are taken into consideration. Computational efficiency is achieved through the use of mathematical techniques including matrix reduction procedures, interaction procedures and variable time steps. A number of analytical solutions are carried out considering a skewed three-span bridge with backfill soils. Different mathematical models are used to study the parameters which may influence the seismic response of the bridge.
Book Synopsis Parametric Study on the Seismic Performance of Typical Highway Bridges in Canada by : Yuling Gao
Download or read book Parametric Study on the Seismic Performance of Typical Highway Bridges in Canada written by Yuling Gao and published by . This book was released on 2015 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquakes are one of the main natural hazards that have caused devastations to bridges around the world. Given the observations from past earthquakes, substantial analytical and experimental research work related to bridges has been undertaken in Canada and other countries. The analytical research is focussed primarily on the prediction of the seismic performance of existing bridges. It includes bridge-specific investigations which are mainly conducted using deterministic approach, and investigations of bridge portfolios which are based on probabilistic approach. In both cases, nonlinear time-history analyses are extensively used. To conduct analysis on a given bridge, analytical (i.e., computational) model of the bridge is required. It is known that the seismic response predictions depend greatly on the accuracy of the input of the modeling parameters (or components) considered in the bridge model. The objective of this study is to investigate the effects of the uncertainties of a number of modeling parameters on the seismic response of typical highway bridges. The parameters considered include the superstructure mass, concrete compressive strength, yield strength of the reinforcing steel, yield displacement of the bearing, post-yield stiffness of the bearing, plastic hinge length, and damping. For the purpose of examination, two typical reinforced concrete highway bridges located in Montreal were selected. Three-dimensional (3-D) nonlinear model the bridge was developed using SAP2000. The effects of the uncertainty of each parameter mentioned above were investigated by conducting time-history analyses on the bridge model. In total, 15 records from the earthquakes around the world were used in the time-history analysis. The response of the deck displacement, bearing displacement, column displacement, column curvature ductility, and moment at the base of the column was considered to assess the effect of the uncertainty of the modeling parameter on the seismic response of the bridge. Recommendations were made for the use of these modeling parameters on the evaluation of the seismic performance of bridges.
Book Synopsis Seismic Vulnerability Assessment of Bridges for Retrofitting and New Design by : Pedram Farokh
Download or read book Seismic Vulnerability Assessment of Bridges for Retrofitting and New Design written by Pedram Farokh and published by . This book was released on 2017 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many bridges in North Eastern region of U.S. were designed prior to the adoption of the AASHTO LRFD Guide Specifications for seismic design and may be vulnerable to damage during an earthquake event. This study evaluates the seismic vulnerabilities of those bridges and the structural factors that could affect their performance during a seismic event. The effects of load demands and age deteriorations were also studied. Aging of certain bridge components such as bearings, columns, and bent caps can affect the capacity and demands of these components and accordingly might affect the global behavior and capacity of a bridge during an earthquake event. The concept of fragility curves was studied as a potential tool for evaluating the seismic performance of new bridges, existing bridges and retrofitted bridges for various bridge types subjected to different peak ground acceleration levels. Fragility curves represent the probability of a structure to experience damage levels higher than specific damage state at different peak ground acceleration. Possible retrofit measures for various bridge components were reviewed, and analyzed for their effectiveness. These include superstructure restrainers, stoppers, shear keys, isolation bearings, bent cap strengthening and column jacketing. Existing research shows that the concept of fragility curves can be used to identify bridge vulnerability and level of damage. They can also be used to identify performance and level of damage of various retrofit measures. The effect of aging of certain components such as stiffening and locking of bearings and corrosion of confining steel in columns need to be included when evaluating bridge load demands and capacities. Different types of concrete bridges (typical in North Eastern United States) were analyzed using elastic response spectrum and nonlinear push-over analysis for low, medium-to-high, and high seismicity levels. The effects of pier configuration, continuity between the superstructure and the substructure, and the number of spans were investigated. Analysis results showed that in the longitudinal direction, the displacement demand increased for multi-column bents compared to single-column bents. However, the overall D/C ratio dropped in both transverse and longitudinal directions. The results also showed that in the longitudinal direction the benefit of having multi-column bent over single-column bents in integral bridges is dependent on the seismicity levels. The D/C (demand/capacity) ratio for single column bents in the longitudinal direction was much lower for integral (monolithic) bents compared to non-integral bents. In the transverse directions, the difference in the D/C ratio was not significant. For multi-column bents, the percent change by having integral bents over non-integral bents was dependent on the seismicity levels. For high seismicity zones, the benefits of having Integral bents becomes more significant. This investigation presents guidance on incorporating the effects of aging and retrofitting in the finite element modeling of bridges subjected to various levels of earthquake ground motions.
Book Synopsis Experimental and Analytical Investigations on the Effects of Live Load on the Seismic Performance of a Highway Bridge by : Hartanto Wibowo
Download or read book Experimental and Analytical Investigations on the Effects of Live Load on the Seismic Performance of a Highway Bridge written by Hartanto Wibowo and published by . This book was released on 2013 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current bridge design specifications have few requirements concerning the inclusion of live load in the seismic design of bridges for perhaps two reasons: 1) the likelihood of the full design live load occurring at the same time as the design earthquake is deemed to be very low, and 2) adverse behavior in an earthquake due to live load has not been observed in practice. However, with increasing congestion in major cities, the occurrence of the design earthquake at the same time as the design live load is now more likely than in the past. But little is known about the effect of live load on seismic response and this dissertation describes an experimental and analytical project that investigates this behavior. The experimental work included shake table testing of a 2/5th -scale model of a three-span, horizontally curved, steel girder bridge loaded with a series of representative trucks. The model spanned four shake tables each synchronously excited with scaled ground motions from the 1994 Northridge Earthquake. Observations from the experimental work show the presence of the live load had a beneficial effect on performance of this bridge, but this effect diminished with increasing amplitude of shaking. During the design earthquake, the bridge with live load was essentially elastic whereas the bridge without live load suffered some yielding and the maximum displacement at the top of the column was approximately 35% less in the live load case. Parameters used to measure performance included column displacement, abutment shear force, and degree of concrete spalling in the plastic hinge zones. Results obtained from nonlinear finite element analyses of the bridge with and without trucks confirm this behavior, that live load reduces the dynamic response of the bridge. The most likely explanation for this phenomenon is that the trucks act as a set of nonlinear multiple mass dampers, a variation of tuned mass dampers that are known to be effective at controlling wind vibrations in buildings. Parameter studies have also been conducted and show the above beneficial effect is generally true for other earthquake ground motions and vehicles with different dynamic properties. Exceptions exist, but adverse effects are usually within 10-15% of the no-live load case. Although the above results were obtained for a particular bridge, earthquake loading, and vehicle configuration, they may also apply to other bridges. Further work is required to confirm this observation.
