Download or read book Seismic Response of Skewed Two span Composite Steel Bridges written by Jincheng Li and published by . This book was released on 1998 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.

Download or read book Seismic Behavior of Bidirectional resistant Ductile End Diaphragms with Unbonded Braces in Straight Or Skewed Steel Bridges written by Oguz C. Celik and published by . This book was released on 2007 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.

Download or read book Quick Release Pullback Testing and Analytical Seismic Analysis of a Six Span Composite Girder Bridge written by Bruce M. Douglas and published by . This book was released on 1976 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance based Seismic Assessment of Skewed Bridges written by Peyman Kavianijopari and published by . This book was released on 2011 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study focuses on identifying, both qualitatively and quantitatively, the seismic behavior of reinforced concrete bridges with seat-type abutments under earthquake loading, especially with respect to abutment skew angle. To that end, the study proposes novel methodologies for modeling skew-angled seat-type abutments and for seismic response assessment of structures whose response is characterized as "multi-phased." The proposed methodologies are applied to a comprehensive database of bridges with combinations of a variety of bridge geometric properties, including: (1) number of spans; (2) number of columns per bent; (3) column-bent height; (4) span arrangement; and (5) abutment skew angle. An extensive nonlinear response history analysis was conducted using three sets of ground motions representing records for rock sites and soil sites, as well as others that contained pronounced velocity pulses, denoted as "pulse-like." We demonstrate that demand parameters for skew-abutment bridges, such as deck rotation, abutment unseating, and column drift ratio, are higher than those for straight bridges. By investigating the sensitivity of various response parameters to variations in bridge geometry and ground motion characteristics, we show that bridges with larger abutment skew angles bear a higher probability of collapse due to excessive rotation, and that shear keys can play a major role in reducing deck rotations and thus the probability of collapse. We further show that resultant peak ground velocity (PGVres) is the most efficient ground motion intensity measure (IM) compared to many other IMs. In view of the skewed bridges' explicit changes in demand parameter behavior due to shear key failure, we propose a probabilistic-based approach for multi-phase structural response assessment. This method, denoted as "Multi-Phase Probabilistic Assessment of Structural Response to Seismic Excitations," or M-PARS, provides a probabilistic framework for computing the complementary probability distribution function of an engineering demand parameter given the ground motion intensity measure, G(EDP\IM).

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.

Download or read book Comparative Seismic Analyses of Two span Comtinuous Steel Girder Bridges written by Qing Wang and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Behavior of a Skew Two Span Reinforced Concrete Box Girder Bridge Model Response during ultimate loading to failure written by and published by . This book was released on 1980 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Non Linear Seismic Analysis of Bridges written by Shrirang Tande and published by LAP Lambert Academic Publishing. This book was released on 2012-06 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge structures had been predominantly analyzed and designed elastically, beginning at the year of 1971 (Since San Fernando earthquake), researchers started to study the nonlinear seismic response of bridges. There are no detailed guidelines addressing the performance of skewed highway bridges. This book presents the performance of bridges for various skew patterns and skew angles and combination of both by performing non linear seismic analysis. The three dimensional finite element analyses of straight and skew bridges with skew angles varying from 0 degrees to 60 degrees are investigated. Response spectrum analysis is considered for analyzing various bridge models. The efforts are made to investigate the effects of parameters such as skew angles, aspect ratios, and unsupported lengths on the bridge behavior. Also the effect of parameters like S/L and B/L ratios (aspect ratio) for the single span bridges are evaluated.

Download or read book Guide Specifications for Seismic Isolation Design written by and published by AASHTO. This book was released on 2010 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edition is based on the work of NCHRP project 20-7, task 262 and updates the 2nd (1999) edition -- P. ix.

Download or read book Performance based Seismic Assessment of Skewed Bridges with and Without Considering Soil structure Interaction Effects for Various Site Classes written by Abdoulreza Ghotbi and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This study aims to investigate the behavior of skewed and straight highway overpass bridges both with and without taking into account the effects of Soil-Structure Interaction (SSI) due to near-fault ground motions. Both deterministic (i.e., pushover and nonlinear dynamic analyses) and probabilistic approaches were utilized. A set of response sensitivity analyses was performed considering various skew angles, column elements, and soil properties for bridge considered both as fixed-base and SSI models. It has been observed that as the skew angle increased, the bridge responded more severely to the ground motion. For instance, the deck rotation and shear-keys displacement increased with an increase in the skew angle. A modal pushover analysis was also performed in conjunction with the nonlinear dynamic analysis. It has been found that combining the bridge responses for various modes of vibration resulted in a relatively accurate seismic response compared to the nonlinear dynamic analysis while saving time and analysis cost, to a great extent. A probabilistic analysis was also performed considering record-to-record variability in ground motion, and a set of probabilistic seismic demand and fragility plots was generated. The effects of change in the skew angle and also SSI were studied to see various bridge responses. The damage probability increased especially with respect to deck rotation as the skew angle increased. The SSI had a decreasing effect on the overall response of the bridge with pile foundation.

Download or read book Internal Forces in Medium Two Span Continuous Multi stringer Composite Skew Steel Bridges written by Dexian Guan and published by . This book was released on 1992 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Design of Bridges Design Example written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Behavior of a Skew Two Span Reinforced Concrete Box Girder Bridges Model written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Response of Concrete Bridges written by Kosalram Krishnan and published by . This book was released on 1999 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Pounding and Supporting Soil on the Seismic Response of Skewed Bridges written by Chern Kun and published by . This book was released on 2018 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observations from major earthquakes in the past have revealed that skewed bridges are more vulnerable to damage than straight bridges. Due to the irregular geometry, they are prone to in-plane rotations of the girder that are not induced by the girders of straight bridges. Previous studies have found that these rotations could be aggravated by the presence of pounding between the bridge segment and abutments. The interaction between the underlying soil support and the bridge footing could also significantly affect the response of the bridge. However, most of the studies on skewed bridges have been conducted either numerically or analytically. Experimental work on the topic had been scarce. Hence, the early parts of this doctoral research aim to provide better understanding on the behaviour of skewed bridges under the influence of bridge-abutment pounding and soil support separately and simultaneously, through experimental studies. The skew angles considered were 0°, 30°, and 45°. The bridge-abutment model was subjected to spatially uniform ground motions. Although the vulnerability of skewed bridges had been known as early as the 1970s, due to simplicity, many design specifications still do not sufficiently consider the effects of the skew angle, pounding, or supporting soil. Pounding is usually ignored, and an idealised fixed base condition is often assumed. For example, the New Zealand Transport Agency Bridge Manual recommends that the seat lengths of skewed bridges in the longitudinal and transverse directions are simply 25% larger than that calculated for a straight bridge. Hence, the later part of this doctoral research aims to address this issue by proposing a simple approach using empirical formulae to provide better prediction of the responses of skewed bridges. For more conservative results, it was suggested that the proposed formulae be incorporated in addition to the current NZTA recommendations, i.e. have a 25% factor of safety.