Author: Konlee Baxter Dobbins
Publisher:
ISBN:
Category : Girders
Languages : en
Pages : 96

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Book Description

Author:
Publisher: Transportation Research Board
ISBN: 0309258391
Category : Curves in engineering
Languages : en
Pages : 199

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Book Description
"TRB's National Cooperative Highway Research Program (NCHRP) Report 725: Guidelines for Analysis Methods and Construction Engineering of Curved and Skewed Steel Girder Bridges offers guidance on the appropriate level of analysis needed to determine the constructability and constructed geometry of curved and skewed steel girder bridges. When appropriate in lieu of a 3D analysis, the guidelines also introduce improvements to 1D and 2D analyses that require little additional computational costs."--Publication information.

Author: Cagri Ozgur
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages :

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Book Description
This thesis investigates the strength behavior of a representative highly skewed and horizontally curved bridge as well as analysis and design procedures for these types of structures. The bridge responses at and above a number of limits in the AASHTO (2007) Specifications are considered. The study includes the evaluation of various attributes of the elastic analysis of the subject bridge. These attributes include: (1) the accuracy of 3-D grid versus 3-D FEA models, (2) first-order versus second-order effects during the construction, (3) the ability to predict layover at bearing lines using simplified equations and (4) the benefit of combining the maximum and concurrent major-axis and flange lateral bending values due to live load compared to combining the maximums due to different live loads when checking the section resistances. The study also addresses the ability of different AASHTO 2007 resistance equations to capture the ultimate strength behavior. This is accomplished by comparing the results from full nonlinear 3-D FEA studies to the elastic design and analysis results. Specifically the use of the 2007 AASHTO moment based one-third rule equations is evaluated for composite sections in positive bending.

Author: Daniel Gattner Linzell
Publisher:
ISBN:
Category : Bending stresses
Languages : en
Pages : 0

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Book Description
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.

Author: Daniel Gattner Linzell
Publisher:
ISBN:
Category : Bending stresses
Languages : en
Pages :

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Book Description
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.

Author: Telmo Andres Sanchez
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages :

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Book Description
The construction of horizontally curved bridges with skewed supports requires careful consideration. These types of bridges exhibit three-dimensional response characteristics that are not commonly seen in straight bridges with normal supports. As a result, engineers may face difficulties during the construction, when the components of the bridge do not fit together or the final geometry of the structure does not correspond to that intended by the designer. These complications can lead to problems that compromise the serviceability aspects of the bridge and in some cases, its structural integrity. : The three dimensional response that curved and skewed bridges exhibit is directly influenced by the bracing system used to configure the structure. In I-girder bridges, cross-frames are provided to integrate the structure, transforming the individual girders into a structural system that can support larger loads than when the girders work separately. In general, they facilitate the construction of the structure. However, they can also induce undesired collateral effects that can be a detriment to the performance of the system. These effects must be considered in the design of a curved and skewed bridge because, in some cases, they can modify substantially its response.

Author: Shree Krishna Tripathi
Publisher:
ISBN:
Category : Box girder bridges
Languages : en
Pages : 188

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Book Description
Many highway bridges are skewed to maintain the profile of natural obstacles to road like rivers, and depressions. Generally, we analyze straight bridge girders making it a line element which makes our hand calculations simpler. However, if we follow the same procedure for skewed bridges like straight ones, we cannot fully visualize and determine their behavior properly which may lead to over estimation or underestimation on different structural forces like bending moment, shear force and most importantly deflection. It is because when we look on skewed bridges in three dimension, the ends of the bridges are skewed to the centerline of the bridges and we can clearly realize that the concrete materials in the acute side is less than that in the obtuse side. If the skew angle is relatively large, it might be the case that there is unbalancing forces along the cross section of the skewed bridge which might lead to the camber at the center of the bridge to be inclined to the vertical which might tend to rotate the entire bridge about the vertical plane. This implies that highly skewed bridges tend to attract more torsion making the design more complicated. If these aspects are not taken into consideration, the skewed bridges might not be good fit while taking the limit state of serviceability. This thesis paper investigates into the three-dimensional analysis of a skewed bridge. Finite element modeling is utilized to analyze the skewed bridges and we can know how it behaves. After the modeling and analysis of a simple span cast in place post tensioned skewed bridge, it is seen that the deflection and bending moment at the mid-span of a skewed bridge is less compared to the non-skewed bridge. Moreover, a skew effect factor is also found which is very useful while designing skewed bridges.

Author: Phillip M. Holthaus
Publisher:
ISBN:
Category :
Languages : en
Pages : 42

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Book Description
In today's textbooks, analyzing prestressed members and bridges takes a two-dimensional approach. Two-dimensional analysis is the only way to analyze prestressed bridges and members because otherwise the hand calculations are extremely difficult. Skewed bridges, however, need to be analyzed and designed three-dimensionally. Based on engineering inspection, it is possible to tell how a non-skewed symmetric bridge will behave. However, the knowledge of how a skewed bridge will behave cannot be obtained by inspection only. Finite element analysis can be used to model a bridge and discover how the bridge will react to dead loads and post-tensioning forces. When a bridge is built on a skew, the acute corners of the bridge support much less concrete weight than the obtuse corners of the bridge. If the post-tensioning force causes a decrease in load at the acute corners of the skewed bridge and if the skew of the bridge is great enough, there is a concern that there could be uplift at these acute corners of the bridge. Uplift at any corner of the bridge should not be allowed. The objective of this study is to investigate a simple span skewed box girder bridge to see if any uplift occurs at the acute corners of the bridge due to post-tensioning forces. After careful study of a skewed simple span cast-in-place post-tensioned box girder bridge, it was found that the post-tensioning force actually transfers more downward force into the acute corners of the bridge. Based on this study, the post-tensioning force will not cause uplift in the acute corners of the skewed bridge.

Author: Jidong Xin
Publisher:
ISBN:
Category : Grillages (Structural engineering)
Languages : en
Pages : 232

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Book Description

Author: U. S. Department Transportation
Publisher: CreateSpace
ISBN: 9781484198179
Category :
Languages : en
Pages : 168

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Book Description
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.