Download or read book Behavior of Trapezoidal Box Girders with Skewed Supports written by Dawei Li and published by . This book was released on 2004 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Behavior of Trapezoidal Box Girders with Skewed Supports written by Dawei Li and published by . This book was released on 2004 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cross frame Bracing of Steel Trapezoidal Box Girder Bridges with Skewed Supports written by Duane Milligan and published by . This book was released on 2002 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design Guidelines for Steel Trapezoidal Box Girder Systems written by and published by . This book was released on 2007 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Behavior of curved steel trapezoidal box girders during construction written by Cem Topkaya and published by . This book was released on 2002 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Composite Action During Construction of Steel Trapezoidal Box Girder Bridges written by and published by . This book was released on 2005 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: In steel trapezoidal box girder bridge systems, the U-shaped steel girder is designed to act compositely with the concrete deck to form a closed box for live loading. During the construction stage, however, the behavior is not well understood. The usual practice of assuming the system to be non-composite during construction requires substantial top flange bracing to form a quasi-closed box section. Composite box girders with live loading, and girders during construction, have to be evaluated during the design of curved steel trapezoidal box girder bridges. Considering both cases, the design for construction loading is the least understood and is the most important. Stresses due to construction loading can reach up to 60-70 percent of the total design stress for a given cross section. A three-phase study was undertaken to investigate the behavior of curved trapezoidal box girders during construction.
Download or read book Bolezni s prirodnoj o agovost ju written by and published by . This book was released on 1983 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Behavior of a Skew Reinforced Concrete Box Girder Bridge Model written by Raymond E. Davis and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cross frame and Diaphragm Behavior for Steel Bridges with Skewed Supports written by Todd Aaron Helwig and published by . This book was released on 2003 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simplified Methods of Evaluating the Redundancy of Twin Trapezoidal Box Girder Bridges written by Vasileios Samaras and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: According to the AASHTO Load and Resistance Factor Design (LRFD) Bridge Design Specifications, a bridge is defined to be fracture critical when a failure of a tension component will result in the collapse of the bridge. In the case of a twin box girder bridge, the tension flanges in the positive moment portion of the bridge, as well as the webs, are considered to be fracture critical elements. Due to this classification, those bridges are subjected to stringent inspections at least every two years. Those inspections are crucial for ensuring the safety of the bridge, yet are expensive and time consuming. Multiple cases of FCBs (Fracture Critical Bridge) that have experienced a fracture in one of their elements without collapse have encouraged owners of those bridges to question the validity of AASHTO's requirements. The Texas Department of Transportation is interested in indentifying when a fracture of an element could lead to a catastrophic collapse of a bridge. A better understanding of fracture critical bridge behavior may allow TxDOT and other state DOTs to reduce the frequency of the inspections, which could potentially reduce the cost of an otherwise attractive bridge design. The goal of this research project is to determine the level of redundancy of twin box girder bridges. Simplified analytical methods and guidelines that will conservatively estimate the behavior of such bridges will be presented in this thesis. Those guidelines will be one of the tools that an engineer in practice could use to determine if a bridge is prone to collapse following the failure of a fracture critical component. A full-size bridge has been constructed at the Ferguson Structural Engineering Laboratory to test the response of these systems following a simulated fracture. A series of tests were conducted to determine the response of the bridge in the event of a tension flange fracture. The results provided important information for the development of the simplified methods. The FSEL test bridge performed extremely well throughout all the testing and supported a load of over four times the AASHTO design truck load. Several elements contributed to create alternative load paths that could sustain the entire applied load with a full-depth fracture of one of its two girders. The large section of the concrete railing above the fractured girder acted as an inverted beam and transmitted a portion of the load back to the supports once the expansion joint closed due to the downward deflection of the bridge. The concrete deck acted as a shear diaphragm and also transferred significant loads in both horizontal directions. Because the performance of the test bridge far exceeded the AASHTO criteria, and because this behavior can be computed using the simplified methods presented in this thesis as well as through detailed finite element models, consideration should be given to revising the current AASHTO specifications and to developing alternate inspection and maintenance requirements that accurately reflect the redundancy available in various types of fracture critical bridges.
Download or read book Behavior at the Corners of Skewed Single span Cast in place Post tensioned Box Girder Bridges written by Phillip M. Holthaus and published by . This book was released on 2009 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Behavior of Steel Tub Girders with Modified Cross sectional Geometry written by Yang Wang (Ph. D.) and published by . This book was released on 2019 with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt: Steel trapezoidal box girders, also referred to as steel tub girders, have been an attractive design option for long-span horizontally curved highway bridges. The completed composite bridge system presents an aesthetic appeal profile as well as large torsional stiffness. However, during construction, the open U-shaped steel girder section is relatively flexible in torsion and requires extensive bracing. A recent application on straight bridge system in Waco, Texas showed potential wider utilization of tub girders for span length normally reserved for precast concrete beams. Current design and fabrication practices have several relatively inefficient aspects regarding the section geometry and bracing details. These details include the restrictions on the slope ratio of the webs and the top flange-web attachment. Due to the use of empirical equation for live load distribution factor, the slopes of tub girder webs are restricted to be no greater than 1 Horizontal: 4 Vertical in current AASHTO specification. Significant economy can be achieved by utilizing flatter webs. While keeping the width of bottom flange constant, the use of flatter webs increases the tributary width of individual girder. This leads to potential reduction of the required number of girder lines to support traffic live loads and considerable savings on fabrication time and cost. Additionally, the webs of the tub girder are usually attached at the mid-width of the top flanges. This leaves limited flange width to connect the top lateral braces directly with the flange. Therefore, large gusset plates are frequently used to provide sufficient space for the connection. However, the use of gusset plates leads to poor load transfer and unnecessary fabrication cost. If the top flanges are allowed to offset toward the inside of the box, more flange width would be available for simple bolted bracing connection without using gusset plates. Since these proposed details are not currently permitted by AASHTO Specification, a TxDOT-sponsored research project has been conducted at UT Austin to demonstrate the impact of these improved tub girder details using large-scale experimental study and finite element analyses. This dissertation presents part of the results of this research project to provide better understanding of tub girder behavior as well as design recommendations to improve the efficiency and economy of the steel tub girder system
Download or read book An Introduction to Longitudinal Design of Post Tensioned Box Girders for Highway and Bridge Structures written by J. Paul Guyer, P.E., R.A. and published by Guyer Partners. This book was released on 2018-09-26 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introductory technical guidance for civil and structural engineers interested in design of post-tension box girders for highway and bridge structures. Here is what is discussed: 1. INTRODUCTION 2. MODELING CONCEPTS 3. STRENGTH LIMIT VERIFICATION—FLEXURE 4. STRENGTH LIMIT VERIFICATION—SHEAR.
Download or read book An Introduction to Longitudinal Design of Post Tensioned Box Girders for Highway and Bridge Structures for Professional Engineers written by J. Paul Guyer, P.E., R.A. and published by Guyer Partners. This book was released on with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introductory technical guidance for civil engineers, structural engineers, highway engineers, bridge engineers and other professional engineers and construction managers interested in design and construction of box girder bridge structures. Here is what is discussed: 1. INTRODUCTION, 2. MODELING CONCEPTS, 3. STRENGTH LIMIT VERIFICATION—FLEXURE, 4. STRENGTH LIMIT VERIFICATION—SHEAR.
Download or read book The Effect of Skewed and Elevated Supports on the Behavior of Curved Girder Bridges written by Donald Wayne Funkhouser and published by . This book was released on 1972 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Behavior of a Skew Reinforced Concrete Box Girder Bridge Model written by Raymond E. Davis and published by . This book was released on 1978 with total page 247 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 written by Alex C. Scordelis and published by . This book was released on 1980 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt:
