The Bump at the End of the Bridge

The Bump at the End of the Bridge
Author: Jeong Bok Seo
Publisher:
Total Pages:
Release: 2005
Genre:
ISBN:

A number of recently constructed bridge approach slabs using an articulation at mid span and the wide flange terminal anchorage system have experienced settlement at their expansion joints. This problem is more commonly referred to as the bump at the end of the bridge. This study investigated reasons for the bumps and recommended ways to improve the current situation. To find out possible causes of the bridge approach slab problem, literature review, questionnaire survey, and a visual inspection for 18 Houston sites were conducted. Based on the results, two bridge sites in Houston, Texas, were selected for detailed investigation. An extensive series of laboratory and field tests were performed at each site. The main causes of bump at two study sites were compression of embankment soil and natural soil, and poor compaction of embankment soil. The finite-element computer program ABAQUS was used to evaluate behavior of the current approach slab design and of a possibly more effective design. The results show that the transition zone is about 12 m with 80 percent of the maximum settlement occurring in the first 6 m for a uniform load case and the optimum width of sleeper and support slabs is 1.5 m. A new approach slab which is 6 m long and has one span from the abutment to a sleeper slab was proposed based on accumulated data. It is designed to carry the full traffic load without support on the soil except at both ends; the support slab is removed and the wide flange is kept on the embankment side as a temperature elongation joint. The BEST device (Bridge to Embankments Simulator of Transition) was built to simulate the bump at the end of the bridge problem. It is a 1/20 [superscript th] scale model of the typical transition and the dimension was determined from dimensional analysis. Multiple BEST tests were conducted using a range of parameters and several influence factors were derived. A computer program was developed which uses the influence factors to predict the bump size from the beginning stage of embankment construction.

The Bump at the End of the Railway Bridge

The Bump at the End of the Railway Bridge
Author: Jennifer Elizabeth Nicks
Publisher:
Total Pages:
Release: 2011
Genre:
ISBN:

The bump at the end of the railway bridge is a result of differential movement between the bridge deck and the approach embankment. The movement can have the form of a bump or a dip. Either defect in the track geometry can cause significant problems in track performance. The current state of practice was evaluated by conducting a literature review and an industry survey. According to the survey, approximately half of all railway bridges are affected by the bump/dip. The total annual cost for repairing these bridge transition problems is estimated at $26 million. This does not take into account the considerable cost resulting from speed reductions that railroads must place on trains at these locations. In addition to the increased maintenance costs, the bump/dip leads to higher impact loads, uncomfortable rides and possible safety hazards. The track response due to the bump at the end of the bridge was evaluated by creating a 4-D finite element model of the train, track structure and track substructure. The motion of the train model across a bridge/approach transition, with and without a bump/dip, was then simulated using LS-DYNA. It was found that a track modulus differential alone (no bump/dip) at a bridge/approach location leads to impact forces as well as increased ballast and subgrade pressures on the approach. This instigates the formation of a bump or dip in the track. The track response is increased when a bump/dip is present in the track profile. A parametric study looking at the influence of train direction, train speed, bump/dip size, approach embankment soil modulus, approach tie material, bridge tie material, bridge deck type, ballast thickness and approach tie length on the magnitude of impact forces, track deflection, ballast and subgrade pressures was also performed with the model. Finally, a design solution to minimize the bump at the end of the bridge is proposed. The solution involves installing varying length steel bars into a soft subgrade approach embankment. The solution addresses both the settlement and track modulus differential between the bridge and the embankment. A full-scale field test of this prototype solution is underway.

The Design and Application of Controlled Low-strength Materials (flowable Fill)

The Design and Application of Controlled Low-strength Materials (flowable Fill)
Author: Amster K. Howard
Publisher: ASTM International
Total Pages: 342
Release: 1998
Genre: Controlled low-strength materials
ISBN: 0803124775

Focuses on a type of material mainly used in place of compacted backfill for pipe embedment and backfill, but gaining widely in applications. It is a mixture of cementitious material, soil, water, and sometimes fly ash and admixtures. Here 26 papers, from a June 1997 symposium in St. Louis, Missouri, describe new design procedures, new applications, and installation innovations in order to help assess the need for new or revised standards. They cover ingredients, properties, test methods, standards and specifications, case histories, and pipeline applications. The five current standards are appended. Annotation copyrighted by Book News, Inc., Portland, OR

Settlement of Bridge Approaches

Settlement of Bridge Approaches
Author: J.-L. Briaud
Publisher:
Total Pages: 88
Release: 1997
Genre: Bridge approaches
ISBN:

This synthesis will be of interest to state Departments of Transportation (DOTs) geotechnical, structural, roadway design, construction, and maintenance engineers; DOT research staff; and personnel in local transportation agencies. This synthesis describes the current state of the practice for the design, construction, and maintenance of bridge approaches to reduce, eliminate, or compensate for settlement at the bridge/abutment/embankment interface or the bump at the end of the bridge. It discusses the geotechnical and structural engineering design and procedural factors to reduce the bump at the end of the bridge, and includes numerous illustrations. This report of the Transportation Research Board presents data obtained from a review of the literature and a survey of the state DOTs. It is a supplemental update to Synthesis of Highway Practice 159: Design and Construction of Bridge Approaches (1990). The synthesis identifies and describes techniques that have been used to alleviate the problem of the bump at the end of the bridge including the location and cause of settlement and methods used to reduce settlement. In addition, the types of interaction between various divisions of the DOTs in the design, construction, and maintenance of bridge approaches are addressed.

Bridge Engineering Handbook, Five Volume Set

Bridge Engineering Handbook, Five Volume Set
Author: Wai-Fah Chen
Publisher: CRC Press
Total Pages: 3130
Release: 2014-01-24
Genre: Technology & Engineering
ISBN: 1482255030

Over 140 experts, 14 countries, and 89 chapters are represented in the second edition of the Bridge Engineering Handbook. This extensive collection provides detailed information on bridge engineering, and thoroughly explains the concepts and practical applications surrounding the subject, and also highlights bridges from around the world.Published

From Fundamentals to Applications in Geotechnics

From Fundamentals to Applications in Geotechnics
Author: D. Manzanal
Publisher: IOS Press
Total Pages: 3344
Release: 2015-12-11
Genre: Technology & Engineering
ISBN: 1614996032

The work of geotechnical engineers contributes to the creation of safe, economic and pleasant spaces to live, work and relax all over the world. Advances are constantly being made, and the expertise of the profession becomes ever more important with the increased pressure on space and resources. This book presents the proceedings of the 15th Pan-American Conference on Soil Mechanics and Geotechnical Engineering (XV PCSMGE), held in Buenos Aires, Argentina, in November 2015. This conference, held every four years, is an important opportunity for international experts, researchers, academics, professionals and geo-engineering companies to meet and exchange ideas and research findings in the areas of soil mechanics, rock mechanics, and their applications in civil, mining and environmental engineering. The articles are divided into nine sections: transportation geotechnics; in-situ testing; geo-engineering for energy and sustainability; numerical modeling in geotechnics; foundations and ground improvement; unsaturated soil behavior; embankments, dams and tailings; excavations and tunnels; and geo-risks, and cover a wide spectrum of issues from fundamentals to applications in geotechnics. This book will undoubtedly represent an essential reference for academics, researchers and practitioners in the field of soil mechanics and geotechnical engineering. In this proceedings, approximately 65% of the contributions are in English, and 35% of the contributions are in Spanish or Portuguese.

Facing the Challenges in Structural Engineering

Facing the Challenges in Structural Engineering
Author: Hugo Rodrigues
Publisher: Springer
Total Pages: 513
Release: 2017-07-11
Genre: Science
ISBN: 3319619144

This edited volume brings together findings and case studies on fundamental and applied aspects of structural engineering, applied to buildings, bridges and infrastructures in general. It focuses on the application of advanced experimental and numerical techniques and new technologies to the built environment. This volume is part of the proceedings of the 1st GeoMEast International Congress and Exhibition on Sustainable Civil Infrastructures, Egypt 2017.