bluuebunny/crossref_metadata_2025 huggingface dataset:
A risk-based approach to corrosion protection and maintenance of steel bridges
Authors: Stiemer S. F. , Chan Phyllis L.
Published: October 2011

A computer-based decision making tool used to minimize the cost of coating maintenance for steel bridges is presented. Variations of the model, adapted for specific usage, are presented. A maintenance approach with the lowest equivalent uniform annual cost is recommended for each analysis using the model. The analysis may be performed for a single bridge structure using deterministic or probabilistic input values, or for many bridge structures of a certain inventory using deterministic input values. Using the model to analyze the entire bridge inventory provides an estimation of the annual budgetary requirements for the coating maintenance in a region and will facilitate the prioritization of these coating maintenance projects. The paper focuses on state-of-theart practices in corrosion protection coating maintenance in the Province of British Columbia, Canada.
The New Metro of Oporto: A variety of bridge projects
Authors: Reis António , Lopes Nuno , Ribeiro Daniel
Published: October 2011

The construction of the new Metro of Oporto was one of the largest infrastructure projects developed in Portugal in the last decade. A light train system, with a large part at ground surface in addition to the underground network was shown to be the most technical and economically convenient option. A variety of bridge projects were developed for this new network, from new long viaducts, upgrade of an old masonry bridge and “last but not least” the railroad addition to the 19th century Luiz I bridge. The design of these bridges were developed by the authors in a turnkey design and built contract. The study of construction and erection schemes was included in the design, namely to insure stability during the retrofitting of Luiz I bridge keeping the roadway traffic in the lower deck.
Projects German Unity – the tunnel chain of A 44 overcomes the division of Germany
Authors: Pelke Eberhard , Seeger K. J.
Published: October 2011

The Motorway A44 Kassel–Eisenach is one of the German Unity traffic projects and a part of the Trans-European Road Network (TERN). One speciality is the sequence of several tunnels within a short distance forming a tunnel chain. The length of these tunnels varies from 280 m up to 4.200 m. The heading also has to master different underground conditions. All tunnels correspond to the new European Community safety standards for tunnels.
Management and design software for the entire bridge life cycle
Authors: Aldayuz Jose , Campbell Jeffrey , Duray James
Published: October 2011

BRIDGEWare® is a suite of state-of-the-art software applications that enable a transportation agency to perform bridge design; bridge load rating; and to manage its bridge inventory, inspection, maintenance and future programming functions by way of a comprehensive Bridge Management System. This paper will discuss the benefits to bridge owners, engineers, bridge inspectors and bridge maintenance and management professionals of a comprehensive, integrated approach provided through a modern software architecture that considers the entire bridge life cycle.
Maintenance Planning for Deteriorating Bridges Using Preference-based
Optimization Method
Authors: Lee Sun-Young , Koh Hyun-Moo , Park Wonsuk , Lee Sung Woo , Kim Hyun-Joong
Published: October 2011

A new method is presented to determine maintenance actions and schedule for deteriorating bridges. The maintenance planning of deteriorating bridges is formulated as multi-objective optimization problem that treats the maintenance cost as well as the condition grade of the bridge deck, girder and pier. To effectively address the multi-objective optimization problem and decision making process for the obtained solution set, we adopt a preference-based optimization model and apply a genetic algorithm as a numerical searching technique. The effectiveness of the proposed method is verified numerically on a typical prestressed concrete girder bridge. The optimal sequence and schedule of maintenance actions such as repair, reinforcement and rebuild are determined by the proposed method. To model the deterioration process of the bridges, actual condition grade data in Korea is used.
Expansion joints subjected to extreme movement conditions - the particular challenges
Authors: Spuler Thomas , Moor Gianni , Brügger Thomas
Published: October 2011

The paper gives a brief introduction into the world of large bridge expansion joints, their special needs and the particular challenges they present.

A special focus is given to the experience gained when designing, manufacturing, shipping and installing modular expansion joints for the Run Yang Bridge, China’s largest and the world’s third largest suspension bridge. With its 27 cells, the larger of the bridge’s modular expansion joints facilitates longitudinal movement of 2,160mm, at the time the largest ever installed, anywhere in the world.
Jointless Concrete Bridges – Development of a Flexible Abutment
Authors: Pötzl Michael
Published: October 2011

For bigger concrete bridges the jointless construction hasn’t been established up to now. Concerns regarding the durability still exist since constraint stresses as a result of temperature alterations and shrinkage lead to crack initiation. With the use of the new flexible abutment these restraint stresses and occurring cracks can be reduced significantly. An efficient decoupling of abutment and subsoil is reached by introducing a buffer layer of polystyrene and a geogrid reinforced backfill. Full size tests and non linear calculations show that only little deformations arise at the backfill material.
Failure Analysis as a Base for Developing Quality Control Systems
Authors: Hertle Robert
Published: October 2011

Recent experiences and wide spread surveys on the quality of building constructions with respect to life-time aspects like alterations in the profile of use, deterioration of the quality of the used materials due to fatigue, climatic effects etc. and in many cases a lack of inspection and maintenance led to the development of new guidelines for addressing these problems. These guidelines, splitted in two parts, one more formal one dealing with general questions and legal aspects, the other laid out to give tangible technical information for the engineer doing on site checks to determine the structural strength of the construction under consideration, are based on a risk assessment concept which judges possible failures against possible hazards of the structure, the profile of use and the robustness and ductility of the structure. These concepts are partly elaborated in analogy to the well know risk assessment concepts of earthquake engineering. The base for the life-time monitoring is a reliable data base of the structural properties in form of a “Project-Book”. For buildings to be constructed it is recommended to develop this project-book parallel to the design, for existing buildings the relevant data must be gathered, if necessary with on site inspection and material testing. Provision for the necessary qualifications of the engineer who is doing the checks are made also with respect to the question of responsibility when judging and certifying the build infrastructure.
A review of 30 years use of UK design check procedures for bridges
Authors: Low Angus
Published: October 2011

The independent design check procedures as used for highway structures in the UK are described, together with how they operate in practice. The procedures have a beneficial effect on the dissemination of design ideas and design procedures across the profession, as well as giving the client a degree of reassurance.
Design of first hybrid UHPC-steel bridge across River Fulda in Kassel, Germany
Authors: Fehling Ekkehard , Bunje Kai , Schmidt Michael , Tue Nguyen Viet , Schreiber Walter , Humburg Erik
Published: October 2011

A 132 m long hybrid UHPC-steel bridge with 6 spans is currently being built across the river Fulda in Kassel, Germany. UHPC offers supreme durability characteristics and, hence, has been selected for the replacement of an existing, damaged timber structure. The novel structural concept consists of a hybrid steel – UHPC truss structure and precast UHPC plates for the bridge deck. The deck plates are glued to the upper chords of the truss structure. For the transfer of shear forces from the truss diagonals (steel tubes) to the UHPC chords, prestressed bolted friction connections are used. The paper describes the conceptual design, the final design, accompanying tests and the erection of the bridge structure. A monitoring system will be installed in order to gather practical experience with the new materials and the novel structural concept.
Green Buildings and Structural Engineering
Authors: Komarek Rebecca L. , VanGeem Martha G. , Corley W. Gene
Published: October 2011

Structural engineers design green buildings using the LEED™ Green Building Rating System™, a point-based system for certifying the level of a building’s sustainability. Structural materials play a large part in increasing a building’s sustainability. Using concrete, for example, can help in brownfield redevelopment, reduce urban heat islands, mitigate water runoff, help meet minimum energy requirements, optimize energy performance, and increase the life of a building. Concrete and its constituents are usually available locally. Both concrete and steel can be recycled. Steel, fabricated in a shop, creates little to no on-site waste and has high recycled content. Attributes of these structural materials, and others, along with decisions made by design professionals help to lessen the impact a structure has on the natural environment.
Design of Externally Plated R.C. Beams Against Premature Interface Debonding Failure
Authors: Heathcote Paul M. , Raoof Mohammed
Published: October 2011

As regards prediction of the premature interface debonding failure load of externally plated R.C. beams, over the last 10 years, a substantial literature of often very mathematical nature has appeared in the public domain, much of which is inconclusive and non of which appear to enjoy general reliability for everyday practical applications. Bearing this in mind, in the present paper, the salient features and the final simple formulations as well as extensive experimental verification of a very simple model (aimed at practising engineers) is presented with its final predictions backed by a substantial body of large-scale experimental data, covering a wide range of first order beam design parameters, with the experimental database including both steel and FRP plated beams. With the general reliability of the model verified, the paper will then report the outcome of a series of theoretical parametric studies aimed at optimising the design procedure against debonding failure. Finally, to facilitate the use of the proposed formulations, a worked example is also included.
Sustainability with adaptive building concepts
Authors: Dressen Tobias , Hegger Josef
Published: October 2011

At present, buildings in urban areas are often broken down or elaborately rebuilt before they reach their economical lifetime. The most common reasons are the inflexibility of the construction to allow a change in utilization (e.g. from residential to office building or v.v.) and the realisation of current architectural requirements or new technical innovations. In order to use a building for a longer period more efficiently, one has to aim at designing more flexible structural systems, which also enable economical and ecological recycling. The paper deals with the comparison of adaptive building concepts with nowadays commonly used structures. Due to the higher service life of flexible structures less environmental impacts can be achieved. Thus, structures allowing flexible utilization can contribute a sustainable progress.
Combined Lower and Upper Bound Plastic Analysis: Better than the Sum of its Parts
Authors: Jackson Andrew , Middleton Campbell
Published: October 2011

Studies have shown that current bridge assessments are often overly conservative. In particular, engineers often use elastic analysis to predict the load at which a concrete slab bridge will fail in flexure and thus may grossly underestimate its ultimate capacity. This leads to bridges being unnecessarily strengthened or even rebuilt, creating wasteful expense and unsustainable use of resources.

Upper bound plastic „yield line‟ analysis is sometimes used to perform less conservative calculations, but it is difficult to apply to cases with complex geometry and engineers are often concerned that the result may an unsafe overestimate of the collapse load. Modern computational methods enable automated lower bound analysis, which has been found to give good results but is still not guaranteed to be accurate. This paper introduces the concept of „combined lower and upper bound plastic analysis‟, in which the results of a lower bound analysis assist in generating an upper bound solution. The resulting close upper and lower bounds on the plastic collapse load prove that the maximum deviation from the theoretical exact solution is small.
Premature Fatigue Failure in a Horizontally Curved Steel Trough Girder Bridge
Authors: Ancich Eric , Brown Steve
Published: October 2011

Fatigue cracking was observed in a three cell, three span, continuously curved steel trough girder bridge in far western NSW. The bridge over the Darling River at Wilcannia had been in service for about 11 years and the fatigue cracks were all associated with asymmetric internal stiffeners.

The bridge was investigated using a structural dynamics based approach and the results showed that the premature fatigue failure was due to the design of the asymmetric internal stiffeners that were not continuous over the full perimeter. As the stiffeners form a partial height U-frame, this allowed the webs, above the stiffeners, and the deck to rack under load. A calibrated FEA model of the bridge was used to investigate a range of solution options including continuing the stiffeners over the full perimeter and the complete removal of the stiffeners. As the confined space inside the box girders was not conducive to welding or cutting, a very unusual and innovative solution using external rib stiffeners was devised, modelled and adopted.
Damage identification for civil infrastructure employing a strain energy based approach
Authors: Oshima Toshiyuki , Aochi Tomoya , Mikami Shuichi , Miyamori Yasunori , Beskhyroun Sherif , Yamazaki Tomoyuki , Hatamura Miki
Published: October 2011

The identification of structural damage is an essential goal of health monitoring for civil infrastructures. Damage of a structure reflects on a change of modal parameters, such as natural frequencies, mode shapes and modal damping. A method of damage identification for civil infrastructures based on strain energy is proposed in this paper. The method is described theoretically and applied to the experimental data from a steel bridge. Several damage scenarios were introduced to the members of the test structure. Experimental results show that the proposed approach may be successfully implemented to detect damage and to locate regions where damage occurred.

This research also aims at establishment of experimental environment to enable the verification of applicability and the effective evaluation of the structural health monitoring (SHM) technology that uses the high performance sensor system on real bridges. The primary goal of the project is the development of test beds that meet wider requests for SHM experiments. Several steel bridges on an abolished railway in Hokkaido, Japan will be available for the establishment of the test beds. The test beds can be utilized by not only researchers of this project but also other researchers. The final goal of the project is international contribution by means of cooperative utilization of the test beds.
IT-based Bridge Health Monitoring for Sustainable Infrastructure
Authors: Miyamoto Ayaho
Published: October 2011

Bridge health monitoring using information technology(IT) and sensors is capable of providing more accurate knowledge of bridge performance than traditional strategies. This paper introduces not only an IT-based bridge health monitoring system incorporate with the latest information technologies for lifetime management of existing bridges but also a data collecting system designed for bridge health monitoring.
Bridge E-8 in the New Railroad of High Velocity to the Northwest of Spain
Authors: Jurado Carlos
Published: October 2011

During the years 2001 and 2007 it has been constructed in Spain the new railway line of high speed, that connects Madrid with the north and northwest of Spain.

This paper exposes one of the more singular bridges in the area near to Madrid between the kilometre points 104+800 and 108+832 including the project and the construction of the bridge E-8, called in Spanish “in pergola”, over the existing railways that connects Madrid with the city of Alcobendas and Madrid with Segovia in the north of Spain.

The project of the bridge was realized by means of a three-dimensional finite element model made with the program SAP2000N that includes all the elements of the structure.

The project of the bridge was realized during the year 2004 and the construction of it during the years 2005 and 2006. Finally during years 2006 and 2007 was made the construction of the superstructure (railways, catenaries, etc) and put in service to the public the 23rd of December of 2007.

The construction was realized without stopping the traffic of the existing trains from Madrid to Alcobendas and from Madrid to the north of Spain.
The Introduction of High-Speed Railway Bridges in Wuhan-Guangzhou Passenger Dedicated Line, China
Authors: Hu Nan
Published: October 2011

Due to its longest mileage under construction as well as the highest technical standards, Wuhan-Guangzhou passenger railway line, with full length of 968 km as well as the speed of 350 km/h, is one of most significant high-speed railway project in China now. Began in June 2005, the Wuhan-Guangzhou passenger line is expected to operation in 2009, since several large bridges projects are near to completion. The sustainability of bridge cannot be neglected in this great railway project. Compared to general railway bridge, high-speed railway bridge will cover the majority mileage of line. Based on the analysis of these bridges in Wuhan-Guangzhou passenger line, the paper gives general condition of the high-speed railway bridges in China. Moreover, numerous technical features of these bridges has been introduced at the same time, such as design standards, building material, design loads, type selection, deck layout, etc.
The implementation of transport systems in Delhi as a way to improve air quality and mobility management
Authors: Schreck Bettina
Published: October 2011

In 2004 and 2005 I contributed to a research program for the cities of South America under the sponsorship of the Clean Air Initiative. While studying vehicle emissions, the key findings were that high levels of air pollution and lack of mobility were a common problem for big cities in that region. By continuing the research of these topics in India, looking at the Asian context, similar conclusions were reached: not only the problems were common, but so were the weaknesses and barriers for implementation. While policies and programs to deal with these issues may be in place, and funds for public spending are made available, inadequate institutional arrangements seem to be the barrier for implementing the necessary actions. The aim of this paper is to describe the common issues that were observed in two different regions of the developing world.
Seismic resistance assessment of multi-span continuous bridge in Vietnam by dynamic response analysis
Authors: Viet Hung Tran , Kiyomiya Osamu , An Tongxiang
Published: October 2011

The response of the bridge subjected to seismic excitation can be evaluated by dynamic response analysis method. Vietnam is located at moderate seismic area; however, the seismic design has been introduced to secure the essential and important bridges. In this study, a typical concrete girder bridge in Vietnam (multiple frames in the longitudinal direction) is used to seismic resistance evaluations. These evaluations are performed by performing nonlinear dynamic response analysis on FEA method. It is found that the stopper and the rubber gasket influence on response of the bridge during Level 1 and Level 2 earthquakes.
Influence of Irregularity of the Substructure on Seismic Behavior of Highway Bridges
Authors: Julieth Daymaru , Megchún Salas , Gómez Soberón Consuelo
Published: October 2011

This article presents the results of elastic analyses performed on three types of bridges, monolithic, continuous, and simple-supported, making changes to the regularity of the substructure. Such variations consist of increasing and reducing the height of the center pier, to determine conditions of vulnerability due to irregularity. The structures were subject to a database of 53 accelerograms recorded on the Mexican Pacific Coast. The maximum responses in displacement and standardized differences between the regular and irregular systems are presented. These data can be applied in preliminary evaluation methodologies and then in maintenance programs.
Sustainable und transparent glass roofs - concept and geometry
Authors: Weller Bernhard , Reich Stefan , Ebert Jan
Published: October 2011

Space grid structures are appropriate to cover large areas. They allow the realization of plain roofs. To improve the transparency of such structures a new type of sustainable und transparent double layer grids is developed. The strict replacement of all bars in the compression layer by glass panes significantly increases the transparency and saves material. The contribution describes the geometry finding for such structures. Basis for the research is the structure geometry of steel space grid structure that is extended to transparent space grids. As result of the research a full-scale mock-up of the most appropriate structure was built to demonstrate the feasibility.
Design and Calculation of Modern Glass Constructions
Authors: Siebert Barbara , Siebert Geralt
Published: October 2011

The use of glass in structural engineering opens a wide field for interesting applications. As it is a quite new subject only few regulations and design rules exist. So it is very important to know the basics of the material glass to build safe and economic constructions.

In this paper an overview is given about the different kind of glass with the different behaviour concerning load carrying capacity and remaining load capacity. Results of testing of the different kind of glass with their different behaviour are presented. The requirements due to safety aspects for the application of glass in Germany and Europe will be presented. Other points are the characteristic of the different kind of bearing (linear and point fixings) and the behaviour of laminated glass. Topics like principle design rules, static calculation of glass (linear and point fixed glass, effects of nonlinear calculation) are presented.
Development of New Hybrid Composite Girders
Authors: Mutsuyoshi Hiroshi , Hai Nguyen Duc , Asamoto Shingo
Published: October 2011

A hybrid FRP bridge girder consisting of CFRP and GFRP has been developed in Japan. A number of tensile and compressive coupon tests were conducted to determine the material properties of hybrid FRP laminates which were used in the analytical investigations of the large-scale FRP beams. A series of beams with wide flange widths varying the volume content of CFRP in flanges were tested under four-points loading. The experimental investigations revealed that the failure mode of these beams was induced by the local buckling of the compressive flange. In order to avoid the

local buckling, stiffeners were installed in the flexural and shear span of beams. Although an appropriate installation of stiffeners can prevent effectively the local buckling, however the hybrid FRP beams failed prematurely due to stress concentration at the loading points. Analyses were carried out and showed a good correlation with experimental results.
Urban Maglev Transportation System and Its Dynamic Coupling Behaviours
Authors: Kwon Soon-Duck , Lee Jun-Seok , Kim Young-Phil , Lim Dong-Jun , Kim Moon-Young
Published: October 2011

The purpose of present study is to develop a framework for dynamic interaction analysis of actively controlled maglev vehicle and flexible guideway structure, and to investigate the effect of vehicle and guideway characteristics on dynamic responses of low and medium speed maglev system.

Dynamic governing equations are derived by combining the five degree of freedom maglev vehicle model, the modal properties of a guideway structures and LQG controller for electromagnetic suspension. And then the effect of vehicle models, vehicle speed, irregularity, guideway deflection ratio, span length, span continuity and damping ratio on dynamic responses of the relatively low speed maglev vehicle and guideway structures are investigated. From the numerical simulation, it is found that the air gap of the vehicle is strongly affected by vehicle speed, tract roughness and guideway deflection ratio. Especially the guideway deflection ratio is the most influential parameter which governs the air gap. Continuous span girders are found to be effective to reduce the air gap because of its smooth curvature and small deflection slope near the support. However the span length and damping ratio of guideway structure do not affect to the air gap. Overall dynamic magnification factor of guideway girder are not severe compared with traditional wheel type vehicle.
Innovative Construction Engineering for Stonecutters Bridge
Authors: Morgenthal Guido , Sham Robin
Published: October 2011

With a main span of 1018m Stonecutters Bridge is the second longest cable-stayed bridge in the world. The construction of the bridge has been an unusual challenge and required innovative solutions to enable an efficient and safe erection. This paper outlines major construction engineering schemes and the solutions developed to harness the challenges of construction.
Global Mechanical Behavior of Kilometer-Level Cable-Stayed Bridge under Static Loads
Authors: Li Y. B. , Zhang Q. W.
Published: October 2011

The global mechanical behaviours of Sutong Bridge, China are presented by using field static load tests and numerical analysis in this paper. A total of 37 loading cases with 64 test trucks which a vehicle’s axle weight is 300kN were conducted on 10 key sections to investigate the bridge

behaviour. The level of test loading is about 50-88% of the code-specified serviceability load. A full three-dimensional finite-element model is developed and calibrated to match the experiment data. The results show that the bridge under the planned load test conditions has good overall static properties and linear superposition characteristics, and incremental deflections and stresses as well as cable force are observed to be linearly proportional to incremental load. Moreover, the transverse shear lag effects of the steel girder are evident and the longitudinal stress distributions of the slab and diaphragm are non-uniform. A very good agreement is achieved between the experimental tests and numerical simulations calculated by existing nonlinear theories of long span bridges.
Application of BIM to a Cable-stayed Bridge Construction
Authors: Jung Doyoung , Kim Hando , Baek Yeongin , Kim Jaehong
Published: October 2011

3D modeling and BIM technology are being used more and more in the construction industry. The scope of this paper arose as we wondered how the general contractor can benefit from the use of 3D models. Presented herewith is the application of BIM to an actual bridge now under construction in Cheongpoong, Choongcheongbuk-Do. This constitutes the first application of BIM in Korea. Virtual construction of the cable-stayed bridge was performed to visualize design and analyze constructability and coordination problems and to integrate the bridge’s visualization, cost, and schedule under location-based conditions with industry-specific solutions for 3D modeling. Two hundred and ninety-two main 3D objects constituted the cable-stayed bridge, which is 442m long with a main span of 327m. BIM application benefits such as clash detection, interdisciplinary communication, and method-statement simulation have been confirmed. In addition, integration of a 3D model, cost, and schedule is shown by comparing the measurements of different structures at a specific time using 2 different construction sequencing scenarios and work breakdown structures (WBS). It is possible to create dynamic graphics and effects and explore complete projects under real-world conditions before they are constructed.
Tsunami Loading - From Experiments to Field Load Test
Authors: Lukkunaprasit Panitan
Published: October 2011

Two important issues arise from the field observations of the buildings that have survived the 2004 Indian Ocean tsunami. First, how effective are openings in reducing the tsunami loading on buildings. Second, the actual velocity that occured in the event might have not been as large as implied in existing guidelines on tsunami loading. This paper presents studies aimed to address these two issues by means of experiments and a field load test. One-to-one hundred scale building models with 0%, 25% and 50% openings were tested in a wave flume under simulated solitary-like waves. A bi-linear pressure profile is proposed for determining the maximum tsunami force acting on solid square buildings. Depending on the sizes of openings, the tsunami forces are reduced by 15% - 30% from that exerted on the solid model. In addition, a building that has survived the 2004 Indian Ocean tsunami was field load tested in order to calibrate the FEMA-55 loading. The maximum velocity that occurred at the site in that event is assessed, and a velocity suitable for computation of tsunami load for southern Thailand is recommended.
Utilization of Calcium Carbide Residue-Fly Ash Mixture as a Cementing Material in Concrete
Authors: Makaratat Nattapong
Published: October 2011

This paper presents the use of ground calcium carbide residue (CR) and fly ash (OF) mixture as a cementing material in concrete. Calcium carbide residue is a by-product from acetylene gas production process, while fly ash is a by-product from thermal power plant. The calcium carbide residue was ground by ball mill to increase its fineness (CR) and was mixed with fly ash (OF) at a ratio of 30:70 (CR:OF) by weight to use as a binder without Portland cement. Effects of water to binder (W/B) ratios on setting times, compressive strength, modulus of elasticity, and splitting tensile strength of CR-OF concrete were investigated. The results revealed that the initial and final setting times of CR-OF concretes were much longer than the normal concrete. The highest compressive strength, 19.0 and 24.7 MPa, respectively at 28 and 90 days, of CR-OF concrete was occurred in 0.45OF specimen. This compressive strength could be achieved without Portland cement. In addition, the lower was the W/B ratio, the higher was the compressive strength of CR- OF concrete. Moreover, hardened concrete from CR-OF mixtures had the same properties as that of the normal concrete.
Practical Use of 60 MPa Cast-in-Placing High-Strength Concrete for PSC Bridges
Authors: Min Kyung-Hwan , Yang Jun-Mo , Cheong Hai-Moon , Ahn Tae-Song , Yoon Young-Soo
Published: October 2011

Despite recent developments in high-performance and multi-functional concrete with a design strength of about 40 MPa is still being used on superstructures of prestressed concrete (PSC) bridges. Therefore, the overall objective of this paper is to obtain experiences and data for the practical construction of cast-in-place high-strength concrete, especially over 60 MPa design strength, in order to apply it to superstructures of PSC bridges. After carrying out laboratory experimental programs of basic properties for seven different mix proportions suited to 60 MPa design strength, three mixtures of ordinary Portland cement (OPC), OPC with 30% blast furnace slag (BS30), and low-heat cement (LHC) were chosen among seven mixtures. Simulations of pumping and adiabatic temperature rise tests were then carried out. For practical application in the field, mock-up tests were performed for pumping conveyance with 150 meters of passing pipes and heat of hydration with 1.2 meter cubic specimens. Then the test results of heat of hydrations were compared with HeatCon program’s results. In the field applications, a 35 meter single span PSC girder bridge with developed high-strength concrete was constructed in the expressway. During the casting of girder concretes, quality controls were carried out with continuing controls of surface moisture and corrections of the unit water using the air-meter method immediately after batching. It was confirmed that the compressive strengths of girder concretes ensure that the target strength and the heat of hydrations of girder concrete were measured.
Experimental Results on Warm Asphalt Mixes in Czech Republic
Authors: Valentin Jan , Mondschein Petr
Published: October 2011

One of the environmentally most important factors of asphalt pavements is the energy demand necessary due to satisfactory workability and compactability of an asphalt layer. Economical energy consumption on one hand and sufficient quality of asphalt pavements on the other hand can be seen as important factors of its sustainability. Both characteristics have therefore crucial role in the so called environmental compatible pavement structure. There are several possibilities or techniques how energy demand can be reduced and durability preserved or increased. Important set of these techniques, called warm asphalt mixes has been in this respect developed during the last ten years in Europe and the United States. There are several possibilities, how these mixes can be produced.

The paper presents warm asphalt mixes experimentally prepared and assessed with various additives of synthetic waxes or polyphosphoric acid. For the experimentally prepared asphalt mixes a comparison of their mechanical as well as rheological properties is summarized and discussed.
Alternate load path method for robust design by ductile steel and composite joints
Authors: Rölle Lars , Kuhlmann Ulrike
Published: October 2011

The paper reports briefly on the experimental and numerical investigations of steel and composite joints aiming at the development of semi-rigid and partial-strength joint solutions allowing large deformations and rotations for redistribution of internal forces in the structural system when local damage e.g. “column loss” occurs. Investigations of steel and composite joints with highly ductile behaviour are presented. Thereby special focus is given to the adjustment of the single joint com- ponents to ensure a high deformation capacity during pure bending as well as combined bending and membrane exposure.
The Application of the Finite Strip Method on Curved Box Girder Bridges
Authors: Tanijaya Jonie , Hardjito Djwantoro
Published: October 2011

Curved bridges have become a major component of highway systems in recent years. Elevated freeways and multi level interchange are very common in densely populated areas and could hardly be constructed without curved bridges. Usually, these bridges are of cellular cross section so that the high torsional moment due to curvature can be resisted economically.

To date, methods of analysis and design have been very approximate, but because of the large number of curved bridges being constructed everywhere, refined methods of analysis are desirable. In this paper, the main geometric parameters of curved bridges are studied. The finite strip method of analysis applied to folded plate structures as a box girder, for which a general computer program was written. This method of analysis is restricted to structures simply supported along their straight radial edges.

Finally, on the basis of this refined analytical method, the behaviour of curved box girder bridges is studied. In particular, wheel load distribution characteristics are investigated especially with respect to the load position of the bridges.
Shortening the Critical Path in the Construction of Concrete Viaducts
Authors: Turmo José , Mozos Carlos M.
Published: October 2011

There are two typical environmentally friendly “in situ” construction methods for building medium- span long concrete viaducts: span by span construction with travelling scaffolding and launching method. Both ways share one important characteristic; the deck can be constructed independently from the valley they are bridging. This is why, sometimes, these construction procedures are imposed by the owner whereas other economical procedures, such as the use of precast concrete beams, are strictly forbidden. Concreting of span by span construction with travelling scaffolding is typically made in two phases. In the first phase, webs and bottom flange of the box girder are concreted. In the second phase, top flange is concreted. Once the cross section is self-supporting, this is to say, once the concrete of the top flange is hardened, the segment can be prestressed and the scaffolding can be shifted to the next span. This procedure takes usually two weeks per span. In order to shorten the critical path, it would be advisable to look for self-supporting cross sections after the concreting of the first phase, prestressing and shifting the scaffolding subsequently and pouring the second phase out of the critical path. First phase would include the concreting of webs, bottom flange and the overhung top flanges. The trade-off of this procedure will imply some structural problems to be studied, such are the connection between different phases and the transverse bending moments to appear until the cross section is closed. The paper will provide an insight into the modification of the traditional construction methods and into the associated structural problems and potential solutions.
Iterative Buckling Analysis for Steel Tower Members in Cable-Stayed Bridges
Authors: Choi Dong-Ho , Yoo Hoon , Song Soo-Ho
Published: October 2011

A new method of iterative buckling analysis is proposed for obtaining the effective length of steel tower members in cable-stayed bridges. The concept of a fictitious axial force, which is derived from the relation between the individual buckling limit of each member and the overall buckling of the bridge, is introduced to overcome the problem associated with system buckling analysis. After presenting the proposed method, it is applied to an example cable-stayed bridge with different girder depths. The results demonstrate that the proposed method not only provides reasonable outcomes by correcting the inaccuracies seen in system buckling analysis, but is also convenient for practical applications.
Numerical Simulation of Consecutive Rockfall Impacts on Reinforced Concrete Slabs
Authors: Khasraghy Sara Ghadimi , Kishi Norimitsu , Vogel Thomas
Published: October 2011

The risk due to falling rocks in Alpine regions is managed by means of various protective structures. Rockfall protection galleries are one of the common types of these structures built to protect the human lives and transportation network. In order to establish a rational method to improve the design of rockfall protection galleries, large-scale tests have been carried out in Switzerland.

Reinforced concrete slabs were subjected to repeated falling-weight impacts with increasing falling height.

The current work presents finite element modeling of some of these tests and the results are compared to the experimental data. Calibrated with the experimental data, finite element analysis provided a reasonable extension of the test results. This facilitates understanding the behaviour of rockfall protection galleries subjected to impacts of more than one rock in their history. Based on the numerical investigation, a comparison was made between the response of a slab subjected to consecutive impact loading and virgin slabs subjected to similar impacts. For the range of the modeled experiment, it was observed that the maximum reaction force of the slab was reduced up to 25% due to the softening of the slab and its cracking. With virtue of the comparison made based on residual deflections, numerical extension of this study may help investigating the extent of damage to the existing structures which have already sustained one or more impacts during their service life to provide a sustainable decision making for their maintenance and strengthening.
Tensioning Process of Sanhao Arch Pylon Cable-Stayed Bridge
Authors: Dong Xu , Bin Chen , Lei Liu
Published: October 2011

Sanhao cable-stayed bridge located in Liaoning Province of China features an impressive arch pylon system including two inclined steel arch ribs laterally across the bridge deck. The two 60m- high arch ribs stretches out from the same base on the main pier foundation and separates up to 55m at the top, which have the appearance of two tennis rackets. Ten pairs of longitudinal cables on both sides connect these two “tennis rackets” forming a triangle pylon system. Twenty pairs of inclined stay cables link the steel arch pylon and the prestressed concrete deck, which carry the self-weight of the deck and service loads. The tensioning process of the horizontal and inclined stay cables, especially the tensioning process of the individual strands for each cable, is the most challenging work of the bridge construction for achieving a sustainable structure, characterized by the smooth lines of the arch pylons and bridge deck, the safe stress of the steel arch ribs and the crack-free prestressed concrete deck.
Developing Modern Bamboo Structures for Sustainable Construction
Authors: Xiao Yan , Shan Bo , Chen Guo , Zhou Quan , She Liyong , Yang Ruizhen
Published: October 2011

The authors are conducting a comprehensive research program, with the goal to develop modern bamboo structures for buildings and bridges. This paper reports the design, construction, testing of modern bamboo bridges and buildings. The authors developed laminated bamboo girders, named as GluBam, and verified their satisfactory mechanical performance through full-scale testing. It was demonstrated that the laminated bamboo girders have satisfactory stiffness and load carrying capacity. The use of FRP can further enhance the stiffness and capacity of the bamboo girders.

Based on the test results and analysis, a 10 m long single lane roadway bridge was designed and constructed, which was the first of its kind in the world. The field tests were carried out using an over loaded two-axel truck with a total weight of 8.6 ton which exceeded the given design truckload of 8.0 ton. The bridge performed satisfactorily with the mid-span deflection corresponding to the critical service loading condition being much smaller than the code required limit. The paper also reports the authors invention of modern bamboo buildings. In the aftermath of the Great Wenchuan Earthquake of May 12, 2008, the authors developed modern bamboo structure earthquake relief shelters and classrooms and deployed in the devastated area.
Experimental investigation of deviated single monostrands
Authors: Dier Florian , Weiher Hermann , Zilch Konrad , Hock Sebastian
Published: October 2011

This paper deals with imprints of steel tendons into corrosion protection ducts (polyethylene, PE- HD) of unbonded deviated monostrands. These strands are mainly used for internal, but also for external post-tensioning in bridges, buildings and tanks. In areas of deviation imprints of the steel into softer plastic occur, because of deviation loads and by friction that occurs when stressing. The influence of bedding to the imprint-behaviour will be investigated experimentally and verified theoretically. Furthermore, some tests were done to investigate the use of new materials for sheathing of prestressing steel.
Proposal of Repair for Corroded Steel Members by Carbon Fiber Sheets
Authors: Sugiura Hiroshi , Nagai Masatsugu , Ohgaki Kazuo , Inaba Naofumi , Kobayashi Akira
Published: October 2011

We propose the repair method for corroded steel members by carbon fiber sheets and its effectiveness is presented using at site measurement data. Based on our theoretical and experimental researches, the design and construction method are given. Working procedures or order of execution at the site is also explained. Finally, using at site measurement data of strain in steel members in a truss bridge in use, the effectiveness of our proposed repair method using carbon fiber sheets is emphasized.
Evaluation of the Risk Management of Structural Safety in 15 Building Projects
Authors: Mans Dirk G. , Rings Louis , van den Brand Roel , Derkink Marcel
Published: October 2011

This paper presents results of a research towards risks in design and building processes with respect to structural safety in contemporary building projects. 15 almost or just finished building projects with different functionalities and different clients were subject of the research. Different ways of cooperation (traditional, design & construct, building team, turn key) were represented.

After document reviews, interviews and site visit with visual inspection, for each project a report with the main facts of the organization of the process, the structural design, costs and fees and interventions related to structural safety was written and verified by the client’s project manager. A risk table was developed in which for each stage of the project risks are distinguished that could lead to the top risk: lack of structural safety. The individual building projects were evaluated. In 12 of the 15 projects interventions related to structural safety occurred. These led to modifications or strengthening of already executed structures. Assessment of the risks and the way these risks were controlled result in an appraisal of the proof of structural safety and the level of risk control. It is concluded that parties in an individual building project do not always have the same view of structural safety, that in most projects no specific decisions are made about the level of structural safety and that the type of contract seems to have no relation with the level of risk control.
Optimal Sensor Layout for Bridges Subject to Ship Collision
Authors: Guo Y. L. , Ni Y. Q. , Chen S. K. , Zhou H. F.
Published: October 2011

Post-collision damage evaluation is of significant importance for decision making on if closure of the bridge to traffic is necessary and for planning the consequent bridge strengthening or retrofitting. On-line structural health monitoring (SHM) systems provide an effective means to monitor the bridge response during ship collisions and evaluate the structural damage. However, reliable

damage evaluation using the monitoring data from a SHM system depends largely on the sensor layout. In this paper, a sensor layout optimization (SLO) method targeting the post-collision damage evaluation of bridges is proposed to select the optimal sensor set so that the measured data are most informative for damage evaluation. The sensor layout is optimized by a multi-objective optimization algorithm which simultaneously minimizes the information entropy index for each ship-bridge collision scenario. The cable-stayed Ting Kau Bridge (TKB) is employed to testify the feasibility and effectiveness of the proposed method.