bluuebunny/crossref_metadata_2025 huggingface dataset:
Upgrading Existing Railway Bridges in Europe for Higher Speeds and Loads - Assessment Procedures and Requirements
Authors: Casas Joan Ramon , Wisniewski Dawid , Sloth Mette
Published: October 2011

This paper presents procedures and requirements for the assessment of existing railway bridges in Europe. The assessment procedures and requirements are the core part of the "Guideline for Load and Resistance Assessment of Existing European Railway Bridges - advices on the use of advanced methods"[1,2], recently developed within the European research project "Sustainable Bridges" (www.sustainablebridges.net). The first part of the paper introduces the step-level assessment methodology recommended in the guideline. The second part is dedicated to the safety requirements for existing railway bridges and gives guidance on the safety levels required for the assessment. Furthermore, it presents several safety formats characterized by different accuracy and complexity, which might be used at different level of assessment.
Strengthening Existing Non-Composite Steel Girder Bridges by the Use of Post-Installed Shear Connectors
Authors: Kwon Gunup , Klingner Richard , Engelhardt Michael D.
Published: October 2011

This paper presents the results of a study examining ways to strengthen existing non-composite steel bridge girders using post-installed shear connectors. Five full-scale beams were tested to evaluate structural performance of composite beams retrofitted with post-installed shear connectors. Results of the study indicate that the addition of a relatively small number of post-installed shear connectors can increase the load capacity of non-composite girders by a factor greater than 1.5. Based on the results of this study, a design approach based on partial composite action was developed for strengthening existing steel bridge girders by using post-installed shear connectors.
The Crack Sliding Model – Unified Approach to Shear and Punching Shear
Authors: Cao Hoang Linh
Published: October 2011

This paper presents a unified mechanical model – The Crack Sliding Model - which can be used to calculate the shear strength as well as the punching shear strength of reinforced concrete structures. The model is based on the upper bound plasticity theorem. Contrary to the classical plasticity models to shear problems, the present model makes a clear distinction between sliding yield lines formed in un-cracked concrete and sliding yield lines formed in cracks. The model applies to simply supported and continuous beams with arbitrary loading configurations. As will be demonstrated, the model provides a simple and transparent explanation to the enhancement of the shear capacity due to prestressing or compressive axial forces. It will be shown that the model can be extended to deal with punching shear in two-way spanning slabs. The results obtained from the model have been compared with a large number of tests. Good agreement has been found.
Evaluation of Design Approaches for Progressive Collapse
Authors: Stevens David , Marchand Kirk , Crowder Brian , Conrath Ed , Campbell Tim
Published: October 2011

Progressive collapse design approaches typically incorporate direct and indirect methods. Direct design techniques include the Alternate Path and Specific Local Resistance methods, in which collapse is explicitly considered during the design process. In indirect design, resistance to progressive collapse is incorporated implicitly through prescriptive requirements for strength and continuity, typically in the form of Tie Forces. These methods were recently re-evaluated and revised, in support of revisions to the Department of Defense Unified Facilities Criteria (UFC) 4- 023-03Design of Buildings to Resist Progressive Collapse. The research and analyses for revisions to the indirect and direct methods are reported in this paper.
Structural optimization of a composite steel and concrete connection through FE analysis and testing
Authors: Zordan Tobia , Briseghella Bruno , Chen Airong , Ruan Xin , Siviero Enzo
Published: October 2011

The increasing ratio between labour cost and the cost of construction materials is urging for the development of construction techniques requiring the smallest number of skilled workers and the optimization of building schedule in order to minimize the overall building time. Composite decks and floors are becoming increasingly widespread due to their structural effectiveness that allows for the optimization of the mechanical properties of the coupled materials and for the possibility of achieving a simplified detailing with a limited number of structural elements involved in the structural response.

In the paper, a newly developed moment resisting connection between a centrifuged high strength concrete pre-fabricated column and a composite steel and concrete beam will be presented. The connection proposed allows for a sustainable construction process based on modern construction technoligies which are suitable for creating improved structures for buildings in urban areas.
Probabilistic Modelling of HSC Slender Columns in High-Rise Buildings
Authors: Schmidt Holger , Six Michael
Published: October 2011

In Europe high performance concrete has been used successfully since 1990. The extremely high compressive strength of this material allows considerable reduction of cross-sectional dimensions of reinforced concrete columns and accordingly fulfils highest architectural and functional requirements. This leads to extremely slender members and therefore increases the risk of failure due to loss of stability in many cases. Because of the positive experience with high performance concrete up to now, the current study questions current conservative design provisions. In this context, code procedures of Eurocode 1 as well as Eurocode 2 are compared with the results of probabilistic analysis and potentials for optimization will be indicated.
Large X-Lam Floor and Roof Plates For Composite Construction
Authors: Smith Ian , Asiz Andi
Published: October 2011

Focus is on using prefabricated Cross Laminated Timber (X-Lam) panels as slab elements in floors and roofs of composite steel framed buildings. The effectiveness of thin X-Lam panels to resist in-plane and out of plane forces is considered based on numerical case studies of two- storey and six-storey buildings. In those studies comparison is made to the performance of matched systems with conventional steel and concrete composite (SRC) slabs. Substituting X- Lam slab elements lieu of SRC slabs was found to be beneficial because of X-Lam’s rigid diaphragm capabilities and lightness. Demands on the steel building frameworks were much reduced with X-Lam over a wide range of loading situations. Stresses levels and building sways during potentially critical seismic events were greatly reduced using X-Lam. Priority is being given now to refining X-Lam construction details with emphasis on slab to frame connections.
Experimental Investigation on Mechanical Behavior of Y-shaped Steel and Concrete Composite Joints
Authors: Zhang Jie , Lu Xilin
Published: October 2011

Phase II of the Pudong (Shanghai) International Airport terminal building has interior spans of 89m, 18m bay spacing, and 26m height above the top story. Upper steel roof and lower concrete frame are assembled with Y-shaped steel and concrete composite columns. These composite columns were formed by upper V-shaped steel columns, lower concrete columns, and cast steel bearings as a connection. This paper describes the mechanical behaviour of these composite column joints as investigated by a series of pseudo static tests at Tongji University. Two of the parameters that were examined include the axial compression ratio and loading direction. Results showed that damage occurred at the bottom of the steel column because the modulus of elasticity and yield strength were both reduced approximately 10% in the Heat Affected Zone (HAZ) along with higher actual strength of cast steel. Cracking, and even spalling were observed at the top of concrete columns due to concentrated moment applied by upper steel columns. Relevant recommendations were presented for improving concrete confinement. Furthermore, a potential critical section in the cast steel bearings was identified based on the free body diagram, strain measurements and results of numerical analyses. Elastic rotational stiffness of the cast steel bearing was included in the analysis of rotation angle. In addition, it was determined that slip between concrete and encased steel could be ignored because sufficient anchorage length and shear connectors were provided as specified in the Chinese Design Code.
Size Effect: What Is Its Rationale and Penalty for Neglect
Authors: Bažant Zdeněk , Yu Qiang
Published: October 2011

Concrete is a typical quasi-brittle material, which inevitably exhibits size effect on the nominal structural strength. This study is focussed on the size effect in shear failure of reinforce concrete beams. By statistical analysis it is shown that if the size effect is ignored, the failure frequency (or probability) of large reinforced beams under shear may typically increase by three orders of magnitude. By computer simulations based on fracture mechanics it is further shown that shear reinforcement cannot eliminate the size effect in large reinforced concrete beams.
Importance and Organisation of Bridge Inspections in Germany
Authors: Naumann Joachim
Published: October 2011

The key element of the safety philosophy in bridge maintenance is the regular check and inspection of the bridges by engineers which are specially trained to perform bridge inspections. Therefore, bridge inspections are an important and integral part of the bridge management system (BMS) and include, besides the inspection activity itself, also inspection-oriented construction, the provision of inventory data, a uniform evaluation method, several expert systems as well as the continuous training of the engineers performing the inspections including a regular exchange of experiences.
Severe Cracking of Viaduct Piers and Pilecaps due to Delayed Ettringite Formation
Authors: White Paul , Buckby Roger , Mills Craig , Wimpenny Don
Published: October 2011

Damage due to Delayed Ettringite Formation (DEF) can be severe, and can compromise the structural adequacy of an existing structure. This paper illustrates the severity of problems that can occur, outlines the diagnosis of DEF and the assessment of structures affected by DEF, and discusses some issues related to potential remedial works schemes.
Design, Implementation and Measurement of Cable Dampers for Large Cable-stayed Bridges
Authors: Sun Limin , Huang Hongwei
Published: October 2011

Installing cable dampers is a most common used countermeasure for suppressing cable vibration of large span cable-stayed bridges induced by wind. The obtainable damping of cable damper is reduced as the cable length increases, due to the height limitation of damper position. Therefore, the damping efficiency of cable damper needs to be improved for longer cables to achieve the required damping. This paper reported the investigations on the design, implementation and measurement of cable dampers for large cable-stayed bridges. Experimental studies were carried out to evaluate the damper performance, and the factors affecting the damper efficiency were investigated. The optimal design of damper was proposed using nonlinear design theories. A simple design approach using equivalent linear damper with efficiency factor was introduced for engineering practice. The performance of the dampers was evaluated based on the site measurement at a large span cable- stayed bridge.
The importance of dense monitoring of long-span bridges for its performance re-evaluation
Authors: Nagayama Tomonori , Siringoringo Dionysium , Fujino Yozo
Published: October 2011

Monitoring of structures is expected to offer rich information on structural performance evaluation. While the performance of existing structures may differ from their designs, monitoring of dynamic behaviors potentially provides indications of how close or far the performance is to the designs and unexpected differences that might be important to the safety. In this paper, monitoring of two bridges in Japan as well as dynamic and structural analyses of the monitoring data is presented. Ambient vibration and seismic response records are utilized in performance evaluation of these bridges. The dense sensor instrumentation on the bridges and long-term monitoring provides exceptional opportunities to obtain insight into the behaviors of the bridges and performance of their components.
Piston stayed bascule bridge: a novel mobile bridge typology at Temse, Belgium
Authors: Adriaenssens Sigrid , Ney Laurent , Maille Matthieu
Published: October 2011

This paper discusses a novel typology for medium span mobile bridges: the piston stayed bascule bridge. The Temse bridge over the river Scheldt (Belgium) illustrates this system. This competition winning project runs 374m over seven fixed parts with spans varying between 18 and 74 m and two mobile spans of 28m. The design considerations and the structural static and kinematic system for this project are discussed. The main design idea is “structural integration” namely that one element fulfils more than one function. The structural innovation lies in the use of the piston stay that doubles up as static structural element and as a kinematic actuator. Combined with counterweights, this structural system presents a new and elegant solution for mobile bridges.
Design of the Canada Line Extradosed Transit Bridge
Authors: Bergman Don , Griezic Andrew , Scollard Chris
Published: October 2011

In 2005, TransLink procured the new Canada Line rapid transit system that will connect Richmond, the Vancouver International Airport and downtown Vancouver. The Line is scheduled for completion in 2009. An extradosed precast segmental box girder bridge was designed for the longest span on the Line, which crosses the Fraser River North Arm. The North Arm Bridge which carries two rail tracks and a suspended walkway/bikeway, is 562 m long with a 180 m main span, 139 m side spans and 52 m transition spans. A single plane of extradosed cables anchored to two 22 m tall pylons supports the main and side spans. New to North America, this bridge form provided an appropriate solution considering the design constraints. In this paper, the extradosed bridge form is introduced prior to describing the design constraints that led to its use for the North Arm Bridge. The analysis of dynamic train-structure interaction, cable anchorage details and the precast segmental composite steel/concrete pylons are also described.
Wichita Riverfront Pedestrian Bridges
Authors: Blakemore Frank
Published: October 2011

As part of the riverfront development program in Wichita, Kansas, two cable-stayed pedestrian bridges were constructed as part of a bike and pedestrian transportation system that is a component of the urban infrastructure. HNTB was responsible for the preliminary and final design of these two unique pedestrian bridges, which spanned 97.5 m and 73.15 m to provide access across the confluence of the Arkansas and Little Arkansas Rivers.
The "TISB" and the "TMG" Concepts. Application on a Proposal for the Railway Tunnel through the Gibraltar Strait
Authors: Pompeu-Santos Silvino
Published: October 2011

The paper presents two innovative and cost-effective concepts for the construction of tunnels using TBMs (“tunnel boring machines”): the “TISB” concept to be used when the referred tunnels are executed in soft soils (e.g., alluviums), in seismic areas, and the “TMG” concept, which allows for the use of a single tunnel that provides the capabilities usually obtained with three parallel tunnels. The paper also presents an alternative proposal for the railway tunnel through the Gibraltar Strait, in which these concepts are applied.
Gautrain – A modern transit project in a progressing country, South Africa
Authors: Martin Olivier , Funck Philippe , Chauliac Alain
Published: October 2011

This article presents the intermediate design phase for the development of Gautrain railway project in South Africa. This phase is specific to concession and develops the project between the Letter of Intent and Financial Close. It is described in terms of objectives, organisation, technical aspects, and more important interface and integration. Gautrain Rail project consists of developing, designing, constructing, operating and maintaining a 77km long railway line to provide domestic and airport train services, together with a dedicated bus network servicing a radius of 10km around each of the 10 stations, and 9,000 specific parking spaces within the station precincts. In this comprehensive and complex project, Bouygues TP is ensuring the technical leadership.
Practical Experience with Wind-Tunnel Predicted Tall Building Motions
Authors: Irwin Peter , Myslimaj Bujar
Published: October 2011

Predictions of peak accelerations from wind tunnel studies of 19 tall buildings are described and compared with full-scale reported experience. All buildings considered in this study were tested and built prior to 2000. More than a third of them have been occupied for more than twenty years. In the early years of this period the target criterion used by RWDI for residential buildings was for the 10-year return period peak acceleration not to exceed 15 milli-g. However, in some cases this proved difficult to achieve structurally, and after the structural designer had done all that was practically possible in terms of adding stiffness and mass, the results came in as high as 18 milli-g. The remaining measure that could be taken was to add a supplementary damping system. Space was set aside for the damping system but, in view of the subjective uncertainties in the 15 milli-g criterion, it was decided only to install such a system if experience proved that it was necessary. While there were rare reports of occupants noticing motion, no major complaints materialized and in those buildings in the 15 to 18 milli-g range no damping system has been installed. Therefore this range was subsequently treated by RWDI as acceptable on other projects. Wind tunnel studies for fourteen of the buildings discussed here predicted peak resultant 10-year accelerations within the 15-18 milli-g range, with no supplementary damping system. For the remaining five buildings, wind tunnel studies predicted peak resultant accelerations in the range of 23-28 milli-g, and supplemental damping systems (SDS) were installed to reduce acceleration responses to the 15 to 18 milli-g range. The only adverse experience we are aware of occurred on one of the buildings with a damping system when the system had inadvertently been immobilized when a windstorm arrived. Therefore our experience indicates that a 10-year criterion in the 15 to 18 milli-g range works in practice. More recent criteria are tending to be couched in terms of the 1-year return period acceleration and we agree with this approach, but the abovementioned experience still serves as a useful benchmark, provided the accelerations are appropriately scaled to compensate for the change in return period.
Performance Based Design for the Fire Situation, leading to Economic and Safe Fire Resistance
Authors: Schleich Jean-Baptiste
Published: October 2011

Jean-Baptiste Schleich, born 1942, received his civil engineering degree from the University of Liège in 1967. In 1984/85 and 1993/94 he has been President of ECCS.

He was Chairman for the final version of the European standards EN1991-1-2, EN1994 -1-2 and EN1993 -1-1.

This contribution describes the present state of the art in fire engineering developments according to EN1991-1-2 (DAV 20.11.2002 ). In the presently described buildings, instead of paying for protection materials in order to fulfill ISO fire requirements of 120 minutes and more, this money was used for the installation of active fire safety measures. Active fire safety produces real safety for people, f.i. by adequate partitioning, by safe escape routes, by proper smoke venting or by conveniently designed & maintained sprinkler systems. But at the same time active fire safety contributes in helping the structure resist realistic heating conditions, as the potential severity of a fire and its probability of occurrence are cut down .
Prediction Methods for Concrete Diagnosis with Electrochemical Test and Probability
Authors: Toda Katsuya , Nishido Takayuki
Published: October 2011

Corrosion of reinforcing bars causes serious damages to concrete structures, for example, initiation and growth of cracks, exfoliation, and losing their durability. In concrete structural integrity assessment and repair, it is very important and difficult to know when the defects will be appeared and where the priority points should be repaired. In this paper, the accuracy of the two prediction methods of concrete deterioration, the electrochemical methods and the probability model, are assessed using experimental data. It is concluded that electrochemical method is useful for the concrete parts and the probability model methods are useful for maintenance planning of many concrete structures.
Fire safety concept for tall timber buildings
Authors: Frangi Andrea , Fontana Mario , Knobloch Markus
Published: October 2011

Based on the current knowledge in the field of fire design of timber structures this paper presents a generic fire safety concept for tall timber buildings. First, the paper gives an overview of fire safety concepts and presents experimental results on the fire performance of timber structures under natural fire conditions relevant for tall timber buildings. Then, the main differences between medium-rise and tall buildings with regard to fire safety are discussed and the formulation of a generic fire safety concept for tall timber buildings is presented.
A New Energy-Efficient Device for Active Control of Bridge Vibrations
Authors: Scheller Joern , Starossek Uwe
Published: October 2011

The system characteristics and effects of a novel active mass damper are investigated by means of its application for control of wind-induced bridge vibrations. Due to the presence of self-excited forces, stability issues are considered and a stability measure proposed. By virtue of the generation mechanism of the control forces, a superior low power demand of the actuators is achieved in comparison to other proposed mass dampers. The performance of the new damper is studied using a numerical example.
Probabilistic Shear and Bending Resistance Models for Assessment of Reinforced and Prestressed Concrete Bridges
Authors: Wisniewski Dawid , Cruz Paulo , Henriques Abel
Published: October 2011

This paper presents newly established probabilistic models of ultimate shear and bending resistance of typical reinforced and prestressed concrete bridge section. The models have been developed using recently collected data regarding variability of mechanical properties of concrete, reinforcing and prestressing steel, and also variability of the section dimensions. The uncertainty of the mathematical models, used for the calculation of the sectional response, has as well been taken into account. The proposed models have been developed to be used in the load capacity evaluation of existing bridges by means of probabilistic methods. However, they can also be used for the calibration of the partial safety factor in the existing design or assessment codes.
Dynamic Amplification Factors of an Urban Maglev Guideway
Authors: Chung Wonseok , Yeo Inho
Published: October 2011

The Korean urban maglev project has been initiated with the intention to build a commercial line by the year 2012. The optimized guideway has been proposed and the relevant tests are currently being conducted. However, the dynamic amplification factor (DAF) for the maglev guideway has not been determined for the guideway design criterion. As the maglev load is distributed rather than concentrated, further examination of the dynamic behavior should be conducted. This study is to identify the DAF of the proposed urban maglev guideway. For this purpose, moving load analyses were performed up to the maximum speed of 110 km/hr by 10 km/hr increments. A field test was conducted on the maglev test track to verify the finite element model. Guideway deflections and accelerations were measured for various vehicle speeds and a DAF was computed. The modal properties of the proposed guideway system were also identified. It was found that the DAF for the maglev guideway is less than 2% up to the maximum speed, which implies that the dynamic amplification is not severe in the proposed maglev system.
Assessment of the Suspension Cables of the Severn Bridge, UK
Authors: Young Jeff , Lynch Martin , Lambert Paul , Fisher Jeff
Published: October 2011

The Severn Bridge in the United Kingdom was completed in 1966 and was the first suspension bridge to adopt a streamlined box girder deck that reduced the dead weight and improved aerodynamic performance. The 988m (3249 ft) span bridge crosses the estuary of the River Severn and is an important asset within the UK’s highway network. In 2006 the UK’s Highways Agency, through the concessionaire Severn River Crossing plc, commissioned a programme of internal intrusive examination of the main suspension cables of the Severn Bridge with Faber- Maunsell/Weidlinger acting as consultant for the inspection. The information obtained during these investigations provided the basic data for use in a formal strength assessment of the suspension cables that has been undertaken by Mott MacDonald. Analytical techniques developed over the past two years have enabled the adoption of limit state principles for the assessment in line with UK practice. In addition deterioration modelling has been developed to improve understanding of the current condition of the cables and also to assist in the future management of the bridge.
Design and development of fiber reinforced elastomeric bearings
Authors: Gerhaher Ulrich , Strauss Alfred , Bergmeister Konrad
Published: October 2011

The use of reinforced elastomeric bearings for simple and cheap earthquake isolation systems has been discussed for some years. The advantages of the use of fiber reinforcement for these isolators (e.g. high damping, large range of horizontal deflection) are known and have often been described. However, the current design codes give no appropriate formulas to calculate the behavior of fiber reinforced elastomeric isolators.

This study presents a first step to develop advanced design guidelines for elastomeric bearings taking nonlinear effects into account. Based on a parametric study on numerical models and the formulas given in the current design codes and other publications a new formula to describe the horizontal stiffness is developed. Hereby specific nonlinearities of fiber reinforced elastomeric bearings are taken into account as well as the influence of vertical loads on the horizontal stability.
The new Pinel Bridge in Rouen, the fifth French road bridge using ultra high performance fiber-reinforced concrete components
Authors: de Matteis Daniel , Marchand Pierre , Petel Aude , Thibaux Thierry , Fabry Nicolas , Chanut Sandrine
Published: October 2011

This paper describes the design and construction of the third Pinel Bridge in France, in 2007. Located just to the west of Rouen, this small bridge has a single 27m long span and is 14m wide. It will increase the traffic capacity of an existing bridge over three railroad tracks from two lanes to five. The bridge deck combines a conventional slab of standard reinforced concrete with seventeen parallel contiguous beams made of self-consolidating ultra high performance fiber-reinforced concrete (UHPFRC). The beams - designed by the contractor Eiffage TP as an alternative to a filler- beam deck – are prestressed with 28 internal strands placed in a very wide bottom flange.
Young Structural Engineers Building Structures for the Poor
Authors: Moreu Fernando , Travers Patrick
Published: October 2011

Structures are key to the development of countries and society in general. The integrity and reliability of structural systems carry out and guarantee the base for the projection of communities and nations, and their economic and social growth. Developing countries today are developing their engineering forces and infrastructure leaders, both designers and builders, to put their skills in service to develop the foundations for their growth. Young structural engineers from any country can make a difference in this scenario through the application of their fresh knowledge of their profession in specific projects that need their help and collaboration today.
Developing teamwork and other professional skills while teaching reinforced concrete design
Authors: Gardner Anne , Willey Keith
Published: October 2011

Professionals, in addition to being technically competent, need a range of generic skills. These include teamwork, communication, being able to think both critically and independently, being able to critically appraise one’s work and the work of others and an appreciation of the need and value of reflection in both their personal and professional life [1, 2]. However, there is a reported competency gap between the skills required by employers and those developed by students during their undergraduate courses [3, 4]. At the University of Technology, Sydney, we are using self and peer assessment in our Engineering program to develop professional competencies in undergraduate engineering students. Its co-ordinated use is providing opportunities for students to practise, develop and assess their professional skills and develop their judgement [5] within subjects where traditional discipline content is taught.
Evaluation of a program for the reconstruction of houses in India
Authors: Payá Zaforteza Ignacio , Calderón García Pedro A.
Published: October 2011

This paper presents the results of the evaluation of a housing reconstruction program carried out by the Non-Government Organisation Intermón-Oxfam in Gujarat, India, in the aftermath of a devastating earthquake in 2001.

The evaluation covered social, economic and technical aspects. Its principal objective was to draw up recommendations to improve actions and strategies in similar future emergency situations. The conclusions of the evaluation show that it is necessary to: a) Consider the project beneficiaries’ views from the start; b) Work with multi-disciplinary teams of technicians and social workers; c) Train local builders in earthquake-resistant construction; d) Obtain external evaluations at different stages of the project, not only at the end.

The paper also provides cost details on low-priced housing built after the catastrophe for different quality levels and construction materials.
Creative Designing – Teaching the Impossible?!
Authors: Bögle Annette
Published: October 2011

Structures as the essential element of architecture are the result of a creative design process. It is accepted, that a design process is a unique, innovative and emotional activity, expressing the personality of the designer. But in contrast today’s engineering is characterized through rationality, computability, technocracy and reproducibility. But who - if not engineers - are designing structures? This paper shows that structural quality can only originate, if the border between art and technology is overcome. One possible and essential way to reach this goal is through teaching creative designing. Therefore so called basic elements of creativity which can be taught will be introduced:
firstly knowledge about the history of structures, secondly to deal with the process of designing, thirdly to know the characteristics of perception and fourthly to be capable of (constructive) criticism that means to criticize and to review.
Point-fixed gGlazing – mMaterials and pProcessing
Authors: Haese Andreas
Published: October 2011

During the last decades structural glazing became the leading technique in realising building envelopes, especially for larger buildings. Due to the requirements of energy conservation and in order to establish the architectural vision of maximal transparency it became necessary to reduce the number of bearing elements thereby enforcing the point-fixed glazing. As forces are transmitted by plates and bolts in and around a hole, stress concentrates in this area. Therefore in most point- supported glass elements the maximum stress arises at the bore edge. This makes the design of the point-fixing the critical point as glass does not have the ability to plastify and the dimensioning is adapted to the stress peak. A lot of research has been done and still is in progress to minimize this stress by optimizing the point supports regarding their geometry and the materials used. A survey of state-of-the-art constructions and new developments will be given below.
Design of Blast Resistant Long-Carbon Fibre Concrete Walls
Authors: Coughlin Andrew , Musselman Eric , Schokker Andrea
Published: October 2011

Since the events of September 11, 2001, there has been a growing awareness of the need to design structures for resistance to terrorist attack. Many of the fatalities and injuries associated with blast on structures are due to shrapnel produced by the blast. The long carbon fibre investigated in this program is one of very few feasible alternatives for providing this resistance to spalling for concrete buildings (in addition to improving other structural properties). The material is a waste product from the Aerospace industry and can be mixed directly into concrete without significant changes to the standard casting process. The material also has potential for use in seismic regions, but the present focus is on blast resistance (explosives) and impact resistance (crash barriers, impact resistant bridge piers).

While the material can be used successfully “as is” in a straight replacement for standard concrete, the true benefits come by taking into account the material as a portion of the reinforcement.

Reinforcement beyond that required results in more difficult placement of the fibre concrete, reduces spalling resistance in low cover situations, and increases cost. Specimens designed for blast resistance (by codes such as the TM5-1300) require extremely heavy reinforcement. This paper will summarize the computational modeling and large-scale blast testing program used to develop design recommendations for long-carbon fibre concrete for wall and barrier applications.
Post Tsunami Reconstruction in Indonesia
Authors: Magliola Robert
Published: October 2011

The 26 December 2004 Indian Ocean tsunami, triggered by the Sumatra-Andaman earthquake, devastated the northwest coast of the Aceh Province in Indonesia. Long segments of the coastal highway and 90 bridges were destroyed. The loss of the highway crippled transportation, hampered post tsunami aid relief, and created great social and economic hardships. Under contract to the U.S. Agency for International Development (USAID), Parsons designed the roadway and replacement structures. Spliced precast I-beams, steel trusses and box culverts were selected as replacement structure types based on local construction means and methods, site accessibility and economy.
Replacement of the US 90 Bridge across St. Louis Bay
Authors: Blakemore Frank , Konda Travis
Published: October 2011

The 3.38 km US 90 Bridge over St. Louis Bay was awarded by the Mississippi DOT five months
after Hurricane Katrina destroyed the original bridge. This Design/Build Project has recently
finished construction and successfully met the deadlines of opening the first two lanes by May 17th
(15 months after award) and the entire bridge on February 15th. The bridge is built as two separate
structures except for the navigation unit, where the deck and substructure are continuous between
the eastbound and westbound structures.<7p>
Seismic Retrofit of an Aged, Historic Signature Concrete Bridge
Authors: Tobolski Matthew , Fitzwilliam Daniel
Published: October 2011

The Cabrillo Bridge was constructed in 1914 for the Panama-California Exposition of 1915. The existing structure consists of eight independent cantilever spans with a total structure length of 479’ and a maximum structure height of approximately 129’. For each independent span there are two twelve foot square hollow columns with unique detailing features. Inspection of the existing condition revealed a significantly deteriorated existing condition of the structure with a variety of steel and concrete issues. A major rehabilitation effort is first required to bring the condition of the existing structure to an acceptable level. Seismic analyses on the assumed rehabilitated structure

revealed the structure is severely deficient in shear and displacement capacity as well as a variety of detailing issues. To resolve many of the issues, the eight independent spans will be tied together with full length, unbonded post-tensioning. Furthermore, inside each column supplemental shear walls will be constructed and the columns will be post-tensioned.

These retrofit details are expected to produce a structure that is capable of withstanding the design level earthquake demands in line with life-safety criterion.

Fig. 1: Bridge Construction, circa 1915
US 90 Bridge Over Biloxi Bay-A Design-Build Solution to Katrina Recovery
Authors: Cassity Patrick
Published: October 2011

This US$339M design-build project includes replacement of a 2.6 kilometer long bridge over Biloxi Bay connecting the gulf coast communities of Biloxi and Ocean Springs, Mississippi that was destroyed by hurricane Katrina. The majority of the design was completed in just 6 months to allow the roadway to be opened to 1 lane of traffic in each direction by November 2007, only 18 months from notice to proceed. The entire project was completed by April 2008. This paper will focus on the strategies implemented to reconstruct the bridge in response to the disaster and reopen the bridge as quickly as possible.
Ship Collision Protection Device for Zhanjiang Bay Bridge
Authors: Cao Yinghong , Luo Linge , Zhou Ying
Published: October 2011

This paper reported the design and implementation of an energy-absorption type ship collision protection device for Zhanjiang Bay Bridge in China. The main bridge is a cable stayed bridge with center span of 480m, crossing a 50,000 tonnage navigation route. The maximum possible impact force by ship to main pier is about 84MN. Due to some reasons such as limited span length, 20m deep water and soft pile ground base, it is hard to design a ship collision protection device (SCPD) for the main pier. A flexible energy-absorption SCPD was developed and applied to this bridge. This double-case self-floated SCPD consists of inner steel case, external steel case and viscous-elastic rings between them. It can reduce the maximum impact force to below 50MN, while the maximum capacity of main pier is 60MN. The capacity of this SCPD was verified by dynamic impact simulation analysis. A new 3 level protection design strategy which generated during the development of SCPD was introduced in this paper.
Damage caused by accidental loads - assessing of damaged reinforced concrete
Authors: Fuchs Maximilian , Keuser Manfred
Published: October 2011

Accidental loads - for example a vehicle impact or blast and shock waves due to detonations - lead to damages in reinforced concrete structures. These damages are characterized by a central zone, which is visually recognizable and also an obvious invisible damage in the surrounding material caused by shock wave propagation through the concrete. To make a statement concerning the structural behaviour of reinforced concrete structures damaged in such a manner and to predict their residual load bearing capacity in a further step, information on the damage is needed. To assess the size of the total damaged zone consisting of visible and obvious invisible parts, non-destructive tests (NDT) have been carried out. Investigations with the acoustical-based Impact-Echo-method and the Radar system based on electro-magnetic waves show good applicability for that problem and help to learn more about damages caused by high dynamic loads.
Analytical Studies on Load Carrying Capacities of Riveted Railway Bridges Subjected to Collision Damages
Authors: Nakayama Taishi , Kimura Motoya , Ikeda Manabu , Kita Kenji , Nagashima Fumio , Matsui Shigeyuki
Published: October 2011

Collision accident to an aged railway bridge girder obstructing train services occasionally occurs due to the collision by the construction vehicle exceeding the limited height passing under the railway bridge. In this study, using a multipurpose FEM code LS-DYNA, we analytically investigate the effects of the damage level and the impact deformation pattern on the load carrying capacities of the riveted steel girders.
Performance-Based Vessel Collision Modelling
Authors: Matusewitch Peter
Published: October 2011

A performance-based aberrant vessel collision analysis was performed to access the vulnerability of the in-water anchorages of a suspension bridge, using the LS-DYNA software package. Simplified models of the design vessels were digitally launched at finite element models of the anchorages.

Failure was defined as either penetration of the vessel through the outer curtain walls or undermining of the main cable saddle supports. The damage to the reinforced concrete was given in terms of plots of maximum principle strain after impact, and before and after plots of stresses in the buttresses supporting the cable saddles. Video simulations of the impacts were also generated.
Reinforced Concrete Precast Structures with Rigid Connections
Authors: Bob Corneliu , Leidal Andras , Bob Liana
Published: October 2011

The solution of rigid joints between columns and beams for precast concrete structures like halls with one level , is presented. The aspects concerning drawn, tests and application of this solution are analyzed in the paper. The rigid connection between the structural elements of the precast constructions have some important technical and economical advantages. The experimental results are in good agreement with the analytical one. The procedure of RC precast structures with rigid joints has been applied with efficiency implications at some buildings with different shapes and spans.
Evaluating Fatigue Performance of Sign, Signal and Luminaire Structures
Authors: Roy Sougata , Park Yeun-Chul , Thompson Reilly , Sause Richard , Fisher John
Published: October 2011

Fatigue performance of welded connections in highway signs, signals and high level luminaire structures are being evaluated as part of ongoing research under NCHRP Project 10-70. Fatigue failure of these structures is increasingly being reported in the United States due to wind induced oscillations, which has serious economic impact on the limited infrastructure resources from safety and maintenance points of view. Most of the fatigue cracking in service has been reported in tube- to-end plate welds at a relatively short life due to the large secondary out of plane stresses developed in the thin walled tubes from incompatibility in deformation, which is precipitated by the flexibility of the end plate. The existing AASHTO specification, which is based on nominal stress and derived from the guidelines that are valid for predominantly in-plane stresses or membrane stresses, is often inadequate in designing these structures against service limit state of fatigue. This paper presents experimental evaluation of welded connections in 12 full size sign/signal and high level luminaire structures, and compares the test results with predicted fatigue lives obtained by a hot-spot stress based analytical protocol.
Casino Parking Garage Collapse Forensic Investigation
Authors: Sheehan Matthew , Vanduyne Eric , Corley Gene
Published: October 2011

The expansion of a casino entertainment complex in the eastern United States was progressing in 2003, when a collapse of an approximate 15 by 60 m area of the parking garage occurred during placement of cast-in-place concrete at an upper garage level. Garage construction generally consisted of stay-in-place, precast, prestressed concrete formwork and cast-in-place composite slab system connected with mild steel reinforcing to cast-in-place concrete columns and shearwalls..

Collapse of multiple levels of the composite floor system occurred, but nearly all perimeter columns and shearwalls in the area remained standing. The authors were retained to investigate and determine the cause of the failure and study the progressive collapse. The investigation results were used to successfully assess failure cause and make recommendations on how to avoid such accidents in the future.
Rehabilitation of Ferry Docks in Southwestern Ontario
Authors: Leblanc David , Shallhorn Mike , Kerr Dennis
Published: October 2011

Three ferry docks are part of a ferry service which connect mainland Southwestern Ontario with Pelee Island, a 10,000 acre island situated in Lake Erie, approximately 30 km south of the mainland. A number of structural and operational deficiencies were identified at each of the ferry docks, and a rehabilitation strategy was developed to address these deficiencies. The existing sheet pile walls at the docks required strengthening to maintain their stability and structural integrity. To determine the strengthening requirements for the sheet pile walls, a mobilized earth pressure coefficient analysis was conducted. The strengthening and rehabilitation strategy developed through this analysis consisted of the installation of a caisson wall in front of the toe of the existing sheet piles below the dredge line, connected by a caisson cap beam. The rehabilitation of the ferry docks included providing scour protection and lowering the dredge line elevations.
Structural Evaluation of Four Frank Lloyd Wright Buildings
Authors: Meade Edmund
Published: October 2011

This paper provides an overview of the investigation and analysis techniques that were used in the structural restoration of four significant buildings designed by Frank Lloyd Wright. The similarities and differences in evaluation and design aspects of the structural work for each building are presented. The lessons learned from each project’s structural review, design, and repair procedures are also noted.
Solomon R. Guggenheim Museum Restoration: Correlating Projected and Actual Movement of Thin Shell Concrete Walls
Authors: Hudson Nancy
Published: October 2011

The Solomon R. Guggenheim Museum in New York City by the architect Frank Lloyd Wright is a recognized international icon of Modern Architecture. The architecture and structure are completely integrated to define the organic architecture of the building. A rehabilitation of the building exterior was undertaken by the museum to address cracks and deterioration of the coating. A comprehensive structural assessment of the building was done to determine the source of cracking, evaluate the global structural stability and determine if structural repairs were required to improve the performance of the walls. To evaluate the structural performance of the building, a finite element model was created from a laser scan. The model was correlated to the actual performance of the building by comparison with monitoring data and with crack patterns in the concrete substrate. This paper presents the process and challenges faced in creating a model that reflected the as-built, real world performance of the building.
Structural Reliability Assessment for existing composite bridges without design documents
Authors: Braml Thomas , Keuse Manfred
Published: October 2011

In order to achieve a fast and reliable determination of the load-bearing capacity of existing bridges while in missions abroad, a system to classify bridges was developed. Generally, no building documents are available in such a case. The assessment system works on two different levels of accuracy: a quick assessment only with geometric input values, and a structural analysis which requires additional material properties. If the generated military load class from the quick assessment is insufficient, a more accurate classification based on structural analysis is carried out.