bluuebunny/crossref_metadata_2025 huggingface dataset:
Staged Structural Assessment of a Large Concrete Box-girder Bridge
Authors: Goede Timo de , Vergoossen Rob , Nosewicz Henryk , Sliedrecht Henk
Published: February 2021

Currently infrastructure owners and operators experience a big challenge when it comes to their existing assets. Increased traffic loads and changing demands often require updates or renovations of existing bridges which may well be decades old. When changes are required, often the structural safety needs assessed. Because building codes and guidelines get updated as the state of the art develops, a particular challenge is that apart from increasing loads, the capacity according to calculations may decrease.

The Maasbrug Grubbenvorst, a post-tensioned concrete box-girder bridge with two cells, is a fine example of these challenges. New requirements cause changes to the traffic lane lay out, which in turn requires a new assessment of the structure. Constructed in the 1970’s, current design practice for shear force has significantly changed compared to the moment the original design was conceived. This paper deals with the structural assessment of the bridge and focusses on the distribution of shear forces over the webs of this bridge.

In beam models the entire cross section of the box-girder is schematized into a single beam element. Because of the skew spans of the bridge, the distribution of shear forces over the webs cannot be predicted by rules of thumb. Therefore, a new method is used that allows to calculate the correct distribution of shear force from these beam models. Hence, the benefits of beam models can be used for skew structures as well.

In this paper it is shown that using this method, insight into the behavior of the structure can be gained rapidly. The method uses framework models for cross section analysis, while the longitudinal analysis is carried out with the beam model. The calculations results from this beam- framework model are compared to 3D FEM calculations. The paper concludes with the conclusion from the assessment as well as peek into the future of the Dutch guidelines on Structural Assessment of existing structures.
Development and Application of FASSTbridge Solution to Jarama bridge (Fast and effective Solution for Steel bridges lifetime extension)
Authors: Chataigner Sylvain , Benzarti Karim , Foret Gilles , Quiertant Marc , Zalbide Maria , Garcia David , Calderon Inigo , Piñero Ignacio , Veneto Vottorio , Birtel Veit , Lehmann Frank , Wahbeh Mazen , Bound Rami
Published: February 2021

One of the goals of sustainable development applied to bridge infrastructure is to provide bridge owners with strengthening solutions that may lead to an increase of existing structures service life. In the case of steel bridges, the assessment of the remaining service life is most often linked to the determination of the structural deterioration caused by corrosion and fatigue. Damage caused by fatigue is very difficult to assess before crack initiation, and is more bound to occur in old structures, for which the phenomenon was not taken into account in design before 1970. In addition, old steel materials present a more brittle behavior. In answer to these challenges, the FASSTbridge project, financed through European Infravation call, aimed at developing a pre- cracking fatigue assessment and strengthening methodology for steel bridges based on the technology of adhesively bonded composite. The proposed article presents some of the results of this project.
Lessons Learnt from the 14th November Kaikōura Earthquake and Next Generation of Resilient Solutions for Bridges
Authors: McHaffie Brandon , Sarkis Ana , Liu Royce , Palermo Alessandro
Published: February 2021

The 14th of November 2016 (New Zealand Time) Kaikōura Earthquake was particular since it was the summation of multiple fault ruptures over a large spatial domain; the transportation network of the entire northeast portion of the South Island was badly affected. Over 300 bridges were assessed by authorities. One bridge almost collapsed and was replaced by a Bailey bridge, while several others close to the epicenter had sustained pier plastic hinging with fractured rebar and massive concrete spalling.

The assessment of this infrastructure raised several questions related to the quantification of the post- earthquake residual capacity that are still to be addressed. Post-earthquake reparability is strictly connected with resilience and the ability to reinstate full functionality to the structure.

The authors will highlight through a series of bridges damaged by the Kaikōura earthquake how current design standards lack resilience and what alternative solutions are resilient. This will be supported by numerical analysis and testing recently undertaken by the University of Canterbury bridge engineering research group.
Shake Table Studies of Seismic Damage of a Kilometre-scale cable- stayed Bridge
Authors: Guo Wei , Li Jianzhong , Guan Zhongguo
Published: February 2021

To investigate the transverse seismic damage of a kilometre-scale cable-stayed bridge, a cable- stayed Bridge with two inverted Y-shaped reinforced concrete towers and a main span of 1088 m was selected as the prototype and a 1/35 scaled bridge model was designed, constructed and tested on 4 linear shake tables at Tongji University, Shanghai, China. Sliding bearings which allow the longitudinal movement of the main girder with little friction effect while prevent the transverse movement were used at the towers and the piers. The bridge model was tested up to failure by using a site specific artificial wave from low to high intensity in transverse direction. Test results showed that: (1) flexure failure occurred at the right tower leg of tower 1 at the level just above the crossbeam; (2) the maximum transverse displacement response of the tower was observed at the mid-height; (3) 4 peak sectional curvature responses were observed along the tower.
Experimental Study on Seismic Behaviour of Precast Piers with Combined Grouted Sleeve Splice and Grouted Central Tenon
Authors: Liu Zhao , Lu Gan , Zhuo Weiding
Published: February 2021

In precast bridge piers, longitudinal bars between prefabricated segments are usually connected by grouted sleeve splices (GS), while the concrete on the joint interface remains discontinuous. The structural behaviour distinction between the precast and cast-in-place piers becomes the main concern in seismic design. In order to improve the seismic performance of precast piers, a new type of intersegment connection with combined grouted sleeve splice and grouted central tenon (GS-GT) was proposed. The main objective of this study was to test, analyse, and evaluate this GS-GT connection for accelerated bridge construction.

An experimental program was conducted with three bridge pier specimens, including a conventional cast-in-place (CIP) benchmark pier, a precast pier with GS, and a precast pier with GS-GT connections. All the three specimens had identical geometry except for the connection details. Their damage scenarios were observed during the cyclic loading tests, and some seismic indices were identified and analysed. Computational analysis using simulation models for GS-GT connections were established with the software OpenSees, which fit well with the experiment results.

Research results indicated precast piers with GS-GT connections can achieve better displacement ductility, lateral force and hysteretic energy dissipation, compared with only GS connection. It was concluded that the GS-GT connection can enhance emulative effects, close to the conventional cast-in-place systems.
Potentials of Autonomous UAS and Automated Image Analysis for Structural Health Monitoring
Authors: Kersten Jens , Rodehorst Volker , Hallermann Norman , Debus Paul , Morgenthal Guido
Published: February 2021

Unmanned aircraft systems (UAS) are increasingly used for the inspection of buildings and critical infrastructures. Manual inspection efforts can be reduced by a camera equipped UAS in combination with advanced image analysis. Tailored methods for the planning of UAS-based image acquisition are required here. In order to ensure efficient inspection procedures, the geo-location, view direction and imaging properties of each image have to be reconstructed. Furthermore, accurate and reliable methods for the extraction of 3D object information as well as visible damages can be exploited to automatically identify potentially affected areas. In this paper, the components and required methods for an inspection system supported by an autonomous UAS and automated image analysis are identified, discussed and evaluated. The results show the great potential and value of process automation and the benefit of image analysis in a decision support system.
Lessons Learnt from Full-Scale Tests of Bridges in Croatia and Sweden
Authors: Duvnjak Ivan , Bartolac Marko , Nilimaa Jonny , Sas Gabriel , Blanksvärd Thomas , Täljste Björn , Elfgren Lennart
Published: February 2021

Load testing is a way to control the capacity and function of a bridge. Methods and recommendations for load testing are described and examples are given form tests carried out in Croatia and Sweden. In order not to damage the bridge being tested, the load must be limited, often to be within the serviceability limit state (SLS). Numerical models can be calibrated by load tests and then be used to check the carrying capacity for higher loads than what has been tested. Need for further work and recommendations are discussed. By effective planning, costs can be saved and a more sustainable use of bridges can be obtained.
Use of low-cost GNSS receivers for Structural Health Monitoring
Authors: Manzini Nicolas , Orcesi Andre , Clément Antoine , Ortiz Miguel , Dumoulin John
Published: February 2021

Global Positioning System (GPS) is a satellite constellation allowing positioning in a constantly updated global reference frame for almost any user on the globe. Over the last decade, GPS has been expanded to Global Navigation Satellite Systems (GNSS) with the progressive addition of three satellite constellations. This evolution enables a more robust and effective positioning calculation, thus improving the performance and reliability of GNSS-based monitoring systems. In parallel, improvements in GNSS receivers provide higher frequency and precision calculations, with shorter computation time, enabling GNSS techniques to be used both for long-term monitoring of slow displacements, and for the analysis of short term events.

This paper explores the performances and possibilities of low-cost GNSS receivers in order to improve structural health monitoring systems of large and flexible structures such as bridges, towers or cooling-towers. Low-cost carrier-phase receivers, coupled with various processing methods and parameters, are evaluated to the extent of characterizing both long term precision and stability, and qualification of short displacements and oscillations. The amplitudes and frequencies of displacements and oscillations tested are selected in accordance with phenomena that may be observed on flexible structures. The use of a high-quality reference station with very short baseline is proven a good alternative over expensive receiver upgrading, with rovers able to qualify abrupt displacements down to 4mm, and accurately monitor oscillations with frequencies up to 0.25Hz and amplitudes down to 1cm with a 1Hz sampling rate. Data acquired from a low- cost receiver installed on the main span of suspended bridge is evaluated in order to highlight quality and reliability of on-site applications, and was found highly correlated to traditional sensors data (resistance temperature detectors, and displacement laser sensors).
New Spatial Correlation Assessment Procedure: Application to Île-de- Ré Bridge Data
Authors: Clerc Romain , Schoefs Franck , Oumouni Mestapha
Published: February 2021

Tomorrow’s Megastructures exploitation will require robust management policies, including Non- Destructive Techniques measurements and Structure Health Monitoring. These inspections strategies already allow acquisition of large amounts of data at reasonable cost. However, the bigger the structure, the costlier the data collecting. This raises the question of spatial optimization, closely related to the determination of spatial variability. Related studies have so far characterized it using covariograms on raw data without paying attention to their conditions of validity. As this lack of rigor may lead to severe misestimating, we propose a mathematically rigorous spatial variability assessment procedure and apply it to measurements coming from the Île de Ré bridge diagnosis, performed during the DéCoF-Ré (Décision par diagnostic de Corrosion en toute Fiabilité sur le pont de l’île de Ré) project. This unique data set of resistivity and corrosion potential measurements allow us to begin a spatial variability database for marine concrete structures.
Effect of Steel Reinforcement on Electrical Measurements on Concrete
Authors: Alhajj Marie Antoinette , Villain Géraldine , Palma-Lopes Sérgio
Published: February 2021

Concrete is a construction material known for its resistance to compression and its durability. There are several methods for evaluating the durability of reinforced concrete structures, falling into two categories: destructive (D) and non-destructive (ND) methods. The DC-electrical resistivity method is devoted to ND evaluation. By measuring sets of concrete apparent resistivities, that are sensitive to water content, the durability of concrete can be evaluated. However, when applying this measurement technique to reinforced concrete structures, the measured apparent resistivity may be highly influenced by the steel reinforcement. The aim of this article is to study the influence of reinforcements on resistivity measurements on concrete. The problem was first studied using numerical analysis, then two applications were considered: the first is based on an experimental campaign and the second is an application to megastructures.
Compatible Deformation in the Condition Assessment of Beam Structures
Authors: Lei Jun , Xu Dong , Turmo José
Published: February 2021

The structural deformations should satisfy some geometric relations. However, this might not hold when the measured deformations are contaminated by measurement errors. In order to filter out the incompatibility in the measured deformation due to errors, the mathematical relation among the displacements within the structure are derived by the structural system identification by observability method. Namely, checking the observability of the parameters and obtaining the symbolical solution of those observable variables in the observability equations. Rearranging the associated solution leads to the geometrical equations that some displacements should satisfy, which is referred as the compatibility conditions. Among all compatible deformations satisfying these conditions, the one closest to the measured deformation is found by an optimization procedure. Finally, the structural parameters are estimated based on the optimal deformation shape. This method can smooth away the incompatibility due to errors and is validated by a simply supported beam and a two-span continuous beam.
Merrison Revolutionised Design after 1970 UK Box Girder Collapses
Authors: Wood Jonathan G. M.
Published: February 2021

Engineers have always pushed the boundaries of the possible to create Megastructures. In the 1960s, UK innovations were replacing traditional steel girder construction designed to simple BS codes using slide rules. The change was to all welded construction of stiffened box girders, some as cable stayed or suspension bridges. Often old codes were used without reviewing or updating them for the very different scale and proportions of these complex slender structures. The UK Merrison Committee was set up after the fatal 1970 collapses of Milford Haven and West Gate Bridges. It developed Interim Design and Workmanship Rules (IDWR) for the design of steel box girder bridges and the assessment and strengthening of the dozens of deficient UK bridges. Later these comprehensive rules were over simplified into BS5400 and then into EN1993. Today’s engineers contemplating Megastructures and those charged with revising EN1993, should re-examine and understand the fundamental basis and source research on which these Codes are based.
Seismic analysis of the San Sebastian Basilica (Philippines)
Authors: O'Hearne Nicole , Mendes Nuno , Lourenço Paulo B.
Published: February 2021

This paper presents the evaluation of the seismic performance of the San Sebastian Basilica, which included dynamic identification tests, preparation of numerical models and pushover analyses. The San Sebastian Basilica, located in Manila and inaugurated in 1891, consists of a fully prefabricated steel structure that has maintained its original design, interior finishes and materials. The dynamic identification tests were carried out using ambient vibration, which allowed to estimate six modes (2.53 Hz to 5.81 Hz). The FEM models employ an evolutionary process to assess the importance of the addition of various elements on the dynamic properties of the basilica. The seismic analysis allowed the conclusion that the transverse direction of the Basilica presents the lowest capacity, namely 2.5 g and 3.6 g for the uniform and first mode loading pattern, respectively. However, further works should be conducted to conclude on the safety of the basilica for seismic action.
Experimental Studies of Seismic Performance of Precast Concrete Columns with High-strength and Conventional Steel Rebar
Authors: Zhuo Weiding , Liu Zhao , Tong Teng
Published: February 2021

Increasing the strength of steel rebar can improve load-bearing capacity of concrete structures and economize their cost. Precast segmental columns incorporated with high-strength rebar facilitate accelerating bridge construction and may upgrade their seismic performance. To evaluate the cyclic loading behaviors between precast circular pier columns with high-strength and conventional rebar, two column specimens with the energy dissipation bars of HRB600E and HRB400 were experimentally studied. The tests showed that seismic performance of the precast column with high-strength rebar was superior to the counterpart with conventional rebar in the aspects of equivalent yielding strength, maximum shear force, ultimate displacement, post- yielding drift increment, residual displacement, and stiffness degradation. On the other hand, precast column with conventional strength rebar dissipated more energy at the cost of substantial joint damage. Therefore, replacing conventional steel rebar with high-strength bar in precast columns can be a good and practical choice to enhance seismic resiliency of precast bridge columns.
Evaluation of Response Modification factors in moment resisting frame buildings considering Soil Structure Interaction
Authors: Kanwal Farheen , Munir Ahmed
Published: February 2021

Seismic response of the multi-storey buildings is created by the interaction of both the structure and underlying soil medium. The seismic design philosophy is incorporated using response modification factor “R”. Current Code based values of “R” factor does not reflect the SSI problem as it is based on fixed base condition. In this study, the modified values of “R” factor for moment resisting frame (MRF) considering SSI are evaluated. The response of structure with and without SSI has been compared using equivalent linear static and nonlinear static pushover analyses for 10- storied moment resisting frame building. The building is located in seismic zone 2B situated on different soils with shear wave velocity (Vs) of 300m/sec (SD) and 1200m/s (SB). Code based “R” factor value for building frame system has been taken as 5.5. Soil medium is modelled using identical but mutually independent horizontal and vertical springs. It was found that the modified “R” factor values have been decreased by 47% and 43% for soil SD & SB respectively as compared to that of code based “R” factor.
Implementing Resilience in Practice: Design for All in Anticipation of Earthquake Disaster
Authors: Moseley Jon , Dritsos Stephanos
Published: February 2021

In the last twenty years, earthquakes and their tsunami sidekick have been responsible for more fatalities than all the other natural disasters put together. Furthermore, it has been shown that destructive earthquakes cause disproportionately many more fatalities among susceptible groups when compared to the rest of the population. This article asserts that, to achieve resilience, the built environment must be specifically designed with vulnerable groups in mind, following design for all concepts. To achieve the highest resilience, both high infrastructure performance and high peoples’ behaviour are required. This paper contains practical solutions concerning how to implement and design for built infrastructure disaster resilience. It is concluded that resilient societies can be achieved by explicitly designing for and actively involving the most vulnerable groups in society and, in this way, the whole of society will benefit.
Seismic Upgrading of Reinforced Concrete Columns by FRP Jacketing
Authors: Liakopoulou Efstathia , Athanasopoulou Sotiria , Dritsos Stephanos E.
Published: February 2021

Many existing structures that have been designed according to older anti-seismic regulations appear to have insufficient seismic behaviour due to the lack of local ductility. This article investigates the use of composite materials (fibre reinforced polymers) and their influence on the increase in local ductility when strengthened reinforced concrete elements. By using available experimental results and comparing with the analytical results of Eurocode 8, part 3, its 2017 draft revision, the Greek Code of Structural Interventions and its 2017 revision, it is found that the most conservative model is the original Greek Code model, whereas its 2017 revision has the best converge with the experimental results for ductility in terms of chord rotation. However, it is found that values of chord rotation at yield and failure obtained according the draft revision of Eurocode 8-Part 3, are closer to the experimental results, when compared to the other models.
Building Complex Shapes with Simple Tools: Fast Track Design of “the Future of Us” Gridshell in Singapore
Authors: Poirriez Catherine , Bouzida Yacine
Published: February 2021

Building freeform gridshell structures usually implies dealing with complex geometries, which nowadays can be managed with integrated digital modelling tools. The ease of use of digital tools to manage complex geometries often leads the designer to neglect some of the project parameters such as the simplicity of buildability or cost. On the contrary, when very short time constraint is the priority, simplicity of fabrication and installation must become the driving design parameters. The “future of us” gridshell is a steel structure that supports 11000 perforated aluminium panels, spanning approx. 50m and rising to 16m. From start of design to completion of installation was only 5 months. This document describes how the boundaries of simplicity have been pushed during all the steps of the project, by using basic construction concepts, digital modelling tools and compromises in order to meet the challenge of building a free form complex structure on time.
Ashalim Solar Tower
Authors: Datry Jean-Bernard , Zonco Audrey , Prongue François , Dum Thomas , Oudin Gilles
Published: February 2021

Ashalim solar tower is the tallest solar tower in the world, reaching a height of 240m. Its unique design allows the solar receiver to be lifted inside the tower, up to the top, resulting in an optimised construction plan but also in a very complex geometry, which required specific wind tunnel tests, as well as a challenging structural design and high expertise in formwork technology.
Design Redundancy Analysis and Optimization for Steel Frame Structure
Authors: Zhao Xin , Zhao Jianzhe
Published: February 2021

Modern design of structure aims to reach a balance between safety and economy. An index, named redundancy quantifies the dynamic balance between these two features. A particular structure with too high redundancy is considered to be diseconomy while the opposite is unsafe; a proper redundancy of structure can save great material costs. As a prerequisite to safety, less redundancy can reduce more structural material wastes, which makes the structure economic and green. Digging deeper, redundancy of structure can be categorized as single constraint redundancy and multi constraint redundancy. The overall redundant state of a structure can be shown reliably by its single constraint redundancy and multiple constraint redundancy. This paper is to analyze and optimize the design redundancy for a one storey steel frame structure.
The First Engineered Pedestrian Bridge using Small Diameter Indonesian Teak Woods: From Design to Project
Authors: Awaludin Ali , Supriadi Bambang , Nugroho Maris Setyo , BuanAnshari  , Ahmad Zakiah
Published: February 2021

A prototype of pedestrian bridge was constructed as a pilot project to utilize small diameter Teak woods planted in community forests. The bridge had a span length of 6 m and a width of 1.2 m consisted of floor deck of plywood and a 3-D space truss. Bolts of 10 mm in diameter and 3 mm thick of steel plates were used at the connection of this 3-D truss. Preliminary tests on Teak wood mechanical properties found an average oven-dry specific gravity, modulus of elasticity, compressive strength, tensile strength, and dowel bearing strength equals to 0.74, 10133 MPa, 53 MPa, 129 MPa, and 45 MPa, respectively.

Various loading programs such as static loads, pedestrian moving loads, and sine waves ranging from 5 to 20 Hz were conducted to evaluate the structural performance of the bridge measured by using accelerometers and displacement transducers. It was found that the first and the second natural frequencies of the bridge were 19.9 and 39.8 Hz, respectively. Under a uniform static load of 400 kgf/m2, the bridge gave a maximum deflection of 9.8 mm, which is much lower than that of the allowable limit 30 mm (L/200). After test completion, the bridge was transported to a nearby river having suitable width and bridge re-erection was conducted at site. The bridge is now being used as a real pedestrian bridge.
Glass Sails of the Fondation Louis Vuitton: Approach to Robustness
Authors: King Matt , Hidalgo Jorge , Garcia Africa
Published: February 2021

The Fondation Louis Vuitton, a contemporary art museum designed by architect Frank Gehry and situated in the Bois de Boulogne in Paris, France, is a building of exceptional engineering complexity. Central to its architectural identity are the 12 sculptural glazed sails that float off the primary building structure. Totalling around 13,400m2, their steel and timber structure is supported by 189 compression struts, known as Tripods.

Suspending structures of this magnitude (the largest sail is around 3,000m2 and weighs over 800 Tonnes, while the smallest is 500m² and weighs around 130 Tonnes) presents an engineering challenge that is rarely seen in buildings and is more aligned with the scale of civil engineering or infrastructure projects.

The structure of each sail had to respond to the constraints imposed by the building’s primary structure, with loads at anchorage points exceeding 1,000 Tonnes. Furthermore, the design had to accommodate the architectural demands of a sculpture, where each Tripod and principal beam formed part of its composition.

The building was designated as Category 5 with a 100-year design life. The relative fragility of the timber elements (particularly their connections) and the unitary nature of the Tripod strut supports required that a full accidental loadcase verification be completed to assess the structures’ susceptibility to progressive collapse. The impact of the failure of any major element or connection on the stability of each sail was evaluated and the structure was iteratively refined, adding or removing supports in response, or locally reinforcing.

This paper sets out the design process for developing the structure of the sails and focuses on the accidental loadcase analyses completed. It explores the balance required between hyperstaticity of redundant structures and the need to control loadpaths and forces, particularly in a timber and steel composite structure.
Modern Wind Turbines - Challenges and New Design Technologies for Tower Structures
Authors: Rauch Marion
Published: February 2021

Wind energy is already significant and will become even more important among the renewable energies in the future. The development of modern wind turbines provides new challenges for tower and foundation structures. Typical tower heights of modern wind turbines are between 100 m and 160 m. The towers are usually made of steel. However, hybrid towers are also common for high towers. This paper gives, firstly, a short overview on the current situation of the wind energy market and thereof the challenges for modern wind turbines. Then, steel and hybrid tower concepts of wind turbines are shown. Typical design guidelines for wind turbines are presented with the focus on special requirements for the tower design as well as recent developments. The paper focuses on the challenges of modern wind turbines and future trends regarding the tower design; particularly on the influence of the fatigue behaviour.
Buckling of Curved Webs in Steel Box Girders
Authors: Van Staen Gilles , De Backer Hans , Van Bogaert Philippe
Published: February 2021

Today, bridge girders with curved flanges and webs are becoming more common in order to increase the aesthetic value and to improve the quality of the structure. Despite the use of these new shapes, not much research has been done in this field. The aim of the present research is to find the influence of the web curvature on the buckling resistance. Therefore, numerical models are created, which have curvature radii of 1500, 5, 3, 5/3, 1, 0.7 and 0.55 times the web height. GMNIA is performed with these models, the first mode shape being used as geometric imperfection. Amplitudes of 0.1 times to 3 times the web thickness are used. The results are analyzed on multiple levels. The imperfection sensitivity towards curved webs is visible by the deformation pattern, the buckling load, and the load- deformation curve of a web. These last curves also give an indication of the behaviour in the post buckling region.
Performance Enhancement of High-Strength Bolted Frictional Girder Connections Focused on Bearing Bolt Hole Deformation
Authors: Moriyama Hitoshi , Yamaguchi Takashi , Sugiyama Hiroki
Published: February 2021

The high-strength bolted frictional girder connections resists bending moment by cooperation of flange and web resistance, but the cooperation resistance mechanism isn’t clear. To improve bending plastic capacity in ultimate limit state, the bearing moment of the connection should be enhanced by utilizing the mechanism and allowing a certain bolt hole deformation. In this study, the pure bending experiment of the I-section girder connection was conducted to investigate the mechanism and evaluate its effect on performance of the connection. From obtained results, the mechanism was interpreted that the flange and web joint resist bending moment integrally. Its effect could be enhanced by enlargement of the slip moment ratio of the flange to the web. In the case that the ratio is 3.36, the bearing resisting moment when the flange bolt hole deformation reached the bolt diameter of 5% was 1.1 times full plastic moment of the girder.
Welded Connections in innovative High Strength Steel Constructions
Authors: Spiegler Jennifer , Kuhlmann Ulrike
Published: February 2021

In addition to the common mild steels, nowadays high performance steels with good weldability and high ductility are available for the construction industry. By using steels with higher resis- tance/weight material ratio savings can be obtained especially in the case of heavy constructions such as bridges, wide spanning roofs and high-rised buildings. However, for the particular situation of joining high strength steel by welds, e.g. in many cases in design codes such as EN 1993-1-8 [1] the rules are inadequate because recent rules and safety margins are developed traditionally for standard steels and then transferred to high strength steels.
Low Temperature Behaviour of High-Strength Structural Bolting Assemblies of Large Diameters
Authors: Lorenz Christoph , Stranghöner Natalie , Citarelli Sandro , Feldmann Markus , Brinnel Victoria , Münstermann Sebastian
Published: February 2021

The application of high-strength structural bolting assemblies of the HV system according to EN 14399-4 and EN 14399-6 and DASt-Richtlinie 021 with large diameters up to M72 as preloaded bolting assemblies in highly loaded steel structures like offshore wind towers, where the connections are exposed to low temperatures beside static and fatigue loads. To close the lack of knowledge on low temperature behaviour of these bolts, systematic investigations were carried out to determine the tendency of brittle fracture of high-strength bolts with large diameters. This paper presents the main results of the experimental investigations on the tendency of brittle fracture in terms of component tests at low temperatures.
Spatial Correlation Characterization using Windowing Method, Transfer through Concrete Carbonation Models
Authors: Ravahatra N. Rakotovao , Bastidas-Arteaga E. , Schoefs F. , De Larrard T. , Duprat F.
Published: February 2021

This paper concerns preventive maintenance strategy against reinforced concrete corrosion. Describing the spatial variability of concrete degradation is of utter importance in such a study. We propose in this study a method to improve spatial correlation characterization using limited quantity of measurements (only one trajectory). It is based on windowing method. We could obtain the distribution of values of the parameter of the continuous autocorrelation function when using the proposed method. The data used in this study were collected within the ANR- EVADEOS project. The parameters measured are: porosity, saturation degree, concrete density and carbonation depth. A preventive maintenance strategy should be supported by predictive models. We focused on concrete carbonation models. Sensitivity analysis of these models to input random fields (RF) is hence carried out. Results highlight which parameters should be stated as RF.
Response of Structural Concrete Assemblages to Thermo-Mechanical Loads
Authors: Svetha V. , Reddy D. Harinadha , Ramaswamy Ananth
Published: February 2021

Fire represents one of the extreme loads that a structure may experience during its design life. In reinforced concrete (RC) structures, the mechanical properties of both concrete and steel deteriorates with rise in temperature. In addition, concrete subjected to elevated temperature shows two kinds of spalling, namely, explosive spalling and thermal spalling. In the present study a three-dimensional (3D) finite element (FE) model that accounts for not only the hygral and thermal effects but also the bond-slip and transient thermal strains for accurate prediction of the behaviour of RC assemblages under combined mechanical and thermal loads is presented. The model considers the degradation of material properties (and the uncertainty associated with their values) with increase in temperature. A hygro-thermal analysis is included for the estimation of temperature and pore pressure variations. Specific attention is paid in explicitly modelling the interfacial bond-slip behaviour between steel reinforcement and the surrounding concrete. The strength of the model is evaluated through the simulation of benchmark problems that includes axial members, flexural members and a RC frame assembly. A comparison of the fire resistance values obtained from the model against those determined from the code-based approaches shows that the code based values are un- conservative in most cases, especially when it involves high strength concrete or very high/low load ratios.
On-site Study of the Time-dependent Behaviour of Concrete: Evaluation of the Application of EC2 Prediction Models in Algeria
Authors: Santos Luís Oliveira , Xu Min , Vieira Tiago
Published: February 2021

A study of the time-dependent behaviour of concrete carried out on-site in a viaduct in Algeria provides an excellent opportunity to assess the suitability of the use of EC2 in non-European countries. This paper presents creep and shrinkage experimental values measured during five years and compares them with the values predicted by EC2 models. A procedure for experimental identification of the parameters included in EN1992-1-1 prediction models of is proposed and tested.
New Paris Law Court, a Major Civil Engineering Structure in the City
Authors: Agez Iari , Zonco Audrey , Fagninou Hermann , Datry Jean-Bernard
Published: February 2021

Unusual within the Paris city limits where building heights are normally restricted to 28 metres, the new Paris Law court is a 160m high 40 storey complex in the new inner city development zone of Clichy-Batignolles. Architect Renzo Piano Building Workshop has designed an emblematic building with a floor area of 104 000m² divided into three horizontal blocks each ten levels high, separated by planted terraces. Behind the horizontal architecture of the project lies a structural design worthy of being classed as a major civil engineering works.
Innovative Prefabricated Robustness Solutions for Story High Buildings
Authors: Cornelius Thomas , Du Guangli
Published: February 2021

Story high buildings need to be designed against robustness (structural integrity). Robustness is fulfilled, if local failure does not lead to a comprehensive structural failure with serious consequence as result. Two main approaches are normally used in design: the ‘indirect design’ specifying minimum levels of tie forces, continuity and ductility of the structure or the ‘direct design’ to ensure a structure’s ability to absorb local damage and resist disproportionate failure. Newly developed innovative prefabricated solutions for story high buildings combining prefabricated aircrete components and steel structures will be presented, including both of the above mentioned design approaches. The design methods and the underlying theoretical approaches will be examined and evaluated. The benefits and disadvantages between different solutions will be evaluated. Further a case study of the prefabricated concrete modular building system developed will be presented.
The Mega Floating City Green Float—Part III: Verification by Experiments and Analysis
Authors: Hasebe Masanobu , Takeuchi Masaki , Ono Shuhei
Published: February 2021

According to the original plan of Green Float, a mega floating structure with a diameter of 2,000 m and supporting a 1,000-m-tall mega-tower is to be constructed on the equatorial ocean. For this paper, however, to perform basic verification of the technology, several hydraulic model experiments and numerical computations regarding wind waves and tsunamis were conducted for “Green Float II,” which is on roughly one-tenth the scale of the original Green Float and is intended to be built on shallow coastal waters. We confirm that the structure of Green Float II is sufficiently safe against winds and waves that have an expected return time of 200 years and also against the tsunami that would result from the largest earthquake scenario envisioned for the area.
The Mega Floating City Green Float—Part II: Construction Planning
Authors: Ono Shuhei , Takeuchi Masaki , Hasebe Masanobu
Published: February 2021

The mega floating city Green Float is a new conceptual model for an environmentally friendly island city and is being developed by Shimizu Corporation, Japan. The idea is to construct artificial islands on the ocean with the aim of achieving a self-efficient zero-carbon and zero-emission city. The aim of this project is to construct a mega floating structure comprising a 1,000-m-tall mega- tower and a floating base with a diameter of 2,000 m. Research is in progress to make Green Float a reality. In the first phase, construction planning and technical development were undertaken to realize the floating structure offshore. This paper reports on the construction planning and technologies devised in this project.
The Long Traffic Tunnels of Tomorrow
Authors: Pompeu-Santos Silvino
Published: February 2021

Two innovative and very cost-effective concepts for traffic tunnels using the TBM (“Tunnel Boring Machine”) technique are presented, the TMG concept for rail tunnels and the TMF concept for road tunnels. The reduction of the construction cost and the improvement of safety during operation with the application of these concepts in the construction of long tunnels are shown.
Combining Bored Tunnels: Optimal Construction Order of Multiple Independent Shield-Driven Tunnels
Authors: Backer Hans De , Outtier Amelie , De Pauw Bart , Schotte Ken , Naseem Ahsan
Published: February 2021

A three-tunnel configuration was proposed to strengthen the North-South connection in Brussels. The optimal construction order of the bored tunnels, mainly focusing on the settlements and deformations of the surrounding soil mass is investigated here. All two-tunnel and three-tunnel construction orders are investigated by mainly focusing on the surface settlements calculated with Plaxis 2D. An extended variant of the grout pressure method is developed to also incorporate the relative magnitude of the different settlement components due to shield tunneling. The accuracy of a simplified version is simultaneously tested by comparison of the obtained final settlement troughs. The influence of the constitutive model on the settlement values is also verified. More specifically, the difference in results between the Mohr-Coulomb model and the Hardened Strain model with small strain stiffness is investigated. Finally, a simple empirical superposition principle is established based on the method of Peck to approximate the Plaxis results. The research is based on the geometry of and other assumptions made for a new tunnel connection in Brussels but presents a general overall design concept. The results can thus be generalized to other multiple tunnel configurations.
Quantification of the Influence of Aerodynamic Model Assumptions for Dynamic Analyses of Bridges
Authors: Kavrakov Igor , Morgenthal Guido , Kareem Ahsan
Published: February 2021

Long-span bridges are sensitive to wind-induced forces. In this paper, we evaluate the influence of the assumptions in the semi-analytical aerodynamic models on the dynamic response of a bridge deck using comparison metrics. These metrics are constructed in such way to evaluate the differences in the signal properties of the time-dependent response. The signal properties include the time-varying frequency and magnitude content, phase and stationarity. The behavior of the metrics is first studied on illustrative examples. Finally, the metrics are used to quantify the discrepancies in the response of a streamlined deck, obtained by utilizing a numerical and two semi-analytical models. The results of the study provide deeper insight into bridge aerodynamics.
Wind Performance Analysis Method Based on a Simplified Model for Tall Buildings with Viscous Outrigger
Authors: Zhao Xin , Li Jiayue
Published: February 2021

With the increasing heights of super tall structures, modern super tall structures become more and more slender, which will cause the human comfort problem of structures to be assignable under wind loads. In result, it becomes more and more common for structural engineers to apply viscous damping systems. Outrigger dampers are efficient devices to provide additional damping for super tall structures. In order to meet the contribution to additional damping of outrigger damper system conveniently, a simplified model of structures with outrigger damper system based on Timoshenko beam is proposed, and the dynamic equilibrium equations of the simplified model are introduced. A design method for outrigger dampers based on the simplified model and the dynamic equilibrium equations is proposed. 729-meter real super tall structure project is employed to validate the simplified model and the design method.
Multi-Modal Flutter Analysis of a Long Floating Bridge
Authors: Svendsen Martin N. , Johannesen Stian Moe
Published: February 2021

This paper presents an assessment of the robustness of a 5200 m straight floating bridge towards aerodynamic instability (flutter). The assessment involves detailed studies of potential flutter mechanisms of the structure which show that critical aeroelastic vibration modes form as combinations of a relatively large number of still-air modes with limited similarity. As such, the aeroelastic behaviour of the long floating bridge is somewhat different from that of long span suspension bridges, where typically a few still-air modes with high similarity dominate the flutter mechanism. A flutter screening is performed with subsets of 50 still-air vibration modes at a time in varying frequency ranges. The screening is performed with realistic modal hydrodynamic damping ratios and it is shown that flutter does not occur for relevant wind speeds. This is primarily due to the presence of significant hydrodynamic damping in the eigenfrequency range of the critical modes.
Seismic Performance Evaluation of Fabricated Concrete Frame with Replaceable Energy Dissipation Connectors
Authors: Li Chunyu , Wu Jing , Xie Luqi
Published: February 2021

A new type of replaceable energy dissipation connectors (REDC) used to connect the beam and column in the fabricated RC frame is presented in this paper. The replaceable energy dissipation connectors are placed at the top and bottom of the beam ends. Through the use of REDCs as the designated energy-dissipation devices, the damage is controlled within the REDCs, which can be replaced easily after the earthquake. This will reduce the structural damage, repair cost, and repair time, which makes this structure more efficient and resilient toward future earthquakes. The seismic performance of the fabricated concrete frame with replaceable energy dissipation connectors(REDC-FCF) and the ordinary reinforced concrete frame (RCF) was contrasted by nonlinear static and dynamic analyses. The result indicates that the REDC-FRCF can be effectively applied in seismic resistance and could be used in high seismic zones.
New Adaptive Pendulum: Reduced Structural Acceleration, Base Shear, Displacement Capacity and Improved Rotation Capability
Authors: Weber Felix , Obholzer Florian , Huber Peter , Braun Christian , Meier Leopold , Hartinger Manfred , Distl Johann
Published: February 2021

A new type of an adaptive curved surface slider (CSS), referred to as SIP-Adaptive, is presented. Due to the articulated slider the relative motions on the two primary sliding surfaces are decoupled which enables to design primary sliding surfaces with different properties. One primary sliding surface is optimized for maximum structural isolation at shaking levels related to the Design Basis Earthquake (DBE) and one primary sliding surface is optimized for smaller but more frequently occurring earthquakes. For shaking levels due to the Maximum Credible Earthquake the design aims at increasing stiffness and friction to reduce displacement capacity. The SIP-Adaptive is characterized by steady-state force displacement curves at different amplitudes and assessed by dynamic simulation in terms of peak structural acceleration, maximum base shear, displacement capacity and re-centring error. The conventional double CSS, which is optimized for the DBE, is used as benchmark. The comparative study demonstrates that the SIP-Adaptive significantly reduces peak structural acceleration, that this achievement is obtained at reduced displacement capacity and base shear and that the re-centring condition is fulfilled. The experimental validation of the SIP-Adaptive confirms its envisaged dynamic behaviour.