bluuebunny/crossref_metadata_2025 huggingface dataset:
From a decrease of web thickness to a reinforcement optimization
Authors: Simon A. , Duclos T. , Lelonard R.
Published: February 2021

A New Coastal Road (NRL) almost completely situated at sea over a length of 12,5 km will allow the inhabitants of the Reunion Island, in the Indian Ocean, to connect quickly and in complete safety Saint-Denis, the capital city located in the East, with its commercial harbor situated about twenty kilometers further west, without interruption due to massive rock falls from the cliff on the 4 lanes current coast road.

Each span of variable depth of the 5,4km viaduct is 120 m long. The cross section is a mono- cellular box girder with two webs and post tensioned overhang. The 28m wide segments of decks were proposed with a web thickness reduction in regards to the tender layout. The alternative removed the transverse ribs, to simplify the segments prefabrication.

The decrease of the web thickness was a challenge for the JV in order to prove to the client that the reinforcement and prestressing will not increase consequently. Therefore, a detailed analysis using the variable strut inclination method and specific behaviour of a precast deck allowed to keep web reinforcement in current ratios.
Preservation of an Existing Original Building by Studying its Dynamic Properties
Authors: Makhoul Nisrine
Published: February 2021

A 100 years old historical building, constructed with an original local concrete material and structural typology, is investigated. This building typology is commonly and exclusively found in Tripoli City located on the North Lebanon coast. The city, as well as Lebanon region, is a highly prone earthquake region. Aiming to mitigate the risk encountered by this original building typology, a preliminary study of the dynamic properties of its structural system is proposed. The approach consists of using the ambient noise method to determine the structural frequency, damping, and other characteristics. Moreover, the horizontal to vertical ratio method, HVNR is used to identify the natural frequencies of the building and of the nearby soil. Then possible resonance occurrence during likely earthquakes is investigated by comparing the obtained results. In parallel, the Finite Element Model of the structure is studied, and the results of the fundamental frequencies are obtained. Results and comparisons of experimental and numerical investigations are presented and discussed. This short-term structural health monitoring study is an essential preliminary and helpful tool to understand the performance of the studied building typology, in order to be able to propose strengthening and preservation solutions.
Bridge Displacement Monitoring using Acceleration Measurement and Development of Efficient Bridge Management System
Authors: Umekawa Yutaro , Suganuma Hisatada
Published: February 2021

In this study, the concept of an efficient bridge management system focused on monitoring bridge displacements, was proposed for maintaining numerous bridges of municipal government in Japan. In order to monitor displacement easily, a displacement estimation method using measured acceleration data was proposed. The applicability of the proposed method, then, was verified through the field measurement using the prepared and weighed loading truck. The management system was proposed, and its application scenario using the developed system and measurement device, was also introduced for further actual operations in municipal government districts.
Highly Sensitive Damage Detection of Reinforced Concrete Bridge Slab by “Time-Variant Deconvolution” of SHF-Band Radar Signal
Authors: Yamaguchi Takahiro , Mizutani Tsukasa , Tarumi Minoru
Published: February 2021

In this paper, we focus on Ground Penetrating Radar (GPR) for the monitoring of reinforced concrete (RC) bridge slab. Though GPR method is non-contact and high-speed, damage detection accuracy depends on inspectors’ skill. Furthermore, the spatial resolution of the system is not enough considering the millimeter-order thickness of target cracks. In this paper, a new algorithm based on deconvolution with the attenuation effect of concrete, “time-variant deconvolution” is proposed, and the effect of the algorithm and frequency range on damage detection accuracy is discussed by real bridge slab model utilizing higher frequency (SHF-band) radar system. When the algorithm was applied to 1 mm horizontal crack above the rebar, only by time-variant deconvolution at SHF-band, dried crack was detectable by its positive-negative peak of the estimated distribution of reflection coefficient at appropriate depth and crack with water was detected by its clear negative peak.
Automatic Modal Operational Analysis of a Long-span Suspended Bridge using Pattern Recognition
Authors: Santos Joao , Crémona Christian , Silveira Paulo
Published: February 2021

The present paper addresses Structural Health Monitoring (SHM) of large bridges by presenting a strategy for automatic Operational Modal Analysis (OMA) based on Stochastic Subspace Identification (SSI) combined with the machine Clustering learning algorithm. Data acquired from a set of accelerometers installed on the 25 de Abril suspended Bridge, located in Lisbon, with over 1km central span, was used to test and validate the strategy. Natural mode information along with mode complexity and collinearity features were obtained and analysed for the purpose of automatic OMA, and allowed concluding that the combination of frequencies and mode shape components were the most effective. Additionally, it was concluded that both partitioning and hierarchical clustering associated with the SSI in its covariance version are effective in identifying natural modes and in distinguishing between these and spurious ones in a fully automated manner. It was also observed that imaginary and non-collinear mode shapes, such as those observed in the case study used, can be challenging to automatic OMA strategies, but were overcome by the strategy proposed herein.
An analytical Method for Evaluating the Fatigue Life of Perfobond Leisten Shear Connector Group under Cyclic Loading
Authors: Zhang Qinghua , Jia Donglin , Xiao Lin , Bu Yizhi , Li Qiao
Published: February 2021

This study presents an analytical method to analyse the effect of cyclic loading on Perfobond Leisten (PBL) shear connector groups. The explicit analytical method of fatigue damage in PBL shear connector group incorporating the plastic slip of single shear connector was derived based on PBL group nonlinear effective stiffness spring model. The fatigue life and internal force distribution of PBL shear connector group under cyclic loading can be calculated by a proposed step-by-step iteration procedure. Based on the analytical method, a reduction coefficient of fatigue life of PBL shear connector group was induced to consider the effect of uneven internal force distribution. And the reduction coefficients of different structural parameters under different fatigue load ratios and number of layers were studied systematically. The analytical results indicate that the fatigue life of PBL shear connector group is far less than that of single PBL shear connector. Under the conditions that certain structural parameters, only very little change of the reduction coefficients was observed between the fatigue load ratios 0.55 and 0.75, and it can be regarded as constants. As the layer number increasing, the internal force of the first layer increases and the fatigue life decrease correspondingly. It is necessary to explore the fatigue life of PBL shear connector group in engineering practice instead of only evaluating the fatigue life of single PBL shear connector.
Design and Construction of UHPFRC Deck for Replacement of Deteriorated Concrete Slab
Authors: Murakami Yojiro , Kosaka Takashi , Sato Akinori , Muragishi Seisuke , Saito Kimio , Kawabata Yasuo
Published: February 2021

Recent study discovered progressing internal cracks in retrofitted reinforced concrete (RC)decks and the difficulties to secure long-term durability of the structure, creating the need to replace the entire deck with more lightweight and durable materials. Thus, Hanshin Expressway has been developing the Ultra High Performance Fiber Reinforced Concrete (UHPFRC) decks and plans to conduct experimental replacement of old decks with new decks. In the meantime, to minimize a period of road closure necessary for replacement of decks, the company has been developing a hydrodemolition technique, a technique to remove concrete with high-pressure water. Experimental introduction is planned to remove the concrete that joins steel girders and decks, while the road is still in service. This paper reports the advantages of the UHPFRC decks and hydrodemolition technique in retrofitting old concrete decks of elevated roads.
Repair of an Orthotropic Slab with UHPFRC Slab: Bridge at Illzach in France, Return from Experience after 5 years
Authors: Généreux Grégory , Champenoy Damien , Perrin Thibaut , Fyon Sébastien , Simon Alain , Pouget Simon
Published: February 2021

Built in 1970, the Illzach Bridge located near Mulhouse in the East of France is a single 106 m span carrying a two traffic lanes with two lateral steel trusses and an orthotropic slab with transverse cross beams. After the detection in 2009 of numerous cracks in the deck welds, a repair solution, based on the replacement of the asphalt layer by a UHPFRC (Ultra High Performances Fibre reinforced Concrete) slab, with local connection to the orthotropic slab, was adopted. The reparation process called Orthodalle® was designed thanks to results of a research national project of 4 years called Orthoplus (2007-2011) and the works took place during summer 2011.

After introducing the bridge and its disorders, this paper presents the design and the works of this innovative repair solution. In the following parts, the paper describes the numerous monitoring and testing operations during the 5 years after the repair, calculations made for the bridge and gives the conclusions of this project.
Performance-Based Fire Engineering for Hazard Assessment of Tall Buildings
Authors: Ghisbain Pierre , Sideri Jenny , Imani Reza , Balsamo Luciana , Ashrafi Ali
Published: February 2021

Performance-based fire engineering (PBFE) is an efficient alternative to the conventional prescriptive design of fire protection. The method allows engineers to develop more cost-effective and resilient designs, whose performance is verified by simulating the response of the structure under various fire scenarios. Tall and supertall buildings can particularly benefit from a performance-based approach to fire protection, as the traditional prescriptive approach does not consider fire hazards and risks more specific to tall buildings.

This paper demonstrates the potential benefits of PBFE for tall buildings through the example of a generic 50-story mixed-use building whose structure combines steel and concrete. Computational fluid dynamics (CFD) analyses are performed with the Fire Dynamic Simulator (FDS) software to simulate the initiation and development of several fire scenarios in typical office and mechanical floors. For each scenario, heat transfer and structural response analyses are then performed on a finite element model of the structure. The scope and complexity of the structural analysis varies from individual members to a large segment of the entire structural system depending on the fire scenario. Particular care is given to the analysis of the steel trusses of a transfer level, as failure or excessive deformation of these trusses could severely damage multiple floors of the building. This demonstrates the flexibility of PBFE and its ability to focus on the fire risk posed by the specific configuration of each building structure.
Chirajara Bridge Collapse
Authors: Georgakis Christos T. , Fujino Yozo , Hopf Siegfried , Müller Michael , Subirá Francisco , Ostenfeld Klaus H. , Svensson S. Eilif , Hindhede Lasse , Krogstrup Martin J. , Rumpelt Thomas
Published: February 2021

On January 15, 2018 at 11:49, the west pylon (B) of the cable-stayed Chirajara Bridge collapsed during construction of the bridge girder. The crossing is located approximately 20km NW of Villavicencio, Colombia. The collapse led to the total destruction of Pylon B, together with the erected span of the bridge girder. Authorities reported nine fatalities resulting from the collapse. Shortly thereafter, the project insurer QBE Segures, Colombia commissioned an independent investigation into the collapse of the bridge, through loss adjusters ONC Adjusters, Bogotá, Colombia. An international team of engineering experts was assembled to undertake the investigation. The investigation was completed in August, 2018. Key findings and recommendations from the investigation are presented herewith.
Machine Learning-based Structural Health Monitoring and Condition Assessment for Long-span Bridges
Authors: Xu Yang , Laima Shujin , Li Hui , Li Na , Jin Yao , Han Feiyang
Published: February 2021

Machine learning (ML) provides a promising paradigm for discovering and modeling structural performances and conditions through the deep mining of structural health monitoring data. This paper exhibits recent progress of ML-based structural health monitoring and condition assessment for long-span bridges. A series of novel algorithms for bridge condition assessment via correlation modeling between structural responses, computer vision-assisted structural damage detection, and data mining for wind effects are introduced. First, correlation modeling between different bridge responses is investigated by both the time series data and probability distribution, further assisting bridge condition assessment. Second, several novel CNN architectures and a few-shot meta-learning framework are also established for CV-assisted bridge damage detection. Third, wind-induced vibrations of the bridge in site are identified and modeled to predicate structural responses and evaluate operation conditions. Results show that ML techniques indeed improve the state of the art in structural health monitoring and condition assessment for long-span bridges.
Unsupervised Deep Neural Network for Near-real-time Damage Identification of Structures Subject to Earthquake Excitations
Authors: Kim Minkyu , Song Junho
Published: February 2021

This paper presents a Deep Neural Network (DNN) framework for near-real-time damage identifi- cation using structural response data from an earthquake event. The proposed network is con- structed by Variational Autoencoder (VAE), which is a self-supervised DNN that can learn probabil- istic characteristics of the latent variables. The network is trained using the flexibility matrix of the target structure at a healthy state obtained by Operational Modal Analysis (OMA) using structural responses. Earthquake-induced damage is located and quantified by using the flexibility disassem- bly-based method in near-real-time. As a numerical example, structural analysis is performed for a 5-story, 5-bay steel frame structure under 20,000 artificial ground motions, which are pre-assigned to train and test datasets in the ratio of 9:1. After training the network, the near-real-time damage identification is performed for each of the simulated damage conditions using real ground motions.
Response variations of a cable-stayed bridge under SVEGM
Authors: Ahmed Waqas Hafiz , Su Di , Nagayama Tomonori
Published: February 2021

Spatially variable earthquake ground motions yield the different structural demands compared to the conventional synchronous ground motions. In this paper, a cable-stayed bridge under on-site recorded spatially variable earthquake ground motions is analyzed and phenomena of response amplification based on in-situ monitoring are investigated. A calibrated numerical model of target bridge is prepared and both multi support excitation and synchronous excitation analyses are performed. The modal amplitudes of different structural components corresponding to different vibration modes are compared. The comparative analysis clarified the variation of overall response and localized amplification of engineering demands. MSE method at design phase should be considered to disclose the critical scenarios which are hard to identify by conventional design approaches.
Practice and research of structural health monitoring in high speed railway station
Authors: Liu Chuanping , Jia Jian
Published: February 2021

In recent years, with the rapid construction and development of China's high-speed railway, a large number of railway stations with large-scale and novel structures have been built. The structures of these stations generally have the following characteristics: large-span, large cantilever space structure; directly bearing dynamic load of high-speed train; long unit structure in size; complex node connection, etc. To follow up the structural safety state of the railway stations in time and control the risk of structures in operation, structural health monitoring systems are applied to high-speed railway stations. This paper introduces the implementation of structural health monitoring in Ningbo railway station, as well as analyses of the monitoring data. The research shows that the health monitoring system can directly obtain static and dynamic responses of structure, and can display its stress state and other structural performance timely, which is very important to secure operation of the station. The health monitoring system can reliably acquire information of structural state variation during and after typhoon, earthquake or other disasters, which has both important practical and scientific meanings in assessing the performances and determining repair schemes of structures after hazards.
Analysis of the Influence of Thermal Environment on Structural Parameters for Bridge Health Monitoring
Authors: Ota Koharu , Yoshida Junji , Takeya Kouichi
Published: February 2021

Damping is affected by changes in the energy distribution of the structural system and can be considered as an indicator of structural deterioration. However, the temperature environment around the bridge also affects the change in damping ratio. In this study, the influences of temperature were analysed by calculating the structural parameters, from acceleration responses of a road bridge by the Natural Excitation Technique and Eigen-system Realization Algorithm method (NExT-ERA method). A solar-powered monitoring system using MEMS-type accelerometers was constructed and installed on a steel girder bridge. The structural parameters were calculated by the NExT-ERA method. Finally, the temperature influence on the structural parameters is evaluated by using the weighted average, based on the observed data.
Monitoring of Cylindrical Rod Tension Force under Varying Temperature using Acoustoelastic Effect
Authors: Kwon Ohjun , Sohn Hoon , Lim Hyung Jin
Published: February 2021

This paper presents the development of a tension force monitoring technique based on bulk wave and acoustoelastic effect for a cylindrical rod in the suspension bridge anchor system under varying temperature. First, a cylindrical rod specimen is fabricated, and macro fiber composites transducers are installed on the specimen. Then, the bulk waves are measured under various tension force levels and temperature conditions. The measured bulk waves are used to estimate the tension force level after compensating the temperature effect. The performance of the developed technique is examined using test data. The uniqueness of the developed technique includes (1) tension force estimation of the mock-up specimen of the real bridge using the acoustoelastic effect and (2) temperature compensation on the tension force monitoring without temperature measurement.
Seismic Analysis of Connection Joint of Earthquake Resilient Coupled Shear Wall to Floor Slab
Authors: Cong Chen , Xianmin Wen
Published: February 2021

Traditional structures could not meet the new demand of structural sustainable earthquake resistance, whereas earthquake resilient structure is an effective way to meet this demand. The research of earthquake resilient coupled shear wall is an important part of earthquake resilient structure research, whose earthquake resilient capacity is acquired by the replaceable coupling beam nowadays. The particularity of this kind of earthquake resilient coupled shear wall makes its connection to other structural component a special setup, and with the traditional solid joint of the shear wall and floor slab, the deformation of the replaceable device would be constrained as well as the damage would be occurred in slab. Based on the previous research, this paper proposes a special connection joint between the earthquake resilient coupled shear wall and the floor slab, and its seismic performance will be studied in depth. The load-carrying mechanism will be determined; the seismic performance of the connection device and the connection joint with different design parameters will be observed. The seismic design target of non-constraint replaceable device’s deformation and non-damaged slab will be realized, and the damage control capacity and the quick recovery ability of the shear wall structure will be actually achieved.
Track irregularity and mechanical characteristics analysis of CRTS I ballastless track under subgrade frost heaving
Authors: Cheng Ruiqi , Yan Bin , Xie Haoran
Published: February 2021

Harbin-Dalian high-speed railway is located in the northeast of China, part of which belongs to seasonal frozen area. In seasonal frozen area, the seasonal frost heaving and thaw settlement of subgrade will lead to local uneven subgrade frost heaving deformation, which will cause overarching deformation of track structure, even cause structural damage and track irregularity, and affect train safety directly. On the basis of full site investigation, taking CRTS I ballastless track in frost heaving area of Harbin-Dalian high-speed railway as research object, the spatial finite element model considering the interlayer contact characteristics was established using ANSYS finite element software. The transfer properties of track irregularity, interlayer separation characteristics and mechanical characteristics under frost heaving condition were analyzed. It provides an important reference for the design of ballastless track in cold and seasonal frozen area.
FEM-MBS Scheme for Ride Comfort Analysis of Vehicle-Bridge Interaction
Authors: Hu Qi , Su Di
Published: February 2021

This study presents a combined method that integrates the FEM (Finite Element Method) and MBS (Multiple Body Simulation) to analyze the ride comfort in the Vehicle-Bridge (VB) interaction system. To solve the vehicles’ responses accurately and efficiently, in this study a new double- dummy coupling method is used to simulate the VB Interaction. Furthermore, other influence factors like tire model, wind force, and road roughness influences are taken into account together. After validating by measurement data, vehicular ride comfort condition is evaluated by the ISO 2631-1 standard, including obtaining the whole-body vibration response, frequency weighting the initial response, and determining the Overall Vibration Total Value (OVTV). This model can also be used for stability and safety analysis of vehicles running on bridges under the strong wind in the future.
Probabilistic Evaluation of Vehicle Stability under Strong Winds on Bridges
Authors: Kim Se-Jin , Kim Ho-Kyung
Published: February 2021

Vehicles running on sea-crossing bridges are often threatened by strong side winds, which can cause loss of steering control or vehicle rollover. In order to protect vehicles from wind hazards, appropriate countermeasures such as traffic restriction or construction of wind barriers are required based on an accurate evaluation method. In this study, a new evaluation method of vehicle stability was introduced which considers two important factors, the shape of bridge girder and vehicle dynamics. In order to consider the effect of the girder shape, wind tunnel test was performed to measure the aerodynamic coefficients of vehicles using scaled bridge and vehicle models. Using the measured coefficients, critical wind speed curves of vehicles were estimated through quasi-static vehicle analysis for all traffic lanes. Then, the number of frequency exceeding critical wind speed per year, which is the vulnerability index, was calculated by performing probabilistic assessment. Long-term wind data was utilized to obtain probabilistic distributions of wind speed for 16 wind directions, then the vulnerability index was calculated for all road sections. As a case study, one of the sea-crossing bridges in Korea, was assessed using the introduced method, and countermeasures to mitigate vulnerability level were also discussed through a parameter study.
Aerodynamic Optimization for the Flutter Performance of the Yang-Si- Gang Yangtze River Bridge with a Double-Deck Truss Girder
Authors: Li Ming , Li Mingshui , Sun Yanguo
Published: February 2021

In this paper, the flutter performance of the Yang-Si-Gang Yangtze River Bridge in China with a main span of 1700 m and a double-deck truss girder was studied via a large number of section model wind tunnel tests. The results show that the soft flutter characterized by no evident wind speed divergence point and a quasi-harmonic single-degree-of-freedom torsional vibration was observed for the double-deck truss girder. The bridge might suffer the risk of sustained vibration at relatively low wind speeds. The upper central stabilizer installed on the upper deck, the lower stabilizer installed on the lower deck and the flaps installed beside the bottoms of the sidewalks can all effectively increase the critical flutter wind speed. The combinations of effective measures can achieve better flutter mitigation effects. The optimal aerodynamic scheme is determined as the truss girder with widening the upper carriers and sidewalks and combining the lower stabilizers with the inspection vehicle rail below the lower deck. In addition, it was also found that the torsional response can be alleviated substantially by increasing the structural torsional damping ratio, indicating that the dampers may be efficient in controlling soft flutter characterized by single-degree-of-freedom torsional vibration. This study aims to provide a useful reference and guidance for the flutter design optimization of long-span bridges with double-deck truss girders.
Data-driven modeling of modal parameters of long-span bridges under environmental and operational variation
Authors: Kim Sunjoong , Spencer Billie F. (Jr) , Kim Ho-Kyung , Kim Se-Jin , Hwang Doyun
Published: February 2021

This study develops the multivariate model of modal parameters under the high variability of structural responses and environmental conditions. The automated operational modal analysis procedure is implemented by synthesizing the algorithms of output-only system identification and density-based clustering algorithm. The Gaussian Process Regression is applied to accumulated modal estimates as well as corresponding environmental/operational conditions for examining the high degree of nonlinear variation in these monitoring data. The performance of the developed model is demonstrated for one-to-one regressions for multivariate structural health monitoring outputs in the presence of environmental and operational variation.
Risk management for bridges: a case study of unforeseen failure mode
Authors: Pucci Alessandro , Sousa Hélder S. , Matos José C. , Puppio Mario Lucio , Giresini Linda , Sassu Mauro
Published: February 2021

Risk management plays a crucial role in the stakeholders’ decision making because it is directly related to safety, serviceability and economy. There is now a growing concern about how to relocate known risks into an acceptance threshold: this implies the evaluation of several options obtained from hazard scenarios considering the related consequences. In parallel, practitioners usually rely on standard tools for risk assessment, and on structural codes to compute performances. Although this approach is currently widely implemented, this research shows that hazardous situations can arise in properly designed infrastructures, due to errors in management. This paper deals with such issue, also highlighting a gap in current codes that could contribute to losses caused by unforeseen failure modes. In this study, a preliminary FMEA assessment was performed to identify the failure modes that required a deeper quantitative analysis. In a second step, a quantitative analysis was implemented, using a modular methodology that combines reliability theory with a risk-based approach. The results evidenced that a wider analysis focused on the identification of vulnerable areas shall be considered in every stage of the asset management. Furthermore, the dynamic of this process is regulated by the established safety level concerning possible damages to people, production sites and commercial activities.
Heat-dependent electrical characteristics of CNT-based hybrid cementitious composites: Literature review
Authors: Farooq Shah Zaib , Kil T. G. , Lee Haeng Ki
Published: February 2021

In recent years, many researchers have worked on the development of cementitious composites as self-heating components. To meet the requirements of self-heating composites, carbon-based nanomaterials have been considered as an electrically conductive filler in the cementitious matrix because of their excellent electrical and thermal characteristics. Most researches have focused on the heating performances of the CNT-incorporated hybrid cementitious composites, while fewer efforts were given to observe heat-dependent electrical characteristics of the modified cementitious composites under self-heating condition. In this regard, this paper summarizes recent studies in literature conducted to investigate heat-dependent electrical characteristics of cementitious composites with carbon-based nanomaterials.
Study on Prevention and Safety Countermeasures of Bridge Risk Accidents
Authors: Lei Jun-Qing , Wang Wu-Qin
Published: February 2021

We do research and classification the current situation of bridge risk accidents at home and abroad, which are mainly caused by natural factors, including natural disasters such as earthquake, flood, debris flow, typhoon and other natural disasters; and human factors, Including design factors, construction factors, operation management factors, overload factors, collision factors (ship collision and vehicle collision) and other factors for the damage of the bridge; aiming at the typical case analysis of collapse risk of multiple bridges. There are summarizes the experience and lessons of bridge risk accidents, puts forward safety countermeasures and methods to prevent risks, emphasizes the importance of bridge life cycle design, construction and maintenance management to prevent risks, and puts forward useful safety measures and suggestions.
Structural characteristics and ultimate strength of branched tied-arch bridge with hanger ropes
Authors: Miyachi Kazuhiro , Nakamura Shunichi
Published: February 2021

A steel tied-arch bridge collapsed due to hanger rope breakage in 2019. This study was focused on steel tied-arch bridges with hanger ropes and branched arch ribs and examined the structural characteristics and the ultimate strength. The branched tide-arch bridge has sufficient ultimate strength, but the branched structure become a weak point because the branched arch ribs become a plastic hinge and reaches the final state. In addition, it was clarified that the structure of fixing the hanger away from the branched part is the main factor that widens the hanger spacing at the ends and reduces the yield strength of the arch rib.
Digital Simulation and Evaluation of Cold Reinforcement using UHPFRC for Distortion-induced Fatigue in Steel Bridges
Authors: Wang Chunsheng , Wang Peng , Wang Yuzhu
Published: February 2021

With the increase of traffic volume and vehicle load, more and more steel bridges are prone to suffer the fatigue problems. Fatigue cracks seriously affect the safety and service life of steel bridges, probably leading to structural failure. In this paper, digital fatigue test was conducted to investigate cold reinforcement method of casting UHPFRC at horizontal gusset plate web gaps in steel bridges. Digital tests were built based on fracture mechanics theory and extended finite element method (XFEM), combining with the full-scale physical fatigue tests data. Parametric analysis was carried out on the dimensions of strengthening elements, so as to determine the optimum reinforcement plan. In addition, the effectiveness of cold strengthening technique was evaluated by comparing the stress intensity factors, and the out-of-plane distortion as well as the fatigue stress of web gap details before and after reinforcement.
Hazard Mitigation Measures for a Cable-stayed Bridge
Authors: Gil Heungbae , Han Kyoungbong
Published: February 2021

Long span cable supported bridges are important transport infrastructure and exposed to number of different hazards such as fire, strong wind, and earthquake. In 2015, a cable-stayed bridge in Korea, Seohae Bridge, experienced uncommon cable fire due to a lightning strike. A fire caused full and partial failure of three stay cables. The Seohae Bridge was closed to traffic for 15 days and repaired by replacing three damaged cables. After reopening, the extensive retrofit works were carried out to prevent and mitigate damages from fire and lightning. A fire hydrant system and a lightning protection system were newly installed on the Bridge. The Korean Highway Bridge Design Code (Limit State Design Method) for Cable-supported Bridges introduced the performance-based design provisions for seismic design in 2016. Three seismic performance level, operational, Long- term repairable, and collapse prevention, was defined and corresponding return periods. The seismic performance of the Bridge, which was designed using force-based method, was recently verified using a detailed non-linear analysis considering material and geometric nonlinearity according to the displacement-based seismic design concept. The results showed that the bridge can satisfy the required seismic performance levels and safety using progressive increment analysis, under the earthquake with very low frequencies of occurrence.
Condition Assessment, Monitoring and Preservation of Some Iconic Concrete Structures of the 20th Century
Authors: Ceravolo R.
Published: February 2021

Great architects and structural engineers such as Berg (1870-1947), Maillart (1872-1940), Freyssinet (1879- 1962), Torroja (1899 -1961), Nervi (1891-1979), Candela (1910-1997), Isler (1926-2009) and many others have designed recognized works of art in their discipline. They conceived extraordinary concrete spatial structures, that are located mostly in Europe and represent a unique legacy. It is important to raise awareness of this heritage, define the criteria for preserving it and begin the process of its renovation and rehabilitation.

While concrete has become a 20th century emblem, much of the world’s heritage from this period is unrecognized or undervalued, and therefore it is at risk and in need of analysis and protection. Innovative technologies and solutions are needed that contribute to the successful reuse of modern concrete built heritage. Indeed, such structures are plagued by significant deterioration and most of them are in urgent need of retrofitting and/or radical refurbishment. In other words, there is a need to bring some of these buildings back to life, while respecting the spirit of their original characters, through new technologies for long-term conservation that can maintain an adequate level of structural performance. Achieving this goal would produce substantial economic impacts through activities such as restoration, maintenance, and cultural industry.

The keynote lecture, more specifically, focuses on the condition assessment, monitoring and preservation of 20th century architectural heritage characterized by a complex spatial structural design. The service life of civil and cultural heritage concrete spatial structures is typically thought to range from 10 to 200 years, but in practice the service environment plays a pivotal role in sustained durability. Indeed, the collapse of Polcevera Viaduct in Genoa has raised strong concerns on the durability of concrete structures conceived at that time. The scientific community has once again underlined the important role played by maintenance and continuous structural health monitoring in avoiding these disastrous events. In order to demonstrate a correct approach to condition monitoring of concrete spatial buildings and bridges, some important experiences are described that were recently obtained at the Polytechnic of Turin on the structural analysis, seismic vulnerability and condition assessment for iconic 20th century heritage buildings.
Challenge for Next Generation of Concrete Bridges, Non-Metallic Bridge with Zero Cement Concrete
Authors: Kasuga Akio
Published: February 2021

Concrete engineers and researchers have been developed durable reinforce concrete technologies for long time. However, we have not reached the goal which gives us a perfect technology against deterioration of reinforced concrete. Basically concrete itself is high durable material. And we recognize this fact when we see Roman concrete structures are still working now. The technologies described in this paper are the challenge to derive the solution against deterioration of reinforced concrete. This research and development has been taking for about 30 years. Then a non-metallic highway bridge is under design and will be built in 2020 with the key technologies of aramid fiber tendons, fiber reinforced concrete and butterfly web.
Bridges in the World Heritage List between Culture and Technical Development
Authors: Siviero E. , Martini V.
Published: February 2021

The aim of this paper is to present some bridges inscribed in the UNESCO World Heritage List and their Outstanding Universal Values, which explain the importance of these works of art in terms of engineering, technology, culture and technical development. The Iron Bridge, the first metal bridge in the history of construction, is of considerable importance, not only in historic, technological and constructive terms: here, architecture and engineering are revealed to the full, making the bridge into a place. The Forth Bridge is a globally-important triumph of engineering, representing the pinnacle of 19th century bridge construction and is without doubt the world’s greatest trussed bridge. The Vizcaya Bridge, completed in 1893, was the first bridge in the world to carry people and traffic on a high suspended gondola and was used as a model for many similar bridges in Europe, Africa and America, only a few of which survive. The Mostar Bridge is an exceptional and universal symbol of coexistence of communities from diverse cultural, ethnic and religious backgrounds. The Oporto bridges, interpreted in Vitruvian terms, represent a heritage, a “set of spiritual, cultural, social or material values that belong, through inheritance or tradition, to a group of people…”, a complex grouping that marks and symbolises an era, the Eiffel's masterpiece. Because the bridge is not only a work of art, but also a thought.
Towards Sustainable Timber Construction Through the Application of Wood-Wood Connections
Authors: Weinand Y.
Published: February 2021

This paper introduces a series of sustainable timber construction using wood-wood connections, which are driven from environmental requirements. These constructions are based on geometries like origami and free-form instead of standard structural elements. In addition, to predict the structural behaviour, the simplified numerical methods for accurately modelling are used. The aim of these case studies is to better explore the value of wood-wood connections as inheritance of ancient culture and extend research on their integration into design processes. Through the design, manufacturing and assembly stage, the connections are investigated as a driver for architectural forms. The utilisation of these innovative connections with minimised metal connectors ensures the rapid, precise and simple assembly process. With in-depth study and innovation of the ancient wood-wood connections, experience in prefabricated timber structure not only offers new geometrical opportunities, but also expands the understanding of integration of ancient and modern cultures.
Stefan Bryła – Polish Creator of the First Welded Road Bridges
Authors: Biliszczuk J. , Hołowaty J. , Rabiega J.
Published: February 2021

The first two welded road bridges in Poland were designed by Stefan Bryła, Professor at the technological universities in Lwów and later in Warsaw. The bridges became operational in 1929 and 1931, respectively. The first bridge is of a truss structure and is the first welded structure of this type in Europe, and indeed the world’s first road welded truss bridge. It became a listed monument in 1968. It was in service up to 1977, when it was relocated due to insufficient horizontal clearance. The second bridge is of a plate girder structure and it is still operational. The two welded road bridges are located over the Słudwia river near Łowicz, central Poland. In 2019, ninety years have passed since the first welded bridge in Poland became operational, while December 2018 saw the 75th anniversary of Professor Stefan Bryła’s tragic death. To mark these occasions, this paper briefly presents the Professor’s design and structural work, and discusses the stories of the first two welded bridges in Poland.
Unusual Composition and Load-Carrying Capacity of a 100-Year Old Early Age Steel Exposition Hall
Authors: Bogaert V.
Published: February 2021

The Floraliahall in Ghent was built during 1912-1913 as part of a series of large infrastructure works for the
world exposition of 1913. The main structure of the hall consists of 18 portal frames having 3 spans of 10.16,
40.18 and 10.16 m. The upper part of the structure is highly slender. Adversely to the customary concepts of
100 years ago, the lighter frames at 7.45 m distance, are hinged twice at the springs, whereas the more heavy
frames, at 15 m distance, are completely clamped at their base. In addition, measurements show that crosssections
of compressed parts have larger area than the tensile parts. From the structural point of view, these
frames sometimes have an unexpected composition. The aim was to determine whether this structure can
comply with contemporary requirements and codes. From measurements and simulations follows that in
limited areas high stresses appear, unacceptable even in serviceability state. This may be partly due to
modifications of the roof that were made inappropriately, from the uncertainty to assess certain details with
the model and from ineffective analysis at the time of construction.
Anchorage Capacity and Performance in Plain and Steel-Fibre-Reinforced Concrete
Authors: Nilforoush R. , Pia G. , Nilsson M. , Elfgren L.
Published: February 2021

Nowadays, prefabricated concrete components made from Steel-Fiber-Reinforced Concrete (SFRC) are widely used in the construction industry. These components are often connected to existing or new structural elements through various fastening systems. Previous studies have shown that the addition of steel fibers to concrete mixture substantially improves the fracture properties of concrete. To date, however, rather limited research is available on the behavior of fastening systems in SFRC. To improve the current knowledge of fastening systems to SFRC structures, a pilot experimental study is carried out on cast-in-place anchor bolts embedded in Plain Concrete (PC) and SFRC members. In this study, the influence of the presence of steel fibers and concrete compressive strength on the anchorage capacity and performance is evaluated. Furthermore, the applicability of current design methods is evaluated for anchorage systems in SFRC.
WEARABLE REAL TIME HEALTH TRACKERS AND ASSISTED-MOBILITY FOR NON-AMBULANT PATIENTS
Authors: Shree Vidya , Sharanabasappa
Published: February 2021

This paper presents an approach to facilitate mobility for the non-ambulant patients using eye movements and wearable health tracking. The patient’s wheelchair movement is controlled using eye ball movements and also some biomedical assistance functionalities are considered to match the current day needs. The proposed work first detects face from input video, then eye portion will be localized, and finally eye ball (pupil) is detected and tracked using computer vision techniques. The direction of movement is assessed and a command is disseminated to the wheelchair control system. The wearable sensors and\or alarms mounted on patients will update current health status indications on to the monitoring panels. The wearable devices have evolved very smartly which are capable enough to take care of the patient health in real time even during assisted mobility.
SURVEY ON SIGNATURE BASED INTRUCTION DETECTION SYSTEM USING MULTITHREADING
Authors: Roka Sanjay , Naik Santosh
Published: February 2021

The traditional way of protecting networks with firewalls and encryption software is no longer sufficient and effective. Many intrusion detection techniques have been developed on fixed wired networks but have been turned to be inapplicable in this new environment. We need to search for new architecture and mechanisms to protect computer networks. Signature-based Intrusion Detection System matches network packets against a pre-configured set of intrusion signatures. Current implementations of IDS employ only a single thread of execution and as a consequence benefit very little from multi-processor hardware platforms. A multi-threaded technique would allow more efficient and scalable exploitation of these multi-processor machines.
A SURVEY FOR ENERGY EFFICIENCY IN CLOUD DATA CENTERS
Authors: Paneru Dinesh Raj , B. R. Madhu , Naik Santosh
Published: February 2021

Services such as Platform as a Service (PaaS), Infrastructure as a Service (IaaS) and Software as a Service (SaaS) are provided by Cloud Computing. Subscription based computing resources and storage is offered in cloud. Cloud Computing is boosted by Virtualization technology. To move running applications or VMs starting with one physical machine then onto the next, while the customer is associated is named as Live VM migration. VM migration is empowered by means of Virtualization innovation to adjust stack in the server farms.

Movement is done fundamentally to deal with the assets progressively. Server Consolidation’s main goal is to expel the issue of server sprawl. It tries to pack VMs from daintily stacked host on to fewer machines to satisfy assets needs. On other hand Load balancing helps in distributing workloads across multiple computing resources. Also in the presence of low loaded machines it avoids machines from getting overloaded and maintains efficiency. To balance the load across the systems in various cases, live migration technique is used with the application of various algorithms. The movement of virtual machines from completely stacked physical machines to low stacked physical machines is the instrument to adjust the entire framework stack. When we are worried about the energy consumption in Cloud Computing, VM consolidation & Server Consolidation comes into scenario in Virtual Machine movement method which itself implies that there is low energy consumption.