bluuebunny/crossref_metadata_2025 huggingface dataset:
Chacao Bridge Foundations
Authors: Pich Benedicte , Cousteix Emilie , Kata'a Habib , Muls Mathieu , Cheikh-Mahmed Aymen , Jakobsen Svein Erik
Published: February 2021

The 2750m-long Chacao Bridge will connect mainland Chile with island Chiloe. The three-tower suspension bridge will have two main spans over 1km length. Due to exceptionally high seismic forces, the foundations of this megastructure have been a challenge to design.

Central and North Pylons are founded in Chacao channel respectively by four and two groups of nine piles. The piles are made of a reinforced concrete part surrounded by a structural steel casing. The steel casing is embedded into the seabed level by 10m at least and into the pilecap by more than one pile diameter. The casing embedment length ensures the transfer of the steel casing internal forces into the pilecap. This transfer is made by three coexisting mechanisms: a direct transfer at casing top level through the continuity of the reinforced concrete, through a pressure/contra-pressure mechanism and through shear connectors welded on the steel casing.
Causes of Resonance in PPC Girder when Shinkansen Passing and External Cable Reinforcement
Authors: Chikami Keishi , Sugita Kiyotaka , Tsukishima Daisuke
Published: February 2021

Some “Partially Prestressed Concrete (PPC)” girders resonated and had large amplitude vibration during high-Speed train, so called “Shinkansen”, passing in the specific velocity. And many flexural cracks occurred frequently in resonance PPC girders. It was found that the effective cross section and the rigidity decreased by flexural cracks opening during Shinkansen passing. Next, although PPC girders were designed with the same standard design, only some PPC girders resonated. We investigated the individual differences and the load situation of train. It was found that the cause related to the occurrence of resonance was more influential to the load situation of train than the individual differences. Finally, we examined the effective countermeasure to stop resonating. By repeated loading experiment, it was found that the external cable reinforcement was the effective countermeasure.
Multi-setup Operational Modal Testing of a Multi-span Viaduct
Authors: Zhang Jie , Maes Kristof , De Roeck Guido , Lombaert Geert
Published: February 2021

Multi-setup operational modal testing has been performed on a multi-span viaduct in Bruges, Belgium. The viaduct consists of two curved integral bridges with a length of about 800 m in parallel with each other. Each bridge has 23 spans and consists of nearly periodic parts. During the measurement, a number of reference sensors is kept fixed, while the other so-called roving sensors are moved in different setups. Modal identification is first carried out for each setup separately. Next, the identified modal data of different setups are merged. It is observed from the stabilization diagrams that the modes are very closely spaced, resulting in a very high modal density, even under 2 Hz. This results in challenges in the modal identification. First, a high model order needs to be considered, leading to a high computational cost. Second, it is difficult to match the partial mode shapes obtained from different setups, due to the closely spaced natural frequencies. This problem is resolved by comparing both the natural frequencies and the mode shapes at the reference locations in the mode matching.
Finite Element Modeling and Verification of a Retrofitted Member of a Long-span Truss Bridge by Employing Stochastic System Identification
Authors: Tashiro Daiki , Nishikawa Takafumi , Nakamura Shozo , Shimizu Makoto
Published: February 2021

This paper presents a method for finite element modeling and its application for a retrofitted member of a long-span truss bridge. A critical fatigue crack occurred and propagated at the bottom of a diagonal member of the bridge due to wind-induced vibrations. In such the case, finite element analysis with a precise structural model is effective for simulating dynamic structural behavior such as changes of stress condition to consider countermeasures. In this study, a model of the retrofitted truss member is refined by model updating method based on the actual dynamic characteristics of the member such as the natural frequencies, mode shapes and modal damping ratios estimated by stochastic system identifications. Model updating consists of FE analysis with a commercial FE analysis tool and optimization analysis with a numerical computing tool. Model parameters such as sectional specifications of the original member, boundary condition and material properties are automatically modified under optimization analysis by minimizing an objective function. The objective function is formulated as a combination of fitness on dynamic characteristics obtained by measurements and analysis. Established FE model was validated by comparing strains collected by measurement and analysis.
Statistical Vibration-based Damage Localization on Saint-Nazaire Bridge Mock-up
Authors: Hossain Bhuyan Md Delwar , Lecieux Yann , Thomas Jean-Christophe , Lupi Cyril , Schoefs Franck , Döhler Michael , Mevel Laurent
Published: February 2021

The characterization of damages from output-only vibration measurements is an important issue for Structural Health Monitoring (SHM), in particular for bridges under ambient excitation. In the last years, a multitude of methods has been proposed for vibration-baseddamage detection, lo- calizationandquantification. In this work, a benchmark application for such methods is proposed, namely a 1/200 scale model of the Saint-Nazaire Bridge, which is a cable-stayed bridge spanning the Loire River near the river's mouth. The region of interest, the central metallic structure, measures 720 meters. The aim of the instrumentation is to assess the capability of damage as- sessment methods to assess a cable failure. The model is instrumented with ten accelerometers and excited by white noise. A damage localization method is applied to test the proposed setup, namely the statistical damage locating vector approach (S-SDDLV). With this method, vibration measurements from the (healthy) reference and damaged states of the structure are confronted to a finite element of the reference state. Damage indicators are provided for the different struc- tural elements that are easy to compute, without updating the model parameters, and taking into account the intrinsic uncertainty of noisy measurements.
Evaluation regarding Fatigue for Various Types of Hangers used for Tied Arch Bridges
Authors: Berthellemy Jacques
Published: February 2021

The roads represent an important heritage. Even more than corrosion, the fatigue is the principal aging process that affects the durability of steel bridges. Several examples illustrate in the article the importance of affecting a right consideration to the fatigue design of bridges.

Details that may appear as accessory to most of the usual bridge designers may be in fact of a crucial importance. It is in particular the case of the welded joints. The fillet joints are much more sensible to the fatigue stresses and should be avoided when there is a doubt, because their evaluation is very complicated. If the designer of a bridge uses such attachment in the project for tender, he has to verify the relevance regarding fatigue because the time for such studies is generally not available during the execution studies.

Calculation FEM techniques are used to evaluate the stress modified by the concentration factor that has to be taken into account for the fatigue design. For bridges, many fatigue details are classified in the Eurocode 3 ( part 9 ) from tests. But some details that cannot be found in the Eurocode, and must however be studied and evaluated by computation. The article presents an example where the fatigue class of the detail regarding longitudinal stresses is evaluated thanks to a FE-modelization according to the 2008 IIW Fatigue Recommendations at the location of the attachment of different types of hangers.
Fatigue Performance of Rib-to-deck Joint in Orthotropic Steel Bridge Deck with New Type of Both-Side Fillet Welded Joints
Authors: Zhang Qinghua , Li Jun , Yuan Daoyun , Bu Yizhi , Xu Gongyi
Published: February 2021

The key fatigue failure modes of rib-to-deck welded joints in orthotropic steel bridge deck (OSD) are fatigue cracks that initiate from toe and root and propagate toward the deck plate. To enhance the fatigue durability of rib-to-deck welded joints, an innovative rib-to-deck joint in OSD with both- side fillet welded joints was proposed. Fatigue performance of the proposed detail was evaluated by the effective notch stress approach, which was compared with the fatigue performance of conventional single-side welding with partial penetration weld detail. The stress range of different penetration rates of both-side fillet welded joints was discussed by finite-element method. The analytical results indicate that both-side fillet welded joints can reduce the maximum effective notch stress amplitude of the weld root and improve the fatigue resistance of rib-to-deck welded joints significantly. Compared with single-side welded joints initiating from weld root, the dominant fatigue failure mode of both-side welded joints is the crack initiating from the weld toe and propagating to deck plate. The results of parametric study indicate the fatigue resistance of novel rib-to-deck welded joints was not distinctly improved by increasing weld penetration ratio.
An Update of Past Visions of Fiber Reinforced Megastructures
Authors: Meier Urs
Published: February 2021

The proposals for the “Arctic City”, an air supported dome of 1971, a suspended very long-span bridge made of carbon fibre reinforced polymers from 1987 and a submerged tunnel made of glass fibre reinforced polymers across the Strait of Gibraltar are presented and based on the state- of-the-art of advanced materials discussed.
Performance-based Evaluation of Fire Resistance for Steel Bridges
Authors: Su Di , Kuniyoshi Ryuta , Kawasaki Hiroki , Nagayama Tomonori
Published: February 2021

Although the fire accidents in the bridge usually don’t cause fatality due to the ease of the prompt withdrawing, traffic on bridges damaged by fire is usually hard to detour and affects the traffic network. However, currently effective evaluation of fire resistance performance is not available. In this paper, two levels of fire hazards, together with the corresponding required structural performance, are first presented by focusing on safety and serviceability for steel bridges. Then the assessment for structural members is proposed. The temperature is chosen as the evaluation index, by comparing the highest temperature caused by fire and the critical resistant temperature. Succeedingly, the evaluation for the entire bridge carries out deflection and temperature analysis incorporating the structural redundancy. Various scenarios, including the fire location and fire scale, are investigated to obtain the general methodology for the evaluation.
Structural Analysis of the Fire Response of a Cut and Cover Tunnel
Authors: Pagan-Martinez Juan , Payá-Zaforteza Ignacio , Hospitaler Antonio
Published: February 2021

This paper analyses the fire response of a 500 m long cut-and-cover tunnel with a rectangular cross section. The tunnel is submitted to the combustion of a truck carrying dangerous goods inside. The analysis uses a performance approach with three basic components: a model of the fire event using Computational Fluid Dynamics, a heat transfer analysis to obtain the temperatures within the structure of the worst tunnel cross section and a simplified model to obtain the tunnel structural response via the isotherm 500° method. Results show that the tunnel top slab is the critical element and that it would collapse 30 minutes after the beginning of the fire. Therefore, the tunnel would require special protective measures. The analysis also shows the advantages of a performance based approach vis-à-vis a prescriptive approach.
Analysis of the Fire Resistance of a Jack Arch Flooring System submitted to the Standard Fire Curve
Authors: Castillo Ester García , Payá-Zaforteza Ignacio , Hospitaler Antonio
Published: February 2021

The use of jack arches supported on joists is very common in the flooring systems of old and heritage buildings around the world. This structural system consists of a series of brick arches that span the distance between two consecutive joists. An infill material is then located above the arch to create a flat surface that serves as support of the pavement. The joists have been done in the past with different materials such as timber, cast iron or steel.

The preservation of the buildings using this structural system is very challenging because the geometry of this structural system does not enable the direct application of the methodologies detailed in current codes such as the Eurocode 5 part 1-2 (Design of timber structures – Structural fire design) to check the fire resistance. Therefore, very often these floors receive a fire protection that, in addition to imply economic expense, reduces significantly the aesthetic value of the building interior space and hides the floor structural system.

Within this context, this paper analyses the fire resistance of a typical floor built in the 18th century using jack arches supported on timber joists. The floor is submitted to the standard fire curve and to the vertical loads as prescribed in the Eurocode 1 part 1-2 (General Actions – Actions on structures exposed to fire) and in the Spanish Building Code. The analysis is carried out in two steps. First of all, temperatures along time in the cross section of the floor are obtained using a non-linear thermal finite element model built with the software Abaqus. Then, the floor time to failure is obtained for different values of the timber strength using a timber joists cross section reduced as a consequence of the fire.

Results show that the use of this method enables the verification of the fire resistance of the floor without requiring any fire protection and that therefore, the goals of structural fire safety, heritage preservation and aesthetic appearance can be achieved.
Study of a railway steel bridge train load model based on measured data
Authors: Liu Xiaoguang , Xiao Xin
Published: February 2021

This paper presents a procedure to obtain more accurate fatigue load onrailway steel bridges， with the characteristics of a single line simply supported riveted steel through truss bridge with a span of 75m, based on the measured data, the train load model is established by using probability theory method. The train model is comprised of four parameters: train types, locomotive, vehicle, and train speeds. The probability distribution of each parameter is achieved by statistical analysis. The Monte-Carlo Method is applied to obtain random train load. The comparison between the simulated and measured values of the fatigue effect on the steel bridge indicates that the simulated stress spectrum matches well with the measured values, the train load model agrees well with the traffic load situation, it can be used in the steel bridge fatigue analysis and is relatively widely applicable.
Developing Time-Variant Filter for Meso-Scale Surface Temperature Prediction
Authors: Choi Byeongseong , Pozzi Matteo , Berges Mario , Bou-Zeid Elie
Published: February 2021

Many urban areas are vulnerable to heat-induced hazards. In the so-called Urban Heat Island (UHI), trapped heat flux within the building canopy increases the surface temperature of cities, and it is revealed that UHI has a non-linear synergy with extreme heatwaves. Therefore, fast/accurate temperature prediction is essential to mitigate the risk, improving the community's resilience. In this paper, we introduce a probabilistic model to forecast the meso-scale surface temperature, at a relatively low computational cost. The proposed model is developed to reduce the computational cost of the Numerical Weather Prediction (NWP) models. We calibrate the proposed model by processing the outcomes of an NWP model (i.e., the Princeton Urban Canopy Model coupled to the Weather Research and Forecast; WRF-PUCM) that reanalyzes historical temperature. The calibrated model is integrated into a Kalman-Filter scheme to update the predictions with the collected data.
Development of Thermoelectric Energy Harvester using the Temperature Gradient between Air and Bridge Materials
Authors: Komori Seita , Takeya Kouichi , Yoshida Junji
Published: February 2021

In this study, to establish a new method for power supply to BHM devices, thermoelectric energy harvesting using the temperature gradient between air and bridge materials was investigated through the environmental measurement at bridge fields. First, the temperature difference between air and bridge materials was measured using a thermographic camera and thermocouples. Next, we attempted several thermoelectric generators and heat sinks (or radiators) to maximize the efficiency of energy harvesting and developed a Thermoelectric Energy Harvester (TEH). After that, we estimated the harvesting energy by formulating the thermoelectric characteristics of the developed TEH. Finally, we installed the developed TEH on an actual bridge. As a result, the electric power required for the MEMS sensors could be achieved.
Acoustic emission monitoring of bridge cable wires crack propagation
Authors: Wang Chunsheng , Wu Yifan , Si Haipeng , Duan Lan
Published: February 2021

This paper introduces a method for monitoring the fatigue crack propagation rate of bridge cable wires using acoustic emission technology. Through the prefabricated damage notch, the comprehensive use of strain gauges and acoustic emission for real-time monitoring of high- strength steel wire specimens in cables，establishing the corresponding relationship between AE count rate and stress intensity factor ΔK. Based on the correlation among crack propagation rate, AE count rate and stress intensity factor range, the relationship between AE count rate and crack propagation rate is derived. The results show that the application of the acoustic emission sensor can intelligently detect the propagation state and rate of fatigue cracks on the cable wire. Acoustic emission count rate can be used to effectively monitor the fatigue crack propagation of cable high- strength steel wire, and then the damage and residual life can be evaluated and predicted.
Development of Composite Non-Destructive Testing Equipment for External Tendon of PSC Bridge
Authors: Son Younki , Nam Wanghyun , Yoo Dongho , Song Sangwon
Published: February 2021

A non-destructive testing equipment and diagnostic technique for external tendons of pre- stressed concrete (PSC) bridge were developed in this study. In this equipment, acoustic emission (AE) and magnetic flux leakage (MFL) type testing equipment were introduced. The use of AE equipment is to detect cavities in external tendons, and the use of MFL equipment is to detect damage to strands. In order to verify the performance of this non-destructive testing equipment, specimens of tendons with artificially damaged strand were fabricated and tested in a laboratory. As a result, it was confirmed that the location of each damage could be detected precisely. It is expected that more precise evaluation will be possible through further analysis and enhancement.
System Development for Performance Evaluation Suitable for Small and Medium Sized Aging Bridges
Authors: Kim Young-Min , Shin Byoung-Gil , Yun Tae-Kang , Chang Seok-Jung
Published: February 2021

Although small and medium-sized bridges are closely related to people’s lives, safety and maintenance are often neglected compared to the large bridges. Moreover, the frequent occurrence of safety accidents due to aging, they are often placed in a blind spot for safety management. This study aims to develop a performance evaluation system suitable for small and medium-sized bridges based on the results of simulations on various performance evaluation methods using facility information.
Bataan-Cavite Interlink Bridge – Preliminary Design of the crossing
Authors: Yip Sammy , Kite Steve , Vishnoi Paresh , Venkatesha Vikas
Published: February 2021

Bataan-Cavite Interlink Bridge (BCIB) in the Philippines is a proposed 32km sea-crossing which will connect Bataan and Cavite provinces, to unlock opportunity for economic growth and expansion outside Metro Manila. A Feasibility Study was carried out to plan the road link, which will involve two major navigation bridges, long marine viaducts, and interchange connections. This paper outlines the Feasibility Study, the navigation clearance study and the Preliminary Design of the crossing. It highlights how the navigation clearances were assessed and confirmed, and how the bridge options were evaluated in order to come up with an optimum solution.
Research on Key Technology of Operation and Maintenance Management of Long Span Railway Steel Bridge Based on BIM
Authors: Liu Xiaoguang , Pan Yongjie , Zhao Xinxin
Published: February 2021

In order to adapt to the development trend of informatization and intelligence of railway bridge operation and maintenance management, the integration of BIM Technology and large-span railway steel bridge operation and maintenance business becomes more and more urgent. Taking one special railway steel bridge as an example, the division levels of bridge structural parts, structural elements and specific components were defined, and the refined BIM model of bridge was established based on the demand of operation and maintenance. The knowledge base systems of component, defect, inspection and maintenance in bridge was formed. The three terminal BIM management system was developed, and the closed-loop management process of bridge inspection, maintenance and repair based on the BIM model was established. At the same time, the monitoring information could be integrated, which can provide the basis for the formation of bridge digital twins. The research results provide a firmly support for data-driven comprehensive evaluation and conditional maintenance of railway steel bridges.
Optimization inspection method for concrete girder bridges using vision‐based deep learning and images acquired by unmanned aerial vehicles
Authors: Wang Shichao , Liu Kaiyu
Published: February 2021

Traditional concrete girder bridge inspection and monitoring techniques are usually carried out by trained inspectors, which are time‐consuming, dangerous and expensive. With the continuous development of unmanned aerial vehicle and computer vision techniques, the crack width identification of concrete girder bridge by unmanned aerial vehicles can meet the engineering precision requirements. Several image processing techniques have been implemented for detecting civil infrastructure defects to replace human‐conducted on‐site inspections. In this study partially, a deep learning algorithm based on a regional convolution neural network is applied, which combines deep learning techniques with image processing techniques to identify the surface crack of concrete girder bridges. The bridge detection images are captured by an unmanned aerial vehicle and transmitted to a computer. The sliding window algorithm is used to divide the bridge crack images into smaller bridge crack patches and bridge background patches. Based on the patches' analysis, the background patches and crack patches of concrete bridges are identified based on the ResNet convolution neural network. The detection process cracks identification of concrete girder bridge is executed in the computer through the proposed algorithm. The results show that the proposed method shows excellent performances and can indeed identify the shape of concrete cracks on the surface of concrete girder bridges.
Camera Motion-Induced Error Compensation for Computer Vision- Based Displacement Measurement
Authors: Lee Junhwa , Lee Kyoung-Chan , Lee Young-Joo , Sim Sung-Han
Published: February 2021

Structural health monitoring (SHM) of civil engineering structures often requires displacement information to assess structural integrity. An unexpected large displacement can be an indication of lurking structural damage. Although structural displacement is a useful physical quantity for SHM purposes, the measurement on full-scale structures is challenging particularly in long-term sensing due to difficulties in finding sensor installation points, insufficient resolution of displacement sensors, or harsh field conditions. Recently, computer vision has been widely adopted as a powerful tool for measuring displacement that offers easy-to-find installation site with sub-mm resolution. The existing research works report successful application of the vision- based system in displacement measurement of full-scale civil structures by using a stationary camera. However, a subtle vibration of the camera results in large displacement error because of the long distance between the camera and the measurement point. This study proposes a long- term displacement measurement method using computer vision with compensation of the camera motion-induced error. The proposed approach uses an additional camera, so-called sub-camera, to the conventional vision-based system. The sub-camera is designed to measure the three- dimensional (3D) motion of the camera body. Attaching the sub-camera to the original camera, the 3D motion of the original camera can be estimated. Deriving the relationship between the 3D motion of the original camera and the displacement error, the camera motion-induced error can be compensated. A field testing on a full-scale railway bridge is presented to show the validity of the proposed method in long-term displacement measurement.
Image-driven Bridge Inspection Framework using Deep Learning and Image Registration
Authors: Cho Soojin , Kim Byunghyun
Published: February 2021

This paper proposes an image-driven bridge inspection framework using automated damage detection using deep learning technique and image registration. A state-of-the-art deep learning model, Cascade Mask R-CNN (Mask and Region-based Convolutional Neural Networks) is trained for detection of cracks, which is a representative damage type of bridges, from the images taken from a bridge. The model is trained with more than a thousand training images containing cracks as well as crack-like objects (hard negative samples). The images taken from a test bridge are input to a deep learning model trained to detect damages, which is further mapped on a large image of each bridge component registered using a commercial registration software. The performance of the proposed framework is evaluated on piers of existing bridges, whose external appearance was imaged using a DSLR with a telescopic lens. The results are compared with the conventional visual inspection to analyse the performance and applicability of the proposed framework.
Inverse Estimation of Influence Line Using Regular Traffic Vehicles for Bridge Weigh-in-Motion
Authors: Mori Junki , Yoshida Junji , Takeya Koichi
Published: February 2021

Investigating traffic loads and the number of vehicles on bridges is essential in order to grasp factors of deterioration in road bridges. Bridge Weigh-in-Motion (B-WIM) is a method for estimating vehicle axle weight from the response of vehicles passing through a bridge. In this study, we construct a new B-WIM, in which vehicles are tracked from video images and influence line of the bridge is estimated from the response by local buses. As a method of tracking vehicles from video images, we applied Faster Regions with Convolutional Neural Network (Faster R-CNN), which is a method of image processing using deep learning. In addition, influence lines are inversely estimated by the direct search method using deflection responses by local buses. Consequently, the proposed method could estimate axle weights of a large vehicle with over 95 % accuracy.
Formation mechanism, detection and evaluation of weathering patina on weathering steel bridges
Authors: Zhang Jingwen , Tan Chenxin , Wang Chunsheng
Published: February 2021

The weathering bridge steel has a lower corrosion rate than low alloy steel bridge, which could produce dense and stable patina on the steel surface, separating the steel substrate from the external corrosion eviroment and preventing the further corrosion. In this paper, the patina of weathering steel for bridge were studied from formation mechanism, evaluation method and patina field and in-suit testing. The formation mechanism and composition of patina was studied, the applicability of detection and evaluation methods of weathering steel bridge were clarified, and the patina stability of weathering steel orthotropic bridge deck and existing bridge in China were evaluated. The purpose of this paper is to provide guidance and selection for the maintenance methods of the patina in the weathering steel bridge.
Probabilistic Modeling and Inference for Structures under Sequence of Hazardous Events Using Matrix-based Bayesian Network
Authors: Mun Changuk , Song Junho
Published: February 2021

Structures are often subject to a sequence of hazardous events, e.g. main earthquake excitation followed by aftershocks. Even though such hazard brings about a crucial risk to our societies, its quantification is generally challenging because of its complexity. To address the technical challenge effectively, this study proposes to use Bayesian networks (BNs). Sequences of main and aftershocks are artificially generated to quantify the BN model representing the complex hazard. In addition, the structural responses of a hysteretic single-degree-of-freedom (SDOF) system under the generated sequences are evaluated by nonlinear dynamic analysis to quantify the BN model. Then, the fragilities of the system are estimated through the BN-based probabilistic inference. The overall modeling and inference are efficiently executed by the Matrix-based Bayesian network (Byunet al.2019). The proposed framework is expected to advance our capability to assess the risk of structures under the sequence of hazardous events and make optimal risk-informed decisions.
Detection of Corrosion of Post-tensioned Tendons Using Replaceable Reference Electrodes Plugged into Surface-mounted Sockets
Authors: Jang Seung Yup , Yoo Bongyoung , Park Soobin , Kwon Seung-Jun , Yoon Yong-Sik
Published: February 2021

Corrosion of tendon, which is currently unseen but finally proceeds to break of tendon, can cause critical disasters of post-tensioned (PT), prestressed concrete (PSC) structures. Many electro- chemical sensors have been developed and attempted for detecting corrosion in PSC structures; however, they still have doubts on their longevity because they can be degraded when exposed to harsh environments. In this study, to overcome this problem, a surface-mounted socket that a reference electrode can be plugged into is proposed. Mounting this socket on the surface allows more accurate and reliable measurement using a reference electrode plugged into this socket after pre-calibrated in the laboratory. To verify the performance of this socket-type sensor system, a mock-up test was designed. Several series of test specimens were manufactured with the plastic ducts and steel wires. The plastic duct containing a steel wire was partially grouted with deficient grout. The sockets proposed in this study were installed on the surface of the ducts, and conventional embedded sensors were installed inside the ducts. To induce the corrosion of wires, the void formed in the upper part of the duct was filled with salt solution or tap water for 2 weeks; afterward, drained and dried for another 2 weeks. This was done periodically for 3 months. After that, the voids were re-grouted with high-quality repair grout. Before re-grouting, some test specimens were socked with corrosion inhibitor for 24 hours. Open-circuit potential (OCP) measurements of the internal steel wires were carried out during the entire repeated wetting- drying period and for 9 months after the re-grout. The measurement from the proposed socket- type sensor shows reliable OCP variations reflecting the effects of corrosive conditions, properties of grout materials and corrosion inhibitors. Not only analysis on the OCP variations with test conditions but also comparative study with conventional embedded electrodes were provided.
Design validation via Infrastructure Health Monitoring of the Circular bridge project
Authors: Grüske-Weißenbach Nils , Fielding Chris
Published: February 2021

As part of the Dutch Government's plan to implement schemes to make bridges re-usable, we are presenting a completed Rijkswaterstaat (Road Authority of the Netherlands) pilot project. The ambitious plan to become "circular" (i.e. re-usable) by 2030 requires to rethink the traditional construction process from the ground up. That means that the conventional way in which bridges are commissioned and build, is no longer applicable. The lifecycle process from design stage to execution and demolition needs to change.

The Circular bridge pilot project demonstrates how bridge engineers designed the structure that utilizing standardized pre-cast concrete segments for a 200-year lifespan. These elements are assembled akin to Lego pieces and post-tensioned (PT) in the longitudinal and transversal directions. When the initial in-place service life of the bridge is reached (say 40 years), these blocks can be de-installed and re-assembled at a different location, hence the term circular.

In order to confirm the design principles and overcome the requirement that the post-tensioning always needs to be bonded within the structure it was necessary to monitor the performance of the bridge during the execution phase. This, in EC terms, is referred to as "design-by-testing". To validate the design, a multi-component Infrastructure Health Monitoring (IHM) system was deployed. The IHM system consisted of camera control of traffic flows (CCTV) measuring vehicle counts, speeds and directions and featured the following sensing instrumentation: temperatures, bridge deflections, bird-gapping between the blocks and force monitoring. As part of the IHM system, alerts and alarms were programmed to be sent to engineers in case measurements exceeded pre-defined thresholds.
Non-Destructive Testing Methods for Cables of Cable Supported Structures – Practical Experiences
Authors: Neteler Thomas , Lobert Hardi
Published: February 2021

DMT’s Rope Testing Centre – a laboratory for non-destructive and destructive testing and part of TÜV NORD GROUP - has long-time experience in the inspection of steel wire ropes and cables in varying applications. DMT provides different non-destructive testing (NDT) methods, which allow a more detailed evaluation of the inner condition of the cables compared to only visual inspection. Ultrasonic testing (UT) at cable end connections is a very effective NDT method which is executed regularly by DMT experts. Another NDT method suitable to inspect the free length of stay or hanger cables is magnetic rope testing (MRT). Starting in 1931 with MRT on steel wire ropes, DMT has since then continuously developed and optimized this testing method and gained extensive operating skills.
Outstanding Civil Engineering Structures Built in Poland
Authors: Biliszczuk J. , Hawryszkow P. , Toczkiewicz R. , Żółtowski K.
Published: February 2021

The development of civil engineering in Poland over 1000 years was discussed. Particular attention was paid to outstanding innovative constructions created after World War II. Innovative buildings, halls, stadiums, masts, high-rises and bridges were presented. It was in Poland where the first welded steel road bridge in Europe and the highest mast in the world were built. Europe's largest extradosed and innovative arched and composite bridges have been built recently.
Composite Dowels: the Way to the new Forms of Steel-Concrete Composite Structures
Authors: Lorenc W.
Published: February 2021

The introduction of composite dowels in Europe at the beginning of the last decade led to the creation of new forms of composite bridges in which a T-profile is used instead of an I-beam. Both the construction and design methods are new. The paper presents the bridges using this new type of shear connection. The variety of forms and dynamic development of a new type of construction is presented. The development history and the latest shear connection design guidelines are summarized. Reference was made to the basic design principle for composite beams with the associated concrete slab: the omission of part of the transverse force transmitted by the concrete slab. To understand design basis for new forms is to deeply understand that they are beyond current version of Eurocode 4: "3 + 2 ≠ 4 and Eurocode 3 + Eurocode 2 ≠ Eurocode 4". The above in a good way reflects the sense of what new forms are and why their design is complicated.
Bridge Aesthetics – Functional and Structural Needs versus Architectural Imagination
Authors: Radomski W.
Published: February 2021

Relations between structural form as well as service function of bridges and their aesthetics are analysed. Irrespective of their scale bridges always affect their surroundings or landscape. Therefore, they not only have an engineering and economic meaning but also a social and a cultural one. In some cases, especially older bridges have an additional symbolic or a historic meaning. Contemporary trends concerning bridge aesthetics are discussed. Commonly modern bridge structures ideas are controversial – their forms often seem to be more important than their service function and classical aesthetic principles are rather rarely observed. Presented problems are exemplified by bridge structures in Poland and in other countries. Conclusions concerning the relations between the bridge aesthetics and bridge function are formulated. Some remarks on the future trends in the bridge engineering are also presented.
Dynamic Investigations on the Health State and Seismic Vulnerability of Morandi’s Pavilion V of Turin Exhibition Center
Authors: Ceravolo R. , Coletta G. , Lenticchia E. , Minervini D. , Quattrone A.
Published: February 2021

Modern architectural heritage raises issues connected to its preservation or rehabilitation and require in-depth analysis and appropriate protections. Just recently, the collapse of the Polcevera Bridge in Genoa cast a shadow on the durability itself of established materials and technologies, in particular prestressed concrete. Another aspect deserving special attention in this heritage is seismic provision. The underground Pavilion V is an iconic structure designed by Morandi, conceived in 1958 as an expansion of the exhibition space hosting the industrial vehicle section of the Turin Automobile Show. The pavilion consists of a single wide space, 69 m in width and 151 m in length, and is located 8 m below ground level. The present contribution illustrates the recent experimental investigations conducted on this stunning building, with emphasis on the dynamic characterization tests. The tests were deemed necessary for the interpretation of the structural system in view of a possible reuse as part of the university campus of architecture. The interpretation of the experimental campaign stimulated a broader range discussion on the structural and seismic reliability of this type of scheme, as well as its possible seismic improvement and rehabilitation.
Long-Term Movement Behaviour of Bridge Bearings and Expansion Joints from SHM Data
Authors: Richli T. , Chrysovergis A. , Meng N. , Treacy M.
Published: February 2021

Accumulated movements induced by temperature and imposed loads contribute to the wearing down of the
sliding materials within bridge bearings and expansion joints, potentially seriously affecting their functioning
and performance. Therefore, there is a need for engineers to be able to assess, with some accuracy, the total
movements to which these critical components, and their sliding materials in particular, are being subjected
(or have been subjected during their service life to date). These movements are difficult to calculate analytically
and design codes generally provide very conservative load models which increases the challenge of accurately
estimating true movements. Nowadays, structural health monitoring can be used to record these movements
with high accuracy, providing data that can support more efficient life-cycle planning of bridge maintenance.
This paper illustrates this with reference to the measurement of longitudinal movements on expansion joints
and bearings of various bridge structures.
IMPLEMENTING CLOUD REVOCATION AUTHORITY WITH IDENTITY BASED ENCRYPTION AND ITS APPLICATIONS
Authors: S. Andal , Tasneem Tahera , Mary Meghana , G. C. Ranjitha , N.A. Deepak
Published: February 2021

Identity-based encryption(IBE) is a public key cryptosystem(encoding and decoding) and eliminates the demands of public key infrastructure(PKI) and certificate administration in conventional public key settings. Due to the absence of PKI, the revocation problem is a critical issue in IBE settings. Several revocable IBE schemes have been proposed regarding this issue. Quite recently, by embedding an outsourcing computation technique into IBE, a revocable IBE scheme with a key-update cloud service provider (KU-CSP) was proposed.However, their scheme has two shortcomings. One is that the computation and communication costs are higher than previous revocable IBE schemes. The other shortcoming is lack of scalability in the sense that the KU-CSP must keep a secret value for each user. In the article, we propose a new revocable IBE scheme with a cloud revocation authority (CRA) to solve the two shortcomings namely, the performance is significantly improved and the CRA holds only a system secret for all the users. For security analysis, we demonstrate that the proposed scheme is semantically secure under the decisional bilinear Diffie-Hellman (DBDH) assumption. Finally,we extend the proposed revocable IBE scheme to present a CRA-aided authentication scheme with period-limited privileges for managing a large number of various cloud services.
BIOMETRICS-A PRELIMINARY APPROACH
Authors: B.R. Rohini , G. Thippeswamy
Published: February 2021

Authentication plays a vital role in Information security. The need for identification of legitimate user has increased in the waking concerns for global security. Biometric recognition Systems is a major tool for Authentication mechanism. Biometrics is the ability to identify and authenticate an individual using one or more of their behavioral or physical characteristics. The Study of Different Biometric Modalities gives a better understanding of Biometric Techniques. We focus our Study on Face Biometrics. This paper emphasizes on better understanding of introduction to Biometrics, Biometric Modalities and Face recognition Techniques.
SURVEY ON E-FINGERPRINT TICKET
Authors: Solomon Zakkam , K M Meghana , Manjula  , B Roshini
Published: February 2021

Earlier work has demonstrated that when going in a transport the installment accomplished for ticket is with money .The transport ticket has such an installment figure which makes the voyager or the conductor shy of cash as far as change. This makes the conductor to keep the change with himself .This makes bother to the explorers. Subsequently there is a requirement for better workplace. To conquer this issue we are making utilization of fingerprints of the voyager which are connected to the database. The enrollment procedure will take every one of the points of interest of the client when going surprisingly. The record is made with some e-cash in it .While venturing out client needs to give his unique mark and pay the cash for ticket through his record naturally .This beats the client bother. What's more, Security is the fundamental calculate all associations and has more significance in transport. Security can be given by any mean can't give greater adaptability, the current E-Ticket framework does not contain adequate security, so we think to execute biometrics in our examination and after that we moved to another imaginative innovation to utilize unique mark module likewise for the extra for client adaptability utilizing Global System for Mobile Communication module for Communication reason for sending and accepting message. By this Survey, we can limit Fraud in transport and give greater office to voyager and enhances security for the general public.
SURVEY ON SENTIMENT ANALYSIS OF STOCK MARKET
Authors: S Nausheen , Kumar Anil , K K Amrutha
Published: February 2021

Sentiment analysis has seen a tremendous growth in the past few years. Sentiment analysis or opinion mining is a process of collecting users’ opinion from user generated content. It has various applications, such as stock market prediction, products’ review collection, etc.  a large amount of work has been done in this field by applying sentiment analysis to various applications. The main goal of this paper is to study the various methods used for sentiment analysis. Further we explain the overview of various related papers and their performances.
A REVIEW ON CLOUD COMPUTING SECURITY ISSUES AND CHALLENGES
Authors: R B Madhumala , Tiwari Harshavardhan
Published: February 2021

The new developments in the field of information technology offered the people enjoyment, comforts and convenience. Cloud computing is one of the latest developments in the IT industry also known as on-demand computing. It provides the full scalability, reliability, high performance and relatively low cost feasible solution as compared to dedicated infrastructures. It is the application provided in the form of service over the internet and system hardware in the data centers that gives these services. This technology has the capacity to admittance a common collection of resources on request. It is proving extremely striking to cash-strapped IT departments that are wanted to deliver better services under pressure. When this cloud is made available for the general customer on pay per use basis, then it is called public cloud. When customer develops their own applications and run their own internal infrastructure then is called private cloud. Integration and consolidation of public and private cloud is called hybrid cloud.
SURVEY ON DESIGN OF PATIENT BLOOD PRESSURE MONITORING SYSTEM USING SECURE IOT
Authors: K M Meghana , C R Manjunath
Published: February 2021

Blood Pressure Monitoring using sensor and cloud technology, Personal biological readings such as blood pressure are collected by sensor networks device from patients at homes and will be transmitted to cloud and get treated accordingly. It is very important that privacy of patient’s medical condition is protected while data are being transmitted over the public network as well as when they are stored in servers. In this paper, a unique Cryptography technique has been used, Cryptography allows privacy of data that is transmitted. This will ensure that it is implemented for small foot print using IOT for secure data transmission. While data is transmitting to cloud Doctor will get email/message notification and Doctor can also view the Patient Blood Pressure Record stored in cloud.
DEVELOPMENT OF AUTONOMOUS GAME AGENT WITH LEARNING AND REACTIVE BEHAVIORS
Authors: T.P. Deepa
Published: February 2021

The main goal of this paper is to develop software agent which is autonomous with reactive behavior and learning abilities. One of the applications of such agents are in gaming. Gaming characters are expected to work in unpredictable environment with decision making capabilities like weapon selection for different targets, wall following. This can be achieved artificial intelligence (AI) techniques and methods. In this paper, agent is designed to exhibit capabilities like - Moving Abilities, Steering behavior and obstacle avoidance, Synthesis of movement enhancing movement, weapon selection, adapting defense strategies, strategic Decision making.
HYBRID APPROACH FOR KEY FRAME EXTRACTION FROM VIDEO SEQUENCE
Authors: Kumar Satish
Published: February 2021

This paper proposed and developed hybrid approach for extraction of key-frames from video sequences from stationary camera. This method first uses histogram difference to extract the candidate key frames from the video sequences, later using Background subtraction algorithm (Mixture of Gaussian) was used to fine tune the final key frames from the video sequences. This developed approach show considerable improvement over the state-of-the art techniques and same is reported in this paper.