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Development of IoT-Based Condition Monitoring System for bridges

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Sound & Vibration 2022年第3期56卷 209-220页

作者： Sheetal A.Singh Suresh S.Balpande Department of Electronics Engineering Shri Ramdeobaba College of Engineering&ManagementNagpurIndia

As of April 2019,India has 1,42,126 kilometres of National Highways and 67,368 kilometres of railway tracks that reach even the most remote parts of the country.bridges are critical for both passenger and freight movement in the country.Because bridges play such an important part in the transportation system,their safety and upkeep must be prioritized.Manual Condition Monitoring has the disadvantage of being sluggish,unreliable,and inefficient.The Internet of Things has given structural monitoring a boost.Significant decreases in the cost of electronics and connection,together with the expansion of cloud platforms,have made it possible to collect large amounts of data remotely,aggregate it,and perform essential analysis to generate actionable insights.This research focuses on a scalable system for monitoring the state of bridges,such as vibration and loading,employing multimodal inputs,controllers,and Wi-Fi modules.The accelerometer and load cells were installed on the prototype,tested for a sample load(56.21 grams_(avg),590 grams_(max),and 147.66 grams_(rms))with induced vibration(5.87 m/sec^(2)_(avg),18 m/sec^(2)_(max),and 7.04 m/sec^(2)_(rms))that are processed,displayed on-board,and uploaded to ThingSpeak cloud service.This system will aid the maintenance personnel in remotely monitoring it.This system can send out notifications if any of these parameters exceeds their threshold value,allowing you to take preventive measures ahead of time.

关键词： Accelerometer bridges IoT sensors structure health monitoring ThingSpeak

A practical multi-lane factor model of bridges based on multi-truck presence considering lane load disparities

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Frontiers of Structural and Civil Engineering 2021年第4期15卷 877-894页

作者： Junyong ZHOU Colin C.CAPRANI School of Civil Engineering Guangzhou UniversityGuangzhou510006China Department of Civil Engineering Monash UniversityMelbourne3800Australia

Many bridge design specifications consider multi-lane factors(MLFs)a critical component of the traffic load model.Measured multi-lane traffic data generally exhibit significant lane disparities in traffic loads over multiple lanes.However,these disparities are not considered in current specifications.To address this drawback,a multi-coefficient MLF model was developed based on an improved probabilistic statistical approach that considers the presence of multiple trucks.The proposed MLF model and approach were calibrated and demonstrated through an example site.The model sensitivity analysis demonstrated the significant influence of lane disparity of truck traffic volume and truck weight distribution on the MLF.Using the proposed approach,the experimental site study yielded MLFs comparable with those directly calculated using traffic load effects.The exclusion of overloaded trucks caused the proposed approach,existing design specifications,and conventional approach of ignoring lane load disparity to generate comparable MLFs,while the MLFs based on the proposed approach were the most comprehensive.The inclusion of overloaded trucks caused the conventional approach and design specifications to overestimate the MLFs significantly.Finally,the benefits of the research results to bridge practitioners were discussed.

关键词： bridges multi-lane factor traffic load lane load disparity multi-truck presence weigh-in-motion data

A shake table investigation of dynamic behavior of pile supported bridges in liquefiable soil deposits

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Earthquake Engineering and Engineering Vibration 2021年第1期20卷 1-24页

作者： Piyush Mohanty Xu Dan Suryakant Biswal Subhamoy Bhattacharya CSIR-Central Building Research Institute Roorkee247667India Fluor Ltd. 140 Pinehurst RoadFarnboroughGU147BFUK Institute of Engineering Mechanics China Earthquake AdministrationSanhe 065201China University of Surrey GuildfordGU27XHUK

bridges are a part of vital infrastructure,which should operate even after a disaster to keep emergency services running.There have been numerous bridge failures during major past earthquakes due to liquefaction.Among other categories of failures,mid span collapse(without the failure of abutments)of pile supported bridges founded in liquefiable deposits are still observed even in most recent earthquakes.This mechanism of collapse is attributed to the effects related to the differential elongation of natural period of the individual piers during liquefaction.A shake table investigation has been carried out in this study to verify mechanisms behind midspan collapse of pile supported bridges in liquefiable deposits.In this investigation,a typical pile supported bridge is scaled down,and its foundations pass through the liquefiable loose sandy soil and rest in a dense gravel layer.White noise motions of increasing acceleration magnitude have been applied to initiate progressive liquefaction and to characterize the dynamic features of the bridge.It has been found that as the liquefaction of the soil sets in,the natural frequency of individual bridge support is reduced,with the highest reduction occurring near the central spans.As a result,there is differential lateral displacement and bending moment demand on the piles.It has also been observed that for the central pile,the maximum bending moment in the pile will occur at a higher elevation,as compared to that of the interface of soils of varied stiffness,unlike the abutment piles.The practical implications of this research are also highlighted.

关键词： bridges midspan failure liquefaction bridge collapse earthquake pile shake table test natural frequency

Ductile steel plate external end diaphragms for steel tub girder straight highway bridges

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Earthquake Engineering and Engineering Vibration 2020年第3期19卷 759-777页

作者： Shervin Maleki Abouzar Dolati Department of Civil Engineering Sharif University of TechnologyTehranIran

The end diaphragm of bridges are normally designed to resist lateral seismic forces imposed on the superstructure in earthquake prone regions.Using ductile diaphragms with high deformation capacity could reduce the seismic demands on the substructure and prevent costly damage under strong ground motions.The end diaphragms of steel tub girder bridges with high lateral stiffness and dominant shear behavior have a potential to be used as ductile fuse elements.In this study,a steel plate shear diaphragm(SPSD)is introduced as an external end diaphragm of tub girder steel bridges to reduce the seismic demands imposed on the substructure.Quasi static nonlinear analyses were conducted to evaluate responses of sixteen SPSDs with different boundary conditions,aspect ratios and diaphragm plate thicknesses.Moreover,nonlinear time history analyses were performed using three different ground motions corresponding to DBE and MCE level spectrums.Cyclic and time history analyses proved the proper behavior of SPSD and its efficiency to reduce seismic demands by more than 25%.

关键词： bridges steel straight

Estimating the resistance of aging service-proven bridges with a Gamma process-based deterioration model

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Journal of Traffic and Transportation Engineering(English Edition) 2019年第1期6卷 76-84页

作者： Cao Wang Kairui Feng Long Zhang Aming Zou School of Civil Engineering The University of Sydney Department of Civil Engineering Tsinghua University CCCC Highway Consultants CO. Ltd.

The environmental or anthropogenic factors, to which the in-service bridges are subjected,are responsible for the reduction of bridge performance, and finally lead to great service risk for bridges and increase the probability of substantial economic losses. Probabilitybased estimate of bridge resistance is an essential indicator for the bridge condition evaluation and for optimization of bridge maintenance/repair decisions. It places an emphasis on the proper probabilistic models of structural properties and assessment methods. Making full use of historical service load information may improve the accuracy of bridge performance assessment with reduced epistemic uncertainty for existing aging bridges. In to-date analyses to update the bridge resistance with past service information,the models of resistance deterioration have been assumed as either deterministic or fully correlated, which may differ significantly from the realistic case. With this regard, this paper proposes a novel method for updating the resistance of service-proven bridges with a realistic deterioration model. The Gamma stochastic process has been suggested in the literature to describe the probabilistic behavior of structural time-dependent resistance and thus is adopted in this paper. An illustrative bridge is presented to demonstrate the applicability of the proposed method. Parametric examples are conducted to investigate the role of resistance deterioration model in the updated estimate of bridge resistance with historical service information.

关键词： Existing aging bridges Historical load information Resistance updating Gamma deterioration process Bridge safety

bridges染色体不分离实验的遗传学分析及释疑

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中学生物教学 2021年第34期 49-51页

作者：谢仁荣刘永生福建省石狮市第三中学 362700 云南省大理市新世纪中学 671000

介绍bridges的染色体不分离实验,分析该实验假说提出及推理验证的科学逻辑关系,帮助师生理解例外子代果蝇的产生并非基因突变,是由X染色体不分离造成的。

关键词： bridges 染色体不分离科学思维

CXXC finger protein 1 (CFP1) bridges the reshaping of genomic H3K4me3 signature to the advancement of lung adenocarcinoma

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Signal Transduction and Targeted Therapy 2023年第10期8卷 5010-5022页

作者： Tao Fan Chu Xiao Hengchang Liu Yu Liu Liyu Wang He Tian Chunxiang Li Jie He Department of Thoracic Surgery National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 10o021China Department of Colorectal Surgery National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBejingChina Department of Intervention National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

Histone H3 lysine 4 trimethylation(H3K4me3)is a canonical chromatin modification associated with active gene transcription,playing a pivotal role in regulating various cellular functions.Components of the H3K4me3 methyltransferase complex,known as the proteins associated with SET1(COMPASS),have been implicated in exerting cancer-protective or cancer-inhibitory effects through inducive H3K4me3 modification.However,the role of the indispensable non-catalytic component of COMPASS CXXC-type zinc finger protein 1(CFP1)in malignant progression remains unclear.

关键词： protective H3K4me3 bridges

The Gift from Nature： Bio-Inspired Strategy for Developing Innovative bridges

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Journal of Bionic Engineering 2013年第4期10卷 405-414页

作者： Nan Hu Peng Feng Gonglian Dai Department of Civil and Environmental Engineering Michigan State University East Lansing MI 48824 USA Department of Civil Engineering Tsinghua University Beijing 100084 P. R. China Department of Bridge Engineering Central South University Changsha 410075 P. R. China

Biology has been a brilliant teacher and a precious textbook to man-made construction for thousands of years, because it allows one to learn and be inspired by nature＇s remarkable and efficient structural systems. However, the emerging biomimetic studies have been of increasing interest for civil engineering design only in the past two decades. Bridge design is one of aspects on structural engineering of biomimeties that offers an enormous potential for inspiration in various aspects, such as the ge- ometry, structure, mechanism, energy use and the intelligence. Recently built bridges and design proposals in which biological systems have produced a range of inspiration are reviewed in this paper. Multidisciplinary cooperation is discussed for the implementation of bio-inspired methods in future design. A case study about using bio-inspired strategy is trying to present a problem-solving approach, yet further cooperation is still needed to utilize biomimetie studies for design inspiration. This paper aims to call a close multidisciplinary collaboration that promotes engineers to build more sustainable and smart structural systems for bridges in the 21 st century.

关键词： bionics bridges bio-inspired method conceptual design form-finding sustainability

Asynchronous earthquake strong motion and RC bridges response

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Journal of Traffic and Transportation Engineering(English Edition) 2018年第6期5卷 454-466页

作者： Davide Lavorato Gabriele Fiorentino Alessandro Vittorio Bergami Bruno Briseghella Camillo Nuti Silvia Santini Ivo Vanzi Department of Architecture Roma Tre University College of Civil Engineering Fuzhou University Department of Engineering and Geology University of Chieti-Pescara "G.d'Annunzio"

The dynamic response of long structures(e.g., bridges) is sensitive to the spatial variability of strong ground motion(asynchronous motion). Ground motion differences increase from point to point with increasing foundation distance. This latter is due to two physical phenomena: soil-wave interaction, that causes the loss of coherence and local amplification; wave traveling with finite velocity, that causes signals time lag. This ground motion variability produces a different structural demand compared to the synchronous one,which is the only one considered by designers in the majority of cases. A few codes consider this type of actions, therefore further research efforts are necessary. In this study,asynchronous ground motions are generated by means of a new generation procedure implemented in the software GAS 2.0 using as input the simultaneous strong motion records from the April 6 th, 2009, L’Aquila(Italy) at the seismic stations AQA and AQV, located in the Aterno River valley. These records are used to calibrate the generation model and to produce sets of asynchronous earthquake sampling. The asynchronous earthquake sets are applied on a typical highway reinforced concrete bridge to study its dynamic response considering two different configurations: non-isolated with traditional supports and isolated bridge with lead rubber bearings. The bridge is placed in two positions along the wave propagation direction: a position near one recording station and a position between the two stations to consider local soil effects. The response parameters investigated are the maximum relative displacements of soil and deck. The results show that there is animportant variation of relative displacement along the direction of wave propagation due to asynchronous motion with effects that designer should consider for the structural details design of isolated and non-isolated bridges.

关键词： Asynchronous motion bridges Seismic response Earthquake spatial variability