Irregularities in railway tracks are a key factor influencing the safety of trains. In this paper, rail track is considered to consist consecutive maintenance units whose individual defect states can be quantified terms quality index. A Markov stochastic process approach used evaluate deterioration unit. hazard model formulated using heterogeneity units, and matrix transition probabilities constructed. The parameters developed models estimated via maximum log-likelihood function. prediction...

Abstract In recent decades, construction project scheduling optimization has received extensive attention from the research community. However, most commonly used approach, critical path method, is often inapplicable to transportation‐type linear projects. Recently, method (LSM) demonstrated many advantages for such projects and become a popular subject. As relatively novel LSM requires further improvement, as there are restrictions associated with scheduling/optimization of By analyzing...

Since 2007, Beijing Metro started to use track geometry car measure quality of its tracks under wheel loading conditions. The measurement data from the were only used assess local by means scoring 1000 m long segments based on exceptions. Track management experience national railroads China shows that, in addition assessment, an overall assessment method should be employed. paper presented research results funded Road Administration Municipal Commission Transport. proposed for and determined...

Condition-based maintenance is believed to be a cost-effective and safety-assured strategy for railroad track management. Implementation of the strongly relies on reliable complete condition data, deterioration models, efficient solvable mathematical models optimal scheduling. In practice, reliability inspection data often in question; therefore, collected need preprocessed before it used implement condition-based strategy. Reliable means accurate positioning noiseless parameter...

In recent times, linear project resource leveling based on the scheduling method (LSM) has attracted considerable interest owing to unique advantages of applying LSM projects. research reported in this paper, problem was described as a constraint satisfaction analyses conducted previous studies and two-stage model for projects proposed. The optimization process reasonably set so fully utilize rate float activity obtain more optimal schedule. programming (CP) technique used solving problem....

Railway track irregularities are key factors that affect the safety of trains and comfort passengers. In this study, a railway is separated into consecutive maintenance units, which used as research objects. We propose novel framework, referred to tree-augmented naïve Bayes-track quality index (TAN-TQI), identify possible underlying patterns or rules for predicting based on characteristic deterioration units. The prediction framework validated using irregularity data measured geometry cars....

Abstract Reasonable maintenance plans are important for ensuring safe train operation and prolonging the service life of tracks. However, previous studies on scheduling optimization railway track possess following limitations. First, models generally operate at planning level with months as time units rather than days units. Second, they fail to consider bidirectional feedback dynamic impact between predicted condition scheduling. Third, actual on‐site strategies (e.g., opportunistic...

Abstract Information technology has significant potential to enhance the engineering quality of risk management railway construction projects. The Shanghai Railway Bureau promoted a method based on “A Figure and Four Tables” (AFFTM) assess quality; however, this still suffers from several problems in project management. In paper, we have combined concepts processes AFFTM with those information presented implementation scheme new system—the system (RCPQRMIS)—that can be used design develop...

Abstract Track geometry car inspections play a vital role in assessing railroad track quality and scheduling maintenance. Effective use of inspection data depends on accurate location measurement. Field surveys reveal that measured milepoint positions can be off by up to 200 m. Previous efforts correct errors resulted the development Key Equipment Identification model, which reduces below 5 m most cases 1 for new inspections. However, analysis segment deterioration requires alignment...

Based on analysis of some existing prediction methods and models for track irregularities, according to the characteristics irregularity development China railroad, this paper has proposed a short-range model (SRPM) which applies calculus thinking method estimate irregularities over small lengths single-day basis using waveform data generated by geometry car. We applied SRPM make predictions many unit sections up-going tacks Beijing-Shanghai Railway Line (Jing-Hu Line) past two-year railway...

Accurate information on future railroad track condition is essential to optimally schedule Maintenance & Renewal activities in order minimize influences of the rail traffic under constraints limited budgets and maintaining allowable tracks. In this paper, a measurement data mining method presented aim. It developed basis deterioration characteristics. Actual used analyze errors predictions by method. The analysis results show that proposed can mine accurate rates from historical thus...

Both Chinese and foreign researchers have developed linear models to predict track irregularities. These adopt the Track Quality Index (TQI) as an index evaluate overall irregularity. In these models, averaging method is employed calculate slope k of irregularity over a particular section then used future TQIs. However, complicated factors affect Roadbed state, passing tonnage, train running speed structure are all important that determine changes. Under joint action various factors, changes...

The railway track geometry condition is a key factor influencing the safety and comfort of train operations, controlling tamping cycles tracks. For scientific disposition limited maintenance resources, infrastructure managers need to predict based on an accurate grasp degradation rules. Taking each 200-m segment as research object, authors analyze uncertainty heterogeneity discrete evaluation condition. On this basis, improved model using Weibull distributions proposed accurately estimate...

Track quality instruments use low-cost accelerometers placed on or attached to the floors of operating trains, and these collect substantial amounts data over short inspection periods. The measurements collected by are main source for track irregularity evaluation. However, considerable measurement bias exists in vertical lateral vibration obtained from such instruments. False positive defects detected occur frequently. This results time effort being expended needlessly because maintenance...

Track Irregularity has a significant influence on the safety of train operation. Due to fact that extremely large number factors affect track irregularity,it is challenging find concise yet effective mathematical method describe evolution irregularity. In this paper, inspection data generated by GJ-4 cars from Jinan Railway Bureau in China were analyzed identify characteristics irregularity changes common different mileage points. Based these characteristics, multi-stage linear fitting model...

Traditional track geometry fault diagnosis methods, such as car, detection trolley and manual measurement, suffer from low frequency. Therefore, using vibration data in-service metro vehicles to diagnose faults can improve the efficiency of condition detection. Hence, a model car-body was established in this study based on convolutional neural network model, effects structural hyperparameters performance were analysed. First, problem collection addressed, mileage-locating without global...

In recent years, with axle loads, train transport volume, and travel speed constantly increasing railway network steadily lengthening, shortcomings of current maintenance strategies are getting to be noticed from an economical safety perspective. To overcome the shortcomings, permanent‐of‐way departments throughout world have given a considerable attention ideal strategy which is carry out appropriate maintenances just in time on track locations really requiring maintenance. This simplified...

Because steel rail is one of the most fundamental components railway operations, accurate estimation residual service life great significance in ensuring safe operation railways. In addition, maintenance expenses must be minimized a manner that allows limited railroad resources to optimally allotted. this study, typical types continuous segments on line are classified into non-sharply curved and sharply segments. Using these classifications, model for estimating lives using discrete-state...

Precise milepoint measurement data are essential for better subway track management and maintenance practices within railroads subways. For estimation, dead reckoning systems of some geometry cars use as pesudolite markers having no unique identification information. In such cases, have to be postprocessed. However, the postprocessing is conducted in a manual fashion time consuming labor intensive. This paper presents an optimal match method automatically postprocess data. The presented...

Rail wear is the most common defect that affects sharply curved metro rails, thus impacting their renewal periods. This article presents a stochastic model, based on Weibull distribution, for estimation of periods rails analysis characteristics rail wear. The model considers several heterogeneous factors to determine effects deterioration process and shown be able estimate life expectancy these in any state, as well remaining lives periods, with respect factors. validated by case study...

As railroad infrastructure becomes older and rail transportation is developing towards higher speed heavier axle, the risk to safe transport expenses for maintenance are increasing. The deterioration (prediction) model vital reducing expenses. A short-range track condition prediction method was developed in our previous research on analysis. It intended provide managers with two or three months of advance schedule activities more smartly. Recent comparison analyses geometrical exceptions...

Efficient and low-cost modes for detecting metro track geometry defects (TGDs) are essential condition-prediction-based preventive maintenance, which can help improve the safety of operations reduce maintenance cost tracks. Compared with traditional TGD detection method that utilizes car, uses a portable detector to acquire car-body vibration data (CVD) be used on an ordinary in-service train without occupying schedule line, thereby improving efficiency reducing cost. A convolutional neural...