Pier Settlement Research Articles

Intrinsic Topological Relationship between Pier Settlement Amplitude and Train Running Performance Dynamic Index

This study develops the train sub-model by multibody dynamic theory and establishes the longitudinally connected ballastless track-bridge sub-model using finite element theory. The two sub-models are assembled into a joint simulation model of train–track–bridge system coupling dynamic (JSTTBS) through wheel–rail contact relationships. Then, the influence of interlayer connection failure and pier settlement on the dynamic index of train–track–bridge system is analyzed, the intrinsic topological relationship (ITR) between pier settlement amplitude and dynamic index considering interlayer connection failure is proved, and the pier settlement threshold is proposed. The results showed that the calculation results of JSTTBS considering the interlayer connection failure and pier settlement are in good agreement with the literature data, verifying the model’s accuracy. The void beneath the slab caused by the pier settlement aggravates the train dynamic index change. After considering the void beneath the slab, the maximum value of each dynamic index is about two times that without accounting for the void. The uneven settlement value of the pier derived from the ITR is within 22.47[Formula: see text]mm, which is in good agreement with the calculation result of the established JSTTBS of 23.08[Formula: see text]mm, indicating the reliability of the ITR to calculate the uneven settlement threshold of the pier.

Riding safety prediction of a high-speed train running on transition zone under foundation settlement

The settlement of piers and subgrade bending deformation are widely recognized as common issues in the transition zones of high-speed railway bridges. This study aims to investigate the settlement behavior within these transition zones and its impact on the dynamic interaction between trains and the track. To achieve this, a vehicle-track-transition zone mapping relationship model is developed to analyze both the settlement behavior and the resulting dynamic response characteristics. The study employs the finite element method and multi-body dynamics to construct the simulation model. Settlement effects are simulated using the Newton-Raphson iterative method, with the additional rail deformation caused by foundation settlement serving as the excitation for the vehicle-track-transition zone dynamic interaction system. In the numerical analysis, the dynamic effects of three key factors—train speed, transition zone length, and the amplitude of foundation settlement—are examined based on the performance of the vehicle-track-transition zone interaction. The time-frequency technique is utilized to comprehensively reveal and clarify the spatial-frequency characteristics of system responses influenced by settlement excitation. Moreover, the relationship between the safety-based settlement threshold and these three factors is calibrated.

Dynamic “Disengagement-Closure” Contact Characteristics of Track–Bridge Interface Caused by High-Speed Train Under Side Pier Settlement

A nonlinear dynamic model of a train–bridge-longitudinal track coupling system considering the dynamic contact of the bridge–track interface (BTI) is established. Based on the previously established BTI contact characterization model and train–bridge coupling joint simulation model, the proposed model is verified from both static and dynamic perspectives. Accordingly, the dynamic displacement variation law of the bridge–track structure before, during and after the train passing through the side pier settlement area, the additional stress dynamic variation law and the interlayer connection dynamic variation law are analyzed. Moreover, the amplification effect of the wheel repeated “beating effect” on the dynamic contact force of “disengagement-closure-redisengagement” of the BTI void area is also analyzed. The results show that the accuracy of the proposed model can be verified from both static and dynamic perspectives. During the train passes through the settlement area, the dynamic deformation of track is the largest. Before and after the train passes through the settlement area, the dynamic deformation of track is basically the same. During the train passes through the settlement area, the BTI completes a dynamic contact process of “disengagement-closure-redisengagement”. The static effect of the side pier settlement on the dynamic bonding force of sliding layer is much larger than the dynamic effect of the train load. The dynamic effect of the train load is much larger than the static effect of the side pier settlement on the dynamic bonding force of the CA mortar and fasteners. The side pier settlement has a dynamic amplification effect on the train wheelset. Along the mileage direction, there are interface voids and contact areas in the dynamic bonding force of sliding layer and CA mortar, while there are no voids and contact areas in the dynamic bonding force of fasteners.

Computer Vision-Based Pier Settlement Displacement Measurement of a Multispan Continuous Concrete Highway Bridge under Complex Construction Environments

Various concrete bridges have been built across oceans, valleys, and mountains; however, the settlement displacement of bridge piers caused by environmental changes or self-weight during construction phases often leads to uneven stresses, cracking, and eventual collapse. To address the labor-intensive and high-cost issues of pier displacement monitoring using contact-type sensors, this paper proposes an automatic vision-based method for measuring pier settlement displacement under complex construction environments, such as complex image backgrounds, varying ambient light, and camera movement. In the proposed method, a deep learning network was first employed to eliminate the adverse effect of complex image backgrounds and varying ambient light on the accuracy of target detection; then, an adaptive displacement extraction algorithm without a human-computer interaction process was developed to automatically extract the center coordinates of targets attaching to the bridge piers and reference platform; finally, the pier settlement displacement was calculated by using the relative displacements obtained by a dual camera system to eliminate the measurement error caused by camera translation and rotation movements. Laboratory tests of a cantilever beam and field tests of a continuous multispan concrete girder highway bridge under construction have successfully validated the effectiveness and robustness of the developed methodology. The results obtained in this paper can provide some insights for engineers in applying computer vision technology for the real-time monitoring of bridge displacements.

Structural Health Monitoring Design and Performance Evaluation of a Middle-Span Bridge

Structural health monitoring (SHM) has attracted significant attention over the past two decades due to its ability to provide real-time insight into the condition of structures. Despite the development of several SHM systems for long-span bridges, which play a crucial role in the assessment of these structures, studies focusing on short- or middle-span bridges remain scarce. This research paper presents an efficient and practical bridge monitoring and warning system established on a middle-span bridge, a key crossroad bridge located in Shenzhen. The monitoring system consists of sensors and measuring points that collect a substantial amount of data, enabling the close monitoring of various operational indicators to facilitate the early detection of threshold exceedances. Based on this system, the subtle condition of the bridge can be evaluated, and the operational condition of the bridge can be studied through the comparative analysis of the collected data. Over four months of monitoring, data including the strain and creep of the main beam, the strain and settlement of piers and the crack width of the bridge body are observed. Furthermore, the real-time operational status of the bridge is analyzed and evaluated through the combination of the collected data and the structural finite element model.

Reliability of super-slope rack railway under bridge pier settlement

Reliability of super-slope rack railway under bridge pier settlement

Long-term settlement of metro viaduct piers: A case study in Shanghai soft soil

Long-term settlement of metro viaduct piers: A case study in Shanghai soft soil

Deformation mapping between pier settlement and maglev track for high-speed multi-span simply supported maglev bridge

Deformation mapping between pier settlement and maglev track for high-speed multi-span simply supported maglev bridge

Combined Prediction Model for High-Speed Railway Bridge Pier Settlement Based on Robust Weighted Total Least-Squares Autoregression and Adaptive Dynamic Cubic Exponential Smoothing

Combined Prediction Model for High-Speed Railway Bridge Pier Settlement Based on Robust Weighted Total Least-Squares Autoregression and Adaptive Dynamic Cubic Exponential Smoothing

Assessment of railway bridge pier settlement based on train acceleration response using machine learning algorithms

Assessment of railway bridge pier settlement based on train acceleration response using machine learning algorithms

Preliminary results of parametric study of structural behaviour of Persian brick masonry groined multipartite (Tarkin) vaults

Preliminary results of parametric study of structural behaviour of Persian brick masonry groined multipartite (Tarkin) vaults

The Network of Railway Settlements of the Tobolsk Province in the Late XIX - Early XX Century

Based on the analysis of mass sources – archival documents of the First General Population Census of the Russian Empire in 1897 and information published by the Tobolsk Provincial Statistical Committee for 1903 and 1909, the number, typical diversity, and population of settlements formed in the exclusion zone of the Perm-Tyumen and West Siberian railways on the territory of the Tobolsk province is determined. A set of statistical methods was used to analyze the sources. A comprehensive interdisciplinary approach allows not only to identify the historical and genetic features of individual documents, but also to give a certain assessment of their representativeness and information potential for specific historical research. Intensive construction of railways has led to the emergence of new types of settlements: stations, independent settlements at stations and on the railway line, barracks and semi-barracks, booths, barracks, guard houses, etc. In 1897, at least 128 railway settlements were functioning on the territory of the province, which was about 2.5% of the total number of all settlements in the studied region. More than two thousand people lived in them permanently and temporarily; on average, there were 18 people per settlement. The major settlements were the Tyumen and Kurgan stations. It is concluded that the primary materials of the 1897 census have the most complete information. In connection with the further construction of the Trans-Siberian railway at the beginning of the XX century, there is an increase in the population of stations and pier settlements, their merger, the emergence of new types of railway settlements.

Failure mode of interlayer connection of longitudinally-connected ballastless track-bridge system under uneven pier settlement

Failure mode of interlayer connection of longitudinally-connected ballastless track-bridge system under uneven pier settlement

An Analytical Solution for the Geometry of High-Speed Railway CRTS Ⅲ Slab Ballastless Track

To study the mapping relationship between girder deformation and rail deformation for the CRTS Ⅲ slab ballastless track (SBT) multi-span simply supported bridge, this study derived a simplified analytical solution, and the corresponding ANSYS finite element model (AFEM) was established. Compared with the fine analytical model (FAM) and the AFEM, the calculation results of the three models under the conditions of pier settlement and girder vertical fault were compared, which verified the universal properties of the simplified analytical model (SAM). Based on the verified SAM, the influence of pier settlement, fastener stiffness, girder span, and girder vertical fault on rail deformation was studied. The results show that the rail deformation is approximately proportional to pier settlement and girder vertical fault. With the increase in fastener stiffness, the fastener internal force increases, the rail mapping deformation increases, and the length of the rail mapping deformation area decreases. With the increase in girder span, the rail deformation curve becomes smooth, the length of the rail mapping deformation area becomes longer, and the fastener internal force is significantly reduced.

Observed performance of a deep excavation of Qingdao Metro Line 4 in China

Observed performance of a deep excavation of Qingdao Metro Line 4 in China

Data driven structural damage assessment using phase space embedding and Koopman operator under stochastic excitations

Data driven structural damage assessment using phase space embedding and Koopman operator under stochastic excitations

Moving Safety Evaluation of High-speed Train on Post-earthquake Bridge Utilizing Real-time Hybrid Simulation

ABSTRACT This study aimed to provide an experimental evaluation method for train’s moving safety on a post-earthquake bridge. First, an improved real-time hybrid simulation (RTHS) framework was constructed, based on utilizing the moving load superposition algorithm to solve the train-track-bridge interaction (TTBI) problem. An RTHS test was then conducted for the TTBI problem. The train model was tested using a shake table and was dynamically linked to the numerical substructure. A post-earthquake seven-span high-speed railway simply supported bridge was studied, in which earthquake-induced damage, such as stiffness reductions, residual displacements of piers, girder gap expansions, and pier settlements were all tested.

A High-Precision Distributed Microdisplacement Monitoring System: System Design and Data Processing Algorithms

For large-scale constructions, micro-displacement may accumulate over time and it is possible that the large-scale constructions have disastrous consequences such as deformation, cracking, or collapse, resulting in irreparable losses. In order to avoid the occurrence of tragedy, it is crucial to monitor the micro-displacement of constructions timely and accurately, apart from the operation and maintenance of large-scale structures. There are several challenges to fully automatic monitoring of micro-displacements of large-scale structures, including the lack of reference points due to structural complexity, various environmental disturbances, and the trade-off between low cost and high precision. In this paper, a measurement device with low cost, high accuracy, and wide applicability is designed to provide real-time monitoring of the micro-displacement of large-scale structures. A comprehensive system is designed and a data processing algorithm based on data reconciliation is proposed to effectively alleviate the influence of measurement errors. This system is successfully applied to pier settlement detection for high-speed railways, which achieves the desired accuracy. The system we developed can be directly applied to many situations of micro-displacement monitoring of large buildings, with high accuracy and low cost.

Uneven settlement threshold of continuous beam pier based on analytic mapping relationship

Currently, there is no regulation on the settlement threshold of continuous beam bridge pier of high-speed railway (HSR), a method is proposed in the present study to calculate the settlement threshold of continuous beam pier based on the analytic mapping relationship. First, the dynamic model of the train-track-continuous beam bridge was established. Then, the mapping rail irregularities caused by pier settlement obtained from the analytic mapping relationship superimposed with the initial rail irregularities converted from the Chinese track irregularities spectrum by using the trigonometric series method. Furthermore, the proposed method was verified by comparative analysis with the measured data and the existing results. Finally, the types and thresholds of uneven settlement of continuous beam bridge pier were revealed based on the parameter discussion method. It was found that the influence of pier settlement on the train dynamic performance index had a strong correlation with the train running direction. The settlement threshold of long-span continuous beam pier was looser than that of simply supported beams with a 32 m span. The settlement threshold of continuous beam piers can be appropriately relaxed in design.

Vibration-based multiclass damage detection and localization using long short-term memory networks

Vibration-based multiclass damage detection and localization using long short-term memory networks