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Understanding the scour process around bridge piers and investigating approaches to reduce these phenomena is an important issue for engineers. Side-by-side piers cause lower scour depth compared to a single pier with the same diameter. In this study, the application of downstream bed sill and continuous footing to control the scour depth around single piers and two side-by-side piers is investigated experimentally. The results show that by using a continuous footing with a thickness equal to the pier diameter, the scour depth in front of the pier is reduced by 50% and 55% for single pier and side-by-side piers, respectively. Moreover, when the continuous footing thickness is doubled, no scour depth is observed in front of the pier. Additionally, incorporating a downstream bed sill adjusted to the pier results in a reduction of approximately 30% in scour depth in front of the piers. [ABSTRACT FROM AUTHOR]

This research examines the influence of peak time, flood duration, and pier position on the variations in scour pattern and the greatest depth of scour cavity surrounding a single pier protected with a collar. The study encompasses a flow velocity range spanning from incipient motion conditions to mobile bed conditions. The findings demonstrate that the implementation of a collar not only reduces the dimensions of the scour cavity surrounding the piers but also alters the location of the greatest depth of scour cavity. On average, the utilization of a collar at 60°, 90°, and 120° positions during four flood durations resulted in respective reductions of 40%, 60%, and 45% in the average scour cavity volumes surrounding the pier. Results further indicate that the collar successfully reduced the greatest depth of scour cavity, volume, and area surrounding the pier in over 95% of the conducted tests. [ABSTRACT FROM AUTHOR]

The present paper addresses the effect of placing an intake, as a diversion structure, in different positions and with various angles in a 180° bend to investigate the scour depth around a circular pier in an SSIIM2 numerical model. The simulation was conducted by placing the intake at the 75°, 90°, 115°, 135°, and 150° positions with 45°, 60°, and 90° angles. The results indicated that the greatest effect was associated with the installation of the intake with a 90° angle at the 135° position, which decreased the maximum scour depth by a considerable amount, about 70%, compared with the bend without an intake. However, the maximum scour depth occurred with the installation of the intake at the 150° position with an intake angle of 45° and increased by 20% compared to the bend without an intake. Furthermore, the maximum and minimum scour hole wall slopes around the pier in the case of the bend with an intake respectively increased by 6.24 times and decreased by 5.1 times compared to the bend without an intake at the upstream pier. The maximum sedimentation height around the pier decreased by about 40% in the bend with an intake compared to the one without an intake. [ABSTRACT FROM AUTHOR]

Prediction of scour at complex or non-uniform piers has been mostly aimed at single piers, while most bridges are constructed on a group of non-uniform piers. The novelty of this study is to investigate the effect of foundation level and piers' distance on local scour around the non-uniform twin-piers. The experiments were carried out considering five foundation levels, under and above the bed, with various piers distances in clear-water conditions. Results show that for the case of foundation level above the bed, scour depth at non-uniform twin piers is larger than that of uniform configuration, and distance between piers has no significant influence on scour depth. For the case of foundation at bed level, the distance between piers has no remarkable effect on scour depth while the scour depth around non-uniform twin piers is found to be less than that of uniform ones. When the foundation is under the bed level, the presence of the foundation reduces the scour depth around both front and rear piers, and the distance between piers has a direct effect on the scour depth. In this zone, the foundation delays the scour process and the scour time increases with increasing foundation depth. This study highlights that a proper design of the foundation level increases the duration of scouring and decreases the scour depth. [ABSTRACT FROM AUTHOR]

Frame piers of double-deck viaducts (DVFP) have been widely studied and applied due to their high levels of space utilisation and significant engineering benefits, but the uncertainty of their information on modelling significantly affects the accuracy of calculation results for structural seismic demand and seismic capacity, which leads to challenges regarding the accuracy and reliability of seismic fragility analysis. In this paper, an accurate non-linear finite element model of DVFPs was established based on the OpenSees open platform. The seismic fragility analysis of DVFPs is carried out by introducing the endurance time method, and the tornado diagram and central point methods were performed to investigate the sensitivity and uncertainty of a seismic fragility of DVFPs to nine modelling parameters, respectively. The results show that the logarithmic standard deviation of fragility when slight damage, moderate damage, significant damage, and collapse occur on DVFP after considering modelling uncertainty will increase by 6.4%, 16.1%, 13.3%, and 20.1%, respectively. Therefore, it is necessary to consider the influence of modelling uncertainty in seismic fragility analysis. [ABSTRACT FROM AUTHOR]

This paper presents a pioneering artificial intelligence (AI) solution - the Arctic Tern-Optimized Weighted Feature Least Squares Support Vector Regression (ATO-WFLSSVR) system to aid civil engineers in accurately predicting scour depth at bridges. This prediction system amalgamates the strengths of hybrid models by uniting a metaheuristic optimization algorithm with weighted features and least squares support vector regression (WFLSSVR). The metaheuristic algorithm concurrently optimizes all hyperparameters of constituent WFLSSVR models, resulting in a highly effective system. Validation involves a comprehensive assessment using two case studies, which include datasets of scour depths across various complexities and pier foundation types. Comparative analyses against single AI models, conventional ensemble models, hybrid techniques, and empirical methods demonstrate that ATO-WFLSSVR's reliability outperforms others in performance evaluation metrics. Specifically, for the field dataset, ATO-WFLSSVR achieves MAPE and R values of 20.92% and 0.9435, respectively, and for scour depth data at complex pier foundations, it records MAPE and R values of 6.49% and 0.9384, respectively. The automated predictive analytics underscore the robustness, efficiency, and stability of ATO-WFLSSVR compared to existing methods. This study's notable contributions include the development of an innovative optimization algorithm named Arctic Terns Optimizer (ATO), proficiency in solving high-dimensional optimization problems, and the creation of a user-friendly graphical interface system, a promising tool for civil engineers to estimate scour depth at bridges. Further testing and evaluation of ATO-WFLSSVR across diverse datasets encompassing more complex scenarios are recommended. The data and source code for this study are currently accessible at https://www.researchgate.net/profile/Jui-Sheng-Chou/publications. [ABSTRACT FROM AUTHOR]

Hammerhead pier is the preferred option in many bridge sites for its limited ground occupation. Since the bearing reactions act on the short cantilever ends of the cap beam, it is usually treated as stress-disturbed region (D region) in structural concrete. Although finite element model (FEM) can predict the response of such structures, the calculation efficiency will be sharply decreased once it enters nonlinearity. Therefore, strut-and-tie model (STM) has been promoted as an alternative approach for analyzing D regions. In this study, a loading pattern was defined to relate the axial force and bending moment of the pier column with the eccentric load ratio. Sectional analysis method and associated codes were developed to generate the STM. In addition, a full-scale hammerhead pier specimen subject to varying eccentric loads was tested. Besides, nonlinear FEM was also established to numerically investigate the response of the pier. The results indicate that the proposed STM has general applicability for modeling the hammerhead pier and shows better prediction than the FEM. The failure pattern of the hammerhead pier with a prefabricated cap beam was defined. Combining the mechanical analysis of STM and experimental results, the recommended design details for hammerhead piers were proposed. [ABSTRACT FROM AUTHOR]

To investigate the correlationf between residual drift and remaining seismic capacity, 24 reinforced concrete pier specimens were subjected to lateral load reversals. By normalizing the specified drift against the value at specimen failure, the normalized residual drift exhibits a strong correlation with the normalized lateral drift, thereby providing a predictive model for residual drift. After determining the remaining seismic capacity derived from energy dissipation, a linear correlation was established between the normalized residual drift and the remaining seismic capacity. Consequently, normalized residual drift was selected as a performance indicator for seismic assessment, enabling the quantitative determination of structural damage states. [ABSTRACT FROM AUTHOR]

Seismic performance of partially concrete-filled steel tube (PCFST) bridge piers is controlled by the coupled failure of ultralow-cycle fatigue (ULCF) and local instability of steel plates. An empirical formula was established for the plastic fracture displacement on average stress triaxiality of the crack intiation process, and the two-stage prediction model for the ULCF cracking of steel was improved. Furthermore, an empirical formula was established for the plastic strain amplification factor on the element size and the stress triaxiality of the coarse model. A complete modeling method was proposed for the seismic performance analysis model of PCFST piers considering ULCF cracking. [ABSTRACT FROM AUTHOR]

In this article, I review an assemblage of London wharf terms hithe, gate, wharf, bridge, stair, quay, dock, and pier, organised according to date. My purpose is to examine semantic change over time and to identify effects of multilingualism, as speakers of Middle Dutch across the North Sea used cognates hide, gat, werf, brug, steiger, kade, dok; riverside -bridge names shared semantic content with Old Norse bryggja 'landing-stage, jetty', and lane-names -gate shared semantic content with Old Norse gata 'passageway, lane'. I suggest that Scandinavian speakers in London under Cnut's reign could have interpreted gate in its Old Norse sense of 'lane', leading to analogical extension of Old English terms hithe, bridge, stair also becoming the names of both wharves and their lanes, even though these words had no intrinsic 'lane' meaning. By contrast, later terms quay, dock, and pier never developed the sense 'lane'. The earliest reference to bridge 'jetty' (ad pontem Wulfuni) occurs 1231–1238. In Snorri Sturluson's Heimskringla of c.1230, Lundúna bryggjur are pulled down, and the assemblage of later -bridge names, productive into the nineteenth century, adds weight to the arguments made by previous scholars that the meaning here is 'jetties' rather than 'road spanning water'. [ABSTRACT FROM AUTHOR]

This article presents a numerical study that aims to explore the dynamic behavior of railway bridges under vibrations induced by heavy-haul traffic. For this purpose, a finite element code that can conduct moving load and moving mass analysis of single span bridges was developed. The software was validated by comparing the numerical response to the analytical solution for various speeds. The numerical analysis of the benchmark bridge under the benchmark train showed the interplay between the natural frequency of the bridge, the mass of the train and the loading frequency. A comprehensive parametric study to investigate the impact of different parameters on the dynamic behavior of railway bridges is also provided. The bridge span length, normalized train length, normalized mass of the train, bridge deck stiffness, and train speed are the variables considered in the parametric study. The results of the extensive numerical analyses improve the understanding of railway bridge behavior under heavy-haul trains, and highlight the impact of the inertial effect of the trains on bridges, especially for varying span length and deck stiffness. It is also demonstrated that, when the train-to-bridge mass ratio exceeds 40%, the inertial effects of the train mass needs to be included in the analysis in order to obtain a reliable estimate of the bridge behavior under different train speeds. [ABSTRACT FROM AUTHOR]

The longitudinal seismic response reduction in railway bridges is worthy of attention because it relates to the engineering cost. It is difficult to further explore the reduction effect because the complexity of traditional analysis model leads to the low efficiency in parametric analysis. In this paper, the track structure was simplified, and a simplified calculation model was established. The parametric analysis considering the span number and pier height on the simplified model seismic responses was carried out. The results showed that the reduction effect was extensive and there was a great internal force transferred to the subgrade-track structure. [ABSTRACT FROM AUTHOR]

Precast segmental bridge piers attract engineers due to the strengths of accelerated construction, reduced traffic disturbance and enhanced quality control. However, their widely applications in high-seismicity areas are hindered, for the insufficient capacities of energy dissipation. In this study, precast segmental piers' seismic behaviors were investigated, focusing on the connection of 'grouted sleeves/bonded tendons'. To this end, four piers were cyclically loaded, of one cast-in-place pier, one precast segmental pier, and two prestressed precast segmental piers. Among them, Benefits of bonded tendons were evidenced, in terms of lateral strength, ductility, energy dissipation capacity and residual drift. Of particular, bonded tendons prevented the shear-induced slip between the shaft and footing segments. Enlightened from observations, cyclic dowel-friction effect is proposed and implemented within a zero-thickness sliding spring in the finite element model, capable of capturing the shear-induced joint slip. Furthermore, seismic vulnerability assessments of the bridge piers are obtained in terms of fragility curves, by performing incremental dynamic analyses. In addition, the effects of bonded or unbounded tendons are also discussed. Two criteria are adopted to define the limit states, namely displacement ductility and residual drift. It is suggested that bonded tendons could significantly ameliorate the fragility curves of precast segmental piers. Four bridge piers were cyclically loaded, with various prestressing levels. A reliable fiber-based model was constructed, considering shear-induced slip at the segmental joint for the first time. Seismic vulnerability assessments were performed to quantify the piers' behaviors. [ABSTRACT FROM AUTHOR]

The flow pattern at the meandering rivers changes to a helical flow. The installation of bridge piers on the meandering river and collision of the flow with pier geometry creates a far more complicated flow. The experiments were performed in a 180-degree bend channel and a radius to curvature ratio of two. The pier groups were installed in convergent-vertical in streamwise direction (CVS) and divergent-vertical in streamwise direction (DVS). The results show that the earliest eddy flows in the convergent-vertical pier groups were formed at near water surface level. According to the findings, the formation of return flow from a 77.5 degree angle and at a distance of 35 to 45 percent of the width of the channel from the inner bank happened. However, the return flows were initiated from the 87.5 degree and at a distance of 60% to 70% of the width of the channel from the inner bank in the divergent-vertical pier group. The power of secondary flow in convergent-vertical and divergent-vertical pier groups occurred at 85 and 87.5 degree sections respectively, and equal to 3.5 and 1.25 times the pier diameter from the center of the piers' location upstream. [ABSTRACT FROM AUTHOR]

Estimation of local scour depth at a bridge pier must be accurate and precise for the safety assessment of pier foundation. Many deterministic scour depth prediction models for bridge piers in sands and gravels have already been reported in the literature. However, the various types of uncertainties may be involved in the deterministic scour depth prediction models and thus affect the accuracy of the scour depth. To account for such uncertainties, a reliability analysis method is generally adopted. A sizable amount of laboratory and field data on scour has been procured in the present study to assess the performance of existing scour prediction models for gravel beds and develop a probabilistic scour prediction model using a First-Order Reliability Method (FORM) based on the object-oriented constraints optimization spreadsheet algorithm for the most appropriate selected deterministic scour prediction model. A new relationship of the silt factor has also been developed to estimate the scour depth in gravel bed as per Indian Practice. A safety factor based on the target reliability index has also been proposed in this study. [ABSTRACT FROM AUTHOR]

Evaluation of the seismic performance of two historical stone arch bridges of the Iranian rail network is presented using a discrete element method. The total length of the bridges is 66.7 m and 106.1 m. The bridges consist of multi-span arches changing from 5 m to 48.6 m. The incremental dynamic analysis method is used to determine the damage, failure patterns, and acceleration of the collapse threshold. Using the discrete element method after static analysis under gravity load, dynamic analysis of bridges under both horizontal components of the earthquakes was performed simultaneously for different earthquake intensities until collapse. The results showed that the most extensive damage occurred in the smaller bridge with the onset of failures in the top spandrels of the arches and then the piers of the bridge, while in the larger bridge which had a large central arch span, damage and failure occurred more in the central arch and its spandrels. The collapse spectral acceleration of the larger bridge is considerably smaller than the smaller bridge such that the ratio of collapse spectral acceleration of the larger to smaller bridge varies only between 45% to 61%. The low spectral acceleration intensity of collapse indicates more seismic vulnerability of the larger bridge. [ABSTRACT FROM AUTHOR]

High-pier railway bridges are mostly applied in mountainous areas. Due to the large spatial flexibility of the high piers under train dynamic loads, especially under braking conditions, the wheel-rail (WR) dynamic interaction may become more intense in the longitudinal direction, which could induce larger deformation and impact on the train-track-bridge (TTB) coupled system. To investigate the dynamic characteristics of such complex and large system during train braking condition, a 3D train-slab track-high pier bridge (TTHPB) coupled dynamics model is established and verified by considering the system longitudinal vibrations and the spatial flexibility of high piers. In this work, the influence of concerned bridge height from 60 to 160 m on the dynamic performances of the TTHPB system under train braking condition is studied. Results indicate that the operation speed has a significant effect on carbody acceleration and WR force. The longitudinal carbody acceleration due to its high-frequency vibration, as well as its noticeable amplitude induced by the long-time frequent braking, should be carefully considered in the evaluation of riding comfort index. The longitudinal dynamic behaviour of the high pier bridge is considerable and should be paid full attention to in bridge design compared with the other two directions. [ABSTRACT FROM AUTHOR]

Earthquake-induced poundings have been identified as a critical factor influencing bridge seismic behavior. However, most previous studies on this topic did not consider link-slabs in the continuous deck, which would influence the pounding occurrence and thus the subsequent seismic response. This paper uses a probabilistic method to evaluate the seismic vulnerability of a simply-supported bridge considering pounding and link-slabs. The damage states of girder ends due to poundings are proposed according to the cumulative damage. To analyze the seismic vulnerability of the whole bridge, both the joint probabilistic seismic demand model considering multiple engineering demand parameters and the joint damage state model considering the capability of each bridge component are established. Based on these models, the fragility curve of the whole bridge is obtained using the Monte Carlo method. The effects of gap sizes between pounding components and pier heights on the bridge seismic vulnerability are also investigated. The result reveals that the fragility of the whole bridge system is higher than that of any individual component. Ignoring the contribution of damage to each component to the whole system will lead to an overestimation of the seismic resistance of the overall bridge, which is detrimental to structural safety. [ABSTRACT FROM AUTHOR]

The article discusses Pier Paolo Pasolini's film "La rabbia" (Rage) and its exploration of rage as a moral emotion. The film challenges the disinterested gaze of the spectator and calls for active interpretation. Despite facing censorship, "Rage" is considered an important part of Pasolini's work. The text also examines the role of anger in moral responsibility and criticizes the media for promoting apathy. It analyzes a sequence in the film that juxtaposes Marilyn Monroe with the atomic bomb, highlighting the ethical implications of voyeuristic gazes. The text raises questions about the power and limitations of images and the need for critical awareness in consuming media. [Extracted from the article]

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. [ABSTRACT FROM AUTHOR]

Drift-based performance assessment has been a practical tool among the research and engineering community. However, several studies showed that there are several critical issues such as seismic damage definitions and their quantifications related to the displacement-based approach when it is applied not only to modern masonry structures but also to historical ones. The main reason is due to (i) failure mode dependency, (ii) geometry, loading and boundary conditions, (iii) inadequate prediction of the failure modes based on in-plane capacity formulations given in the codes. The present article discusses the reliability of drift limit values proposed by different codes and guidelines by comparing drift values derived in two datasets of masonry piers through considering an application to a real case study. It is observed that performance-based assessment is mainly based on the failure mode of the masonry structure, while the Guideline for Earthquake Risk Management of Historical Structures in Turkey, which is widely used in practice, proposes drift limits that are independent of the masonry behavior. Without consideration of the behavior mode can lead to incorrect assumptions and hence unconservative performance assessment outcomes for the architectural heritage. [ABSTRACT FROM AUTHOR]

The effect of unsteady currents on scour at piers was investigated. The tests were run for nine pier shapes, three installation positions along a 180° bend, four flood durations, and four ratios of rising limb to flood duration for the 100-minute flood durations. Overall, including seven tests performed in the bend without piers, 196 tests were performed. The flow rapidity ranged from the movement threshold to live bed situations. The results indicated that the deepest scour-hole in front of the piers with different shapes was a function of flood duration and the ratio of ascending branch to descending branch had little effect on the final maximum scour-hole depth around the pier. The scour-hole volume is affected by the nose and the cross-sectional shape of the pier. For the rectangular pier, the scour-hole volume is greater than that of the other piers. The average shape coefficient was calculated. [ABSTRACT FROM AUTHOR]

For the bridges of the present article, the envelope curves of the load-deformation diagram that resulted from experimental measurements of wall specimens and the application of literature and novel equations are considered. For these load-deformation envelope curves, the behavior factors of the considered bridge models are estimated graphically by considering the envelope curves and applying the equal energy law. The aforementioned behavior factors are calculated by the use of methodology that takes into account the poor inelastic response of walls with an aspect ratio of 1.0 and 1.5. In addition, the sliding shear dominated response of the wall-like piers and the top displacement of the pier are calculated by considering the three main deformation mechanisms. Furthermore, comparative studies are performed for the definition of the plastic hinge length that should be considered for a more rational approach to the inelastic design and checking of the wall-like piers of the bridges under examination. In this way, the use of behavior factors with values higher than those determined by Eurocode 8 is justified. In the case of bridges with damaged, repaired and strengthened walls, the achieved behavior factors are significantly lower than in the case of bridges with virgin walls. [ABSTRACT FROM AUTHOR]

This paper uses the vibration-based damage detection method for structural health monitoring of a Railway Bridge. Hence, the bridge had been exactly modelled in finite element analysis software. Due to the elastomeric bridge bearing, direct calculating of the natural frequencies and extracting the mode shapes of the bridge is not suitable and effective. Therefore, a time-dependent transient analysis of the train movement on the bridge is done and then the vibrations of all truss cells during the train crossing period were extracted. Afterwards, the relevant data is transformed, which represents the natural frequencies of the bridge vibration and their amplitude at each point. In the following, the mode shapes of vibration and the distribution of vibration energy are calculated. Applying any artificial damages in the model, occurring changes in the natural frequencies, mode shapes, and the vibration energies of the modes, are examined. Consequently, detecting and locating damages in the structure has been done with acceptable accuracy. Finally, for validation of the results, an accelerometer is installed on the bridge truss in the middle part of the bridge to extract the acceleration of bridge vibration at the train crossing time interval. In the end, the results are compared and presented. [ABSTRACT FROM AUTHOR]

In the assessment and design of masonry buildings, several strength criteria can be applicable according to the prevailing mechanism, since masonry walls subjected to horizontal cyclic excitations, such as seismic actions, can be characterized by flexural/rocking modes, shear and sliding failures or by a combination of them. Several studies and correlations between different existing formulations have been performed in the past and are already available in the literature, but a lack of unanimous consensus still remains on the more rational criteria for the evaluation of the lateral strength of unreinforced masonry (URM) walls. This topic becomes even more relevant after the recent release of new structural codes, which propose, for existing buildings, different alternative formulations for the calculation of the in-plane shear strength of URM piers, making the choice of the more suitable approach to adopt rather intricate, above all when dealing with brick masonry. The aim of this study is to clarify the application of the different strength expressions specifically for the case of brick masonry walls. In order to achieve that, a systematic comparison between the results obtained from the application of different expressions with the experimental data coming from in-plane cyclic tests of brick masonry walls has been performed. This study has allowed to identify a more rational application of the various strength formulations in the case of brick walls, providing a basis for the improvement of the codified approaches and an useful tool for professionals. [ABSTRACT FROM AUTHOR]

The uplifting slide shoe (UPSS) bearing, consisting of multiple sliding surfaces, is a new type of bearing which has been proposed to achieve reduced displacement under strong earthquakes without losing advantage of the slide bearing to deal with the thermal effects on bridges girders. In the present study, bi-directional implementation of the UPSS devices is proposed to achieve effectiveness in controlling the bi-directional seismic response of girder bridges induced by bi-directional ground motions. A simplified multi-spring model of the bi-directional UPSS, considering the coupling effect of the friction mechanism and the geometric contact condition of the slider, is established to assess the bi-directional bridge response including the integrated nonlinear interaction between the longitudinal and transverse components. Numerical simulations demonstrate that the bi-directional UPSS is effective in reducing the pier response in the transverse direction compared with the conventional UPSS. The seismic performance of the bridge with the application of the bi-directional UPSS is shown to be superior to that of the functionally discrete bearing (FDB) systems in effectively reducing both the bearing displacement and the pier response ductility factor. [ABSTRACT FROM AUTHOR]

The new bridge across the deep gorge of the Chenab River in the remote mountains of Jammu and Kashmir is a key component of the Udhampur–Srinagar–Baramulla Rail Link (USBRL) project. The bridge is 1315 m long in total. Its main arch with a span of 467 m and land pier heights of up to 131 m place the bridge at an imposing 362 m above the river water level, making it the World's tallest railway bridge. Although the site location has been carefully chosen, yet the terrain itself is the most difficult from an engineering design and construction point of view. The slopes of the bank are very steep and consist of highly jointed dolomite strata. Extensive slope stabilization analysis was carried out and optimum measures were adopted and implemented successfully for slope stabilization works. The steel superstructure was erected using the incremental launching method. The report briefly highlights the various challenges faced in the project implementation and presents the most salient design aspects. [ABSTRACT FROM AUTHOR]

Modelling the cyclic response for the evaluation of the seismic capacity of existing corroded RC bridges is important as it is well recognised in literature. Procedures exist in the literature for the inclusion of corrosion effects through variation in different parameters like cross-sectional area of reinforcement, stress–strain behaviour, yield strength, ultimate strength and elastic modulus. In the present study, change in the inelastic buckling behaviour of reinforcement and variation in the core concrete damage characteristic under different levels of corrosion are also modelled in detail with OpenSees computational software. Modelling procedures for pristine and corroded bridge piers are validated by comparison of the cyclic response results and backbone curves obtained from analytical modelling with the experimental results reported in the literature. In this paper, the procedure for the cyclic response evaluation of piers for different mass loss percentages for corrosion has been demonstrated. From cyclic response results, the backbone curves for corroded bridge pier specimens are developed for different mass loss percentages of corrosion. The modelling strategy proposed in this paper for the cyclic response evaluation of bridge piers can be adopted for quantifying the effect of corrosion on the cyclic response of similar important structures. [ABSTRACT FROM AUTHOR]

The re-centring ability and durability of important bridges have been the main objectives in recent provisions of seismic design codes. To achieve better recoverability and durability for piers, this article presents a double-reinforced pier configuration, in which the outer layer is reinforced with fibre-reinforced polymer (FRP) rebar and the inner layer is reinforced with steel rebar. An equal flexural capacity design method was used to determine the double-reinforced configurations. The effects of the potentially influential design parameters on the seismic response of piers were studied and compared to those of conventional RC piers. The results show that the proposed design method can satisfy the ultimate capacity and durability demands. The double-reinforced piers had a better performance than conventional piers in terms of the ductility, post-yield stiffness and residual deformation. The maximum deformation and energy dissipation capacity of the double-reinforced piers were comparable to those of the conventional RC piers. The results also demonstrated that the proportion of steel reinforcement had a clear effect on the performance of double-reinforced piers. However, FRP reinforcement with a high modulus of elasticity should be avoided due to the adverse effect on ductility. [ABSTRACT FROM AUTHOR]

This study proposes a new type of reinforced concrete (RC) coupled shear wall with replaceable coupling beams and replaceable corner components (RCCs) installed at the bottom corners of wall piers. To assess the seismic performance of the new coupled shear wall and verify the proposed design methodology, four 1/2-scale specimens including one conventional RC coupled shear wall and three new coupled shear walls were tested under lateral cyclic loading. The test results indicate that compared with conventional RC coupled shear walls the seismic performance of the new coupled shear wall is significantly improved. [ABSTRACT FROM AUTHOR]

Literature review revealed that scour modeling using artificial intelligence (AI) lacks majorly in two aspects - one is the Input variable selection (IVS) and secondly, the relative ranking of scour models based on their performance. In this study, state-of-the-art AI algorithms, including artificial neural network (ANN), artificial neuro-fuzzy interface system (ANFIS), support vector machine (SVM), model tree (M5P), gene expression programming (GEP), and group method of data handling (GMDH) were employed to compute the Local Scour Depth (LSD) and to address identified lacunas. A total of 378 data set consisting of laboratory and field data was used for modeling. Evaluation criteria such as the index of agreement (IOA), Root Mean Square Error (RMSE), Mean Absolute Percentage Error (MAPE), Skill Score (SS), Correlation (Correl), and Taylor diagram were employed to check the goodness-of-fit of the proposed models. IVS was performed using partial mutual information (PMI). The findings of the study showed that velocity (V), the diameter of the pier (b), Reynolds pier number (Rp), and particle densimetric Froude number (Frd) were highly sensitive parameters to the scour. Quantitative and qualitative results indicated that SVM performed better with RMSE (0.06), MAPE (0.04) and SS (0.9). Tayler diagram also confirmed the above findings. [ABSTRACT FROM AUTHOR]

Piers Bohl (1865–1921) was an outstanding Latvian mathematician whose name is particularly connected with several crucial achievements that were ahead of their time. Unfortunately, the contemporary mathematical community did not recognize their significance. This paper discusses one of Bohl's results from 1908 that remained nearly unnoticed, even up until the present. It concerns a general complex trinomial and answers the problem of the distribution of its roots with respect to a given modulus. During the last few decades, this and other related problems have been extensively studied in numerous particular cases, without knowledge of this existing answer. This paper recalls the aforementioned Bohl's result and illustrates how easily it can imply conclusions of recent as well as older works regarding this topic. [ABSTRACT FROM AUTHOR]

This article proposes a seismic fragility analysis framework of bridges, which considers the freeze–thaw cycles and scour comprehensively. The time-varying seismic fragility analysis method is used to analyse the bridge system based on the degradation law of mechanical properties of concrete under the freeze–thaw cycles, combined with the uncertainty of earthquake, scour depth and freeze–thaw cycles. Under the condition of the scour, with the growth of service time, the seismic fragility of piers and bearings increased and the exceeding probability of bearing is higher than the pier, which makes the bearing more easily damaged than the pier in the case of an earthquake, thus reduces the seismic damage of the pier. The plastic hinge of the bridge pier transfers from the immersion zone to the freeze–thaw zone in freeze–thaw cycles. In this process, the curvature in the freeze–thaw zone grows up, dissipates seismic energy and leads the pier's fragility to decrease before the plastic hinge transfer. When combined with the scours and freeze–thaw cycles, the failure probability of the pier is slightly lower than that of only the scour action due to the phenomenon of plastic hinge transfer. [ABSTRACT FROM AUTHOR]

HuSuTong Yangtze River Bridge is a control project of the newly built HuTong Railway. The structure system is a cable-stayed bridge for highway and railway with a main span of 1092 m. The main girder is a steel truss structure with three main trusses. The upper deck of the highway is an orthotropic steel slab structure and the lower railway deck is a steel box structure. The upper and lower decks bear the force together with the main truss. The stay cables of the bridge are set as a three-cable plane structure. To meet the stress requirements, high strength bridge steel Q500qE and parallel wire stay-cables with a strength of 2000 MPa were developed. In terms of dynamic performance, the wind resistance of the structure is improved by using steel truss girders with good air permeability and setting the transverse wind resistance bearings at the pier towers. The damping and energy dissipation effect of the structure is remarkable by adopting a damping restraint system consisting of dampers and a friction pendulum bearings. In addition, through track geometry analysis and wind–vehicle–track–bridge coupling vibration analysis, a reference for running safety and comfort have been provided. [ABSTRACT FROM AUTHOR]

This paper presents the results of a numerical study about the effectiveness of a new multi-component timber retrofit solution for unreinforced masonry buildings in seismic regions. The proposed retrofit consists of timber frames fastened to the internal surface of masonry piers, with oriented strand boards eventually nailed to the frames. This technique aims at improving both in-plane and out-of-plane capacities of masonry piers as well as wall-to-diaphragm connections. Numerical models were built and calibrated against experimental data from quasi-static cyclic shear-compression tests on two isolated piers and dynamic shake-table tests on two full-scale buildings, in bare and retrofitted conditions. The building prototype represented the end-unit of a cavity-wall terraced house. A strategy to include the retrofit contribution in equivalent-frame masonry models is proposed. Starting from the calibrated models, two additional strengthening schemes were numerically generated to investigate the influence of increasing retrofit levels on the building performance. For each model, a cloud nonlinear time-history analysis was performed using 250 ground-motion records to derive damage-state fragility functions. The numerical outcomes can assist in the selection of an optimal level of the proposed retrofit solution, balancing structural and economic goals. [ABSTRACT FROM AUTHOR]

In this study, the principle of minimum potential energy has been used to deduce the mapping relationship between beam deformation and rail deformation with consideration of the constraint effects of a subgrade system. Based on the above mapping relationship, a dynamic simulation analysis on the train-track-bridge coupled system has been carried out. Taking the index of riding comfort as the investigation object, in combination with the specified limits in the relevant specification, an analysis has been carried out to determine the control threshold of beam deformation of high-speed railways. According to the simulation results, the dynamic response of different types of high-speed trains shows significantly different sensitivities to the pier settlement and the beam faulting. The threshold value in settlement control in the case of simultaneous settlement of two adjacent piers is smaller than that in the case of the single-pier settlement. Under the operating condition of beam faulting, the wheel unloading rate is more sensitive to the faulting of the beams than the vertical acceleration and Sperling's ride index. To avoid the vertical acceleration specified limit of car body, it is recommended to maintain the pier settlement to less than 9.7 mm, and the beam faulting to less than 5.3 mm. [ABSTRACT FROM AUTHOR]

To understand the longitudinal seismic damage progress and failure mode of extradosed bridges, an experimental investigation was conducted on a 1/20 scaled shake table test model. Detailed design of the test model is firstly introduced. During the experimental investigation, the test model was longitudinally subjected to the site-specific artificial ground motion with the peak ground acceleration (PGA) ranging from 0.1 g to 1.5 g. Test results show that the seismic damage progress of the extradosed bridge could be categorized into four stages: (1) No damage (PGA = 0.1 g − 0.3 g); (2) Mild damage (PGA = 0.4 g − 0.6 g); (3) Moderate damage (PGA = 0.7 g − 1.2 g); (4) Severe damage (PGA = 1.3 g − 1.5 g). The bottom and top regions of four-column piers are earthquake-vulnerable regions, while short towers are not. The failure mode of the test model could be characterized by buckling of the rebar and crushing of the core concrete at the bottom region of four-column piers. Moreover, unlike conventional cable-stayed bridges, the longitudinal deformation of the short tower is quite small in each loading case, and the residual longitudinal displacement of the test model is negligible after the whole tests. [ABSTRACT FROM AUTHOR]

Various protective methods are incorporated in order to change the flow pattern and reduce the intensity of the vortices around the piers with the aim of reducing scour at bridge piers. One of these methods is the employment of submerged vanes at the upstream side of the bridge piers. This study investigated the effect of the submergence ratio of the submerged vanes in scour reduction around a single pier and a group of piers. The results indicated that the greatest reduction in the maximum scour depth, the scour hole volume, the maximum sedimentary bar, and the scour hole area around the piers occurred in experiments with a single pier and triad piers with a longitudinal direction in combination with 75%-submerged vanes. At this submergence ratio, the maximum scour depth and the scour hole volume decreased by nearly 30 and 59% respectively in the single pier test including the submerged vanes, and by nearly 23 and 37% respectively in the triad pier group test with a longitudinal direction including the submerged vanes in comparison to the test with no submerged vane installed. [ABSTRACT FROM AUTHOR]

The use of precast post-tensioned segmental (PPS) piers is growing in the bridge industry, particularly in Accelerated Bridge Construction (ABC). To increase their use in high-seismicity regions, this study focuses on the seismic performance of the PPS piers under pulse-like near-field earthquakes. Two ensembles of 40 pulse-like near-field ground motions and 44 far-field ground motions along with three bridge piers of various heights are used in a series of incremental dynamic analyses. The piers are analysed under the original pulse-like near-field ground motions, their extracted pulse ground motions, and their corresponding non-pulse ground motions. It is found that the effect of the pulse ground motion is pronounced, when the pulse period is in proximity to the natural period of the pier. It is also seen that pulse-like near-field and far-field ground motions generally have similar effects on the response of PPS piers. [ABSTRACT FROM AUTHOR]

Local scour of piers is a potential danger threatening the operational safety of the sea-crossing bridge. Reliable scour depth prediction of piers can make the economic maintenance of the sea-crossing bridge. Considering the Hangzhou Bay Sea-crossing Bridge as the research prototype, based on the measured data and numerical simulation, the flow-field structure in front of the pier and the shape of the scour hole around the pier are simplified, and the prediction equation of the maximum depth of local scour is derived based on the energy balance theory. Based on the measured data, the equation is verified and compared with the local scour calculation equation in the design code, and the sensitivity of the parameters in the equation is analyzed. The results reveal that the equation is feasible and accurate and can provide guidelines for future decision-making regarding the early warning and maintenance of local scour of sea-crossing bridges. [ABSTRACT FROM AUTHOR]

It is an important study direction in the field of seismic engineering to accurately evaluate the damage degree of RC pier columns under seismic action in saline soil environment. Based on this, eight RC pier columns were designed and manufactured. Based on the residual drift of the specimen, a seismic damage assessment method suitable for saline soil environment was propsed. The corrosion rate, axial compression ratio and residual drift were considered in this model. The results showed that the model is simple and accurate. It can provide reference for post-earthquake damage assessment of RC columns in saline soil environment. [ABSTRACT FROM AUTHOR]

The paper briefly describes the mechanics of local scour process around bridge pier and gives an in-depth review of the various techniques employed for local scour control and protection. The most common armoring device is placing of riprap stones around the pier. Despite the effectiveness of riprap armoring countermeasure, it faces some limitations such as cost ineffectiveness and susceptible to channel bed degradation. The performance of various flow-altering devices is studied. The combination of slot and collar plate can be a suitable solution to prevent the local scour if well designed and constructed properly. The combination of permeable sheet piles with riprap can even reduce the scour depth effectively up to 91% in live bed scour conditions. The combination of vanes and collar plate around oblong bridge pier results into less extent of scour and produces a higher degree performance potential of 86.36% as compared with unprotected oblong pier. Although the composite device has higher scour reduction potential than individual device, there is no guarantee that there will be complete elimination of local scour. Therefore, more research is needed to analyze the stability of this device on the prototype and field application and enhance their efficacy furthermore. [ABSTRACT FROM AUTHOR]

The characteristics of scour hole around the submerged tandem pier in alluvial bed plays an important role in analyzing the problem of parallel bridge failures. The present study investigates the scour hole properties around single and tandem pier arrangements with spacing 2d (d, diameter of pier) under varying flow conditions. Experiments were carried out on a mobile bed channel having mean sediment size 0.75 mm and geometric standard deviation (σg) of 1.27. The cylindrical piers of diameter 4.5 cm are vertically embedded in the mobile channel bed having flow depth of 15 cm with a flow range of 0.02–0.035 m3/s in clear water conditions (U0/Uc= 0.45–0.79). The scour depth around the rear pier is 30% less than the front pier in tandem case for all the flow conditions. Further, with increments of 0.005 m3/s discharge, 20–30% more scour depths are observed around the piers (single and front pier of tandem). In all, 40% more sediment erosion is observed around the piers in tandem case vis-à-vis single pier case. The study reveals that parallel bridge piers are more prone to local scour/erosion than single pier in alluvial beds for similar flow conditions. [ABSTRACT FROM AUTHOR]

Temporary steel bridge (HHB 265) with structural slenderness of only 1/24.New Pooley Bridge, United Kingdom The New Pooley Bridge is an innovative arch bridge with a composite stainless-steel/concrete structure replacing a historic stone bridge washed away during a storm. The bridge does not require any supports.Nanjing Jiangxinzhou Yangtze River Bridge, China Nanjing Jiangxinzhou Yangtze River Bridge is a three-towered cable-stayed bridge with a main span length of 2×600 meters. It has a steel truss cable-stayed main bridge with span of 1092 meters, which is the 1st kilometer-scale rail-cum-road cable-stayed bridge in the world.Brigandsbrug Bridge, Belgium This is an open steel-concrete arch bridge with multiple spans. [Extracted from the article]

Experimental investigation with reference to vorticity fields around circular bridge pier having diameter, d = 8.8 cm, at different angles, namely, θ = 0°, 90°, and 180° with respect to center of pier diameter, on rigid and mobile beds, is compared for identical flow conditions. The instantaneous velocity measurements were carried out using 16 MHz down looking micro-Acoustic Doppler Velocimeter (ADV) at different grids along the flow depths. The sediments having mean size, d50 = 0.75 mm, and geometric standard deviation, σg = 1.29, are used in experimentation. The results reveal that, on both rigid and mobile bed, with increasing the angle, the strength of primary vortex is decreased. On the other hand, the strength of secondary vortex has been found to increase with the angle, that is, the primary vortex is found to be strong in front of the pier, whereas the secondary vortex is predominant behind the pier. Further, the strengths of primary and secondary vortices are found to be ≈30% more on rigid bed than mobile bed for same flow condition. [ABSTRACT FROM AUTHOR]

This study discusses the effects of geometrical parameters of flaring gate piers, such as contraction ratio, sidewall extension ratio and plunge angle, on the impinging pressure and flood atomization based on hydraulic model tests and atomization simulations. It is found that the impinging pressure decreases and the length of rainstorm increases with the increasing impact collision of aerated jets. Decreasing the plunge angle and increasing the extension length of sidewall for violent collision should be considered in the design stage and protection measures for rainstorms should be taken into account. Reducing the atomization hazard by collision avoidance could be selected in the operational phase on the premise of safety factor of plunge pool. A simplified formula is developed to predict the length of rainstorm as a function of the maximum impinging pressure, for use as a reference in the design and modification of similar projects. [ABSTRACT FROM AUTHOR]

Seismic performance evaluation is carried out for reinforced concrete bridge columns using both normal (SD400) and high (SD700) yield strength of reinforcement. A total of 12 column specimens are tested under lateral load reversals. Primary design parameters are types of cross-section, yield strength of both longitudinal and lateral reinforcements, longitudinal reinforcement ratio, and vertical spacing of lateral reinforcement. Lateral force-displacement hysteretic response reveals that experimental lateral forces are well above code-specified lateral forces in overall displacement range. Specimens using SD700 show higher lateral force carrying capacity than those with SD400. On the other hand, specimens using SD400 exhibit more ductile behaviour than those with SD700. Deformation capacity is also investigated in terms of displacement ductility and cumulative energy dissipation. Whereas experimental ductility values are in general greater than code-specified values, margin of safety is slightly reduced as yield strength and longitudinal reinforcement ratio increase. It is thus believed that use of SD700 in reinforced concrete columns seems to be promising. [ABSTRACT FROM AUTHOR]

A new technique is proposed for online model identification and updating in multi-platform pseudo-dynamic simulation of steel structures which brings novelty through eliminating the need for optimization during the identification stage of material/section behavior. Furthermore, the proposed procedure requires no prior information about the updated component of the numerical substructure and free of backward inconsistency. The efficiency of the proposed online model updating procedure is investigated by fourteen simulations which have real physical experimental substructures. A three span, small-scale bridge model with different pier heights is selected as the investigated structure. The simulations are performed under two different types of dynamic loads: instantaneous constant loading and strong ground motion records. The repeatability of tests, the effects of strong ground motion records and different pier heights are investigated. Furthermore completely numerical dynamic analyses with advanced models are also performed for comparison purposes. The results demonstrated that the proposed online model identification and updating procedure can be used with sufficient precision in multi-platform pseudo-dynamic simulations of steel structures. [ABSTRACT FROM AUTHOR]

Originally imagined as both granary and church writ large, Langland's Barn of Unity morphs into a space of refuge-in-crisis as it is besieged by Antichrist and the Seven Deadly Sins in Piers Plowman's apocalyptic finale. Central to Langland's imagining is a conundrum at the heart of hospitality, the Latin root of which means not only guest and friend but also stranger and enemy. Within Unity, the allegorical figure of Conscience practices hospitality, welcoming others, yet attempting to set conditions for entry to keep his space morally intact. Unity is intended to be a refuge from the violence of sin, but with every act of welcome Conscience risks letting sin in. This essay breaks new ground by interrogating Langland's representation of these acts of welcome in relation to recent hospitality theory (of Derrida and others) to illuminate how the satirical bent of the ending of Piers Plowman coexists with reformist idealism. [ABSTRACT FROM AUTHOR]

Little direct evidence remains for the original 1090s roof structure of Westminster Hall. The prevailing view has been that, until its replacement in the 1390s, the interior must have been divided by aisles to support the very wide span of the roof. This view was challenged by Roland Harris and Daniel Miles in 2013, with a proposal for a clear-spanning roof structure, which would be quite exceptional for the period. This article uses evidence from both Westminster and comparable buildings to explore the feasibility of alternative structural forms in some detail, with reconstruction drawings. Significant problems are encountered with all of the alternative forms, leading to a strong affirmation of the theory proposed by Harris and Miles. The Norman hall at Westminster was planned and roofed without internal arcades or piers, whether of timber or masonry. Westminster Hall thus played no part in the development of the English aisled hall. [ABSTRACT FROM AUTHOR]