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Estimating the frequency of traffic overloading on road bridges

Journal of Traffic and Transportation engineering(English Edition) 2024年第4期11卷 776-796页

作者： Roberto Ventura Benedetto Barabino Giulio Maternini department of civil Environmental Architectural Engineering and Mathematics University of Brescia

Load limits, which appear to be routinely exceeded by trucks, occasionally result in road bridge failures. Therefore, predicting failures is crucial for safeguarding road safety. Past studies have largely focused on forecasting bridge failure event probability using the reliability analysis method, whilst occasionally accounting for vehicular overloading effects. Only recently, a study has investigated design traffic overloading event frequency using generalised linear regression models(GLRMs), including a power component and negative binomial regressions(NBRs). However, as far as the authors know, artificial neural network models(ANNMs) have never been applied to this field. This paper is an attempt to fill in these gaps. First a frequencybased metric of traffic overloading was adopted as a driver of failure probability. Second, two alternative ‘frequency' models were specified, calibrated, and validated. The former was based on a GLRM, the latter on ANNMs. Then, these models were compared using regression plots(RPs), measures of errors(Mo Es) and the ratio between the number of observed vs predicted design load overcoming events to evaluate their performance. The models analysed more than 2 million weigh-in-motion(WIM) data records from a pilot station on a bridge on a heavily used ring road in Brescia(Italy). Results showed that ANNMs outperformed *** have a higher correlation coefficient(between predicted and target frequencies),lower Mo Es, and a closer-to-unity ratio(between predicted and target frequencies). These findings may increase prediction accuracy of design traffic overloading events and give road authorities more effective traffic management to protect bridges from load hazards.

关键词： Road bridges Traffic load hazard Econometry Machine learning Weigh-in-motion Big-data analysis

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A New Formulation of the Scaled Boundary Finite Element Method for Heterogeneous Media:Application to Heat Transfer Problems

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Acta Mechanica Solida Sinica 2024年第2期37卷 285-296页

作者： Nima Noormohammadi Nazanin Pirhaji Khouzani department of civil engineering Isfahan University of TechnologyIsfahan84156-83111Iran

The solution to heat transfer problems in two-dimensional heterogeneous media is attended based on the scaled boundary finite element method(SBFEM)coupled with equilibrated basis functions(EqBFs).The SBFEM reduces the model order by scaling the boundary solution onto the inner *** this end,tri-lateral elements are emanated from a scaling center,followed by the development of a semi-analytical solution along the radial direction and a finite element solution along the circumferential/boundary *** discretization is thus limited to the boundaries of the model,and the semi-analytical radial solution is found through the solution of an eigenvalue problem,which restricts the methods’applicability to heterogeneous *** this research,we first extracted the SBFEM formulation considering the heterogeneity of the ***,we replaced the semi-analytical radial solution with the EqBFs and removed the eigenvalue solution step from the *** varying coefficients of the partial differential equation(PDE)resulting from the heterogeneity of the media are replaced by a finite series in the radial and circumferential directions of the element.A weighted residual approach is applied to the radial *** equilibrated radial solution series is used in the new formulation of the SBFEM.

关键词： Scaled boundary finite element method Equilibrated basis functions Heat transfer

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Direct scaling of residual displacements for bilinear and pinching oscillators

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Earthquake engineering and engineering Vibration 2024年第1期23卷 129-149页

作者： Mohammad Saifullah Vinay K.Gupta department of civil engineering Indian Institute of Technology KanpurKanpur 208016India

The estimation of residual displacements in a structure due to an anticipated earthquake event has increasingly become an important component of performance-based earthquake engineering because controlling these displacements plays an important role in ensuring cost-feasible or cost-effective repairs in a damaged structure after the *** attempt is made in this study to obtain statistical estimates of constant-ductility residual displacement spectra for bilinear and pinching oscillators with 5%initial damping,directly in terms of easily available seismological,site,and model *** of the available models for the bilinear and pinching oscillators are useful when design spectra for a seismic hazard at a site are not *** statistical estimates of a residual displacement spectrum are proposed in terms of earthquake magnitude,epicentral distance,site geology parameter,and three model parameters for a given set of ductility demand and a hysteretic energy capacity coefficient in the case of bilinear and pinching models,as well as for a given set of pinching parameters for displacement and strength at the breakpoint in the case of pinching model *** proposed scaling model is applicable to horizontal ground motions in the western *** earthquake magnitudes less than 7 or epicentral distances greater than 20 km.

关键词： residual displacement spectrum bilinear hysteresis model pinching hysteresis model nonlinear analysis scaling model

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Seismic performance evaluation of hybrid coupled shear wall system with shear and flexural fuse-type steel coupling beams

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Earthquake engineering and engineering Vibration 2024年第3期23卷 691-712页

作者： Zahra Ramezandoust Abbas Tajaddini Panam Zarfam department of civil engineering Science and Research branchIslamic Azad UniversityTehran 14778-93855Iran department of civil engineering Karaj BranchIslamic Azad UniversityKaraj 31485-313Iran

Replaceable flexural and shear fuse-type coupling beams are used in hybrid coupled shear wall(HCSW)systems,enabling concrete buildings to be promptly recovered after severe *** study aimed to analytically evaluate the seismic behavior of flexural and shear fuse beams situated in short-,medium-and high-rise RC buildings that have *** building groups hypothetically located in a high seismic hazard zone were studied.A series of 2D nonlinear time history analyses was accomplished in OpenSees,using the ground motion records scaled at the design basis earthquake *** was found that the effectiveness of fuses in HCSWs depends on various factors such as size and scale of the building,allowable rotation value,inter-story drift ratio,residual drift quantity,energy dissipation value of the fuses,*** results show that shear fuses better meet the requirements of rotations and *** contrast,flexural fuses dissipate more energy,but their sectional stiffness should increase to meet other *** was concluded that adoption of proper fuses depends on the overall scale of the building and on how associated factors are considered.

关键词： hybrid coupled shear wall steel fuse coupling beam shear and flexural fuse nonlinear dynamic analysis seismic performance

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Nonlinear vibration of Timoshenko FG porous sandwich beams subjected to a harmonic axial load

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Earthquake engineering and engineering Vibration 2024年第3期23卷 649-662页

作者： Milad Lezgi Moein Zanjanchi Nikoo Majid Ghadiri department of civil engineering Sharif University of TechnologyTehran ***Iran civil engineering department K.N.Toosi University of TechnologyTehran ***Iran Faculty of engineering Department of MechanicsImam Khomeini International UniversityQazvin ***Iran

In this study,the instability and bifurcation diagrams of a functionally graded(FG)porous sandwich beam on an elastic,viscous foundation which is influenced by an axial load,are investigated with an analytical *** do so,the Timoshenko beam theory is utilized to take the shear deformations into account,and the nonlinear Von-Karman approach is adopted to acquire the equations of ***,to turn the partial differential equations(PDEs)into ordinary differential equations(ODEs)in the case of equations of motion,the method of Galerkin is employed,followed by the multiple time scale method to solve the resulting *** impact of parameters affecting the response of the beam,including the porosity distribution,porosity coefficient,temperature increments,slenderness,thickness,and damping ratios,are explicitly *** is found that the parameters mentioned above affect the bifurcation points and instability of the sandwich porous beams,some of which,including the effect of temperature and porosity distribution,are less noticeable.

关键词： sandwich beam Timoshenko beam parametric excitation bifurcation diagrams dynamic instability

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Evaluation of the coefficient of lateral stress at rest of granular materials under repetitive loading conditions

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Journal of Rock Mechanics and Geotechnical engineering 2024年第5期16卷 1709-1721页

作者： Heerym Han Hyunwook Choo Junghee Park department of civil and Environmental engineering Hanyang UniversitySeoul04763South Korea department of civil and Environmental engineering Incheon National UniversityIncheon22012South Korea

Although the internal stress state of soils can be affected by repetitive loading,there are few studies evaluating the lateral stress(or K_(0))of soils under repetitive *** study investigates the changes in K_(0) and directional shear wave velocity(V_(s))in samples of two granular materials with different particle shapes during repetitive loading.A modified oedometer cell equipped with bender elements and a diaphragm transducer was developed to measure the variations in the lateral stress and the shear wave velocity,under repetitive loading on the loading and unloading *** study produced the following results:(1)Repetitive loading on the loading path resulted in an increase in the K_(0) of test samples as a function of cyclic loading number(i),and(2)Repetitive loading on the unloading path resulted in a decrease in K_(0) according to *** shear wave velocity ratio(i.e.V_(s)(HH)/V_(s)(VH),where the first and second letters in parentheses corresponds to the directions of wave propagation and particle motion,respectively,and V and H corresponds to the vertical and horizontal directions,respectively)according to i supports the experimental observations of this ***,when the tested material was in lightly over-consolidated state,there was an increase in K_(0) during repetitive loading,indicating that it was the initial K_(0),rather than the loading path,which is responsible for the change in K_(0).The power model can capture the variation in the K_(0) of samples according to ***,the K_(0)=1 line acts as the boundary between the increase and decrease in K_(0) under repetitive loading.

关键词： Coefficient of lateral stress at rest Repetitive loading Granular materials Shear wave velocity Stiffness anisotropy

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A methodology for damage evaluation of underground tunnels subjected to static loading using numerical modeling

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Journal of Rock Mechanics and Geotechnical engineering 2024年第6期16卷 1993-2005页

作者： Shahriyar Heidarzadeh Ali Saeidi Rock Mechanics engineer AtkinsRéalisMontrealQuebecCanada department of Applied Sciences Universitédu QuébecàChicoutimiChicoutimiQuebecCanada

We have proposed a methodology to assess the robustness of underground tunnels against potential *** involves developing vulnerability functions for various qualities of rock mass and static loading *** account for these variations,we utilized a Monte Carlo Simulation(MCS)technique coupled with the finite difference code FLAC^(3D),to conduct two thousand seven hundred numerical simulations of a horseshoe tunnel located within a rock mass with different geological strength index system(GSIs)and subjected to different states of static *** quantify the severity of damage within the rock mass,we selected one stress-based(brittle shear ratio(BSR))and one strain-based failure criterion(plastic damage index(PDI)).Based on these criteria,we then developed fragility ***,we used mathematical approximation techniques to produce vulnerability functions that relate the probabilities of various damage states to loading intensities for different quality classes of blocky rock *** results indicated that the fragility curves we obtained could accurately depict the evolution of the inner and outer shell damage around the ***,we have provided engineers with a tool that can predict levels of damages associated with different failure mechanisms based on variations in rock mass quality and in situ stress *** method is a numerically developed,multi-variate approach that can aid engineers in making informed decisions about the robustness of underground tunnels.

关键词： Fragility curves Underground tunnels Vulnerability functions Brittle damage FLAC3D Numerical modeling

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Artificial Intelligence Prediction of One-Part Geopolymer Compressive Strength for Sustainable Concrete

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Computer Modeling in engineering & Sciences 2024年第10期141卷 525-543页

作者： Mohamed Abdel-Mongy Mudassir Iqbal M.Farag Ahmed.M.Yosri Fahad Alsharari Saif Eldeen A.S.Yousef department of civil engineering College of EngineeringJouf UniversitySakaka72388Saudi Arabia department of civil engineering University of Engineering and TechnologyPeshawar54890Pakistan civil engineering department Faculty of EngineeringAl-Azhar UniversityCairo11884Egypt civil engineering department Faculty of EngineeringAswan UniversityAswan81528Egypt

Alkali-activated materials/geopolymer(AAMs),due to their low carbon emission content,have been the focus of recent studies on ecological *** terms of performance,fly ash and slag are preferredmaterials for precursors for developing a one-part ***,determining the optimum content of the input parameters to obtain adequate performance is quite challenging and scarcely ***,in this study,machine learning methods such as artificial neural networks(ANN)and gene expression programming(GEP)models were developed usingMATLAB and GeneXprotools,respectively,for the prediction of compressive strength under variable input materials and content for fly ash and slag-based one-part *** database for this study contains 171 points extracted from literature with input parameters:fly ash concentration,slag content,calcium hydroxide content,sodium oxide dose,water binder ratio,and curing *** performance of the two models was evaluated under various statistical indices,namely correlation coefficient(R),mean absolute error(MAE),and rootmean square error(RMSE).In terms of the strength prediction efficacy of a one-part geopolymer,ANN outperformed *** and parametric analysis were also performed to identify the significant contributor to *** to a sensitivity analysis,the activator and slag contents had the most effects on the compressive strength at 28 *** water binder ratio was shown to be directly connected to activator percentage,slag percentage,and calcium hydroxide percentage and inversely related to compressive strength at 28 days and curing temperature.

关键词： Artificial intelligence techniques one-part geopolymer artificial neural network gene expression modelling sustainable construction polymers

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Interaction Mechanisms between Natural Debris Flow and Rigid Barrier Deflectors:A New Perspective for Rational Design and Optimal Arrangement

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Computer Modeling in engineering & Sciences 2024年第5期139卷 1679-1699页

作者： Yu Huang Beilei Liu Dianlei Feng Hao Shi department of Geotechnical engineering College of Civil EngineeringTongji UniversityShanghai200092China department of Hydraulic engineering College of Civil EngineeringTongji UniversityShanghai200092China

Rigid barrier deflectors can effectively prevent overspilling landslides,and can satisfy disaster prevention ***,the mechanisms of interaction between natural granular flow and rigid barrier deflectors require further *** date,few studies have investigated the impact of deflectors on controlling viscous debris flows for geological disaster *** investigate the effect of rigid barrier deflectors on impact mechanisms,a numerical model using the smoothed particle hydrodynamics(SPH)method with the Herschel–Bulkley model is proposed to simulate the interaction between natural viscous flow and single/dual barriers with and without *** model was validated using laboratory flume test data from the ***,the model was used to investigate the influence of the deflector angle and multi-barrier *** optimal configuration of multi-barriers was analyzed with consideration to the barrier height and distance between the barriers,because these metrics have a significant impact on the viscous flow pile-up,run-up,and overflow *** investigation considered the energy dissipation process,retention efficiency,and dead-zone *** with bare barriers with similar geometric characteristics and spatial distribution,rigid barriers with deflectors exhibit superior effectiveness in preventing the overflow and overspilling of viscous debris *** for the rational design of deflectors and the optimal arrangement of multi-barriers are provided to mitigate geological disasters.

关键词： Rigid barrier deflectors deflector angle single-barrier dual-barrier arrangements viscous debris flow over-spilling delta-plus-SPH

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Simultaneous removal of critical rare earth elements and chalcogen oxyanions by anaerobic granular sludge

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Rare Metals 2024年第9期43卷 4595-4611页

作者： Chiara Belloni Mohanakrishnan Logan Stefano Papirio Piet N.L.Lens University of Galway department of civil Architectural and Environmental EngineeringUniversity of Naples Federico II

Conventional mining of economically and strategically important critical rare earth elements(REEs)(such as neodymium, lanthanum and dysprosium), and chalcogens(such as selenium and tellurium) are associated with a huge economic and environmental cost. Therefore,the need to recover REEs as well as chalcogens from different waste streams including wastewaters is becoming urgent. Batch assays on synthetic chalcogen/REE-laden wastewater showed that the presence of REEs significantly improved the tellurite removal rate(> 80%) and enhanced selenate removal by 66% ± 10%. Three 3.9 L continuous upflow anaerobic granular sludge bed(UASB) reactors were operated at a hydraulic retention time of 24 h and30 °C. Selenate reduction was achieved with a removal efficiency of ～ 98% with an influent p H of 4.0 for more than 28 days. The effect of REEs on tellurite removal in the UASB bioreactor could not be clearly established since a soluble tellurium removal efficiency of more than 98%was observed already before the addition of REEs at elevated tellurite concentrations. The complete REE removal in both batch assays and UASB reactors at higher pH (7.0 ± 0.5) was attributed to precipitation, whereas chalcogen oxyanions removal was due to microbial reduction. However, at acidic p H, biosorption was responsible for REE's removal, and the Se-enriched sludge exhibited a superior REE's removal efficiency than the non-enriched and Te-enriched sludge.

关键词： Adsorption Bioreduction Rare earth elements Selenium Tellurium

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