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Surrogate modeling for unsaturated infiltration via the physics and equality-constrained artificial neural networks

Journal of Rock Mechanics and Geotechnical engineering 2024年第6期16卷 2282-2295页

作者： Peng Lan Jingjing Su Sheng Zhang school of civil engineering Central South UniversityChangsha410075China Discipline of civil Surveying and Environmental EngineeringPriority Research Centre for Geotechnical Science and EngineeringThe University of NewcastleCallaghanNSW2308Australia Qinghai University Qinghai810016China

Machine learning(ML)provides a new surrogate method for investigating groundwater flow dynamics in unsaturated *** pure data-driven methods(*** neural network,DNN)can provide rapid predictions,but they do require sufficient on-site data for accurate training,and lack interpretability to the physical processes within the *** this paper,we provide a physics and equalityconstrained artificial neural network(PECANN),to derive unsaturated infiltration solutions with a small amount of initial and boundary *** takes the physics-informed neural network(PINN)as a foundation,encodes the unsaturated infiltration physical laws(*** equation,RE)into the loss function,and uses the augmented Lagrangian method to constrain the learning process of the solutions of RE by adding stronger penalty for the initial and boundary *** unsaturated infiltration cases are designed to test the training performance of PECANN,***-dimensional(1D)steady-state unsaturated infiltration,1D transient-state infiltration,two-dimensional(2D)transient-state infiltration,and 1D coupled unsaturated infiltration and *** predicted results of PECANN are compared with the finite difference solutions or analytical *** results indicate that PECANN can accurately capture the variations of pressure head during the unsaturated infiltration,and present higher precision and robustness than DNN and *** is also revealed that PECANN can achieve the same accuracy as the finite difference method with fewer initial and boundary training ***,we investigate the effect of the hyperparameters of PECANN on solving RE *** provides an effective tool for simulating unsaturated infiltration.

关键词： Richards equation(RE) Unsaturated infiltration Data-driven solutions Numerical modeling Machine learning(ML)

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Intelligent extraction of road cracks based on vehicle laser point cloud and panoramic sequence images

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Journal of Road engineering 2024年第1期4卷 69-79页

作者： Ming Guo Li Zhu Ming Huang Jie Ji Xian Ren Yaxuan Wei Chutian Gao school of Geomatics and Urban Spatial Informatics Beijing University of Civil Engineering and ArchitectureBeijing 102616China engineering Research Centre of Representative Building and Architectural Heritage Database Ministry of EducationBeijing 100044China Key Laboratory of Modern Urban surveying and Mapping National Administration of SurveyingBeijing 102616China school of civil and Transportation engineering Beijing University of Civil Engineering and ArchitectureBeijing 102616China

In light of the limited efficacy of conventional methods for identifying pavement cracks and the absence of comprehensive depth and location data in two-dimensional photographs,this study presents an intelligent strategy for extracting road *** methodology involves the integration of laser point cloud data obtained from a vehicle-mounted system and a panoramic sequence of *** study employs a vehicle-mounted LiDAR measurement system to acquire laser point cloud and panoramic sequence image data simultaneously.A convolutional neural network is utilized to extract cracks from the panoramic sequence *** extracted sequence image is then aligned with the laser point cloud,enabling the assignment of RGB information to the vehicle-mounted three dimensional(3D)point cloud and location information to the two dimensional(2D)panoramic ***,a threshold value is set based on the crack elevation change to extract the aligned roadway point *** three-dimensional data pertaining to the cracks can be *** experimental findings demonstrate that the use of convolutional neural networks has yielded noteworthy outcomes in the extraction of road *** utilization of point cloud and image alignment techniques enables the extraction of precise location data pertaining to road *** approach exhibits superior accuracy when compared to conventional ***,it facilitates rapid and accurate identification and localization of road cracks,thereby playing a crucial role in ensuring road maintenance and traffic ***,this technique finds extensive application in the domains of intelligent transportation and urbanization *** technology exhibits significant promise for use in the domains of intelligent transportation and city development.

关键词： Road crack extraction Vehicle laser point cloud Panoramic sequence images Convolutional neural network

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Tidal modeling based on satellite altimetry observations of TOPEX/ Poseidon, Jason1, Jason2, and Jason3 with high prediction capability: A case study of the Baltic Sea

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Geodesy and Geodynamics 2024年第4期15卷 404-418页

作者： Alireza A.Ardalan Asiyeh Hashemifaraz school of surveying and Geospatial engineering College of EngineeringUniversity of TehranTehran 11155-4563Iran

This research aims to optimize the utilization of long-term sea level data from the TOPEX/Poseidon,Jason1,Jason2,and Jason3 altimetry missions for tidal *** generate a time series of along-track observations and apply a developed method to produce tidal models with specific tidal constituents for each *** tidal modeling methodology follows an iterative process:partitioning sea surface height(SSH)observations into analysis/training and prediction/validation parts and ultimately identi-fying the set of tidal constituents that provide the best predictions at each time series *** study focuses on developing 1256 time series along the altimetry tracks over the Baltic Sea,each with its own set of tidal *** of the developed tidal models against the sSH observations within the prediction/validation part reveals mean absolute error(MAE)values ranging from 0.0334 m to 0.1349 m,with an average MAE of 0.089 *** same validation process is conducted on the FES2014 and EOT20 global tidal models,demonstrating that our tidal model,referred to as BT23(short for Baltic Tide 2023),outperforms both models with an average MAE improvement of 0.0417 m and 0.0346 m,*** addition to providing details on the development of the time series and the tidal modeling procedure,we offer the 1256 along-track time series and their associated tidal models as supplementary *** encourage the satellite altimetry community to utilize these resources for further research and applications.

关键词： Satellitealtimetry Baltic Sea Ocean tide modeling Jason3 Jason2 Jason1 TOPEX/Poseidon EOT20 FES2014

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Probabilistic back-analysis of rainfall-induced landslides for slope reliability prediction with multi-source information

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Journal of Rock Mechanics and Geotechnical engineering 2024年第9期16卷 3575-3594页

作者： Shui-Hua Jiang Hong-Hu Jie Jiawei Xie Jinsong Huang Chuang-Bing Zhou school of Infrastructure engineering Nanchang UniversityXuefu Road 999Nanchang330031China Discipline of civil Surveying and Environmental EngineeringFaculty of Engineering and Built EnvironmentThe University of NewcastleCallaghanNSW2308Australia

Probabilistic back-analysis is an important means to infer the statistics of uncertain soil parameters,making the slope reliability assessment closer to the engineering ***,multi-source information(including test data,monitored data,field observation and slope survival records)is rarely used in current probabilistic *** the probabilistic back-analysis of spatially varying soil parameters and slope reliability prediction under rainfalls by integrating multi-source information is a challenging task since thousands of random variables and high-dimensional likelihood function are usually *** this paper,a framework by integrating a modified Bayesian Updating with Subset simulation(mBUS)method with adaptive Conditional Sampling(aCS)algorithm is established for the probabilistic back-analysis of spatially varying soil parameters and slope reliability *** this framework,the high-dimensional probabilistic back-analysis problem can be easily tackled,and the multi-source information(*** pressure heads and slope survival records)can be fully used in the back-analysis.A real Taoyuan landslide case in Taiwan,China is investigated to illustrate the effectiveness and performance of the established *** findings show that the posterior knowledge of soil parameters obtained from the established framework is in good agreement with the field ***,the updated knowledge of soil parameters can be utilized to reliably predict the occurrence probability of a landslide caused by the heavy rainfall event on September 12,2004 or forecast the potential landslides under future rainfalls in the Fuhsing District of Taoyuan City,Taiwan,China.

关键词： Rainfall-induced landslide Spatial variability Probabilistic back-analysis Slope reliability analysis Bayesian updating

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Dynamic prediction of over-excavation gap due to posture adjustment of shield machine in soft soil

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Underground Space 2024年第3期16卷 44-58页

作者： Wenyu Yang Junjie Zheng Rongjun Zhang Sijie Liu Wengang Zhang school of civil and Hydraulic engineering Huazhong University of Science and TechnologyWuhan 430074China school of civil engineering Wuhan UniversityWuhan 430072China school of civil engineering Chongqing UniversityChongqing 400045China

The probability analysis of ground deformation is becoming a trend to estimate and control the risk brought by shield *** gap parameter is regarded as an effective tool to estimate the ground loss of tunnelling in soft *** specifically,x,which is a gap parameter component defined as the over(or insufficient)excavation due to the change in the posture of the shield machine,may contribute more to the uncertainty of the ground ***,the existing uncertainty characterization methods for x have several limitations and cannot explain the uncertain correlations between the relevant *** these lines,to better characterize the uncertainty of x,the multivariate probability distribution was developed in this work and a dynamic prediction was proposed for *** attain this goal,1523 rings of the field data coming from the shield tunnel between Longqing Road and Baiyun Road in Kunming Metro Line 5 were utilized and 44 parameters including the construction,stratigraphic,and posture parameters were collected to form the *** to the variance filter method,the mutual information method,and the value of the correlation coefficients,the original 44 parameters were reduced to 10 main parameters,which were unit weight,the stoke of the jacks(A,B,C,and D groups),the pressure of the pushing jacks(A,C groups),the chamber pressure,the rotation speed,and the total *** multivariate probability distribution was constructed based on the Johnson system of ***,the distribution was satisfactorily verified in explaining the pairwise correlation between x and other parameters through 2 million simulation *** last,the distribution was used as a prior distribution to update the marginal distribution of x with any group of the relevant parameters *** performance of the dynamic prediction was further validated by the field data of 3 shield tunnel cases.

关键词： Shield tunnel Ground loss Gap parameter Multivariate probability distribution Bayesian updating Dynamic prediction

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Assessing the impacts of traffic calming at network level:A multimodal agent-based simulation

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Journal of Traffic and Transportation engineering(English Edition) 2024年第1期11卷 41-54页

作者： Eftychia Zargiannaki Panagiotis G.Tzouras Eleni Antoniou Christos Karolemeas Konstantinos Kepaptsoglou school of Rural Surveying and Geoinformatics EngineeringNational Technical University of AthensZografou 15780Greece

The reduction of speed limits in urban roads through traffic calming schemes intends to ensure safer traffic conditions among road users by reducing the probability related to the occurrence of severe *** it from a different perspective,traffic calming measures can potentially resolve congestion problems at the same time by lowering the overall accessibility and attractiveness of private cars in urban *** study proposes a new methodological approach to explore and assess the direct impacts of traffic calming in the transport system efficiency of a metropolitan *** multi-agent transport simulation(MATSim)and Open-Berlin scenario are utilized to perform this simulation *** developing a new external tool,the free flow speed and road capacity of each network link is updated based on new speed limits and different compliance rates,which are defined per road hierarchy *** test scenarios that are formulated present radical conditions,where the speed limit in most urban roads of Berlin drops to 30 km/h or even 15 km/*** findings of this study show a considerably high increase in trips,passenger hours,and passenger kilometers using public transport modes,when traffic calming links are introduced,the reserve change is observed in private cars *** the speed limits are decreased in inner urban roads in most of the scenarios,the decrease of average travel speed of private cars is not so high as it was ***,private cars are used for longer distances in all test *** drivers seem to use already existed motorways and private road to *** simulations,driver compliance to the new speed limits seems to be a determinant factor that is strongly influenced by the design interventions applied in a traffic calming area.

关键词： Agent-based simulation Traffic calming Impact assessment Urban road network

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2.5-dimension soil seismic response to oblique incident waves based on exact free-field solution

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Frontiers of Structural and civil engineering 2024年第2期18卷 216-235页

作者： Yeongbin Yang Zeyang Zhou Xiaoli Wang Xiongfei Zhang Zhilu Wang school of civil engineering Chongqing UniversityChongqing 400045China school of civil engineering and Architecture Chongqing University of Science and TechnologyChongqing 401331China

With the three dimensional(3D)oblique incident waves exactly determined for the free field,the soil seismic responses in both frequency and time domains are studied by the 2.5 dimension(2.5D)finite/infinite element ***,the free-field responses in frequency domain are solved exactly for 3D arbitrary incident P and SV waves,which requires no coordinate conversion or extra effort for SV waves with super-critical incident ***,the earthquake spectra are incorporated by the concept of equivalent seismic forces on the near-field boundary,based only on the displacements input derived for unit ground accelerations of each frequency using the 2.5D *** the asymmetric 2.5D finite/infinite element model adopted,the procedure for soil seismic analysis is *** solutions computed by the proposed method are verified against those of Wolf’s and de Barros and Luco’s and for inversely calculated ground *** interest is that abrupt variation in soil response occurs around the critical angle on the wave propagation plane for SV *** addition,the horizontal displacements attenuate with increasing horizontal incident angle,while the longitudinal ones increase inversely for 3D incident P and SV waves.

关键词： 3D oblique incident wave seismic response analysis 2.5D approach infinite element half-space

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Evolution mechanism and quantitative characterization of initial micro-cracks in marble under triaxial compression

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2024年第7期25卷 586-595页

作者： Zhiliang WANG Songyu LI Jianguo WANG Ao LI Weixiang WANG Chenchen FENG Jingjing FU school of civil engineering Hefei University of TechnologyHefei230009China school of Mechanics and civil engineering China University of Mining and TechnologyXuzhou221116China

The initial micro-cracks affect the evolution characteristics of macroscopic deformation and failure of rock but are often ignored in theoretical calculation,numerical simulation,and mechanical *** this study,we propose a quantitative analysis model to investigate the effects of initial micro-cracks on the evolution of marble deformation and *** relationship between the micro-crack propagation and the marble failure characteristics was comprehensively studied by combining theoretical analysis with a micro-computed tomography(micro-CT)scanning *** found that with the increase of confining pressure,the matrix elastic modulus of the marble first increased and then tended to be stable,while the micro-cracks increased *** sensitivity ranges of the marble sample matrix elastic modulus and micro-cracks to confining pressure were 0–30 MPa and 30–50 MPa,*** porosity and Poisson’s ratio decreased *** increasing proportion of internal micro-cracks led to an increase in the sample *** samples presented mainly shear failure under triaxial compression,and the failure angle decreased linearly with the increase of confining *** convergence direction of cracks decreased *** quantitative analysis model could accurately portray the relationship between the overall macroscopic deformation and the deviatoric stress of the samples at the compaction and the linear elastic stages,thus deepening the understanding of the stress–strain behavior of rocks.

关键词： Marble Initial micro-cracks Triaxial compression Constitutive relationship Crack evolution

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Bending strength degradation of a cantilever plate with surface energy due to partial debonding at the clamped boundary

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Applied Mathematics and Mechanics(English Edition) 2024年第9期45卷 1573-1594页

作者： Zhenliang HU Xueyang ZHANG Xianfang LI school of civil engineering University of South ChinaHengyang 421001Hunan ProvinceChina school of civil engineering Central South UniversityChangsha 410075China

This paper investigates the bending fracture problem of a micro/nanoscale cantilever thin plate with surface energy,where the clamped boundary is partially debonded along the thickness *** fundamental mechanical equations for the bending problem of micro/nanoscale plates are given by the Kirchhoff theory of thin plates,incorporating the Gurtin-Murdoch surface elasticity *** two typical cases of constant bending moment and uniform shear force in the debonded segment,the associated problems are reduced to two mixed boundary value *** solving the resulting mixed boundary value problems using the Fourier integral transform,a new type of singular integral equation with two Cauchy kernels is obtained for each case,and the exact solutions in terms of the fundamental functions are determined using the PoincareBertrand *** elastic fields near the debonded tips including the bending moment,effective shear force,and bulk stress components exhibit the oscillatory *** dependence relations among the singular fields,the material constants,and the plate's thickness are analyzed for partially debonded cantilever *** surface energy is neglected,these results reduce the bending fracture of a macroscale partially debonded cantilever plate,which has not been previously reported.

关键词： micro/nanoscale cantilever plate partially debonded bending fracture singular integral equation oscillatory singularity

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A novel cylindrical sandwich plate inspired by beetle elytra and its compressive properties

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Science China Technological Sciences 2024年第11期67卷 3465-3476页

作者： SONG YiHeng RUAN SiHan HAO Ning OKABE YoJi school of engineering The University of Tokyo school of civil engineering Southeast University school of engineering RMIT University Institute of Industrial Science The University of Tokyo

The design and experimental analysis of a semi-cylindrical structure known as the cylindrical beetle elytron plate(CBEP) were presented. Radial compression tests and finite element simulation were performed on CBEPs under 30° and 45° inclined sliding support constraints, with a comparison made to cylindrical honeycomb plate(CHP). The study aims to investigate the superior compression performance and enhancement mechanisms of CBEPs. The results demonstrate that CBEPs exhibit a 14%–26% increase in specific load-bearing capacity and a 20% increase in specific energy absorption compared with CHPs with equal core wall thickness. Distinct “Z-shaped” tearing failures were observed, with honeycomb plates showing tearing at the center of the honeycomb walls, while beetle elytron plates exhibited tearing along the midline of the trabeculae. Three different stress patterns,including elastic-plastic development stage of arch, plastic hinge node stage, and rigid node stage, were identified and analyzed to explain the mechanical performance improvements and failure characteristics. Considering that structural damage to trabeculae mostly occurs at its junction with the skin, it is recommended to add chamfers to the junctions of CBEP. Therefore, this paper lays the groundwork for the engineering application of CBEP.

关键词： beetle elytron cylindrical beetle elytron plate compression performance failure characteristics enhancement mechanism

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