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Earthquake engineering and engineering Vibration 2024年第1期23卷 227-240页

作者： Elham Aghabarari Fereidoun Amini Pedram Ghaderi department of civil engineering Iran University of Science and TechnologyTehran 16844Iran

The combination of structural health monitoring and vibration control is of great importance to provide components of smart *** synthetic algorithms have been proposed,adaptive control that is compatible with changing conditions still needs to be used,and time-varying systems are required to be simultaneously estimated with the application of adaptive *** this research,the identification of structural time-varying dynamic characteristics and optimized simple adaptive control are ***,reduced variations of physical parameters are estimated online using the multiple forgetting factor recursive least squares(MFRLS)***,the energy from the structural vibration is simultaneously specified to optimize the control force with the identified parameters to be *** is also performed based on the probability density function of the energy under the seismic excitation at any ***,the optimal control force is obtained by the simple adaptive control(SAC)algorithm and energy coefficient.A numerical example and benchmark structure are employed to investigate the efficiency of the proposed *** simulation results revealed the effectiveness of the integrated online identification and optimal adaptive control in systems.

关键词： integrated online identification time-varying systems structural energy multiple forgetting factor recursive least squares optimal simple adaptive control algorithm

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

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

Prediction of the undrained shear strength of remolded soil with non-linear regression,fuzzy logic,and artificial neural network

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Journal of Mountain Science 2024年第9期21卷 3108-3122页

作者： YÜNKÜL Kaan KARAÇOR Fatih GÜRBÜZ Ayhan BUDAK TahsinÖmür department of civil engineering Faculty of Engineering and ArchitectureTokat Gaziosmanpaşa UniversityTokat 60100Türkiye department of civil engineering Faculty of Engineering and ArchitectureKafkas UniversityKars 36000Türkiye department of civil engineering Faculty of EngineeringGazi UniversityAnkara 06570Türkiye Ministry of Youth and Sports Ankara 06090Türkiye

This study aims to predict the undrained shear strength of remolded soil samples using non-linear regression analyses,fuzzy logic,and artificial neural network modeling.A total of 1306 undrained shear strength results from 230 different remolded soil test settings reported in 21 publications were collected,utilizing six different measurement *** water content,plastic limit,and liquid limit were used as input parameters for fuzzy logic and artificial neural network modeling,liquidity index or water content ratio was considered as an input parameter for non-linear regression *** non-linear regression analyses,12 different regression equations were derived for the prediction of undrained shear strength of remolded ***-Forward backpropagation and the TANSIG transfer function were used for artificial neural network modeling,while the Mamdani inference system was preferred with trapezoidal and triangular membership functions for fuzzy logic *** experimental results of 914 tests were used for training of the artificial neural network models,196 for validation and 196 for *** was observed that the accuracy of the artificial neural network and fuzzy logic modeling was higher than that of the non-linear regression ***,a simple and reliable regression equation was proposed for assessments of undrained shear strength values with higher coefficients of determination.

关键词： Undrained shear strength Liquidity index Water content ratio Non-linear regression Artificial neural networks Fuzzy logic

Seismic-induced surficial failure of cohesive slopes using three-dimensional limit analysis:A case study of the Wangjiayan landslide in Beichuan, China

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Earthquake engineering and engineering Vibration 2024年第3期23卷 537-545页

作者： Gao Yufeng Liu Yang Geng Weijuan Zhang Fei Key Laboratory of the Ministry of Education for Geomechanics and Embankment engineering College of Civil and Transportation EngineeringHohai UniversityNanjing 210098China department of civil engineering Faculty of Civil Engineering and MechanicsJiangsu UniversityZhenjiang 212013China

A seismic-induced landslide is a common geological catastrophe that occurs in *** Wangjiayan landslide,which was triggered by the Wenchuan earthquake,is a typical case in *** Wanjiayan landslide caused many casualties and resulted in enormous property *** study constructs a simple surficial failure model based on the upper bound approach of three-dimensional(3D)limit analysis to evaluate the slope stability of the Wangjiayan case,while a traditional two-dimensional(2D)analysis is also conducted as a reference for comparison with the results of the 3D analysis.A quasi-static calculation is used to study the effect of the earthquake in terms of horizontal ground acceleration,while a parametric study is conducted to evaluate the critical cohesion of *** than employing a 3D analysis,using the 2D analysis yields an underestimation regarding the safety *** the Wangjiayan landslide,the difference in the factors of safety between the 3D and 2D analyses can reach 20%.The sliding surface morphology as determined by the 3D method is similar to actual morphology,and the parameters of both are also compared to analyze the reliability of the proposed 3D method.

关键词： landslide Wenchuan earthquake surficial failure limit analysis stability quasi-static

Eigenfrequency analysis of bridges using a smartphone and a novel low-cost accelerometer prototype

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Frontiers of Structural and civil engineering 2024年第2期18卷 202-215页

作者： Seyedmilad KOMARIZADEHASL Ye XIA Mahyad KOMARY Fidel LOZANO department of civil and Environment engineering Universitat Politècnica de CatalunyaBarcelona 08034Spain department of Bridge engineering Tongji UniversityShanghai 200092China department of civil engineering Universidad de Castilla-La ManchaCiudad Real 13071Spain

Researchers are paying increasing attention to the development of low-cost and microcontroller-based accelerometers,in order to make structural health monitoring feasible for conventional bridges with limited monitoring *** with the low-cost sensor development,the use of the embedded accelerometers of smartphones for eigenfrequency analysis of bridges is becoming popular in the civil engineering *** paper,for the first time in the literature,studies these two promising technologies by comparing the noise density and eigenfrequency analysis of a self-developed,validated and calibrated low-cost Internet of things based accelerometer LARA(low cost adaptable reliable accelerometer)with those of a state of the art smartphone(iPhone XR).The eigenfrequency analysis of a footbridge in San Sebastian,Spain,showed that the embedded accelerometer of the iPhone XR can measure the natural frequencies of the under study bridge.

关键词： smartphone modal analysis eigenfrequency analysis low-cost accelerometers Arduino Raspberry Internet of things

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

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

Using neural network modeling to improve the detection accuracy of land subsidence due to groundwater withdrawal

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Journal of Mountain Science 2024年第7期21卷 2320-2333页

作者： Ali M.RAJABI Ali EDALAT Yasaman ABOLGHASEMI Mahdi KHODAPARAST department of engineering Geology University of TehranTehran ***Iran department of civil engineering University of QomQom ***Iran

Despite the high efficiency of remote sensing methods for rapid and large-scale detection of subsidence phenomena,this technique has limitations such as atmospheric impact and temporal and spatial decorrelation that affect the accuracy of the *** paper proposes a method based on an artificial neural network to improve the results of monitoring land subsidence due to groundwater overexploitation by radar interferometry in the Aliabad plain(Central Iran).In this regard,vertical ground deformations were monitored over 18 months using the Sentinel-1A SAR *** model the land subsidence by a multilayer perceptron(MLP)artificial neural network,four parameters,including groundwater level,alluvial thickness,elastic modulus,and transmissivity have been *** model's generalizability was assessed using data derived for 144 *** to the results,the neural network estimates the land subsidence at each ground point with an accuracy of 6.8 mm.A comparison between the predicted and actual values indicated a significant *** MLP model can be used to improve the results of subsidence detection in the study area or other areas with similar characteristics.

关键词： DInSAR Land subsidence Groundwater withdrawal Aliabad plain Artificial neural network

Limit load and failure mechanisms of a vertical Hoek-Brown rock slope

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Journal of Rock Mechanics and Geotechnical engineering 2024年第3期16卷 1106-1111页

作者： Jim Shiau Warayut Dokduea Suraparb Keawsawasvong Pitthaya Jamsawang School of engineering University of Southern QueenslandToowoomba4350QLDAustralia department of civil engineering Faculty of EngineeringKing Mongkut’s University of Technology ThonburiBangkokThailand Research Unit in Sciences and Innovative Technologies for civil engineering Infrastructures Department of Civil EngineeringThammasat School of EngineeringThammasat UniversityPathumthani12120Thailand Soil engineering Research Center Department of Civil EngineeringKing Mongkut’s University of Technology North BangkokBangkok10800Thailand

The problem considered in this short note is the limit load determination of a vertical rock *** classical limit theorem is employed with the use of adaptive finite elements and nonlinear programming to determine upper and lower bound limit loads of a Hoek-Brown vertical rock *** objective function of the mathematical programming problem is such as to optimize a boundary load,which is known as the limit load,resembling the ultimate bearing capacity of a strip *** focusing on the vertical slope,parametric studies are carried out for several dimensionless ratios such as the dimensionless footing distance ratio,the dimensionless height ratio,and the dimensionless rock strength ratio.A comprehensive set of design charts is presented,and failure envelopes shown with the results explained in terms of three identified failure mechanisms,*** face,the toe,and the Prandtl-type *** novel results can be used with great confidence in design practice,in particularly noting that the current industry-based design procedures for the presented problem are rarely found.

关键词： Bearing capacity Rock slope Vertical slope Finite element limit analysis Hoek-Brown yield criterion