The Structural Eurocodes Systems, which are developed by the European Committee for Standardization (CEN), have come into trial use in the 28 countries of European Union (EU), and will lay a significant influence on t...The Structural Eurocodes Systems, which are developed by the European Committee for Standardization (CEN), have come into trial use in the 28 countries of European Union (EU), and will lay a significant influence on the development of the construction industry and on the international market of construction.展开更多
In recent years,with the explosion of the 4.0 industrial revolution,terms such as machine learning(ML)have become familiar and are increasingly widely applied in the engineering field.This study focuses on proposing t...In recent years,with the explosion of the 4.0 industrial revolution,terms such as machine learning(ML)have become familiar and are increasingly widely applied in the engineering field.This study focuses on proposing two new hybrid models named exponential-trigonometrie optimized extreme gradient boosting(ETO-XGBoost)and whale optimization algorithm extreme gradient boosting(WOA-XGBoost),which are developed based on extreme gradient boosting combined with exponential-trigonometric optimization and whale optimization algorithm.A data set has been built and analyzed using ABAQUS software,and combined with data from the empirical formula to construct a training data set for the proposed models.The two proposed hybrid models are compared with the available models including Kolmogorov-Arnold networks(KAN),artificial neural networks(ANN)and Eurocode 4 standard through important statistical indices such as mean absolute error(MAE),mean absolute percentage error(MAPE),root mean square error(RMSE)and correlation coefficient R.The analysis results show that the ETO-XGBoost model and the WOA-XGBoost model are the most effective ML models when compared with other models.The correlation index R of both models reached very high values(0.9963 for ETO-XGBoost and 0.9956 for WOA-XGBoost,respectively).At the same time,the error indexes of the ETO-XGBoost model were the smallest among the compared models,with MAPE=63.3738,MAE=47.4643 and RMSE=1.8221;meanwhile,the WOA-XGBoost model had corresponding indexes of MAPE=67.8956,MAE=49.1825 and RMSE=1.9040.Besides,the predicted data from the ETO-XGBoost model and the WOAXGBoost model showed the highest similarity with the actual data in predicting the axial strength of concrete-filled steel tubular(CFST)columns.Therefore,the ETO-XGBoost model and the WOA-XGBoost model can be considered as a powerful and accurate tool in predicting the compressive strength of CFST columns.展开更多
This article aims to enhance seismic hazard assessment methods for Kazakhstan’s seismotectonic conditions.It combines probabilistic seismic hazard analysis(PSHA),ground motion simulation,sitespecific geological and g...This article aims to enhance seismic hazard assessment methods for Kazakhstan’s seismotectonic conditions.It combines probabilistic seismic hazard analysis(PSHA),ground motion simulation,sitespecific geological and geotechnical data analysis,and seismic scenario analysis to develop Probabilistic General Seismic Zoning(GSZ)maps for Kazakhstan and Probabilistic Seismic Microzoning maps for Almaty.These maps align with Eurocode 8 principles,incorporating seismic intensity and engineering parameters like peak ground acceleration(PGA).The new procedure,applied in national projects,has resulted in GSZ maps for the country,seismic microzoning maps for Almaty,and detailed seismic zoning maps for East Kazakhstan.These maps,part of a regulatory document,guide earthquake-resistant design and construction.They offer a comprehensive assessment of seismic hazards,integrating traditional Medvedev-Sponheuer-Karnik(MSK-64)intensity scale points with quantitative parameters like peak ground acceleration.This innovative approach promises to advance methods for quantifying seismic hazards in specific regions.展开更多
The interpretation and application of CPT(cone penetration test)results is characterized by considerable variability of data,either in measured or correlated parameters.According to the requirements of Eurocode 7 the ...The interpretation and application of CPT(cone penetration test)results is characterized by considerable variability of data,either in measured or correlated parameters.According to the requirements of Eurocode 7 the existing variability in soil properties has to be taken into account statistically during the determination of the characteristic values of each parameter.This should be done by selecting a cautious estimate of the value affecting the limit state.Obtaining the characteristic values of CPT measurements is not an easy task and on this aspect nor clear neither unified guidelines exist.This paper focuses in several approaches to characterize the cone resistance and the sleeve friction using simple statistical analysis,in order for these parameters to be applicable in design.Similar procedures are then applied to determine the characteristic values of correlated parameters from CPT such as the effective friction angle for sands and the undrained shear strength for clays.The resulting characteristic values of the considered parameters emphasize the fact that the prediction and the interpretation of characteristic values of soil properties is a complicated and biased procedure.展开更多
A full-scale composite floor plate was tested to investigate the flexural behavior and in-plane effects of the floor slab in a grillage of composite beams that reduces the tendency for longitudinal splitting of the co...A full-scale composite floor plate was tested to investigate the flexural behavior and in-plane effects of the floor slab in a grillage of composite beams that reduces the tendency for longitudinal splitting of the concrete slab along the line of the primary beams. This is important in cases where the steel decking is discontinuous when it is orientated parallel to the beams. In this case, it is important to demonstrate that the amount of transverse reinforcement required to transfer local forces from the shear connectors can be reduced relative to the requirements of Eurocode 4. The mechanism under study involved in-plane compression forces being developed in the slab due to the restraining action of the floor plate, which was held in position by the peripheral composite beams;while the secondary beams acted as transverse ties to resist the forces in the floor plate that would otherwise lead to splitting of the slab along the line of the primary beams. The tendency for cracking along the center line of the primary beam and at the peripheral beams was closely monitored. This is the first large floor plate test that has been carried out under laboratory conditions since the Cardington tests in the early 1990s, although those tests were not carried out to failure. This floor plate test was designed so that the longitudinal force transferred by the primary beams was relatively high (i.e., it was designed for full shear connection), but the transverse reinforcement was taken as the minimum of 0.2% of the concrete area. The test confirmed that the primary beams reached their plastic bending resistance despite the discontinuous decking and transverse reinforcement at the minimum percentage given in Eurocode 4. Based on this test, a reduction factor due to shear connectors at edge beams without U-bars is proposed.展开更多
This study is focused on?nonlinear analysis and design of?spatial and perimeter moment resisting frames for a 9-storeys?office building?having?9.15?m span.?Seismic?design criteria of Eurocode 8?Ductility Class High (D...This study is focused on?nonlinear analysis and design of?spatial and perimeter moment resisting frames for a 9-storeys?office building?having?9.15?m span.?Seismic?design criteria of Eurocode 8?Ductility Class High (DCH)?with behavior factor (q) of 6.5 and AISC/ASCE code,?Special Moment resisting Frame (SMF) with response modification factor (R) of 8 were employed.?The design outcomes?are?expressed in terms of frame performance?(non-linear analysis), section profiles?(code recommendations), strength-demand to capacity ratios, drift-demand to capacity?ratios and structural weight. The consequences of the research compare?two codes in term of weights and design performances.?This will aid professional engineers and researchers to select effective design criteria and capacity design rules?efficiently.展开更多
The depth adjustment factor for bending strength stated in Eurocode 5(EC5)is only applicable to timbers having a characteristic density below 700 kg/m3.However,most Malaysian timbers are hardwood,some with a charac...The depth adjustment factor for bending strength stated in Eurocode 5(EC5)is only applicable to timbers having a characteristic density below 700 kg/m3.However,most Malaysian timbers are hardwood,some with a characteristic density reaching above 700 kg/m3.Therefore,the objective of this study was to examine whether the depth adjustment factor stipulated in EC5 is valid for Malaysian hardwood timbers.Six timber species were selected for this study,namely Kapur(Dryobalanops C.F.Gaertn.),Kempas(Koompassia Maingay ex Benth.),Keruing(Dipterocarpus C.F.Gaertn.),Light red meranti(Shorea Roxb.ex C.F.Gaertn.),Geronggang(Cratoxylum Blume)and Balau(Shorea Roxb.ex C.F.Gaertn.).The determination of bending strength and characteristic density was conducted according to BS EN 408:2010 and BS EN 384:2016,respectively.A graph for mean bending strength vs.(150/h)was plotted for each timber species.The power function was selected to analyze the relationship between the two variables.The power of the regression equations varied depending on the characteristic density of the timber species.For species with a characteristic density below 700 kg/m3,such as Kapur,Keruing,and Light red meranti,the power was between 0.16 to 0.17.In contrast,for species having a characteristic density above 700 kg/m3,namely Kempas and Balau,the power was higher at 0.23 and 0.24,respectively.Geronggang was an exception to this pattern.These values are close to the depth adjustment factor given in EC5,which is 0.2.Based on the results,it can be suggested that the adjustment factor of 0.2 is also applicable to Malaysian hardwood timbers with a characteristic density above 700 kg/m3.展开更多
摘要The Structural Eurocodes Systems, which are developed by the European Committee for Standardization (CEN), have come into trial use in the 28 countries of European Union (EU), and will lay a significant influence on the development of the construction industry and on the international market of construction.
基金the financial support granted by the Scientific Research Fund of the Ministry of Education and Training(MOET),Vietnam(No.B2024-MBS-04).
摘要In recent years,with the explosion of the 4.0 industrial revolution,terms such as machine learning(ML)have become familiar and are increasingly widely applied in the engineering field.This study focuses on proposing two new hybrid models named exponential-trigonometrie optimized extreme gradient boosting(ETO-XGBoost)and whale optimization algorithm extreme gradient boosting(WOA-XGBoost),which are developed based on extreme gradient boosting combined with exponential-trigonometric optimization and whale optimization algorithm.A data set has been built and analyzed using ABAQUS software,and combined with data from the empirical formula to construct a training data set for the proposed models.The two proposed hybrid models are compared with the available models including Kolmogorov-Arnold networks(KAN),artificial neural networks(ANN)and Eurocode 4 standard through important statistical indices such as mean absolute error(MAE),mean absolute percentage error(MAPE),root mean square error(RMSE)and correlation coefficient R.The analysis results show that the ETO-XGBoost model and the WOA-XGBoost model are the most effective ML models when compared with other models.The correlation index R of both models reached very high values(0.9963 for ETO-XGBoost and 0.9956 for WOA-XGBoost,respectively).At the same time,the error indexes of the ETO-XGBoost model were the smallest among the compared models,with MAPE=63.3738,MAE=47.4643 and RMSE=1.8221;meanwhile,the WOA-XGBoost model had corresponding indexes of MAPE=67.8956,MAE=49.1825 and RMSE=1.9040.Besides,the predicted data from the ETO-XGBoost model and the WOAXGBoost model showed the highest similarity with the actual data in predicting the axial strength of concrete-filled steel tubular(CFST)columns.Therefore,the ETO-XGBoost model and the WOA-XGBoost model can be considered as a powerful and accurate tool in predicting the compressive strength of CFST columns.
基金The work was carried out in the framework of earmarked funding“Assessment of seismic hazard of territories of Kazakhstan on modern scientific and methodological basis”,programme code number F.0980.Source of funding-Ministry of Science and Higher Education of the Republic of Kazakhstan.
摘要This article aims to enhance seismic hazard assessment methods for Kazakhstan’s seismotectonic conditions.It combines probabilistic seismic hazard analysis(PSHA),ground motion simulation,sitespecific geological and geotechnical data analysis,and seismic scenario analysis to develop Probabilistic General Seismic Zoning(GSZ)maps for Kazakhstan and Probabilistic Seismic Microzoning maps for Almaty.These maps align with Eurocode 8 principles,incorporating seismic intensity and engineering parameters like peak ground acceleration(PGA).The new procedure,applied in national projects,has resulted in GSZ maps for the country,seismic microzoning maps for Almaty,and detailed seismic zoning maps for East Kazakhstan.These maps,part of a regulatory document,guide earthquake-resistant design and construction.They offer a comprehensive assessment of seismic hazards,integrating traditional Medvedev-Sponheuer-Karnik(MSK-64)intensity scale points with quantitative parameters like peak ground acceleration.This innovative approach promises to advance methods for quantifying seismic hazards in specific regions.
摘要The interpretation and application of CPT(cone penetration test)results is characterized by considerable variability of data,either in measured or correlated parameters.According to the requirements of Eurocode 7 the existing variability in soil properties has to be taken into account statistically during the determination of the characteristic values of each parameter.This should be done by selecting a cautious estimate of the value affecting the limit state.Obtaining the characteristic values of CPT measurements is not an easy task and on this aspect nor clear neither unified guidelines exist.This paper focuses in several approaches to characterize the cone resistance and the sleeve friction using simple statistical analysis,in order for these parameters to be applicable in design.Similar procedures are then applied to determine the characteristic values of correlated parameters from CPT such as the effective friction angle for sands and the undrained shear strength for clays.The resulting characteristic values of the considered parameters emphasize the fact that the prediction and the interpretation of characteristic values of soil properties is a complicated and biased procedure.
基金part of a collaborative project between the Steel Construction Institute, the University of Stuttgart, the University of Luxembourg, Arcelor Mittal S.A., and the University of Bradford funded by the European Community’s Research Fund for Coal and Steel (RFSR-CT-2012-00030)
摘要A full-scale composite floor plate was tested to investigate the flexural behavior and in-plane effects of the floor slab in a grillage of composite beams that reduces the tendency for longitudinal splitting of the concrete slab along the line of the primary beams. This is important in cases where the steel decking is discontinuous when it is orientated parallel to the beams. In this case, it is important to demonstrate that the amount of transverse reinforcement required to transfer local forces from the shear connectors can be reduced relative to the requirements of Eurocode 4. The mechanism under study involved in-plane compression forces being developed in the slab due to the restraining action of the floor plate, which was held in position by the peripheral composite beams;while the secondary beams acted as transverse ties to resist the forces in the floor plate that would otherwise lead to splitting of the slab along the line of the primary beams. The tendency for cracking along the center line of the primary beam and at the peripheral beams was closely monitored. This is the first large floor plate test that has been carried out under laboratory conditions since the Cardington tests in the early 1990s, although those tests were not carried out to failure. This floor plate test was designed so that the longitudinal force transferred by the primary beams was relatively high (i.e., it was designed for full shear connection), but the transverse reinforcement was taken as the minimum of 0.2% of the concrete area. The test confirmed that the primary beams reached their plastic bending resistance despite the discontinuous decking and transverse reinforcement at the minimum percentage given in Eurocode 4. Based on this test, a reduction factor due to shear connectors at edge beams without U-bars is proposed.
摘要This study is focused on?nonlinear analysis and design of?spatial and perimeter moment resisting frames for a 9-storeys?office building?having?9.15?m span.?Seismic?design criteria of Eurocode 8?Ductility Class High (DCH)?with behavior factor (q) of 6.5 and AISC/ASCE code,?Special Moment resisting Frame (SMF) with response modification factor (R) of 8 were employed.?The design outcomes?are?expressed in terms of frame performance?(non-linear analysis), section profiles?(code recommendations), strength-demand to capacity ratios, drift-demand to capacity?ratios and structural weight. The consequences of the research compare?two codes in term of weights and design performances.?This will aid professional engineers and researchers to select effective design criteria and capacity design rules?efficiently.
基金funded by Geran Penyelidikan Khas(GPK),(600-RMC/GPK 5/3(071/2020)).
摘要The depth adjustment factor for bending strength stated in Eurocode 5(EC5)is only applicable to timbers having a characteristic density below 700 kg/m3.However,most Malaysian timbers are hardwood,some with a characteristic density reaching above 700 kg/m3.Therefore,the objective of this study was to examine whether the depth adjustment factor stipulated in EC5 is valid for Malaysian hardwood timbers.Six timber species were selected for this study,namely Kapur(Dryobalanops C.F.Gaertn.),Kempas(Koompassia Maingay ex Benth.),Keruing(Dipterocarpus C.F.Gaertn.),Light red meranti(Shorea Roxb.ex C.F.Gaertn.),Geronggang(Cratoxylum Blume)and Balau(Shorea Roxb.ex C.F.Gaertn.).The determination of bending strength and characteristic density was conducted according to BS EN 408:2010 and BS EN 384:2016,respectively.A graph for mean bending strength vs.(150/h)was plotted for each timber species.The power function was selected to analyze the relationship between the two variables.The power of the regression equations varied depending on the characteristic density of the timber species.For species with a characteristic density below 700 kg/m3,such as Kapur,Keruing,and Light red meranti,the power was between 0.16 to 0.17.In contrast,for species having a characteristic density above 700 kg/m3,namely Kempas and Balau,the power was higher at 0.23 and 0.24,respectively.Geronggang was an exception to this pattern.These values are close to the depth adjustment factor given in EC5,which is 0.2.Based on the results,it can be suggested that the adjustment factor of 0.2 is also applicable to Malaysian hardwood timbers with a characteristic density above 700 kg/m3.