The Chongwen Pagoda is the tallest masonry pagoda in China, with numerous openings inside the pagoda body. It is prone to damage during earthquakes, and the patterns of damage are complex. In order to scientifically analyze the dynamic performance, earthquake damage patterns, and mechanisms of the pagoda structure, on‐site dynamic testing was conducted to obtain the dynamic characteristics of the structure. A numerical model was established using Abaqus finite element software to calculate the dynamic characteristics of the structure. The results were compared with the testing results and showed a close agreement. El‐Centro earthquake wave, Taft earthquake wave, and Lanzhou artificial earthquake wave were selected as earthquake inputs based on site conditions, simulating frequent earthquakes, fortification earthquakes, and rare earthquakes with a magnitude of 9. The dynamic response of the pagoda structure was calculated, and the relationship between acceleration amplification factor, interstorey displacement, and interstorey displacement angle with floor height was analyzed. The seismic damage to the structure and the distribution of primary tensile stresses were studied, revealing the seismic damage mechanisms and the distribution characteristics of vulnerable areas in the Chongwen Pagoda. The research results provide references for the seismic assessment of this ancient pagoda.
{"title":"Analysis of seismic damage and seismic capacity of the structure of the ultrahigh pagoda","authors":"Junlong Lu, Jingyi Tian, Zhenshan Wang, Feng Jiang, Xiaoqin Wu","doi":"10.1002/tal.2181","DOIUrl":"https://doi.org/10.1002/tal.2181","url":null,"abstract":"The Chongwen Pagoda is the tallest masonry pagoda in China, with numerous openings inside the pagoda body. It is prone to damage during earthquakes, and the patterns of damage are complex. In order to scientifically analyze the dynamic performance, earthquake damage patterns, and mechanisms of the pagoda structure, on‐site dynamic testing was conducted to obtain the dynamic characteristics of the structure. A numerical model was established using Abaqus finite element software to calculate the dynamic characteristics of the structure. The results were compared with the testing results and showed a close agreement. El‐Centro earthquake wave, Taft earthquake wave, and Lanzhou artificial earthquake wave were selected as earthquake inputs based on site conditions, simulating frequent earthquakes, fortification earthquakes, and rare earthquakes with a magnitude of 9. The dynamic response of the pagoda structure was calculated, and the relationship between acceleration amplification factor, interstorey displacement, and interstorey displacement angle with floor height was analyzed. The seismic damage to the structure and the distribution of primary tensile stresses were studied, revealing the seismic damage mechanisms and the distribution characteristics of vulnerable areas in the Chongwen Pagoda. The research results provide references for the seismic assessment of this ancient pagoda.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The isolator units in a seismically isolated structure shall have a surplus yield strength under wind loads. The isolation interface must have enough strength to state at an elastic stage under wind loads. This necessitates an accurate evaluation of wind‐induced base shear force. Initially, to calculate the equivalent static wind load (ESWL) and the base shear force of a base‐isolated building, the validity of the inertial wind load (IWL) method and Chinese load code (CLC) method, the simplification based on the IWL method, are examined via comparison with response‐history analysis results. Comparative analysis reveals that the IWL method was more accurate in evaluating the ESWL and the base shear force of base‐isolated building, while the CLC method underestimated them due to the following reasons: inaccurate fundamental modal shape, a reduced peak factor, the omission of the ESWL contribution from the isolation interface, and flawed assumptions of uniform mass distribution. Subsequently, an improved CLC method that combined the exponential modal shape and first modal generalized mass modification coefficient is proposed and verified by a case study. Compared with the CLC method, the fluctuating base shear force calculated by the improved CLC method increased by 10% in the case study. Finally, the effect of non‐uniformly distributed mass is further considered in the proposed method by devising a mass conversion coefficient, and the case study has also validated this method. Without considering the effect of the non‐uniform mass, the fluctuating base shear force will be underestimated by 7.8% in the case study.
{"title":"An improved Chinese load code method for the evaluation of wind‐induced base shear force on base‐isolated buildings","authors":"Hehong Zhou, Wenchen Lie","doi":"10.1002/tal.2173","DOIUrl":"https://doi.org/10.1002/tal.2173","url":null,"abstract":"The isolator units in a seismically isolated structure shall have a surplus yield strength under wind loads. The isolation interface must have enough strength to state at an elastic stage under wind loads. This necessitates an accurate evaluation of wind‐induced base shear force. Initially, to calculate the equivalent static wind load (ESWL) and the base shear force of a base‐isolated building, the validity of the inertial wind load (IWL) method and Chinese load code (CLC) method, the simplification based on the IWL method, are examined via comparison with response‐history analysis results. Comparative analysis reveals that the IWL method was more accurate in evaluating the ESWL and the base shear force of base‐isolated building, while the CLC method underestimated them due to the following reasons: inaccurate fundamental modal shape, a reduced peak factor, the omission of the ESWL contribution from the isolation interface, and flawed assumptions of uniform mass distribution. Subsequently, an improved CLC method that combined the exponential modal shape and first modal generalized mass modification coefficient is proposed and verified by a case study. Compared with the CLC method, the fluctuating base shear force calculated by the improved CLC method increased by 10% in the case study. Finally, the effect of non‐uniformly distributed mass is further considered in the proposed method by devising a mass conversion coefficient, and the case study has also validated this method. Without considering the effect of the non‐uniform mass, the fluctuating base shear force will be underestimated by 7.8% in the case study.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142265365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mineral admixtures play an important part in improving the strength characteristics of concrete. This manuscript presents the incorporation of silica fume (SF) and ground granulated blast furnace slag into the concrete mix to decrease the cement content and enhance the strength and concrete's durability. In addition, river sand deposits have started to dry up. Also, eco‐friendly disposal of industrial wastes acts as a major threat to industries. Hence, the use of waste foundry sand (WFS) and M‐sand (MS) as fine aggregate is attempted in this study. In the first phase of this research work, concrete specimens have been prepared by partially replaced cement with 0%, 10%, 20%, 30%, and 40% by Ground Granulated Blast Furnace Slag (GGBFS) and 0%, 5%, 10%, and 15% by SF to find their optimum replacements in Ternary Blended Concrete (TBC). In the second phase, concrete specimens replaced with 0%, 10%, 20%, 30%, and 40% by WFS for fine aggregate (MS) were prepared and found optimum usage of foundry sand in waste foundry sand concrete (WFSC). In the third phase, a ternary blended green concrete (TBGC) was prepared by partially replaced cement with 30% GGBFS and 10% SF and replaced MS with 30% WFS and conducted strength (flexural strength, compressive and split tensile strength) and durability (acid and sulfate attack) studies. The above combination was found to be a promising way for the development of environmentally friendly concrete.
{"title":"Enhancing Concrete Performance with Waste Foundry Sand Using Ternary Blended Mixes of Ordinary Portland Cement, Silica Fume, and Ground Granulated Blast Furnace Slag","authors":"S. Yamini Roja, K. Murali, V. M. Shanthi","doi":"10.1002/tal.2180","DOIUrl":"https://doi.org/10.1002/tal.2180","url":null,"abstract":"Mineral admixtures play an important part in improving the strength characteristics of concrete. This manuscript presents the incorporation of silica fume (SF) and ground granulated blast furnace slag into the concrete mix to decrease the cement content and enhance the strength and concrete's durability. In addition, river sand deposits have started to dry up. Also, eco‐friendly disposal of industrial wastes acts as a major threat to industries. Hence, the use of waste foundry sand (WFS) and M‐sand (MS) as fine aggregate is attempted in this study. In the first phase of this research work, concrete specimens have been prepared by partially replaced cement with 0%, 10%, 20%, 30%, and 40% by Ground Granulated Blast Furnace Slag (GGBFS) and 0%, 5%, 10%, and 15% by SF to find their optimum replacements in Ternary Blended Concrete (TBC). In the second phase, concrete specimens replaced with 0%, 10%, 20%, 30%, and 40% by WFS for fine aggregate (MS) were prepared and found optimum usage of foundry sand in waste foundry sand concrete (WFSC). In the third phase, a ternary blended green concrete (TBGC) was prepared by partially replaced cement with 30% GGBFS and 10% SF and replaced MS with 30% WFS and conducted strength (flexural strength, compressive and split tensile strength) and durability (acid and sulfate attack) studies. The above combination was found to be a promising way for the development of environmentally friendly concrete.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142265364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Detailed wind pressure information plays a critical role in the accurate estimation of wind loads on high‐rise buildings, especially for complex‐shaped supertall buildings. However, owing to the limited internal space of a scaled building model and the capacity of data‐acquisition devices, it is often difficult to acquire the wind pressures at all positions of interest on the entire model in wind tunnel testing. To this end, a novel approach that combines the proper orthogonal decomposition (POD) and machine learning (ML) is presented in this paper for the prediction of wind pressure time series (WPTS) on supertall building models in wind tunnel testing. In this approach, the prediction of WPTS is converted into the estimation of several main eigenmodes and mean wind pressures by combining the POD with ML. This strategy can effectively reduce the computational effort compared to the direct prediction of WPTS. A combined ML model consisting of the Gaussian process regression (GPR), decision tree regression (DTR), and random forest (RF) (i.e., POD‐GPR‐DTR‐RF model) is utilized for the prediction of eigenmodes and mean wind pressures. Wind pressure records from a wind tunnel experiment of a 600‐m‐high building are employed to verify the accuracy and effectiveness of the presented approach. The results show that the combined ML model (i.e., POD‐GPR‐DTR‐RF model) developed based on the proposed approach performs satisfactorily in the prediction of WPTS and outperforms the conventional method that combines POD with backpropagation neural network model (i.e., POD‐BPNN model), demonstrating that the proposed approach is an effective tool for prediction of WPTS on supertall buildings.
详细的风压信息对于准确估算高层建筑，尤其是形状复杂的超高层建筑的风荷载起着至关重要的作用。然而，由于缩尺建筑模型的内部空间和数据采集设备的能力有限，在风洞试验中往往难以获取整个模型上所有相关位置的风压。为此，本文提出了一种结合适当正交分解（POD）和机器学习（ML）的新方法，用于预测风洞试验中超高层建筑模型的风压时间序列（WPTS）。在这种方法中，通过将 POD 与 ML 相结合，将 WPTS 预测转换为几个主要特征模式和平均风压的估计。与直接预测 WPTS 相比，这种策略可以有效减少计算量。由高斯过程回归（GPR）、决策树回归（DTR）和随机森林（RF）组成的组合 ML 模型（即 POD-GPR-DTR-RF 模型）被用于预测特征模式和平均风压。为了验证该方法的准确性和有效性，我们使用了 600 米高建筑物风洞实验的风压记录。结果表明，基于所提方法开发的组合 ML 模型（即 POD-GPR-DTR-RF 模型）在预测 WPTS 方面表现令人满意，并且优于将 POD 与反向传播神经网络模型相结合的传统方法（即 POD-BPNN 模型），这表明所提方法是预测超高层建筑 WPTS 的有效工具。
{"title":"Prediction of wind pressures on supertall buildings based on proper orthogonal decomposition and machine learning","authors":"Jia‐Xing Huang, Qiu‐Sheng Li, Xu‐Liang Han","doi":"10.1002/tal.2174","DOIUrl":"https://doi.org/10.1002/tal.2174","url":null,"abstract":"Detailed wind pressure information plays a critical role in the accurate estimation of wind loads on high‐rise buildings, especially for complex‐shaped supertall buildings. However, owing to the limited internal space of a scaled building model and the capacity of data‐acquisition devices, it is often difficult to acquire the wind pressures at all positions of interest on the entire model in wind tunnel testing. To this end, a novel approach that combines the proper orthogonal decomposition (POD) and machine learning (ML) is presented in this paper for the prediction of wind pressure time series (WPTS) on supertall building models in wind tunnel testing. In this approach, the prediction of WPTS is converted into the estimation of several main eigenmodes and mean wind pressures by combining the POD with ML. This strategy can effectively reduce the computational effort compared to the direct prediction of WPTS. A combined ML model consisting of the Gaussian process regression (GPR), decision tree regression (DTR), and random forest (RF) (i.e., POD‐GPR‐DTR‐RF model) is utilized for the prediction of eigenmodes and mean wind pressures. Wind pressure records from a wind tunnel experiment of a 600‐m‐high building are employed to verify the accuracy and effectiveness of the presented approach. The results show that the combined ML model (i.e., POD‐GPR‐DTR‐RF model) developed based on the proposed approach performs satisfactorily in the prediction of WPTS and outperforms the conventional method that combines POD with backpropagation neural network model (i.e., POD‐BPNN model), demonstrating that the proposed approach is an effective tool for prediction of WPTS on supertall buildings.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hu Qi, Yelei Shen, Haishan Guo, Wenxuan Zhang, Zheng Lu
The precast concrete frame with unbonded post‐tensioned beam‐column connections (UPBC) has been emphasized in recent years for it is capable of sustaining a design‐basis earthquake with minor damage. The fiber hinge model (FHM), which is a simple and effective approach, is proposed in this paper for the simulation of UPBC. In the FHM, the mild steels and prestressed tendons crossing the interface are integrated into one element. The mechanism and behavior of the FHM are presented in this paper. The proposed model, which is developed in OpenSees, has been validated by tests, and the FHM is able to accurately describe the shift of compressive center induced by the opening of the interface between the precast beam and column, as well as “beam elongation effects.”
{"title":"The fiber hinge model for unbonded post‐tensioned beam‐column connections","authors":"Hu Qi, Yelei Shen, Haishan Guo, Wenxuan Zhang, Zheng Lu","doi":"10.1002/tal.2176","DOIUrl":"https://doi.org/10.1002/tal.2176","url":null,"abstract":"The precast concrete frame with unbonded post‐tensioned beam‐column connections (UPBC) has been emphasized in recent years for it is capable of sustaining a design‐basis earthquake with minor damage. The fiber hinge model (FHM), which is a simple and effective approach, is proposed in this paper for the simulation of UPBC. In the FHM, the mild steels and prestressed tendons crossing the interface are integrated into one element. The mechanism and behavior of the FHM are presented in this paper. The proposed model, which is developed in OpenSees, has been validated by tests, and the FHM is able to accurately describe the shift of compressive center induced by the opening of the interface between the precast beam and column, as well as “beam elongation effects.”","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the effects of the spectral acceleration at the superstructure first‐mode period on the isolator displacement are investigated for far‐field ground motions. For this purpose, two different base‐isolated models are subjected to 165 far‐field ground motions. It is demonstrated that considering the spectral acceleration at the superstructure first‐mode period, besides that at the effective period, improves the estimation accuracy of isolator displacement. ASCE 7‐22 modifies the scaling period range to consider the superstructure first mode period and proposes the new period range from the superstructure first‐mode period to the 1.25 times effective period. In the ASCE 7‐22, the same weight factor is used for the whole period range. However, the present study shows that adding the superstructure first‐mode related period range with appropriate weight factor to the effective period‐based scaling range decreases the dispersion of isolator displacement in the nonlinear response history analyses (NRH). Then, to overcome the spectral shape effects on the fragility curves, a vector‐valued intensity measure parameter is obtained by combining spectral acceleration at the effective period and reduced spectral acceleration at the superstructure first‐mode period. The optimum contribution factor for the spectral acceleration at the superstructure first‐mode period is defined as the ratio of the superstructure first‐mode period to the effective period. The article shows that the proposed parameter is efficient and sufficient to be used as an intensity measure for far‐field ground motions. Furthermore, regression analysis results indicate that this vector‐valued intensity measure parameter correlates well with the isolator displacement. Further, the article shows that using the proposed IM parameter in the fragility curves makes the collapse margin ratio of these curves less sensitive to the spectral shape of the selected ground motions.
{"title":"A vector‐valued ground motion intensity measure for base‐isolated buildings in far‐field regions","authors":"Necmettin Güneş","doi":"10.1002/tal.2168","DOIUrl":"https://doi.org/10.1002/tal.2168","url":null,"abstract":"In this study, the effects of the spectral acceleration at the superstructure first‐mode period on the isolator displacement are investigated for far‐field ground motions. For this purpose, two different base‐isolated models are subjected to 165 far‐field ground motions. It is demonstrated that considering the spectral acceleration at the superstructure first‐mode period, besides that at the effective period, improves the estimation accuracy of isolator displacement. ASCE 7‐22 modifies the scaling period range to consider the superstructure first mode period and proposes the new period range from the superstructure first‐mode period to the 1.25 times effective period. In the ASCE 7‐22, the same weight factor is used for the whole period range. However, the present study shows that adding the superstructure first‐mode related period range with appropriate weight factor to the effective period‐based scaling range decreases the dispersion of isolator displacement in the nonlinear response history analyses (NRH). Then, to overcome the spectral shape effects on the fragility curves, a vector‐valued intensity measure parameter is obtained by combining spectral acceleration at the effective period and reduced spectral acceleration at the superstructure first‐mode period. The optimum contribution factor for the spectral acceleration at the superstructure first‐mode period is defined as the ratio of the superstructure first‐mode period to the effective period. The article shows that the proposed parameter is efficient and sufficient to be used as an intensity measure for far‐field ground motions. Furthermore, regression analysis results indicate that this vector‐valued intensity measure parameter correlates well with the isolator displacement. Further, the article shows that using the proposed IM parameter in the fragility curves makes the collapse margin ratio of these curves less sensitive to the spectral shape of the selected ground motions.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a new connection between the H‐beam and rectangular concrete‐filled hot‐rolled‐steel tubular column (CFHRSTC) was proposed to prevent the steel beam‐column joint protruded from the inside wall in residential buildings. The quasi‐static test and finite element analysis were conducted on four new joints to study the influence of the haunch stiffener configuration, internal steel plate thickness, and axial force on the failure mode, load‐carrying capacity, ductility, energy dissipating capacity, and stiffness degradation of the joint. The results revealed that the hysteretic curve of every joint was full. The damage to the joint was concentrated in the H‐beam, and the CFHRSTC remained elastic. The joint configuration could realize a weak beam‐strong column and joint core connection. Using the haunch stiffener on two sides of the H‐beam flange could effectively optimize load transfer at the end of the H‐beam and joint core. As the axial force increased, the ultimate load‐carrying capacity and ductility gradually decreased. Reducing the thickness of the internal steel plate did not significantly influence the seismic performance of the joint. Compared with the use of cover plate joints, the use of haunch stiffeners can effectively enhance the seismic performance of joints.
本文提出了一种 H 型钢与矩形混凝土填充热轧钢管柱（CFHRSTC）之间的新型连接，以防止住宅建筑中钢梁-柱连接处从内墙突出。对四种新型接头进行了准静力试验和有限元分析，研究了支撑加劲件配置、内部钢板厚度和轴向力对接头破坏模式、承载能力、延性、耗能能力和刚度退化的影响。结果表明，每个接头的滞后曲线都是饱满的。接头的损坏集中在 H 型梁，而 CFHRSTC 仍保持弹性。该连接构造可实现弱梁-强柱和连接核心筒的连接。在 H 型梁翼缘板两侧使用拱形加劲件可有效优化 H 型梁端部和连接核心筒的荷载传递。随着轴向力的增加，极限承载能力和延性逐渐降低。减小内部钢板的厚度对接头的抗震性能没有明显影响。与使用盖板连接相比，使用拱形加劲件可有效提高连接的抗震性能。
{"title":"Seismic performance of joint between steel H‐beam and rectangular concrete‐filled hot‐rolled‐steel tubular column","authors":"Hanqin Wang, Qing Jiang, Zhipeng Huang, Junqi Huang, Xun Chong","doi":"10.1002/tal.2179","DOIUrl":"https://doi.org/10.1002/tal.2179","url":null,"abstract":"In this paper, a new connection between the H‐beam and rectangular concrete‐filled hot‐rolled‐steel tubular column (CFHRSTC) was proposed to prevent the steel beam‐column joint protruded from the inside wall in residential buildings. The quasi‐static test and finite element analysis were conducted on four new joints to study the influence of the haunch stiffener configuration, internal steel plate thickness, and axial force on the failure mode, load‐carrying capacity, ductility, energy dissipating capacity, and stiffness degradation of the joint. The results revealed that the hysteretic curve of every joint was full. The damage to the joint was concentrated in the H‐beam, and the CFHRSTC remained elastic. The joint configuration could realize a weak beam‐strong column and joint core connection. Using the haunch stiffener on two sides of the H‐beam flange could effectively optimize load transfer at the end of the H‐beam and joint core. As the axial force increased, the ultimate load‐carrying capacity and ductility gradually decreased. Reducing the thickness of the internal steel plate did not significantly influence the seismic performance of the joint. Compared with the use of cover plate joints, the use of haunch stiffeners can effectively enhance the seismic performance of joints.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yang‐yang Guo, Zu‐zhi Tian, Xiang‐fan Wu, Li‐yuan Tan, Hao‐peng Li
The conventional vertical circulation stereo garage is susceptible to deformation and instability when subjected to extreme seismic loads and complex working conditions. The present study introduces the combination arrangement of steel pipe and friction damper to optimize vertical circulation stereo garage while also investigating their seismic suppression performance under three representative seismic waves (EL‐CNENTRO, TH1TG025(TH), and RH1TG025(RH)). The results showed that the garage structure hasbetter seismic suppression performance when the combination of steel pipes and friction dampers is applied in Scheme 4 compared to relying solely on diagonal tie rod, steel pipe or friction damper. And Scheme 4 achieves inhibition rates of up to 61.27%, 22.12%, 56.07%, and 12.84% for overall maximum deformation response, maximum Y‐direction deformation response, vertex acceleration response, and bottom shear response, respectively. This enhancement significantly improves the garage's seismic stability, providing valuable theoretical references for advancing the development and market promotion of vertical circulation stereo garages.
{"title":"Research on seismic suppression performance of vertical circulation stereo garage based on friction damper and steel pipe","authors":"Yang‐yang Guo, Zu‐zhi Tian, Xiang‐fan Wu, Li‐yuan Tan, Hao‐peng Li","doi":"10.1002/tal.2177","DOIUrl":"https://doi.org/10.1002/tal.2177","url":null,"abstract":"The conventional vertical circulation stereo garage is susceptible to deformation and instability when subjected to extreme seismic loads and complex working conditions. The present study introduces the combination arrangement of steel pipe and friction damper to optimize vertical circulation stereo garage while also investigating their seismic suppression performance under three representative seismic waves (EL‐CNENTRO, TH1TG025(TH), and RH1TG025(RH)). The results showed that the garage structure hasbetter seismic suppression performance when the combination of steel pipes and friction dampers is applied in Scheme 4 compared to relying solely on diagonal tie rod, steel pipe or friction damper. And Scheme 4 achieves inhibition rates of up to 61.27%, 22.12%, 56.07%, and 12.84% for overall maximum deformation response, maximum Y‐direction deformation response, vertex acceleration response, and bottom shear response, respectively. This enhancement significantly improves the garage's seismic stability, providing valuable theoretical references for advancing the development and market promotion of vertical circulation stereo garages.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ehsan Ekhveh, Rasoul Mirghaderi, Sina Kavei, Mehdi Ghassemieh, Farshid Rashidiyan
The reduced beam section (RBS) connections in steel structures are widely used to achieve sufficient ductility and avoid creating brittle failures in moment‐resisting frames. Compared to other types of connections, conventional RBS connections have the potential to reduce moment capacity and induce larger lateral deformation in the structure. In order to resolve this problem, novel forms of RBS connections have been proposed in recent years, such as tubular web RBS connections, which have shown a desirable performance under various loading conditions in previous studies. Therefore, this study conducted an analytic and numerical investigation of this connection under seismic loading. In this regard, the first step is to introduce the analytic equations related to the structural properties and stability of the reduced beam with the tubular web. Using these equations, a comprehensive procedure for the design of the tubular web RBS connections is presented. After that, a numerical model of the tubular web RBS connections is created and then analyzed under cyclic loading using the finite element method in ABAQUS software. Based on the results of this simulation, the suggested connection meets the criteria of valid international standards and can be used in the special moment‐resisting frame. In order to assess the impact of using the proposed connection in moment‐resisting frames, the performance of two 2D moment‐resisting frames with this connection is studied. This study shows that the maximum percentage increase in relative displacement caused by using tubular web RBS connections is 1.68%, whereas this figure rises to 10.6% when conventional RBS connections are used. Therefore, the designers can use tubular web RBS connections instead of conventional RBS connections to increase the lateral stability of the structure and control its lateral deflection due to the seismic loadings without having to increase the dimensions of the frame elements.
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Under the action of the fluctuating wind load, the low frequency part produces background response to the structures, while the high frequency part produces resonance response to the structures. In structural design, equivalent static wind load is usually used to equate the fluctuating wind load. Although there are various methods of evaluating the equivalent static wind load, they did not consider the correlation between modal responses or considered them insufficiently. Therefore, in this paper, the correlation between modal response is considered to evaluate the equivalent static wind load, the displacement response is decomposed by proper orthogonal decomposition (POD) method, the correlation between modal displacement is removed, the equivalent static wind load is expressed in the form of displacement mode, and then the correlation between modal response is fully considered in the extreme value combination. This paper combines the equivalent static wind loads in order to make the wind resistance design more reasonable for high‐rise buildings. First, the formulas of equivalent static wind loads expressed by displacement modes of background and resonant response are deduced based on modal decomposition and POD method. Second, the combination formulas of square‐root‐of‐sum‐square (SRSS) and complete‐quadratic‐combination (CQC) rules for the equivalent static wind loads considering the mean wind loads are proposed. Both the linear combination formula of SRSS for the equivalent static wind load and the weighting factor expressions of background and resonance equivalent static wind load are given. Third, the accuracy and validity of the formulas of equivalent static wind load are verified by a wind tunnel pressure test of a high‐rise building. Finally, the simplified combination coefficient formulas for the equivalent static wind loads are proposed, and the combination of the high‐rise building base's fluctuating equivalent static wind loads of along‐wind direction, across‐wind direction, and torsional direction is analyzed.
在波动风荷载作用下，低频部分对结构产生背景响应，而高频部分对结构产生共振响应。在结构设计中，通常使用等效静风荷载来等效波动风荷载。虽然有多种评估等效静风荷载的方法，但都没有考虑模态响应之间的相关性，或者考虑得不够充分。因此，本文在评估等效静风荷载时考虑了模态响应之间的相关性，采用适当的正交分解（POD）方法对位移响应进行分解，去除模态位移之间的相关性，以位移模态的形式表示等效静风荷载，然后在极值组合中充分考虑模态响应之间的相关性。本文结合等效静风荷载，使高层建筑的抗风设计更加合理。首先，基于模态分解法和 POD 法，推导出以背景位移模态和共振响应表示的等效静风荷载公式。其次，提出了考虑平均风荷载的等效静风荷载平方根求和平方规则（SRSS）和完全二次方规则（CQC）的组合公式。给出了等效静风荷载 SRSS 的线性组合公式以及背景和共振等效静风荷载的权重系数表达式。第三，通过高层建筑的风洞压力试验验证了等效静风荷载公式的准确性和有效性。最后，提出了简化的等效静风荷载组合系数公式，并对高层建筑基座沿风向、跨风向和扭转方向的波动等效静风荷载组合进行了分析。
{"title":"Equivalent static wind load based on displacement mode and load combination for high‐rise buildings","authors":"Haiwei Guan, Yuji Tian, Weihu Chen, Yuliang Qi","doi":"10.1002/tal.2169","DOIUrl":"https://doi.org/10.1002/tal.2169","url":null,"abstract":"Under the action of the fluctuating wind load, the low frequency part produces background response to the structures, while the high frequency part produces resonance response to the structures. In structural design, equivalent static wind load is usually used to equate the fluctuating wind load. Although there are various methods of evaluating the equivalent static wind load, they did not consider the correlation between modal responses or considered them insufficiently. Therefore, in this paper, the correlation between modal response is considered to evaluate the equivalent static wind load, the displacement response is decomposed by proper orthogonal decomposition (POD) method, the correlation between modal displacement is removed, the equivalent static wind load is expressed in the form of displacement mode, and then the correlation between modal response is fully considered in the extreme value combination. This paper combines the equivalent static wind loads in order to make the wind resistance design more reasonable for high‐rise buildings. First, the formulas of equivalent static wind loads expressed by displacement modes of background and resonant response are deduced based on modal decomposition and POD method. Second, the combination formulas of square‐root‐of‐sum‐square (SRSS) and complete‐quadratic‐combination (CQC) rules for the equivalent static wind loads considering the mean wind loads are proposed. Both the linear combination formula of SRSS for the equivalent static wind load and the weighting factor expressions of background and resonance equivalent static wind load are given. Third, the accuracy and validity of the formulas of equivalent static wind load are verified by a wind tunnel pressure test of a high‐rise building. Finally, the simplified combination coefficient formulas for the equivalent static wind loads are proposed, and the combination of the high‐rise building base's fluctuating equivalent static wind loads of along‐wind direction, across‐wind direction, and torsional direction is analyzed.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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