Pub Date : 2021-05-01DOI: 10.12989/EAS.2021.20.5.473
Nima Farshidfar, A. Keshavarz, S. M. Mirhosseini
The limit equilibrium analysis through the horizontal slice method is used to study the seismic stability of reinforced soil slopes by satisfying the equilibrium of the horizontal and vertical forces as well as moments. Unlike the pseudo-static (PS) method, the pseudo-dynamic method consideres the effects of time and phase difference of the P and S waves propagation inside the soil mass. In this paper, the PS, the conventional pseudo-dynamic (CPD), and the modified pseudo-dynamic (MPD) methods are used to study the seismic stability of reinforced soil slopes. In addition, the equivalent linear method is implemented to analyze the site response for the purpose of calculating the soil dynamics parameters required for the seismic stability analysis of soil slopes via the MPD method. A MATLAB code is developed to calculate via the abovementioned methods. Using the log-spiral slip surface, this code considers the distribution of reinforcements as uniform and variable spacing. In addition, the effect of surcharge pressure on the seismic stability of the slope is included in this study. The obtained results showed that, in general, the MPD method combined with the equivalent linear analysis would produce more critical results than other methods.
{"title":"Seismic stability of reinforced soil slopes using the modified pseudo-dynamic method","authors":"Nima Farshidfar, A. Keshavarz, S. M. Mirhosseini","doi":"10.12989/EAS.2021.20.5.473","DOIUrl":"https://doi.org/10.12989/EAS.2021.20.5.473","url":null,"abstract":"The limit equilibrium analysis through the horizontal slice method is used to study the seismic stability of reinforced soil slopes by satisfying the equilibrium of the horizontal and vertical forces as well as moments. Unlike the pseudo-static (PS) method, the pseudo-dynamic method consideres the effects of time and phase difference of the P and S waves propagation inside the soil mass. In this paper, the PS, the conventional pseudo-dynamic (CPD), and the modified pseudo-dynamic (MPD) methods are used to study the seismic stability of reinforced soil slopes. In addition, the equivalent linear method is implemented to analyze the site response for the purpose of calculating the soil dynamics parameters required for the seismic stability analysis of soil slopes via the MPD method. A MATLAB code is developed to calculate via the abovementioned methods. Using the log-spiral slip surface, this code considers the distribution of reinforcements as uniform and variable spacing. In addition, the effect of surcharge pressure on the seismic stability of the slope is included in this study. The obtained results showed that, in general, the MPD method combined with the equivalent linear analysis would produce more critical results than other methods.","PeriodicalId":49080,"journal":{"name":"Earthquakes and Structures","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48855020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-01DOI: 10.12989/EAS.2021.20.5.487
Raushan Ranjan, Ashok Kumar V
This paper presents the selection and scaling of ground motion of Patna, Bihar (India) using Response Spectra (Rsp) Match technique MATLAB code and soil amplification using Equivalent-linear Earthquake site Response Analyses (EERA) excel macro. North Bihar including Patna is in seismic zone IV hence preventive measure are to be explored to avoid catastrophic earthquake damages. The earthquake ground motion data of Patna is required for economic and effective earthquake resistant constructions in Patna. Five earthquake ground motions obtained from RspMatch2005 technique used to estimate soil movement response for six selected sites in Patna. In present work, the earthquake ground motion data of Patna is generated which is not available earlier in literature. The interpolated shear wave velocity of Patna obtained by SPT test and earthquake ground motion obtained from RSP Match software used as input in EERA to acquire the amplification factor. After that amplification of Earthquake, ground motion using local soil behaviour explored. In present study, it is found the amplification factor is 1.8 to 5 at 5 Hz. This amplified ground motion may be used for linear and nonlinear earthquake structural analysis.
{"title":"Forecasting ground movement of Patna Region, India","authors":"Raushan Ranjan, Ashok Kumar V","doi":"10.12989/EAS.2021.20.5.487","DOIUrl":"https://doi.org/10.12989/EAS.2021.20.5.487","url":null,"abstract":"This paper presents the selection and scaling of ground motion of Patna, Bihar (India) using Response Spectra (Rsp) Match technique MATLAB code and soil amplification using Equivalent-linear Earthquake site Response Analyses (EERA) excel macro. North Bihar including Patna is in seismic zone IV hence preventive measure are to be explored to avoid catastrophic earthquake damages. The earthquake ground motion data of Patna is required for economic and effective earthquake resistant constructions in Patna. Five earthquake ground motions obtained from RspMatch2005 technique used to estimate soil movement response for six selected sites in Patna. In present work, the earthquake ground motion data of Patna is generated which is not available earlier in literature. The interpolated shear wave velocity of Patna obtained by SPT test and earthquake ground motion obtained from RSP Match software used as input in EERA to acquire the amplification factor. After that amplification of Earthquake, ground motion using local soil behaviour explored. In present study, it is found the amplification factor is 1.8 to 5 at 5 Hz. This amplified ground motion may be used for linear and nonlinear earthquake structural analysis.","PeriodicalId":49080,"journal":{"name":"Earthquakes and Structures","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49546507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, the dynamic behaviour and seismic damages of concrete cylindrical water storage tanks are investigated. Furthermore, by modeling the reservoirs, using normal concrete and engineered cementitious composite (ECC), the effects of ECC on reducing the seismic damages of reservoirs are investigated. For this purpose, ANSYS software is used to perform the nonlinear dynamic analysis of the tanks and different parameters including the hoop force and bending moment of the wall and cracking or crushing of the concrete were examined. According to the results, the relationships and criteria provided in the ACI standard for design of tanks are recommended to be revised in certain parts. Unlike the normal concrete tanks, in those made of ECC, concrete fracture is not observed and the crack width remains very small at a level that is not problematic. Finally, the use of ECC in cylindrical water storage tanks is suggested as a strategy for reducing the seismic vulnerability of this type of hydraulic structures.
{"title":"Dynamic response of cylindrical water storage tanks made byECC compared to normal concrete","authors":"Pouria Sheikh Bahaeia, F. Behnamfar, A. Samani","doi":"10.12989/.2021.20.5.513","DOIUrl":"https://doi.org/10.12989/.2021.20.5.513","url":null,"abstract":"In this paper, the dynamic behaviour and seismic damages of concrete cylindrical water storage tanks are investigated. Furthermore, by modeling the reservoirs, using normal concrete and engineered cementitious composite (ECC), the effects of ECC on reducing the seismic damages of reservoirs are investigated. For this purpose, ANSYS software is used to perform the nonlinear dynamic analysis of the tanks and different parameters including the hoop force and bending moment of the wall and cracking or crushing of the concrete were examined. According to the results, the relationships and criteria provided in the ACI standard for design of tanks are recommended to be revised in certain parts. Unlike the normal concrete tanks, in those made of ECC, concrete fracture is not observed and the crack width remains very small at a level that is not problematic. Finally, the use of ECC in cylindrical water storage tanks is suggested as a strategy for reducing the seismic vulnerability of this type of hydraulic structures.","PeriodicalId":49080,"journal":{"name":"Earthquakes and Structures","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45067545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-01DOI: 10.12989/EAS.2021.20.5.571
Shuhe Wang, Ximing Li, Jubing Zhang
According to the PEER probabilistic seismic loss assessment methodology, a structure-level seismic risk assessment method was proposed and implemented for a set of RC frames designed according to Chinese seismic code. These frames were designed for fortification intensities of 6,7 and 8 and classified into 4,6 and 8 stories. Through incremental dynamic time history analysis (IDA), the statistical relationships of the maximum inter-story drift ratio with the seismic spectral acceleration were obtained and used to determine fragility curve for each damage states. The site seismic hazard model was established based on Chinese seismic code, and the probability distribution of each discrete intensity levels was derived. Using loss index from the Chinese standard and Hazus, the structure means annual frequency of collapse, the Expected Annual Financial Loss (EAL) and the Expected Annual Fatalities (EAF) were calculated. The variation trends of these performance metrics with seismic fortification intensities and structure heights were evaluated, and the weaknesses of the current seismic code of China were pointed out. It was concluded that the method proposed in this paper is simple and reliable for practical applications.
{"title":"Seismic loss risk assessment of RC frame structures designed according to Chinese code","authors":"Shuhe Wang, Ximing Li, Jubing Zhang","doi":"10.12989/EAS.2021.20.5.571","DOIUrl":"https://doi.org/10.12989/EAS.2021.20.5.571","url":null,"abstract":"According to the PEER probabilistic seismic loss assessment methodology, a structure-level seismic risk assessment method was proposed and implemented for a set of RC frames designed according to Chinese seismic code. These frames were designed for fortification intensities of 6,7 and 8 and classified into 4,6 and 8 stories. Through incremental dynamic time history analysis (IDA), the statistical relationships of the maximum inter-story drift ratio with the seismic spectral acceleration were obtained and used to determine fragility curve for each damage states. The site seismic hazard model was established based on Chinese seismic code, and the probability distribution of each discrete intensity levels was derived. Using loss index from the Chinese standard and Hazus, the structure means annual frequency of collapse, the Expected Annual Financial Loss (EAL) and the Expected Annual Fatalities (EAF) were calculated. The variation trends of these performance metrics with seismic fortification intensities and structure heights were evaluated, and the weaknesses of the current seismic code of China were pointed out. It was concluded that the method proposed in this paper is simple and reliable for practical applications.","PeriodicalId":49080,"journal":{"name":"Earthquakes and Structures","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46642861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-01DOI: 10.12989/EAS.2021.20.5.495
M. Mohebbi, S. Bakhshinezhad
In this paper, a procedure to seismic risk assessment of structures equipped with magnetorheological (MR) damper considering multiple performance criteria has been presented while accounting for uncertainties of the applied excitation, structure and damper properties, and damage state thresholds. The procedure employes the Latin hypercube sampling (LHS) method to generate 30 sample random MR-Structure systems and incremental dynamic analysis (IDA) has been conducted under 20 earthquakes to evaluate engineering demand parameters. Fragilities have been evaluated using the Monte Carlo simulation (MCS) method in each intensity measure and have been integrated with the hazard curve to determine the reliability during lifetime. For numerical analysis, an eight-story nonlinear shear building with bilinear hysteresis behavior has been adopted. The effectiveness of the introduced methodology is illustrated through a seismic risk assessment of the structure equipped with passive-off and passive-on MR dampers. Numerical results have shown the capability of MR dampers in significant mitigation of the seismic risk of the nonlinear structure. Moreover, it is observed that considering multiple performance criteria of the structural system, non-structural components, and MR damper stroke length and the interaction between them has led to increase the seismic risk. Also, the uncertainty of the applied excitation shows more remarkable influence with respect to the other sources of uncertainties.
{"title":"Multiple performance criteria-based risk assessment forstructures equipped with MR dampers","authors":"M. Mohebbi, S. Bakhshinezhad","doi":"10.12989/EAS.2021.20.5.495","DOIUrl":"https://doi.org/10.12989/EAS.2021.20.5.495","url":null,"abstract":"In this paper, a procedure to seismic risk assessment of structures equipped with magnetorheological (MR) damper considering multiple performance criteria has been presented while accounting for uncertainties of the applied excitation, structure and damper properties, and damage state thresholds. The procedure employes the Latin hypercube sampling (LHS) method to generate 30 sample random MR-Structure systems and incremental dynamic analysis (IDA) has been conducted under 20 earthquakes to evaluate engineering demand parameters. Fragilities have been evaluated using the Monte Carlo simulation (MCS) method in each intensity measure and have been integrated with the hazard curve to determine the reliability during lifetime. For numerical analysis, an eight-story nonlinear shear building with bilinear hysteresis behavior has been adopted. The effectiveness of the introduced methodology is illustrated through a seismic risk assessment of the structure equipped with passive-off and passive-on MR dampers. Numerical results have shown the capability of MR dampers in significant mitigation of the seismic risk of the nonlinear structure. Moreover, it is observed that considering multiple performance criteria of the structural system, non-structural components, and MR damper stroke length and the interaction between them has led to increase the seismic risk. Also, the uncertainty of the applied excitation shows more remarkable influence with respect to the other sources of uncertainties.","PeriodicalId":49080,"journal":{"name":"Earthquakes and Structures","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49587280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-01DOI: 10.12989/EAS.2021.20.2.431
Chen Zong Ping, Su Weiwei, Yang Yang
T-shaped column is usually used as side column in buildings, which is one of the weak members in structural system. This paper presented a quasi-static cyclic loading experiment of six specimens of reinforced concrete (RC) T-shaped columns under compression-flexure-shear-torsion combined loadings to investigate the effect in the ratio of torsion to moment (T/M) and axial compression ratio (n) and height-thickness ratio of flange plate (Φ) on their seismic performance. Based on the test results, the failure characteristics, hysteretic curves, ductility, energy dissipation, stiffness degradation and strength degradation were analyzed. The results show that the failure characteristics of RC T-shaped columns mainly depend on the ratio of torsion to moment, which can be divided into bending failure, bending-torsion failure and shear-torsion failure. With the increase of T/M ratio, the torsion ductility coefficient increased, and in a suitable range, the torsion and horizontal displacement ductility coefficient of RC T-shaped columns could be effectively improved with the increase of axial compression ratio and the decrease of height-thickness ratio of flange plate. Besides, the energy dissipation capacity of the specimens mainly depended on the bending and shear energy dissipation capacity. On the other hand, the increase of axial compression ratio and the ratio of torsion to moment could accelerate the torsional and bending stiffness degradation of RC T-shaped columns. Moreover, the degradation coefficient of torsion strength was between 0.80 and 0.98, and that of bending strength was between 0.75 and 1.00.
{"title":"Seismic behavior of reinforced concrete T-shaped columns under compression-bending-shear and torsion","authors":"Chen Zong Ping, Su Weiwei, Yang Yang","doi":"10.12989/EAS.2021.20.2.431","DOIUrl":"https://doi.org/10.12989/EAS.2021.20.2.431","url":null,"abstract":"T-shaped column is usually used as side column in buildings, which is one of the weak members in structural system. This paper presented a quasi-static cyclic loading experiment of six specimens of reinforced concrete (RC) T-shaped columns under compression-flexure-shear-torsion combined loadings to investigate the effect in the ratio of torsion to moment (T/M) and axial compression ratio (n) and height-thickness ratio of flange plate (Φ) on their seismic performance. Based on the test results, the failure characteristics, hysteretic curves, ductility, energy dissipation, stiffness degradation and strength degradation were analyzed. The results show that the failure characteristics of RC T-shaped columns mainly depend on the ratio of torsion to moment, which can be divided into bending failure, bending-torsion failure and shear-torsion failure. With the increase of T/M ratio, the torsion ductility coefficient increased, and in a suitable range, the torsion and horizontal displacement ductility coefficient of RC T-shaped columns could be effectively improved with the increase of axial compression ratio and the decrease of height-thickness ratio of flange plate. Besides, the energy dissipation capacity of the specimens mainly depended on the bending and shear energy dissipation capacity. On the other hand, the increase of axial compression ratio and the ratio of torsion to moment could accelerate the torsional and bending stiffness degradation of RC T-shaped columns. Moreover, the degradation coefficient of torsion strength was between 0.80 and 0.98, and that of bending strength was between 0.75 and 1.00.","PeriodicalId":49080,"journal":{"name":"Earthquakes and Structures","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41703635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-01DOI: 10.12989/EAS.2021.20.4.445
A. Büyüksaraç, Ercan Işık, Ehsan Harirchian
Lake Van Basin, located in Eastern Turkey, is worth examining in terms of seismicity due to large-scale losses of property and life during the historical and instrumental period. The most important and largest province in this basin is Van. Recent indicators of the high seismicity risk in the province are damage occurring after devastating earthquakes in 2011 (Mw=7.2 and Mw=5.6) and lastly in 2020 Khoy (Mw=5.9). The seismic hazard analysis for Van and its districts in Eastern Turkey was performed in probabilistic manner. Analyses were made for thirteen different districts in Van. In this study, information is given about the tectonic setting and seismicity of Van. The probabilistic seismic hazard curves were obtained for a probability of exceedance of 2%, 10% and 50% in 50-year periods. The PGA values in the Van province vary from 0.24 g – 0.43 g for earthquakes with repetition period of 475 years. Risk priorities were determined for all districts. The highest risk was calculated for Caldiran and the lowest risk was found for Gurpinar. Risk priorities for buildings in all districts were also determined via rapid seismic assessment for reinforced-concrete and masonry buildings in this study.
{"title":"A case study for determination of seismic risk priorities in Van (Eastern Turkey)","authors":"A. Büyüksaraç, Ercan Işık, Ehsan Harirchian","doi":"10.12989/EAS.2021.20.4.445","DOIUrl":"https://doi.org/10.12989/EAS.2021.20.4.445","url":null,"abstract":"Lake Van Basin, located in Eastern Turkey, is worth examining in terms of seismicity due to large-scale losses of property and life during the historical and instrumental period. The most important and largest province in this basin is Van. Recent indicators of the high seismicity risk in the province are damage occurring after devastating earthquakes in 2011 (Mw=7.2 and Mw=5.6) and lastly in 2020 Khoy (Mw=5.9). The seismic hazard analysis for Van and its districts in Eastern Turkey was performed in probabilistic manner. Analyses were made for thirteen different districts in Van. In this study, information is given about the tectonic setting and seismicity of Van. The probabilistic seismic hazard curves were obtained for a probability of exceedance of 2%, 10% and 50% in 50-year periods. The PGA values in the Van province vary from 0.24 g – 0.43 g for earthquakes with repetition period of 475 years. Risk priorities were determined for all districts. The highest risk was calculated for Caldiran and the lowest risk was found for Gurpinar. Risk priorities for buildings in all districts were also determined via rapid seismic assessment for reinforced-concrete and masonry buildings in this study.","PeriodicalId":49080,"journal":{"name":"Earthquakes and Structures","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45202316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-01DOI: 10.12989/EAS.2021.20.4.365
Xiang Zhao, Cai Hengli, T. Zhou, Ling Liu, Yi-jie Ding
Rammed earth (RE) buildings have existed all over the world for thousands of years, and have gained increasing attention because of its sustainable advantages, however, the shrinkage cracks reduce its bearing capacity and seriously affect its durability and applicability. In this study, the shrinkage cracks test was carried out to investigate the effects of initial water content, proportion of sand and gravel, compaction degree, thickness and the additives (polypropylene fiber, cement and sodium silicate) of shrinkage cracks in RE buildings, ten groups of RE samples were prepared and dried outdoors to crack. Four quantitative parameters of geometrical structure of crack patterns were used to evaluate the development of cracks. The results show that the specimens cracking behavior and the geometrical structure of crack patterns are significantly influenced by these considered factors. The formation of crack can be accelerated with the increase of initial water content and thickness of specimen, while restricted with the increase of the compaction degree and the proportion of sand and gravel. Moreover, the addition of 1% polypropylene fiber, 10% cement and 0.5 volume ratio sodium silicate can significantly restrain the form and development of cracks. In RE construction, these factors should be considered comprehensively to prevent the harm caused by shrinkage cracks. Further works should be carried out to obtain the optimum dosage of the additives, which can benefit the construction of RE buildings in future.
{"title":"Research on the factors affecting the development of shrinkage cracks of rammed earth buildings","authors":"Xiang Zhao, Cai Hengli, T. Zhou, Ling Liu, Yi-jie Ding","doi":"10.12989/EAS.2021.20.4.365","DOIUrl":"https://doi.org/10.12989/EAS.2021.20.4.365","url":null,"abstract":"Rammed earth (RE) buildings have existed all over the world for thousands of years, and have gained increasing attention because of its sustainable advantages, however, the shrinkage cracks reduce its bearing capacity and seriously affect its durability and applicability. In this study, the shrinkage cracks test was carried out to investigate the effects of initial water content, proportion of sand and gravel, compaction degree, thickness and the additives (polypropylene fiber, cement and sodium silicate) of shrinkage cracks in RE buildings, ten groups of RE samples were prepared and dried outdoors to crack. Four quantitative parameters of geometrical structure of crack patterns were used to evaluate the development of cracks. The results show that the specimens cracking behavior and the geometrical structure of crack patterns are significantly influenced by these considered factors. The formation of crack can be accelerated with the increase of initial water content and thickness of specimen, while restricted with the increase of the compaction degree and the proportion of sand and gravel. Moreover, the addition of 1% polypropylene fiber, 10% cement and 0.5 volume ratio sodium silicate can significantly restrain the form and development of cracks. In RE construction, these factors should be considered comprehensively to prevent the harm caused by shrinkage cracks. Further works should be carried out to obtain the optimum dosage of the additives, which can benefit the construction of RE buildings in future.","PeriodicalId":49080,"journal":{"name":"Earthquakes and Structures","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47272872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-01DOI: 10.12989/EAS.2021.20.4.417
Bo-Shiuan Wang, G. Cao, Kehua Yang, H. Dai, Chao-gang Qin
Due to functional requirements, SRC column-RC beam abnormal joints with characteristics of strong beam weak column, variable column section, unequal beam height and staggered height exist in the Steel reinforced concrete (SRC) frame-bent main building structure of thermal power plant (TPP). This paper presents the experimental results of these abnormal joints through cyclic loading tests on five specimens with scaling factor of 1/5. The staggered height and whether adding H-shaped steel in beam or not were changing parameters of specimens. The failure patterns, bearing capacity, energy dissipation and ductile performance were analyzed. In addition, the stress mechanism of the abnormal joint was discussed based on the diagonal strut model. The research results showed that the abnormal exterior joints occurred shear failure and column end hinge flexural failure; reducing beam height through adding H-shaped steel in the beam of abnormal exterior joint could improve the crack resistance and ductility; the abnormal interior joints with different staggered heights occurred column ends flexural failure; the joint with larger staggered height had the higher bearing capacity and stiffness, but lower ductility. The concrete compression strut mechanism is still applicable to the abnormal joints in TPP, but it is affected by the abnormal characteristics.
{"title":"Cyclic loading test of abnormal joints in SRC frame-bentmain building structure","authors":"Bo-Shiuan Wang, G. Cao, Kehua Yang, H. Dai, Chao-gang Qin","doi":"10.12989/EAS.2021.20.4.417","DOIUrl":"https://doi.org/10.12989/EAS.2021.20.4.417","url":null,"abstract":"Due to functional requirements, SRC column-RC beam abnormal joints with characteristics of strong beam weak column, variable column section, unequal beam height and staggered height exist in the Steel reinforced concrete (SRC) frame-bent main building structure of thermal power plant (TPP). This paper presents the experimental results of these abnormal joints through cyclic loading tests on five specimens with scaling factor of 1/5. The staggered height and whether adding H-shaped steel in beam or not were changing parameters of specimens. The failure patterns, bearing capacity, energy dissipation and ductile performance were analyzed. In addition, the stress mechanism of the abnormal joint was discussed based on the diagonal strut model. The research results showed that the abnormal exterior joints occurred shear failure and column end hinge flexural failure; reducing beam height through adding H-shaped steel in the beam of abnormal exterior joint could improve the crack resistance and ductility; the abnormal interior joints with different staggered heights occurred column ends flexural failure; the joint with larger staggered height had the higher bearing capacity and stiffness, but lower ductility. The concrete compression strut mechanism is still applicable to the abnormal joints in TPP, but it is affected by the abnormal characteristics.","PeriodicalId":49080,"journal":{"name":"Earthquakes and Structures","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47638386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-01DOI: 10.12989/EAS.2021.20.4.457
S. Yaghmaei‐Sabegh
{"title":"Evaluation of pulse effect on frequency content of ground motions and definition of a new characteristic period","authors":"S. Yaghmaei‐Sabegh","doi":"10.12989/EAS.2021.20.4.457","DOIUrl":"https://doi.org/10.12989/EAS.2021.20.4.457","url":null,"abstract":"","PeriodicalId":49080,"journal":{"name":"Earthquakes and Structures","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43773409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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