The 10 major cities in the West Bank (WB), Palestine—Nablus, Ramallah and Al-Bireh, Jenin, Qalqilia, Salfit, Tubas, Jericho, Bethlehem, Tulkarem, and Hebron—are experiencing rapid urban transformation and changing land cover. This study explores the relationship between land cover (built-up and unbuilt areas) and soil type in these cities across benchmark years 1995, 2000, 2005, 2010, 2015, and 2021. In addition to the former, the paper argues that the expansion and increase of the built-up area and the change in soil type of the aforementioned cities in the West Bank, Palestine, are leading to changes in the land surface temperature (LST). This conclusion was reached through a methodological framework that was developed to measure the relationship between the changing land cover (built-up and unbuilt-up areas), soil type, and LST in the 10 major cities in the region. The framework relies on data retrieved through remote sensing in the years from 1995 to 2021. The results of the analysis conducted through this methodological framework showed that there is an inverse relationship between the increase in built-up areas and LST; however, LST is less inside the built-up areas than in the surrounding areas (open spaces) due to different land cover (unbuilt area with grass and shrubs) and different soil type.
{"title":"Land Cover and Land Surface Temperature in the West Bank, Palestine","authors":"Ayah Helal, Zahraa Zawawi","doi":"10.1155/2024/1107242","DOIUrl":"https://doi.org/10.1155/2024/1107242","url":null,"abstract":"The 10 major cities in the West Bank (WB), Palestine—Nablus, Ramallah and Al-Bireh, Jenin, Qalqilia, Salfit, Tubas, Jericho, Bethlehem, Tulkarem, and Hebron—are experiencing rapid urban transformation and changing land cover. This study explores the relationship between land cover (built-up and unbuilt areas) and soil type in these cities across benchmark years 1995, 2000, 2005, 2010, 2015, and 2021. In addition to the former, the paper argues that the expansion and increase of the built-up area and the change in soil type of the aforementioned cities in the West Bank, Palestine, are leading to changes in the land surface temperature (LST). This conclusion was reached through a methodological framework that was developed to measure the relationship between the changing land cover (built-up and unbuilt-up areas), soil type, and LST in the 10 major cities in the region. The framework relies on data retrieved through remote sensing in the years from 1995 to 2021. The results of the analysis conducted through this methodological framework showed that there is an inverse relationship between the increase in built-up areas and LST; however, LST is less inside the built-up areas than in the surrounding areas (open spaces) due to different land cover (unbuilt area with grass and shrubs) and different soil type.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140830406","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}
Benjamin Labar, Nurullah Bektaş, Orsolya Kegyes-Brassai
Approximately 20,000 people are killed annually on average by building and infrastructure collapses and failures caused by seismic activities. In earlier times, seismic design codes and specifications set minimal requirements for life safety performance levels. Earthquakes can be thought of as recurring events in seismically active areas, with severity states ranging from serviceability to ultimate levels. Buildings designed in accordance with site-specific response spectra, which take into account soil properties based on ground motion amplification data, are better at withstanding such forces and serving their design purposes. This study aims to investigate the site response of reinforced and masonry buildings, considering the effect of soil properties based on the amplification of ground motion data, and to compare the life cycle assessment of the buildings under consideration based on the design and the site-specific response spectrum. In terms of soil properties and site-specific response spectra, STRATA is used to determine the site-specific response for the considered locations for a return period of 475 years for 100 realizations based on the randomization of site properties. For structural analysis, AxisVM software, which is a compatible finite element analysis, is used for building design and analysis, generating comparative results based on the design- and site-specific spectra. To determine and identify potential failures in the model, response spectra were applied to understand the difference in horizontal deflection in two different instances (for elastic design- and site-specific spectra). After building design and analysis is performed, a life cycle analysis in terms of environmental impact assesments using OpenLCA and IdematLightLCA is done. This is done to ascertain the additional expenses in terms of ecocosts and carbon footprints on some failed elements in the structure which are required to make the buildings more resilient when the site-specific response spectrum is applied and to compare the potential economic losses that may occur based on ecological costs. The study presents a comprehensive investigation into the seismic response of masonry and reinforced concrete buildings in Győr, Hungary, incorporating advanced geophysical techniques like multichannel surface wave (MASW) and structural analysis software, AxisVM. Additionally, tailored retrofitting strategies are explored to enhance structural resilience in seismic-prone regions. Significant ground amplifications in soil properties across different profiles are revealed, emphasizing the effectiveness of these strategies in reducing structural deflection and improving resilience. Highlights of the results are observed where the site-specific response spectra are higher than the EC8 design response spectrum. Furthermore, the research underscores the substantial environmental impact, considering both ecocosts and CO2 emissions associated with retrofitting measur
{"title":"Enhancing Seismic Performance: A Comprehensive Study on Masonry and Reinforced Concrete Structures Considering Soil Properties and Environmental Impact Assessment","authors":"Benjamin Labar, Nurullah Bektaş, Orsolya Kegyes-Brassai","doi":"10.1155/2024/4505901","DOIUrl":"https://doi.org/10.1155/2024/4505901","url":null,"abstract":"Approximately 20,000 people are killed annually on average by building and infrastructure collapses and failures caused by seismic activities. In earlier times, seismic design codes and specifications set minimal requirements for life safety performance levels. Earthquakes can be thought of as recurring events in seismically active areas, with severity states ranging from serviceability to ultimate levels. Buildings designed in accordance with site-specific response spectra, which take into account soil properties based on ground motion amplification data, are better at withstanding such forces and serving their design purposes. This study aims to investigate the site response of reinforced and masonry buildings, considering the effect of soil properties based on the amplification of ground motion data, and to compare the life cycle assessment of the buildings under consideration based on the design and the site-specific response spectrum. In terms of soil properties and site-specific response spectra, STRATA is used to determine the site-specific response for the considered locations for a return period of 475 years for 100 realizations based on the randomization of site properties. For structural analysis, AxisVM software, which is a compatible finite element analysis, is used for building design and analysis, generating comparative results based on the design- and site-specific spectra. To determine and identify potential failures in the model, response spectra were applied to understand the difference in horizontal deflection in two different instances (for elastic design- and site-specific spectra). After building design and analysis is performed, a life cycle analysis in terms of environmental impact assesments using OpenLCA and IdematLightLCA is done. This is done to ascertain the additional expenses in terms of ecocosts and carbon footprints on some failed elements in the structure which are required to make the buildings more resilient when the site-specific response spectrum is applied and to compare the potential economic losses that may occur based on ecological costs. The study presents a comprehensive investigation into the seismic response of masonry and reinforced concrete buildings in Győr, Hungary, incorporating advanced geophysical techniques like multichannel surface wave (MASW) and structural analysis software, AxisVM. Additionally, tailored retrofitting strategies are explored to enhance structural resilience in seismic-prone regions. Significant ground amplifications in soil properties across different profiles are revealed, emphasizing the effectiveness of these strategies in reducing structural deflection and improving resilience. Highlights of the results are observed where the site-specific response spectra are higher than the EC8 design response spectrum. Furthermore, the research underscores the substantial environmental impact, considering both ecocosts and CO<sub>2</sub> emissions associated with retrofitting measur","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140830288","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}
Yonghui Shang, Linrong Xu, Xiaofei Hao, Qichuan Zhu, Donghong Li
The dynamic characteristics of the filler are intricately linked to the stability of the subgrade. In this investigation, relying on Haoji (Haolebaoji-Ji’an, China) heavy-haul railway engineering, cyclic triaxial tests were executed to scrutinize the dynamic attributes exhibited by the 3%–5% cement-stabilized expansive soil (CSES) across a series of diverse cyclic stress, confining pressures, and frequencies. Concurrently, in situ vibration trials were undertaken to dissect the dynamic characteristics inherent to the CSES subgrade. The outcomes of cyclic triaxial tests indicate that the augmentation in both the dynamic shear strength and modulus of CSES by a factor of 2–3, coupled with an escalation of the critical dynamic stress threshold by five tosix times, is attributed to the heightened internal structural density within the CSES compared to virgin expansive soil. In identical settings, it is noteworthy that the mean critical dynamic stress threshold observed for CSES surpasses that of Group A filling by a factor of 1.5–1.7. Furthermore, the maximum critical dynamic stress exhibited by CSES achieves a 1.2-fold superiority over its lime-stabilized expansive soil (LSES). The outcomes gleaned from the in situ vibration tests elucidate that, when subjected to the passage of a high-velocity train traveling at 120 km/hr, bearing the load of 25–30 tons per axle, the subgrade surface exhibits dynamic stress ranging from 98.57 to 116.07 kPa. Meanwhile, the dynamic stress undergoes a notable escalation due to rainfall infiltration, intensifying by a factor of 1.02–1.28 times its original magnitude. The influence depth of dynamic stress extends 1.4–1.6 times beyond the designed subgrade bed thickness of 2.5 m. Notably, the critical dynamic stress of the filler surpasses the dynamic stress at the same position, underscoreing the capacity of 3%–5% CSES filling for heavy-haul railways to ensure long-term dynamic stability.
{"title":"Investigation on Dynamic Stability of Cement-Stabilized Expansive Soil Subgrades Subjected to Repeated Heavy-Haul Train Loads","authors":"Yonghui Shang, Linrong Xu, Xiaofei Hao, Qichuan Zhu, Donghong Li","doi":"10.1155/2024/7126022","DOIUrl":"https://doi.org/10.1155/2024/7126022","url":null,"abstract":"The dynamic characteristics of the filler are intricately linked to the stability of the subgrade. In this investigation, relying on Haoji (Haolebaoji-Ji’an, China) heavy-haul railway engineering, cyclic triaxial tests were executed to scrutinize the dynamic attributes exhibited by the 3%–5% cement-stabilized expansive soil (CSES) across a series of diverse cyclic stress, confining pressures, and frequencies. Concurrently, in situ vibration trials were undertaken to dissect the dynamic characteristics inherent to the CSES subgrade. The outcomes of cyclic triaxial tests indicate that the augmentation in both the dynamic shear strength and modulus of CSES by a factor of 2–3, coupled with an escalation of the critical dynamic stress threshold by five tosix times, is attributed to the heightened internal structural density within the CSES compared to virgin expansive soil. In identical settings, it is noteworthy that the mean critical dynamic stress threshold observed for CSES surpasses that of Group A filling by a factor of 1.5–1.7. Furthermore, the maximum critical dynamic stress exhibited by CSES achieves a 1.2-fold superiority over its lime-stabilized expansive soil (LSES). The outcomes gleaned from the in situ vibration tests elucidate that, when subjected to the passage of a high-velocity train traveling at 120 km/hr, bearing the load of 25–30 tons per axle, the subgrade surface exhibits dynamic stress ranging from 98.57 to 116.07 kPa. Meanwhile, the dynamic stress undergoes a notable escalation due to rainfall infiltration, intensifying by a factor of 1.02–1.28 times its original magnitude. The influence depth of dynamic stress extends 1.4–1.6 times beyond the designed subgrade bed thickness of 2.5 m. Notably, the critical dynamic stress of the filler surpasses the dynamic stress at the same position, underscoreing the capacity of 3%–5% CSES filling for heavy-haul railways to ensure long-term dynamic stability.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140830286","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}
Surface harmless storage of concentrated full tailings (CFTs) involves the technology of adding a curing agent to the tailings slurry discharged from the thickener to realize the modification of the tailings and centralized storage of the tailings on the surface to realize the harmless treatment of the tailings. High water content of tailings is still the key technical problem that restricts the harmless storage of piles at present. Regarding the above problems, we implemented the consolidation test and numerical simulation of seepage-stress coupling consolidation of CFT, clarified the consolidation characteristics and parameters of CFT under different curing ages, and conducted a comparative analysis of pore water pressure in the whole cross-section of piles with different drainage schemes based on the results of the test. In addition, we also clarified the drainage effect of interlayer drainage on reducing the excess pore water pressure of piles and compared the simulation results of the pore water pressure of piles under different permeability coefficients. The results show that as the permeability coefficient of the concentrated tailings material decreases, the pore pressure accumulation inside piles under the same drainage scheme is more serious, and the length of time for consolidation and stabilization becomes longer. Therefore, it is recommended that the excess porous water pressure be relieved by means of increased drainage facilities under a small permeability coefficient.
{"title":"Experimental Study on Consolidation Characteristics of Concentrated Full Tailings and Research on Pore Water Relief Methods of Piles","authors":"Sha Wang, Guodong Mei, Yifan Chu, Weixiang Wang, Yali Wang, Lijie Guo","doi":"10.1155/2024/6644300","DOIUrl":"https://doi.org/10.1155/2024/6644300","url":null,"abstract":"Surface harmless storage of concentrated full tailings (CFTs) involves the technology of adding a curing agent to the tailings slurry discharged from the thickener to realize the modification of the tailings and centralized storage of the tailings on the surface to realize the harmless treatment of the tailings. High water content of tailings is still the key technical problem that restricts the harmless storage of piles at present. Regarding the above problems, we implemented the consolidation test and numerical simulation of seepage-stress coupling consolidation of CFT, clarified the consolidation characteristics and parameters of CFT under different curing ages, and conducted a comparative analysis of pore water pressure in the whole cross-section of piles with different drainage schemes based on the results of the test. In addition, we also clarified the drainage effect of interlayer drainage on reducing the excess pore water pressure of piles and compared the simulation results of the pore water pressure of piles under different permeability coefficients. The results show that as the permeability coefficient of the concentrated tailings material decreases, the pore pressure accumulation inside piles under the same drainage scheme is more serious, and the length of time for consolidation and stabilization becomes longer. Therefore, it is recommended that the excess porous water pressure be relieved by means of increased drainage facilities under a small permeability coefficient.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140808917","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}
The fatigue phenomenon significantly weakens road pavement due to repeated reloading. To enhance fatigue resistance, numerous studies have explored various additives in asphalt mixtures. This review focuses on key variables influencing the effectiveness of additives, including fibers, polymers, nanomaterials, waste materials, and biomaterials, in improving the fatigue performance of asphalt mixtures. The study initially identifies different additives and fatigue testing methods used for asphalt mixtures. It evaluates the impact of factors such as modifier content and size, base asphalt binder type, mixing processes, dispersion behavior, and testing conditions on the fatigue behavior of modified asphalt mixtures. The cost-effectiveness and environmental impact of additive application have also been assessed. Additionally, research gaps and future prospects for modified asphalt mixes are outlined. Existing studies demonstrate the benefits of additives like basalt fiber, polyester fiber, styrene–butadiene–styrene (SBS), nanosilica, crumb rubber, and biooils in enhancing the fatigue life of pavement constructions. However, challenges exist in the application of modifiers due to limited practical implications and insufficient knowledge. Further research is needed on factors such as additives’ dispersity, compatibility, aging resistance, economic viability, and modifying mechanisms in morphological and micromechanical aspects to enhance the fatigue performance of the modified asphalt mixture.
{"title":"A Review of the Studies on the Effect of Different Additives on the Fatigue Behavior of Asphalt Mixtures","authors":"Mahmoud Ameri, Mehdi Ebrahimzadeh Shiraz","doi":"10.1155/2024/6695747","DOIUrl":"https://doi.org/10.1155/2024/6695747","url":null,"abstract":"The fatigue phenomenon significantly weakens road pavement due to repeated reloading. To enhance fatigue resistance, numerous studies have explored various additives in asphalt mixtures. This review focuses on key variables influencing the effectiveness of additives, including fibers, polymers, nanomaterials, waste materials, and biomaterials, in improving the fatigue performance of asphalt mixtures. The study initially identifies different additives and fatigue testing methods used for asphalt mixtures. It evaluates the impact of factors such as modifier content and size, base asphalt binder type, mixing processes, dispersion behavior, and testing conditions on the fatigue behavior of modified asphalt mixtures. The cost-effectiveness and environmental impact of additive application have also been assessed. Additionally, research gaps and future prospects for modified asphalt mixes are outlined. Existing studies demonstrate the benefits of additives like basalt fiber, polyester fiber, styrene–butadiene–styrene (SBS), nanosilica, crumb rubber, and biooils in enhancing the fatigue life of pavement constructions. However, challenges exist in the application of modifiers due to limited practical implications and insufficient knowledge. Further research is needed on factors such as additives’ dispersity, compatibility, aging resistance, economic viability, and modifying mechanisms in morphological and micromechanical aspects to enhance the fatigue performance of the modified asphalt mixture.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140802614","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}
During the construction of concrete ship locks, prolonged interruptions between the casting of the floor and lock wall are inevitable. In terms of mass concrete, long placement delays are one of the major reasons for the presence of cracks in newly placed concrete. Therefore, this study examines both the placement and structural characteristics of ship locks after long casting interruptions based on the mass concrete thermal stress theory to determine the major causal factors for cracks in newly poured concrete. Specifically, a block placement method is proposed to reduce thermal stress in newly placed concrete, and the temperature control and crack prevention capacities of the proposed method are verified using the finite element method. The development of the structure’s thermal stress under different temperature control measures is analyzed, finding that thermal stress in the lock walls can be effectively reduced by 50% through low-temperature block casting. The results demonstrate that the proposed method can significantly reduce the internal thermal stress of newly placed concrete after prolonged casting interruptions, thereby highlighting its applicability for achieving effective temperature control and crack prevention in concrete ship locks.
{"title":"Temperature Control and Crack Prevention Measures for Concrete Ship Locks Subjected to Prolonged Casting Interruptions","authors":"Songhui Li, Xiangyu Luo, Guoxin Zhang, Yi Liu","doi":"10.1155/2024/5201498","DOIUrl":"https://doi.org/10.1155/2024/5201498","url":null,"abstract":"During the construction of concrete ship locks, prolonged interruptions between the casting of the floor and lock wall are inevitable. In terms of mass concrete, long placement delays are one of the major reasons for the presence of cracks in newly placed concrete. Therefore, this study examines both the placement and structural characteristics of ship locks after long casting interruptions based on the mass concrete thermal stress theory to determine the major causal factors for cracks in newly poured concrete. Specifically, a block placement method is proposed to reduce thermal stress in newly placed concrete, and the temperature control and crack prevention capacities of the proposed method are verified using the finite element method. The development of the structure’s thermal stress under different temperature control measures is analyzed, finding that thermal stress in the lock walls can be effectively reduced by 50% through low-temperature block casting. The results demonstrate that the proposed method can significantly reduce the internal thermal stress of newly placed concrete after prolonged casting interruptions, thereby highlighting its applicability for achieving effective temperature control and crack prevention in concrete ship locks.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140802613","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}
This paper introduces a novel steel–concrete composite column referred to as the core-steel tube with T-shaped steel reinforced concrete (CSTRC) column, which is composed of a core steel tube with T-shaped steel embedded in a reinforced concrete column. To investigate the mechanical performance of the CSTRC column under eccentric compressive load, the load–deformation response, stress, and strain distribution of CSTRC columns under eccentric load are analyzed by finite element software. Furthermore, the effects of slenderness ratio, concrete and steel strength on the eccentric compression performance of CSTRC columns are also discussed. Finally, a set of formulas for predicting the ultimate strength of the CSTRC columns is proposed. The study results reveal that: (1) The established finite element model accurately predicts bearing capacity and strain development. (2) When the eccentricity is 0.2, the specimen exhibits characteristics indicative of small eccentricity failure. Conversely, when the eccentricity is 0.8, the specimen demonstrates traits associated with large eccentricity failure. Furthermore, as the eccentricity increases, there is a notable decrease in the bearing capacity of the specimen. (3) The slenderness ratio affects the failure mode of the CSTRC columns, with consideration for second-order effects necessary when the ratio exceeds 22. (4) Increasing the concrete strength, steel strength, and steel ratio significantly enhances the ultimate load values of the CSTRC columns. (5) A comparison between calculated and simulated values demonstrates good agreement, validating the accuracy of the proposed method.
{"title":"Eccentric Compression Performance of Core-Steel Tube with T-Shaped Steel Reinforced Concrete Column","authors":"Liang Gao, Peng Wang, Xuehui You","doi":"10.1155/2024/4561737","DOIUrl":"https://doi.org/10.1155/2024/4561737","url":null,"abstract":"This paper introduces a novel steel–concrete composite column referred to as the core-steel tube with T-shaped steel reinforced concrete (CSTRC) column, which is composed of a core steel tube with T-shaped steel embedded in a reinforced concrete column. To investigate the mechanical performance of the CSTRC column under eccentric compressive load, the load–deformation response, stress, and strain distribution of CSTRC columns under eccentric load are analyzed by finite element software. Furthermore, the effects of slenderness ratio, concrete and steel strength on the eccentric compression performance of CSTRC columns are also discussed. Finally, a set of formulas for predicting the ultimate strength of the CSTRC columns is proposed. The study results reveal that: (1) The established finite element model accurately predicts bearing capacity and strain development. (2) When the eccentricity is 0.2, the specimen exhibits characteristics indicative of small eccentricity failure. Conversely, when the eccentricity is 0.8, the specimen demonstrates traits associated with large eccentricity failure. Furthermore, as the eccentricity increases, there is a notable decrease in the bearing capacity of the specimen. (3) The slenderness ratio affects the failure mode of the CSTRC columns, with consideration for second-order effects necessary when the ratio exceeds 22. (4) Increasing the concrete strength, steel strength, and steel ratio significantly enhances the ultimate load values of the CSTRC columns. (5) A comparison between calculated and simulated values demonstrates good agreement, validating the accuracy of the proposed method.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140802305","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}
The concrete-faced rockfill dam (CFRD) has been widely constructed worldwide, and the reliability of the concrete panels, the most important containment structure, is critical to the safety of the CFRDs and downstream communities. Several practical projects show that concrete slab cracking usually occurs during the water storage period, which can be attributed to the rapid increase of hydrostatic pressure and uneven settlement of the dam body. In this paper, a time-dependent reliability analysis method considering the fuzziness of the failure criterion is presented to assess the slab cracking risk of the Houziyan CFRD during the water storage period. Based on the observed deformation, the material parameters are calibrated to ensure the fidelity of the numerical simulation. Based on the Drucker–Prager yield criterion and tensile strength criterion, the response surface method is utilized to construct the performance functions at different moments, and then the time-dependent reliability analysis considering the fuzzy failure criteria is implemented for the concrete slab. The case study of the Houziyan CFRD shows that, during the initial period of water storage, the reliability index of the concrete slab decreases with the rise of the water level. With a stable water level, the probability of cracking of the concrete slab slowly decreases as the deformation of the dam body and slab tend to be coordinated. Especially, considering the fuzziness of the failure criteria, the reliability index decreased by about 2%, indicating that the proposed evaluation method is biased toward safety. The method proposed in this paper can reflect the evolution law of concrete slab reliability with the operating environment and provides a new approach to evaluate the performance of the concrete slab during the water storage period.
{"title":"Time-Dependent Fuzzy Reliability Analysis of Concrete Slab during the Initial Water Storage Period of CFRD: A Case Study","authors":"Gang Sun, Kongzhong Hu, Lifang Liu, Junru Li","doi":"10.1155/2024/1150405","DOIUrl":"https://doi.org/10.1155/2024/1150405","url":null,"abstract":"The concrete-faced rockfill dam (CFRD) has been widely constructed worldwide, and the reliability of the concrete panels, the most important containment structure, is critical to the safety of the CFRDs and downstream communities. Several practical projects show that concrete slab cracking usually occurs during the water storage period, which can be attributed to the rapid increase of hydrostatic pressure and uneven settlement of the dam body. In this paper, a time-dependent reliability analysis method considering the fuzziness of the failure criterion is presented to assess the slab cracking risk of the Houziyan CFRD during the water storage period. Based on the observed deformation, the material parameters are calibrated to ensure the fidelity of the numerical simulation. Based on the Drucker–Prager yield criterion and tensile strength criterion, the response surface method is utilized to construct the performance functions at different moments, and then the time-dependent reliability analysis considering the fuzzy failure criteria is implemented for the concrete slab. The case study of the Houziyan CFRD shows that, during the initial period of water storage, the reliability index of the concrete slab decreases with the rise of the water level. With a stable water level, the probability of cracking of the concrete slab slowly decreases as the deformation of the dam body and slab tend to be coordinated. Especially, considering the fuzziness of the failure criteria, the reliability index decreased by about 2%, indicating that the proposed evaluation method is biased toward safety. The method proposed in this paper can reflect the evolution law of concrete slab reliability with the operating environment and provides a new approach to evaluate the performance of the concrete slab during the water storage period.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140667960","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}
The high-strength red sandstone in its natural state is subjected to significant strength deterioration under alternating wet and dry conditions, which can cause many catastrophic problems in the process of engineering construction. It is important to deeply understand the damage mechanism of red sandstone under the action of dry and wet cycles. Therefore, this paper explores the mechanism of red sandstone’s uniaxial deformation and failure through indoor uniaxial compression tests, studies the damage to the microstructure of red sandstone under wet–dry cycles using scanning electron microscopy, and establishes a damage variable based on fractal dimension. The results show that with the increase of wet–dry cycles, the peak stress of red sandstone shows a decreasing trend, and the minimum peak stress is 17.3 MPa, which is a 46.62% decrease compared to the sample with 0 wet–dry cycles. During the wet–dry cycle process, there are four deformation characteristics of red sandstone samples, namely, crack compression, crack extension, progressive fracture, and crack penetration. SEM images show that the porosity, pore area, and fractal dimension all show a nonlinear increase, and the maximum damage variable can reach 10.41%. The research results can provide guidance for engineering design and slope failure mechanism research in red sandstone areas.
{"title":"Experimental Study of Macro- and Micro-Scopic Damage in Red Sandstone under Dry and Wet Cycling","authors":"Xiangmei Chen, Yongqiang Ren, Baoli Tang, Guojin Li, Feitian Zhang, Yunfei Liu","doi":"10.1155/2024/6681592","DOIUrl":"https://doi.org/10.1155/2024/6681592","url":null,"abstract":"The high-strength red sandstone in its natural state is subjected to significant strength deterioration under alternating wet and dry conditions, which can cause many catastrophic problems in the process of engineering construction. It is important to deeply understand the damage mechanism of red sandstone under the action of dry and wet cycles. Therefore, this paper explores the mechanism of red sandstone’s uniaxial deformation and failure through indoor uniaxial compression tests, studies the damage to the microstructure of red sandstone under wet–dry cycles using scanning electron microscopy, and establishes a damage variable based on fractal dimension. The results show that with the increase of wet–dry cycles, the peak stress of red sandstone shows a decreasing trend, and the minimum peak stress is 17.3 MPa, which is a 46.62% decrease compared to the sample with 0 wet–dry cycles. During the wet–dry cycle process, there are four deformation characteristics of red sandstone samples, namely, crack compression, crack extension, progressive fracture, and crack penetration. SEM images show that the porosity, pore area, and fractal dimension all show a nonlinear increase, and the maximum damage variable can reach 10.41%. The research results can provide guidance for engineering design and slope failure mechanism research in red sandstone areas.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140669273","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}
WooKeol Cho, Kyoungtae Kim, Inmook Lee, Soyoung (Iris) You
Urban railways have become a prominent mode of public transportation within cities owing to their connectivity with other modes of transport and environmental friendliness. Various policies, such as the expansion of metropolitan areas and the development of megacities, have further emphasized the pivotal role of urban railways. Consequently, more railway stations are expected to be constructed in developed cities. However, the temporal variation in boarding and alighting patterns at each railway station is often overlooked. Failing to account for this variation, specifically the differences in peak-hour concentration rates, in railway station design may cause increased conflicts among users owing to concentrated demands during specific time periods, exacerbating congestion and diminishing the appeal of the urban railway systems. Therefore, this study investigated the correlation between the temporal variation in boarding and alighting patterns and the attributes (location) of railway stations in Seoul, South Korea, and analyzed the spatial heterogeneity of this correlation. Initially, the factors influencing the peak-hour concentration rates in railway stations were identified using a linear regression model. Peak hours were defined as morning and afternoon peaks and boarding and alighting were differentiated to account for the directional aspects of temporal variations in boarding and alighting patterns. The correlation between boarding and alighting patterns and the attributes of railway station influence zones was determined, and a geographically weighted regression model was estimated to analyze the spatial heterogeneity of this correlation based on railway station location. The analysis results revealed that railway stations in the southeastern and downtown areas of Seoul exhibited varying impacts of station attributes on boarding and alighting patterns even when the station attribute influence zones were identical. The contribution of this study is to evaluate the priorities of railway projects and its corresponding transportation policies. Regarding the policy goal recently announced by the Korean government, “Achieving Commute Times in 30-min range,” our finding will provide a good measure of accessibility whether it succeeds or not.
{"title":"Temporal Variation and Spatial Heterogeneity in Boarding/Alighting Patterns at Urban Railway Stations: Implications for Estimating Optimal Construction Scale—A Case Study in Seoul, South Korea","authors":"WooKeol Cho, Kyoungtae Kim, Inmook Lee, Soyoung (Iris) You","doi":"10.1155/2024/9540718","DOIUrl":"https://doi.org/10.1155/2024/9540718","url":null,"abstract":"Urban railways have become a prominent mode of public transportation within cities owing to their connectivity with other modes of transport and environmental friendliness. Various policies, such as the expansion of metropolitan areas and the development of megacities, have further emphasized the pivotal role of urban railways. Consequently, more railway stations are expected to be constructed in developed cities. However, the temporal variation in boarding and alighting patterns at each railway station is often overlooked. Failing to account for this variation, specifically the differences in peak-hour concentration rates, in railway station design may cause increased conflicts among users owing to concentrated demands during specific time periods, exacerbating congestion and diminishing the appeal of the urban railway systems. Therefore, this study investigated the correlation between the temporal variation in boarding and alighting patterns and the attributes (location) of railway stations in Seoul, South Korea, and analyzed the spatial heterogeneity of this correlation. Initially, the factors influencing the peak-hour concentration rates in railway stations were identified using a linear regression model. Peak hours were defined as morning and afternoon peaks and boarding and alighting were differentiated to account for the directional aspects of temporal variations in boarding and alighting patterns. The correlation between boarding and alighting patterns and the attributes of railway station influence zones was determined, and a geographically weighted regression model was estimated to analyze the spatial heterogeneity of this correlation based on railway station location. The analysis results revealed that railway stations in the southeastern and downtown areas of Seoul exhibited varying impacts of station attributes on boarding and alighting patterns even when the station attribute influence zones were identical. The contribution of this study is to evaluate the priorities of railway projects and its corresponding transportation policies. Regarding the policy goal recently announced by the Korean government, “Achieving Commute Times in 30-min range,” our finding will provide a good measure of accessibility whether it succeeds or not.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140669344","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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