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":"34 1","pages":""},"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 re-excavation roadway in the filling body is a common engineering demand in mines. In order to solve the problem of instability and failure of the filling body caused by the excavation disturbance in the filling body and improve the comprehensive economic benefits of the technology, it is proposed to use the filling body formed by membrane bag filling in the goaf and the steel arch frame to form a prefabricated load-bearing structure, reserve the required roadway space, avoid the safety risks caused by roadway excavation, and reduce the difficulty and cost of roadway support in the later stage. Based on the background of a mine goaf, the mechanical model of the load-bearing structure is established, and the analytical solution of the bearing capacity of the steel arch is obtained. The optimal ratio of the membrane bag filling of the load-bearing structure is obtained by indoor test, and the deformation of the surrounding rock and the distribution range of the plastic zone after the formation of the reserved roadway are numerically simulated and analyzed. The results show that the best cementing material is cement : fly ash of 8 : 2, and the ratio of cement to sand is 1 : 3. The vertical displacement of the roof is 45.1 mm, the vertical displacement of the floor is 5.1 mm, and the horizontal displacement of the left side is 55.5 mm. The load on the load-bearing structure is within the allowable range, and the field monitoring results show that the deformation of the reserved roadway is small. The research results can provide reference for the prefabricated roadway engineering in the filling body.
{"title":"Research on the Application of Prefabricated Load-Bearing Structure in Prefabricated Roadway in Filling Body","authors":"Ke Jiang, Gaofeng Ren, Jia Sheng, Liang Peng, Hao Zhu, Xinyu Tan, Bokun Zheng, Congrui Zhang","doi":"10.1155/2024/8307250","DOIUrl":"https://doi.org/10.1155/2024/8307250","url":null,"abstract":"The re-excavation roadway in the filling body is a common engineering demand in mines. In order to solve the problem of instability and failure of the filling body caused by the excavation disturbance in the filling body and improve the comprehensive economic benefits of the technology, it is proposed to use the filling body formed by membrane bag filling in the goaf and the steel arch frame to form a prefabricated load-bearing structure, reserve the required roadway space, avoid the safety risks caused by roadway excavation, and reduce the difficulty and cost of roadway support in the later stage. Based on the background of a mine goaf, the mechanical model of the load-bearing structure is established, and the analytical solution of the bearing capacity of the steel arch is obtained. The optimal ratio of the membrane bag filling of the load-bearing structure is obtained by indoor test, and the deformation of the surrounding rock and the distribution range of the plastic zone after the formation of the reserved roadway are numerically simulated and analyzed. The results show that the best cementing material is cement : fly ash of 8 : 2, and the ratio of cement to sand is 1 : 3. The vertical displacement of the roof is 45.1 mm, the vertical displacement of the floor is 5.1 mm, and the horizontal displacement of the left side is 55.5 mm. The load on the load-bearing structure is within the allowable range, and the field monitoring results show that the deformation of the reserved roadway is small. The research results can provide reference for the prefabricated roadway engineering in the filling body.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"77 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140623862","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}
Tareg Abdalla Abdalla, Stanley Muse Shitote, Mohammed Matallah, David Otieno Koteng
Using ordinary Portland cement (OPC) in concrete has significant environmental and sustainability concerns. Notably, in the production of OPC, large volumes of greenhouse gases are produced, which contribute to global warming, and large amounts of natural raw materials are used, which can lead to the depletion of nonrenewable resources with time. In addition, OPC production is highly energy-intensive. To mitigate these concerns, it has become common practice to reduce the amount of OPC used in concrete production by partially replacing OPC with a supplementary cementitious material (SCM). Most of the SCMs used have pozzolanic properties and react with free lime in OPC to provide more cementitious material, which increases the long-term strength of concrete and also densifies the pore structure, resulting in improved durability in harsh environments. This study explored the effect of OPC on the resistance to sulfuric acid attack and drying shrinkage when OPC is partially replaced by processed bagasse ash (PBA) at dosages of up to 50%, together with 5% silica fume. Both materials are pozzolanic and are expected to react with free lime in OPC concrete to increase the strength and densify the concrete; however, with increased PBA dosage, the cement is diluted, and a reduction in strength can be expected. This study explores the benefits that can be realized, focusing primarily on sulfuric acid resistance and the reduction of drying shrinkage.
{"title":"Effect on Sulfuric Acid Resistance and Shrinkage of Concrete Incorporating Processed Bagasse Ash and Silica Fume","authors":"Tareg Abdalla Abdalla, Stanley Muse Shitote, Mohammed Matallah, David Otieno Koteng","doi":"10.1155/2024/5534536","DOIUrl":"https://doi.org/10.1155/2024/5534536","url":null,"abstract":"Using ordinary Portland cement (OPC) in concrete has significant environmental and sustainability concerns. Notably, in the production of OPC, large volumes of greenhouse gases are produced, which contribute to global warming, and large amounts of natural raw materials are used, which can lead to the depletion of nonrenewable resources with time. In addition, OPC production is highly energy-intensive. To mitigate these concerns, it has become common practice to reduce the amount of OPC used in concrete production by partially replacing OPC with a supplementary cementitious material (SCM). Most of the SCMs used have pozzolanic properties and react with free lime in OPC to provide more cementitious material, which increases the long-term strength of concrete and also densifies the pore structure, resulting in improved durability in harsh environments. This study explored the effect of OPC on the resistance to sulfuric acid attack and drying shrinkage when OPC is partially replaced by processed bagasse ash (PBA) at dosages of up to 50%, together with 5% silica fume. Both materials are pozzolanic and are expected to react with free lime in OPC concrete to increase the strength and densify the concrete; however, with increased PBA dosage, the cement is diluted, and a reduction in strength can be expected. This study explores the benefits that can be realized, focusing primarily on sulfuric acid resistance and the reduction of drying shrinkage.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"20 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140623959","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}
Jaeyoun Cho, Hyunkyu Shin, Yonghan Ahn, Jongnam Ho
As demand for indoor thermal comfort increases, occupants’ subjective thermal sensation is becoming an important indicator of the building environment. Traditional models like the predicted mean vote-based model may not be reliable for individual comfort. This study proposed the multihead long short-term memory (LSTM) model to reflect physical and environment-driven data variation. Controlled experiments were conducted with individual temperature measurements of six participants, and the collected data showed significant potential to predict individual thermal comfort using a model trained for each person. The results derived from this study can be utilized, in future, for predicting the thermal comfort and for optimizing the thermal environments using personal body temperature and surrounding environmental data in a space where mainly independent activities are performed. This study contributes to the relevant literature by suggesting a method that predicts thermal comfort based on the multihead LSTM method.
{"title":"The Personalized Thermal Comfort Prediction Using an MH-LSTM Neural Network Method","authors":"Jaeyoun Cho, Hyunkyu Shin, Yonghan Ahn, Jongnam Ho","doi":"10.1155/2024/2106137","DOIUrl":"https://doi.org/10.1155/2024/2106137","url":null,"abstract":"As demand for indoor thermal comfort increases, occupants’ subjective thermal sensation is becoming an important indicator of the building environment. Traditional models like the predicted mean vote-based model may not be reliable for individual comfort. This study proposed the multihead long short-term memory (LSTM) model to reflect physical and environment-driven data variation. Controlled experiments were conducted with individual temperature measurements of six participants, and the collected data showed significant potential to predict individual thermal comfort using a model trained for each person. The results derived from this study can be utilized, in future, for predicting the thermal comfort and for optimizing the thermal environments using personal body temperature and surrounding environmental data in a space where mainly independent activities are performed. This study contributes to the relevant literature by suggesting a method that predicts thermal comfort based on the multihead LSTM method.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"58 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140615520","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}
Fire evacuation path planning involves multiple data sources. In order to develop a dynamic planning, a comprehensive knowledge of the environment involving building information and fire development is required. This article presents a semantic approach that integrates Building Information Modeling (BIM) and Internet of Things (IoT) information to provide a data foundation for dynamic path planning. First, a fire evacuation (FE) ontology is introduced to fuse both knowledge and information relevant to dynamic path planning. Next, a dynamic knowledge graph that evolves according to the development of fire situation is instantiated based on the relevant FE ontology. Finally, to validate the feasibility of the semantic approach based on the ontology and knowledge graph, an example of application is conducted using a specific building as an example. This study provides a data foundation for more intelligent and precise decision-making in fire evacuation scenarios and offers a new approach for safety design and management in the field of construction.
{"title":"A Semantic Approach to Dynamic Path Planning for Fire Evacuation through BIM and IoT Data Integration","authors":"Bo Pang, Jianyong Shi, Liu Jiang, Zeyu Pan","doi":"10.1155/2024/8839865","DOIUrl":"https://doi.org/10.1155/2024/8839865","url":null,"abstract":"Fire evacuation path planning involves multiple data sources. In order to develop a dynamic planning, a comprehensive knowledge of the environment involving building information and fire development is required. This article presents a semantic approach that integrates Building Information Modeling (BIM) and Internet of Things (IoT) information to provide a data foundation for dynamic path planning. First, a fire evacuation (FE) ontology is introduced to fuse both knowledge and information relevant to dynamic path planning. Next, a dynamic knowledge graph that evolves according to the development of fire situation is instantiated based on the relevant FE ontology. Finally, to validate the feasibility of the semantic approach based on the ontology and knowledge graph, an example of application is conducted using a specific building as an example. This study provides a data foundation for more intelligent and precise decision-making in fire evacuation scenarios and offers a new approach for safety design and management in the field of construction.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"86 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140615553","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}
Jinling Chai, Ke Wang, Shihao Wang, Yong Wang, Yi Liu
This paper investigates segmental lining, developing a numerical model to explore the dynamic interaction between saturated soil and the lining structure, and analyses the effects of the angle of incident load and the wavelength-to-diameter ratio on the displacement, deformation, and distribution of the plastic zone of the structure. The findings demonstrate that the structure experiences vertical compressive deformation during ground shock predominantly. The structure can be categorised into the major deformation region (with an angle within 60° of the vertical direction) and the minor deformation region (with an angle within 30° of the horizontal direction), determined by the structure’s radial deformation. The maximum radial velocity of the nodes in the major deformation area is greater and swifter, whereas the maximum radial velocity of the nodes in the minor deformation region is lesser and mostly equivalent in extent. The maximum radial displacement of the nodes in the major deformation area is highly receptive to the loading wavelength–diameter ratio (L/D) (the ratio of the load wavelength to the structure’s outer diameter) when the wavelength-to-diameter ratio (L/D) is small (1 ≤ L/D ≤ 5). Conversely, the maximum radial displacement in the minor deformation area is considerably sensitive to the wavelength–diameter ratio when 5 ≤ L/D ≤ 30. The total displacement and velocity of the structure remain unaffected by the angle of load incidence. However, it affects the maximum deformation of the structure as well as the location where the maximum node velocity occurs. In addition, the joint surface of the structure experiences the highest plastic strain at an angle of load incidence of 60°.
{"title":"Response and Damage Characteristics of Segmental Tunnel Lining under Various Dynamic Load Conditions","authors":"Jinling Chai, Ke Wang, Shihao Wang, Yong Wang, Yi Liu","doi":"10.1155/2024/1008274","DOIUrl":"https://doi.org/10.1155/2024/1008274","url":null,"abstract":"This paper investigates segmental lining, developing a numerical model to explore the dynamic interaction between saturated soil and the lining structure, and analyses the effects of the angle of incident load and the wavelength-to-diameter ratio on the displacement, deformation, and distribution of the plastic zone of the structure. The findings demonstrate that the structure experiences vertical compressive deformation during ground shock predominantly. The structure can be categorised into the major deformation region (with an angle within 60° of the vertical direction) and the minor deformation region (with an angle within 30° of the horizontal direction), determined by the structure’s radial deformation. The maximum radial velocity of the nodes in the major deformation area is greater and swifter, whereas the maximum radial velocity of the nodes in the minor deformation region is lesser and mostly equivalent in extent. The maximum radial displacement of the nodes in the major deformation area is highly receptive to the loading wavelength–diameter ratio (<i>L</i>/<i>D</i>) (the ratio of the load wavelength to the structure’s outer diameter) when the wavelength-to-diameter ratio (<i>L</i>/<i>D</i>) is small (1 ≤ <i>L</i>/<i>D</i> ≤ 5). Conversely, the maximum radial displacement in the minor deformation area is considerably sensitive to the wavelength–diameter ratio when 5 ≤ <i>L</i>/<i>D</i> ≤ 30. The total displacement and velocity of the structure remain unaffected by the angle of load incidence. However, it affects the maximum deformation of the structure as well as the location where the maximum node velocity occurs. In addition, the joint surface of the structure experiences the highest plastic strain at an angle of load incidence of 60°.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"48 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140615775","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 burgeoning urbanization of major cities has precipitated a critical examination of deep foundation pit projects, with escalating costs, protracted construction phases, complex site conditions, and specialized technical requirements. Selecting the optimal design scheme from multiple alternatives in a multiattribute decision-making environment poses a significant challenge. This study presents a novel model tailored for the design of deep foundation pits in design-build (DB) contracting projects. The model combines multiattribute ideal point theory with the analytic hierarchy process to evaluate 22 key factors and their uncertainties. It computes the deviations of potential design schemes from ideal benchmarks across all considered attributes. By employing the lexicographic hierarchy aggregation operator, the model aggregates group-level deviations and linguistically weighted evaluations to calculate a comprehensive score for each design scheme. This approach aids in identifying the most suitable design to meet the deep foundation requirements of DB projects. The effectiveness of the model is demonstrated through its application in the decision-making process for a commercial hotel’s deep foundation pit design scheme. The empirical findings affirm the model’s ability to identify critical factors and accurately assess their impact on engineering design decisions in DB contracting projects. Among the four evaluated designs, the continuous retaining wall scheme achieved the lowest group deviation score, marking it as the preferred option. Consequently, this research offers a robust framework for making informed decisions in the design of deep foundation pits within DB contracting projects, effectively handling the complexities of uncertain linguistic evaluations and the collaboration of multiple attributes.
随着各大城市城市化进程的不断加快，深基坑项目的成本不断攀升，施工阶段旷日持久，现场条件复杂，技术要求专业，这些都促使我们对深基坑项目进行严格审查。在多属性决策环境中，从多个备选方案中选择最佳设计方案是一项重大挑战。本研究针对设计-建造（DB）承包项目中的深基坑设计提出了一个新模型。该模型将多属性理想点理论与层次分析法相结合，对 22 个关键因素及其不确定性进行评估。该模型可计算潜在设计方案在所有考虑属性方面与理想基准的偏差。通过使用词典层次聚合运算符，该模型聚合了组级偏差和语言加权评价，从而计算出每个设计方案的综合得分。这种方法有助于确定最合适的设计方案，以满足 DB 项目对深基础的要求。该模型在一家商业酒店深基坑设计方案决策过程中的应用证明了它的有效性。实证研究结果肯定了该模型识别关键因素并准确评估其对 DB 承包项目工程设计决策影响的能力。在四个受评估的设计方案中，连续挡土墙方案的群体偏差得分最低，成为首选方案。因此，这项研究为在 DB 承包项目中的深基坑设计中做出明智决策提供了一个强大的框架，有效地处理了不确定的语言评估和多属性协作的复杂性。
{"title":"Expression and Analysis of Uncertainty in Deep Foundation Pit Design Scheme Decision-Making","authors":"Yu Cui, Qun Wang, Tiebing Chen, Ronghui Deng, Xiaoliang Chen","doi":"10.1155/2024/9972743","DOIUrl":"https://doi.org/10.1155/2024/9972743","url":null,"abstract":"The burgeoning urbanization of major cities has precipitated a critical examination of deep foundation pit projects, with escalating costs, protracted construction phases, complex site conditions, and specialized technical requirements. Selecting the optimal design scheme from multiple alternatives in a multiattribute decision-making environment poses a significant challenge. This study presents a novel model tailored for the design of deep foundation pits in design-build (DB) contracting projects. The model combines multiattribute ideal point theory with the analytic hierarchy process to evaluate 22 key factors and their uncertainties. It computes the deviations of potential design schemes from ideal benchmarks across all considered attributes. By employing the lexicographic hierarchy aggregation operator, the model aggregates group-level deviations and linguistically weighted evaluations to calculate a comprehensive score for each design scheme. This approach aids in identifying the most suitable design to meet the deep foundation requirements of DB projects. The effectiveness of the model is demonstrated through its application in the decision-making process for a commercial hotel’s deep foundation pit design scheme. The empirical findings affirm the model’s ability to identify critical factors and accurately assess their impact on engineering design decisions in DB contracting projects. Among the four evaluated designs, the continuous retaining wall scheme achieved the lowest group deviation score, marking it as the preferred option. Consequently, this research offers a robust framework for making informed decisions in the design of deep foundation pits within DB contracting projects, effectively handling the complexities of uncertain linguistic evaluations and the collaboration of multiple attributes.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"111 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140615690","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}
Mingxi Cai, Lijun Shao, Jiawei Zhang, Kaijin Xu, Jie Zhang, Penggang Li
To investigate the mechanical properties of carbon-fiber-reinforced-polymer (CFRP)-restrained concrete in a saline soil environment, the degradation of the mechanical properties of CFRP-restrained concrete columns under the effect of continuous sulfate semisoak erosion is investigated based on sulfate continuous semisoak erosion, and unrestrained concrete columns with the same specifications are used in comparison tests. The results show that the strength, stiffness, and ductility of both plain concrete columns and CFRP-confined concrete columns first increase and then decrease after the continuous semi-submersion erosion by sulfate; compared with plain concrete columns, the decline rates of strength and stiffness of CFRP-confined concrete columns are significantly lower, and the CFRP demonstrates a certain protective effect on the core concrete. Through a regression analysis of experimental data, strength and ultimate strain models of CFRP-confined concrete columns under the continuous semi-submergence of sulfate are proposed based on the existing ultimate strength and ultimate strain models of CFRP-confined ordinary concrete columns, and a stress–strain model of CFRP-confined concrete columns under the continuous semi-submergence of sulfate is established. Based on a comparison with experimental data, the model prediction curves indicate good agreement with the experimental curves and can therefore provide a theoretical basis and practical reference for CFRP-reinforced semi-submerged concrete in saline soil areas.
{"title":"Experimental Study on Mechanical Properties of CFRP-Confined Concrete Columns under Continuous Semi-Submergence of Sulfate","authors":"Mingxi Cai, Lijun Shao, Jiawei Zhang, Kaijin Xu, Jie Zhang, Penggang Li","doi":"10.1155/2024/2560804","DOIUrl":"https://doi.org/10.1155/2024/2560804","url":null,"abstract":"To investigate the mechanical properties of carbon-fiber-reinforced-polymer (CFRP)-restrained concrete in a saline soil environment, the degradation of the mechanical properties of CFRP-restrained concrete columns under the effect of continuous sulfate semisoak erosion is investigated based on sulfate continuous semisoak erosion, and unrestrained concrete columns with the same specifications are used in comparison tests. The results show that the strength, stiffness, and ductility of both plain concrete columns and CFRP-confined concrete columns first increase and then decrease after the continuous semi-submersion erosion by sulfate; compared with plain concrete columns, the decline rates of strength and stiffness of CFRP-confined concrete columns are significantly lower, and the CFRP demonstrates a certain protective effect on the core concrete. Through a regression analysis of experimental data, strength and ultimate strain models of CFRP-confined concrete columns under the continuous semi-submergence of sulfate are proposed based on the existing ultimate strength and ultimate strain models of CFRP-confined ordinary concrete columns, and a stress–strain model of CFRP-confined concrete columns under the continuous semi-submergence of sulfate is established. Based on a comparison with experimental data, the model prediction curves indicate good agreement with the experimental curves and can therefore provide a theoretical basis and practical reference for CFRP-reinforced semi-submerged concrete in saline soil areas.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"5 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140591436","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}
Jinhua Li, Yang Yang, Pan Wang, Tianyu Zhang, Peili Su, Songwei Zhao
The properties of soft–hard interbedded rock masses are significantly impacted by the strength of rock layers and the characteristics of interface surfaces. This study investigates the mechanical properties of soft–hard interlayered rock masses by preparing rock-like specimens with different interface angles. Uniaxial and triaxial compression tests were conducted to examine the compression mechanical characteristics of the specimens. Experimental results demonstrated that in the uniaxial compression tests, the peak strength of the two-layer rock-like specimen exhibits an initial decrease followed by an increase as the interface angle increases. Similarly, the peak strength of the three-layer rock-like specimen also follows a “U-shaped” pattern. The failure of both specimens shifts from tensile failure to shear failure. In the triaxial tests, the strength of the two-layer rock-like specimen initially increases and subsequently decreases as the interface angle increases. In contrast, the intensity of the three-layer rock-like specimen exhibits a decreasing trend, transitioning from shear dilation or tensile failure to shear failure. By utilizing the damage constitutive model to compute the compressive strength of the composite specimen, it was observed that the deviation from the experimental value did not exceed 2.5%, and the overall shape of the curves was in good agreement. Consequently, it is affirmed that the damage constitutive model developed in this study can accurately capture the pre-peak phase of the stress–strain relationship in soft–hard interlayered rock-like specimens, thus providing a valid representation of their mechanical behavior.
{"title":"Compression Mechanical Properties and Constitutive Model for Soft–Hard Interlayered Rock Mass","authors":"Jinhua Li, Yang Yang, Pan Wang, Tianyu Zhang, Peili Su, Songwei Zhao","doi":"10.1155/2024/1693495","DOIUrl":"https://doi.org/10.1155/2024/1693495","url":null,"abstract":"The properties of soft–hard interbedded rock masses are significantly impacted by the strength of rock layers and the characteristics of interface surfaces. This study investigates the mechanical properties of soft–hard interlayered rock masses by preparing rock-like specimens with different interface angles. Uniaxial and triaxial compression tests were conducted to examine the compression mechanical characteristics of the specimens. Experimental results demonstrated that in the uniaxial compression tests, the peak strength of the two-layer rock-like specimen exhibits an initial decrease followed by an increase as the interface angle increases. Similarly, the peak strength of the three-layer rock-like specimen also follows a “U-shaped” pattern. The failure of both specimens shifts from tensile failure to shear failure. In the triaxial tests, the strength of the two-layer rock-like specimen initially increases and subsequently decreases as the interface angle increases. In contrast, the intensity of the three-layer rock-like specimen exhibits a decreasing trend, transitioning from shear dilation or tensile failure to shear failure. By utilizing the damage constitutive model to compute the compressive strength of the composite specimen, it was observed that the deviation from the experimental value did not exceed 2.5%, and the overall shape of the curves was in good agreement. Consequently, it is affirmed that the damage constitutive model developed in this study can accurately capture the pre-peak phase of the stress–strain relationship in soft–hard interlayered rock-like specimens, thus providing a valid representation of their mechanical behavior.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"215 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590978","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}
Deep foundation pit excavations have become more extensive for the construction of underground spaces with rapid urbanization. Diaphragm walls are commonly used to support deep excavations. However, due to the complex geological conditions in karst areas, construction accidents frequently occur during the excavation of foundation pits. This study aims to investigate the performance of diaphragm walls in karst areas through field monitoring analysis. A kick-in deformation mode of the diaphragm wall is revealed during the foundation pit excavation. Furthermore, the results show that the diaphragm walls present multiple deformation modes rather than a single mode. Additionally, this study proposes a method to calculate the lateral displacement of the diaphragm walls at different depths. It is found that the karst caves have a considerable impact on the stability of diaphragm walls, as demonstrated by their lateral displacement. The hidden karst caves reduce the bearing capacity of the bedrock, rendering it insufficient to resist the active earth pressure. As a result, the bottom of the diaphragm wall is kicked into the foundation pit, causing significant lateral displacement and posing risks during excavation. The findings of this study contribute to the design and construction of similar excavations in karst areas.
{"title":"Performance of Diaphragm Walls during Ultra-Deep Excavations in Karst Areas: Field Monitoring Analysis","authors":"Xingzhong Nong, Yanhong Wang, Benhai Lin, Wentian Xu, Wuzhang Luo, Ren Tang","doi":"10.1155/2024/5834253","DOIUrl":"https://doi.org/10.1155/2024/5834253","url":null,"abstract":"Deep foundation pit excavations have become more extensive for the construction of underground spaces with rapid urbanization. Diaphragm walls are commonly used to support deep excavations. However, due to the complex geological conditions in karst areas, construction accidents frequently occur during the excavation of foundation pits. This study aims to investigate the performance of diaphragm walls in karst areas through field monitoring analysis. A kick-in deformation mode of the diaphragm wall is revealed during the foundation pit excavation. Furthermore, the results show that the diaphragm walls present multiple deformation modes rather than a single mode. Additionally, this study proposes a method to calculate the lateral displacement of the diaphragm walls at different depths. It is found that the karst caves have a considerable impact on the stability of diaphragm walls, as demonstrated by their lateral displacement. The hidden karst caves reduce the bearing capacity of the bedrock, rendering it insufficient to resist the active earth pressure. As a result, the bottom of the diaphragm wall is kicked into the foundation pit, causing significant lateral displacement and posing risks during excavation. The findings of this study contribute to the design and construction of similar excavations in karst areas.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"239 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590975","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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