To meticulously dissect the cracking issue in the transverse diaphragm concrete,situated at the anchor point of a colossal large-span,single cable plane cable-stayed bridge,this research paper adopts an innovative lay...To meticulously dissect the cracking issue in the transverse diaphragm concrete,situated at the anchor point of a colossal large-span,single cable plane cable-stayed bridge,this research paper adopts an innovative layered modeling analysis methodology for numerical simulations.The approach is structured into three distinct layers,each tailored to address specific aspects of the cracking phenomenon.The foundational first layer model operates under the assumption of linear elasticity,adhering to the Saint Venant principle.It narrows its focus to the crucial zone between the Bp20 transverse diaphragm and the central axis of pier 4’s support,encompassing the critically cracked diaphragm beneath the N1 cable anchor.This layer provides a preliminary estimate of potential cracking zones within the concrete,serving as a baseline for further analysis.The second layer model builds upon this foundation by incorporating material plasticity into its considerations.It pinpoints its investigation to the immediate vicinity of the cracked transverse diaphragm associated with the N1 cable,aiming to capture the intricate material behavior under stress.This layer’s predictions of crack locations and patterns exhibit a remarkable alignment with actual detection results,confirming its precision and reliability.The third and most intricate layer delves deep into the heart of the matter,examining the cracked transverse diaphragm precisely where the cable force attains its maximum intensity.By leveraging advanced extended finite element technology,this layer offers an unprecedented level of detail in tracing the progression of concrete cracks.Its findings reveal a close correlation between predicted and observed crack widths,validating the model’s proficiency in simulating real-world cracking dynamics.Crucially,the boundary conditions for each layer are meticulously aligned with those of the overarching model,ensuring consistency and integrity throughout the analysis.These results not only enrich our understanding of the cracking mechanisms but also underscore the efficacy of reinforcing cracked concrete sections with external steel plates.In conclusion,this study represents a significant contribution to the field of bridge engineering,offering both theoretical insights and practical solutions for addressing similar challenges.展开更多
With the continuous improvement of people's safety awareness, the attention of building structure reinforcement technology is also increasing. During the construction period of housing construction, we must combin...With the continuous improvement of people's safety awareness, the attention of building structure reinforcement technology is also increasing. During the construction period of housing construction, we must combine with the actual situation of the project, reasonably carry out the structural reinforcement design, and make targeted use of the reinforcement construction technology. But at present, in the construction period, due to the weak awareness of technical personnel and other factors, the structural reinforcement is often ignored, resulting in the durability and seismic resistance of the building structure cannot meet the standard, there are relatively many potential safety hazards, causing a greater threat to people's life safety. In the future housing construction process, we must strengthen the emphasis on structural reinforcement. In view of this, this paper mainly analyzes the application of building structure reinforcement design and reinforcement construction technology in order to provide reference for relevant personnel.展开更多
With the development of Chinas social economy, the scale of water conservancy construction is expanding day by day, and the important role of water conservancy facilities in daily life and its positive influence on ag...With the development of Chinas social economy, the scale of water conservancy construction is expanding day by day, and the important role of water conservancy facilities in daily life and its positive influence on agricultural production are increasingly prominent. While improving the service quality, water conservancy construction also faces many problems, and the number of dangerous reservoirs is also increasing. In recent years, the state has attached great importance to water conservancy, which has made great progress in the quality of water conservancy. However, at the same time, there are many problems. According to the reinforcement requirements during the construction of water conservancy projects, the methods and approaches of reservoir reinforcement are analyzed and discussed, and the reinforcement design method and scheme with certain practical value are obtained, which can be used as a reference for similar projects.展开更多
Carbon fiber reinforced polymer(CFRP)is an advanced material widely used in bridge structures,demonstrating a promising application prospect.CFRP possesses excellent mechanical properties,construction advantages,and d...Carbon fiber reinforced polymer(CFRP)is an advanced material widely used in bridge structures,demonstrating a promising application prospect.CFRP possesses excellent mechanical properties,construction advantages,and durability benefits.Its application in bridge reinforcement can significantly enhance the overall performance of the reinforced bridge,thereby improving the durability and extending the service life of the bridge.Therefore,it is necessary to further explore how CFRP can be effectively applied in bridge reinforcement projects to improve the quality of such projects and ensure the safety of bridges during operation.展开更多
Study on efficient mining of the steep incline and fractured ore-bodies in Yongshaba mine of Guizhou Kailin Group shows that ore-body is fractured and difficult to support the roadways in-vein.After research of the ac...Study on efficient mining of the steep incline and fractured ore-bodies in Yongshaba mine of Guizhou Kailin Group shows that ore-body is fractured and difficult to support the roadways in-vein.After research of the actual conditions about the ore-bodies,we have made the initial decision to adopt reconstruction of roof downward sublevel cut-and-fill mining.The men work safely under the false roof supporting the top plate.However,the difficult problem is how to determine the strength of the false roof.In this case,the method based on reliability theory has been put forward.Combined with elastic mechanics and field practice,when practical value of reliable probability is 90 %,the value of the false roof strength has been calculated,and the study shows that stope span greatly influences the false roof strength.With the strength of artificial roof,the reasonable reinforcement design ensures the false roof which can supply the demand of strength under large span and load.展开更多
To improve the bending load-carrying capacity （ BLCC） of under-matched butt joint under four-point bending load in the elastic stage, the shape design of the reinforcement is studied based on the theoretics of mecha...To improve the bending load-carrying capacity （ BLCC） of under-matched butt joint under four-point bending load in the elastic stage, the shape design of the reinforcement is studied based on the theoretics of mechanics of materials. The concept, criterion, realization condition and design proposal of equal bending load-carrying capacity （EBLCC） are put forward. The theoretical analysis results have been verified by the finite element method. The simulation results are coincident basically with the ones of theoretical analysis. The research results show that the shape design of the reinforcement of EBLCC can improve BLCC of under-matched butt joint and the unilateral-side type reinforcement can replace double-side symmetry展开更多
In the concrete water conservancy construction, the sluice is widely used in various water conservancy projects, which has irreplaceable significance. If there is a certain problem in the sluice, it will inevitably ca...In the concrete water conservancy construction, the sluice is widely used in various water conservancy projects, which has irreplaceable significance. If there is a certain problem in the sluice, it will inevitably cause serious consequences to the whole project, and will also cause some potential safety hazards to the downstream area. More seriously, it will cause the lives and property of the residents to be threatened, thus causing serious economic losses and seriously hindering the development of society. In order to solve this problem, we must do a good job in the reinforcement design of water conservancy projects, carry out a comprehensive design of the reinforcement work of the sluice in strict accordance with various engineering standards, and ensure the smooth progress of water conservancy projects.展开更多
A design method of reinforced concrete (R. C.) offshore platforms with nonlinear finite element analysis is proposed. According to the method, a computer program is developed. In this program nonlinear constitutive re...A design method of reinforced concrete (R. C.) offshore platforms with nonlinear finite element analysis is proposed. According to the method, a computer program is developed. In this program nonlinear constitutive relationships and strength criteria of concrete and steel bars are included, and the progressive cracking and crushing of the concrete are taken into account. Based on the stress distribution obtained by the nonlinear finite element analysis, the amount of reinforcement in the control sections can be computed and adjusted automatically by the program to satisfy the requirement of the design. The amount of reinforcement required in the control sections, which are obtained with the nonlinear finite element analysis, is agreeable to that obtained in the experiment. This shows that the design method of R. C. offshore platform with the nonlinear finite element method proposed by the authors is reliable for practical use.展开更多
Currently,the reinforcement design of shield tunnel secondary linings mainly depends on engineering experience,with a lack of clear guidance from relevant codes and literature.Relying only on experience during constru...Currently,the reinforcement design of shield tunnel secondary linings mainly depends on engineering experience,with a lack of clear guidance from relevant codes and literature.Relying only on experience during construction can cause structural flaws and safety hazards.This study,based on the Guangzhou-Shenzhen-Hong Kong Shiziyang Tunnel project,uses model tests to study shield tunnel double-layer lining structures.It compares and analyzes the mechanical features and interaction mechanisms of reinforced and unreinforced secondary linings.Results show that in such structures,segmental linings bear the main load,and secondary linings offer extra support and adjust deformation.Reinforcement in secondary linings affects the constraint on segmental linings.Reinforcement enhances overall performance significantly.Although it has little impact on ultimate bearing capacity,it prolongs the load-bearing process.Specifically,it increases the ultimate bearing capacity of segmental and secondary linings by 21.2%and 26.1%,respectively.For 10-m-diameter shield tunnels,secondary lining reinforcement design should be adopted when the equivalent overburden thickness at the tunnel crown exceeds three times the tunnel diameter.展开更多
The main concern of this paper is to provide an extensive study for the structural behavior of low/medium/high rise office buildings aiming to deepen structure and architect designers understanding for such type of bu...The main concern of this paper is to provide an extensive study for the structural behavior of low/medium/high rise office buildings aiming to deepen structure and architect designers understanding for such type of buildings. The study is performed on reinforced concrete and emphasized only on Kuwait city conditions for wind. Regular layout plan building with different heights ranging from five to fifty typical office stories are investigated in this study. Three dimensional finite element techniques through ETABS software are used in conducting analysis for structures presented here-in. A serviceability study is performed to ensure that buildings have sufficient stability to limit lateral drift and peak acceleration within the acceptable range of occupancy comfort. In addition, an ultimate strength study is carried out to design and verify that all the structural elements are designed to withstand factored gravity and lateral loadings in a safe manner according to the international building codes. The building slenderness ratio and the building core size and location are the studied parameters since they are the key drivers for the efficient structural design. Analysis results are presented and discussed and finally conclusions are summarized as guidelines for designers of concrete office buildings in Kuwait.展开更多
The main concern of this paper is to study the influence of the building slenderness ratio on the structural behavior of the residential concrete tall buildings aiming to deepen structure and architect designers under...The main concern of this paper is to study the influence of the building slenderness ratio on the structural behavior of the residential concrete tall buildings aiming to deepen structure and architect designers understanding for such type of buildings. The study is emphasized only on Kuwait city design conditions for wind and seismic loadings. The paper presents an actual case study for adding two thirty stories residential towers with two different slenderness ratios to an existing residential complex. Wind loading is considered using both code values and wind tunnel results. Three dimensional finite element techniques through ETABS software are used in conducting analysis for structures presented here. A serviceability study is performed to ensure that buildings have sufficient stability to limit lateral drift and peak acceleration within the acceptable range of occupancy comfort. In addition, an ultimate strength study is carried out to verify that all the structural elements are designed to withstand factored gravity and lateral loads in a safe manner according to the international building codes. Analysis results are presented and discussed. A brief idea about foundation design of the new towers and its connection to the existing foundation is presented. Finally conclusions are summarized as guidelines for the structural professions of concrete residential tall buildings.展开更多
基金financially supported by National Natural Science Foundation of China(Project No.51878156,received by Wenwei Wang).
文摘To meticulously dissect the cracking issue in the transverse diaphragm concrete,situated at the anchor point of a colossal large-span,single cable plane cable-stayed bridge,this research paper adopts an innovative layered modeling analysis methodology for numerical simulations.The approach is structured into three distinct layers,each tailored to address specific aspects of the cracking phenomenon.The foundational first layer model operates under the assumption of linear elasticity,adhering to the Saint Venant principle.It narrows its focus to the crucial zone between the Bp20 transverse diaphragm and the central axis of pier 4’s support,encompassing the critically cracked diaphragm beneath the N1 cable anchor.This layer provides a preliminary estimate of potential cracking zones within the concrete,serving as a baseline for further analysis.The second layer model builds upon this foundation by incorporating material plasticity into its considerations.It pinpoints its investigation to the immediate vicinity of the cracked transverse diaphragm associated with the N1 cable,aiming to capture the intricate material behavior under stress.This layer’s predictions of crack locations and patterns exhibit a remarkable alignment with actual detection results,confirming its precision and reliability.The third and most intricate layer delves deep into the heart of the matter,examining the cracked transverse diaphragm precisely where the cable force attains its maximum intensity.By leveraging advanced extended finite element technology,this layer offers an unprecedented level of detail in tracing the progression of concrete cracks.Its findings reveal a close correlation between predicted and observed crack widths,validating the model’s proficiency in simulating real-world cracking dynamics.Crucially,the boundary conditions for each layer are meticulously aligned with those of the overarching model,ensuring consistency and integrity throughout the analysis.These results not only enrich our understanding of the cracking mechanisms but also underscore the efficacy of reinforcing cracked concrete sections with external steel plates.In conclusion,this study represents a significant contribution to the field of bridge engineering,offering both theoretical insights and practical solutions for addressing similar challenges.
文摘With the continuous improvement of people's safety awareness, the attention of building structure reinforcement technology is also increasing. During the construction period of housing construction, we must combine with the actual situation of the project, reasonably carry out the structural reinforcement design, and make targeted use of the reinforcement construction technology. But at present, in the construction period, due to the weak awareness of technical personnel and other factors, the structural reinforcement is often ignored, resulting in the durability and seismic resistance of the building structure cannot meet the standard, there are relatively many potential safety hazards, causing a greater threat to people's life safety. In the future housing construction process, we must strengthen the emphasis on structural reinforcement. In view of this, this paper mainly analyzes the application of building structure reinforcement design and reinforcement construction technology in order to provide reference for relevant personnel.
文摘With the development of Chinas social economy, the scale of water conservancy construction is expanding day by day, and the important role of water conservancy facilities in daily life and its positive influence on agricultural production are increasingly prominent. While improving the service quality, water conservancy construction also faces many problems, and the number of dangerous reservoirs is also increasing. In recent years, the state has attached great importance to water conservancy, which has made great progress in the quality of water conservancy. However, at the same time, there are many problems. According to the reinforcement requirements during the construction of water conservancy projects, the methods and approaches of reservoir reinforcement are analyzed and discussed, and the reinforcement design method and scheme with certain practical value are obtained, which can be used as a reference for similar projects.
文摘Carbon fiber reinforced polymer(CFRP)is an advanced material widely used in bridge structures,demonstrating a promising application prospect.CFRP possesses excellent mechanical properties,construction advantages,and durability benefits.Its application in bridge reinforcement can significantly enhance the overall performance of the reinforced bridge,thereby improving the durability and extending the service life of the bridge.Therefore,it is necessary to further explore how CFRP can be effectively applied in bridge reinforcement projects to improve the quality of such projects and ensure the safety of bridges during operation.
基金"973 " Subjects (No. 2010CB732004)National Natural Science Foundation Project (No.50934006)
文摘Study on efficient mining of the steep incline and fractured ore-bodies in Yongshaba mine of Guizhou Kailin Group shows that ore-body is fractured and difficult to support the roadways in-vein.After research of the actual conditions about the ore-bodies,we have made the initial decision to adopt reconstruction of roof downward sublevel cut-and-fill mining.The men work safely under the false roof supporting the top plate.However,the difficult problem is how to determine the strength of the false roof.In this case,the method based on reliability theory has been put forward.Combined with elastic mechanics and field practice,when practical value of reliable probability is 90 %,the value of the false roof strength has been calculated,and the study shows that stope span greatly influences the false roof strength.With the strength of artificial roof,the reasonable reinforcement design ensures the false roof which can supply the demand of strength under large span and load.
文摘To improve the bending load-carrying capacity （ BLCC） of under-matched butt joint under four-point bending load in the elastic stage, the shape design of the reinforcement is studied based on the theoretics of mechanics of materials. The concept, criterion, realization condition and design proposal of equal bending load-carrying capacity （EBLCC） are put forward. The theoretical analysis results have been verified by the finite element method. The simulation results are coincident basically with the ones of theoretical analysis. The research results show that the shape design of the reinforcement of EBLCC can improve BLCC of under-matched butt joint and the unilateral-side type reinforcement can replace double-side symmetry
文摘In the concrete water conservancy construction, the sluice is widely used in various water conservancy projects, which has irreplaceable significance. If there is a certain problem in the sluice, it will inevitably cause serious consequences to the whole project, and will also cause some potential safety hazards to the downstream area. More seriously, it will cause the lives and property of the residents to be threatened, thus causing serious economic losses and seriously hindering the development of society. In order to solve this problem, we must do a good job in the reinforcement design of water conservancy projects, carry out a comprehensive design of the reinforcement work of the sluice in strict accordance with various engineering standards, and ensure the smooth progress of water conservancy projects.
文摘A design method of reinforced concrete (R. C.) offshore platforms with nonlinear finite element analysis is proposed. According to the method, a computer program is developed. In this program nonlinear constitutive relationships and strength criteria of concrete and steel bars are included, and the progressive cracking and crushing of the concrete are taken into account. Based on the stress distribution obtained by the nonlinear finite element analysis, the amount of reinforcement in the control sections can be computed and adjusted automatically by the program to satisfy the requirement of the design. The amount of reinforcement required in the control sections, which are obtained with the nonlinear finite element analysis, is agreeable to that obtained in the experiment. This shows that the design method of R. C. offshore platform with the nonlinear finite element method proposed by the authors is reliable for practical use.
基金supported by the National Natural Science Foundation of China(Grant Nos.52178398 and 51991394).
文摘Currently,the reinforcement design of shield tunnel secondary linings mainly depends on engineering experience,with a lack of clear guidance from relevant codes and literature.Relying only on experience during construction can cause structural flaws and safety hazards.This study,based on the Guangzhou-Shenzhen-Hong Kong Shiziyang Tunnel project,uses model tests to study shield tunnel double-layer lining structures.It compares and analyzes the mechanical features and interaction mechanisms of reinforced and unreinforced secondary linings.Results show that in such structures,segmental linings bear the main load,and secondary linings offer extra support and adjust deformation.Reinforcement in secondary linings affects the constraint on segmental linings.Reinforcement enhances overall performance significantly.Although it has little impact on ultimate bearing capacity,it prolongs the load-bearing process.Specifically,it increases the ultimate bearing capacity of segmental and secondary linings by 21.2%and 26.1%,respectively.For 10-m-diameter shield tunnels,secondary lining reinforcement design should be adopted when the equivalent overburden thickness at the tunnel crown exceeds three times the tunnel diameter.
文摘The main concern of this paper is to provide an extensive study for the structural behavior of low/medium/high rise office buildings aiming to deepen structure and architect designers understanding for such type of buildings. The study is performed on reinforced concrete and emphasized only on Kuwait city conditions for wind. Regular layout plan building with different heights ranging from five to fifty typical office stories are investigated in this study. Three dimensional finite element techniques through ETABS software are used in conducting analysis for structures presented here-in. A serviceability study is performed to ensure that buildings have sufficient stability to limit lateral drift and peak acceleration within the acceptable range of occupancy comfort. In addition, an ultimate strength study is carried out to design and verify that all the structural elements are designed to withstand factored gravity and lateral loadings in a safe manner according to the international building codes. The building slenderness ratio and the building core size and location are the studied parameters since they are the key drivers for the efficient structural design. Analysis results are presented and discussed and finally conclusions are summarized as guidelines for designers of concrete office buildings in Kuwait.
文摘The main concern of this paper is to study the influence of the building slenderness ratio on the structural behavior of the residential concrete tall buildings aiming to deepen structure and architect designers understanding for such type of buildings. The study is emphasized only on Kuwait city design conditions for wind and seismic loadings. The paper presents an actual case study for adding two thirty stories residential towers with two different slenderness ratios to an existing residential complex. Wind loading is considered using both code values and wind tunnel results. Three dimensional finite element techniques through ETABS software are used in conducting analysis for structures presented here. A serviceability study is performed to ensure that buildings have sufficient stability to limit lateral drift and peak acceleration within the acceptable range of occupancy comfort. In addition, an ultimate strength study is carried out to verify that all the structural elements are designed to withstand factored gravity and lateral loads in a safe manner according to the international building codes. Analysis results are presented and discussed. A brief idea about foundation design of the new towers and its connection to the existing foundation is presented. Finally conclusions are summarized as guidelines for the structural professions of concrete residential tall buildings.
