In recent years, China's construction industry has been developing very rapidly. At the same time, many new construction technologies have emerged, among which the deep foundation pit supporting technology, as a c...In recent years, China's construction industry has been developing very rapidly. At the same time, many new construction technologies have emerged, among which the deep foundation pit supporting technology, as a construction technology with obvious advantages, plays a significant role in the foundation pit supporting construction. Foundation and various foundation constructions have an important impact on the overall quality of the project. Therefore, in order to fully guarantee the quality of foundation and foundation construction and the quality of the overall construction project, it is necessary to continuously strengthen the deep foundation pit support technology, select the appropriate construction technology scheme according to the actual situation of the project, and carry out detailed management on the key points of deep foundation pit support, so as to ensure the smooth development of the deep foundation pit support technology to the greatest extent and provide a solid and reliable guarantee for the quality of the whole project. Therefore, in this paper, we take the actual case as the basis to carry on the detailed analysis and the discussion to the construction project foundation pit support construction key point, for the reference.展开更多
The increasing occurrence of sinkholes caused by water main bursts has attracted significant research attention in recent years.This study addresses the gap in evaluating soil blowout stability resulting from water ma...The increasing occurrence of sinkholes caused by water main bursts has attracted significant research attention in recent years.This study addresses the gap in evaluating soil blowout stability resulting from water main failures by investigating the three-dimensional stability of blowouts with circular,hemispherical,and spherical openings.Advanced finite element limit analysis(FELA)combined with adaptive meshing is employed to analyze critical factors,including soil cover depth,surcharge pressure,and internal water pressure,that contribute to blowout failure.In addition,dimensionless ratios are used throughout the paper to assess the influence of these factors.Numerical findings are rigorously validated,ensuring reliability and accuracy.Practical design charts are provided to accommodate a wide range of design scenarios,offering valuable guidance for engineers.This study introduces a pioneering sinkhole simulation methodology,leading to the understanding of three-dimensional blowout stability mechanisms.展开更多
In this paper,Isogeometric analysis(IGA)is effectively integrated with machine learning(ML)to investigate the bearing capacity of strip footings in layered soil profiles,with a focus on a sand-over-clay configuration....In this paper,Isogeometric analysis(IGA)is effectively integrated with machine learning(ML)to investigate the bearing capacity of strip footings in layered soil profiles,with a focus on a sand-over-clay configuration.The study begins with the generation of a comprehensive dataset of 10,000 samples from IGA upper bound(UB)limit analyses,facilitating an in-depth examination of various material and geometric conditions.A hybrid deep neural network,specifically the Whale Optimization Algorithm-Deep Neural Network(WOA-DNN),is then employed to utilize these 10,000 outputs for precise bearing capacity predictions.Notably,the WOA-DNN model outperforms conventional ML techniques,offering a robust and accurate prediction tool.This innovative approach explores a broad range of design parameters,including sand layer depth,load-to-soil unit weight ratio,internal friction angle,cohesion,and footing roughness.A detailed analysis of the dataset reveals the significant influence of these parameters on bearing capacity,providing valuable insights for practical foundation design.This research demonstrates the usefulness of data-driven techniques in optimizing the design of shallow foundations within layered soil profiles,marking a significant stride in geotechnical engineering advancements.展开更多
In this paper,the dynamic response of a fixed offshore platform subjected to the underwater explosion(UNDEX)and probable events following it have been investigated.The pressure load due to UNDEX in a specified depth h...In this paper,the dynamic response of a fixed offshore platform subjected to the underwater explosion(UNDEX)and probable events following it have been investigated.The pressure load due to UNDEX in a specified depth has been applied with a model that considers the effect of blast bubble fluctuations into account.The effect of water on the natural frequency and Fluid-Structure interaction has been modeled as equivalent added mass formulation.The effect of explosion distance on platform response is studied.In this regard,three cases of near,medium,and far-distance explosions are considered.For a case study,a real fixed offshore jacket platform,installed in the Persian Gulf,has been examined.Only the UNDEX pressure load is considered and other dynamic loads such as surface water waves and winds have been neglected.Dead loads,live loads and hydrostatic pressure has been considered in the static case based on the design codes.The results indicated that in near-distance explosions,the UNDEX pressure load can locally damage parts of the platform that are located at the same level as that of explosive material and it can destabilize the platform.In the medium to far distance explosion,a very large base shear was applied to the platform because more elements were exposed to the UNDEX load compared to the near-distance explosion.Therefore,precautionary measures against UNDEX such as risk assessment according to design codes are necessary.As a result of this,member strengthening against explosion may be required.展开更多
Immunization and upgrading of structures are for the prevention of physical and financial losses due to earthquake. The importance of structures is not the same regarding the physical and financial losses caused by th...Immunization and upgrading of structures are for the prevention of physical and financial losses due to earthquake. The importance of structures is not the same regarding the physical and financial losses caused by the earthquake damage, although the responsibility to improve and secure them in terms of providing financing according to the type of ownership is different. The formulation of rules, regulations and necessary letters, the supervision over the various stages of immunization, and the establishment of appropriate facilities are in accordance with the financial and executive capacity of the country, the prioritization and preparation of a major plan for the improvement and securing of government responsibilities. Old buildings in worn-out textures generally have a wall system without vertical and horizontal shafts. The experiences from Boijin Zahra, Tabas, Rudbar and Bam earthquakes indicate that the destruction of such buildings in the time of devastating shakes is definite. The importance of structures is not the same considering the physical and financial losses caused by the earthquake damage. The principal destruction and rehabilitation for prevention of physical and financial losses due to the earthquake in terms of providing financing and according to the type of ownership varies, and this requires a rebuild time and high costs for the employer. Therefore, it is recommended that according to the conditions of the buildings of the country, arrangements and decisions, whether for financial facilities, etc. are considered so that everyone can carry out the executive steps of the safe room according to their existing structures.展开更多
We investigate the approximate solution of the Dirac equation for energy-dependent pseudoharmonic and Mie-type potentials under the pseudospin and spin symmetries using the supersymmetry quantum mechanics. We obtain t...We investigate the approximate solution of the Dirac equation for energy-dependent pseudoharmonic and Mie-type potentials under the pseudospin and spin symmetries using the supersymmetry quantum mechanics. We obtain the bound-state energy equation in an analytical manner and comment on the system behavior via various figures and tables.展开更多
Polypropylene(PP) fibres have primarily used to control shrinkage cracks or mitigate explosive spalling in concrete structures exposed to fire or subjected to impact/blast loads, with limited investigations on capacit...Polypropylene(PP) fibres have primarily used to control shrinkage cracks or mitigate explosive spalling in concrete structures exposed to fire or subjected to impact/blast loads, with limited investigations on capacity improvement. This study unveils the possibility of using PP micro-fibres to improve the impact behaviour of fibre-reinforced ultra-high-performance concrete(FRUHPC) columns. Results show that the addition of fibres significantly improves the impact behaviour of FRUHPC columns by shifting the failure mechanism from brittle shear to favourable flexural failure. The addition of steel or PP fibres affected the impact responses differently. Steel fibres considerably increased the peak impact force(up to 18%) while PP micro-fibres slightly increased the peak(3%-4%). FRUHPC significantly reduced the maximum midheight displacement by up to 30%(under 20°impact) and substantially improved the displacement recovery by up to 100%(under 20° impact). FRUHPC with steel fibres significantly improved the energy absorption while those with PP micro-fibres reduced the energy absorption, which is different from the effect of PP-macro fibre reported in the literature. The optimal fibre content for micro-PP fibres is 1% due to its minimal fibre usage and low peak and residual displacement. This study highlights the potential of FRUHPC as a promising material for impact-resistant structures by creating a more favourable flexural failure mechanism, enhancing ductility and toughness under impact loading, and advancing the understanding of the role of fibres in structural performance.展开更多
The excavation of deep foundation pits can cause variations in the displacement and stress fields of surrounding soils, which hence induces adverse effects on adjacent structures. This study presents a two-stage metho...The excavation of deep foundation pits can cause variations in the displacement and stress fields of surrounding soils, which hence induces adverse effects on adjacent structures. This study presents a two-stage method to quantify the impact of the excavation of a deep foundation pit on the adjacent double-curved arch bridge in the historical city of Nanjing, Southeastern China. The entire process of the foundation pit excavation was simulated and the induced deformation of the arch foot was obtained in the first stage by hardening soil model with small-strain stiffness. Then, the obtained deformation of the arch foot was applied to the bridge structure as a displacement boundary in the second stage to calculate the internal forces and deformations of the double-curved arch bridge structure. The tensile strength of concrete is taken as the limit value of the tensile stress of the double-curved arch bridge. The limit values of arch foot displacement under four evaluation conditions are obtained by step loading calculation. The present results provide construction guidance and safety warning for the process of foundation pit excavation adjacent to double-curved arch bridges for historical preservation.展开更多
Concrete expansion and cracking at high altitudes present persistent challenges in construction,primarily due to extreme solar radiation and low night temperatures.Current mitigation strategies largely overlook energy...Concrete expansion and cracking at high altitudes present persistent challenges in construction,primarily due to extreme solar radiation and low night temperatures.Current mitigation strategies largely overlook energy regulation,relying instead on material modification and subsequent repair.However,these approaches fail to address the root cause of thermal cracking:Excessive temperature gradient within the concrete and constant temperature stress fluctuations.Recognizing that mitigating the excessive solar energy input at high altitudes is the key to solving this problem,this study introduces a highaltitude anti-cracking coating(HAAC)designed to leverage radiative cooling technology.The coating employs an innovative cooling strategy to reduce the temperature gradient and mitigate stress fluctuations in the concrete from the source successfully achieving zero-energy thermal protection for the concrete.Preliminary outdoor cooling tests,high-altitude concrete thermal protection tests,and thermal stress analyses were conducted on these materials.The results show that the application of HAAC to the concrete substrate reduced the maximum temperature by 9.9℃,decreased the day-night temperature differential by 10℃,lowered the surface thermal stress by 1.1 MPa,and limited the maximum thermal stress to only 1.9 MPa.Additionally,HAAC exhibited good weathering resistance,offering long-term thermal protection to concrete.These attributes make HAAC suitable for large-scale construction projects in high-altitude areas.展开更多
Trenchless technology is often used in congested urban areas or river crossings to install underground pipelines to minimize disturbance to surface traffic or other activities.Pipe jacking is a typical technique appli...Trenchless technology is often used in congested urban areas or river crossings to install underground pipelines to minimize disturbance to surface traffic or other activities.Pipe jacking is a typical technique applied to jack pipe segments between two working shafts.However,the design of the jacking force is usually implemented using empirical methods.It should be emphasized that the jacking force will change for each site,depending on the magnitude of overcut,lubricants,work stoppages,geology and misalignment.A particle method is proposed to estimate the jacking force along the pipe.The microparameters are calibrated for sandy soils in Shenyang,so that the macroscale material behavior can be reproduced using the particle model.Hence,the normal force around the pipe circumference can be derived in the particle model,after which the interface friction coefficient is applied to evaluate the friction resistance mobilized at the soil-pipe interface.A modified Protodyakonov’s arch model can be used to assess the magnitude of earth pressure acting on the shield face.In the end,the combination of friction resistance and face pressure provides the jacking force.The efficacy of the proposed particle method is demonstrated by comparing calculated jacking forces with those measured in the field for three types of jacking machines in sandy soils under the Hun River,Shenyang.展开更多
We investigate the approximate solution of the Dirac equation for a combination of Mobius square and Mie type potentials under the pseudospin symmetry limit by using supersymmetry quantum mechanics. We obtain the boun...We investigate the approximate solution of the Dirac equation for a combination of Mobius square and Mie type potentials under the pseudospin symmetry limit by using supersymmetry quantum mechanics. We obtain the bound-state energy equation and the corresponding spinor wave functions in an approximate analytical manner. We comment on the system via various useful figures and tables.展开更多
In sugar industries,the growing amount of sugarcane bagasse ash(SBA),a byproduct released after burning bagasse for producing electricity,is currently causing environmental pollution.The residual ash displays a pozzol...In sugar industries,the growing amount of sugarcane bagasse ash(SBA),a byproduct released after burning bagasse for producing electricity,is currently causing environmental pollution.The residual ash displays a pozzolanic potential;and hence,it has potential as a cement addictive.This study focuses on enhancing suitability of SBA through incorporating ground blast furnace slag(BFS)in manufacturing self-compacting concretes(SCCs).For this purpose,SBA was processed by burning at 700°C for 1 h,before being ground to the cement fineness of 4010 cm2/g.SCC mixtures were prepared by changing the proportions of SBA and BFS(i.e.,10%,20%,and 30%)in blended systems;and their performance was investigated.Test results showed that the presence of amorphous silica was detected for the processed SBA,revealing that the strength activity index was above 80%.The compressive strength of SCC containing SBA(without BFS)could reach 98%–127%of that of the control;combination of SBA and 30%BFS gets a similar strength to the control after 28 d.Regarding durability,the 10%SBA+30%BFS mix exhibited the lowest risk of corrosion.Moreover,the joint use of SBA and BFS enhanced significantly the SCC’s sulfate resistance.Finally,a hyperbolic formula for interpolating the compressive strength of the SBA-based SCC was proposed and validated with error range estimated within±10%.展开更多
The scouring phenomenon is one of the major problems experienced in hydraulic engineering.In this study,an adaptive neuro-fuzzy inference system is hybridized with several evolutionary approaches,including the ant col...The scouring phenomenon is one of the major problems experienced in hydraulic engineering.In this study,an adaptive neuro-fuzzy inference system is hybridized with several evolutionary approaches,including the ant colony optimization,genetic algorithm,teaching-learning-based optimization,biogeographical-based optimization,and invasive weed optimization for estimating the long contraction scour depth.The proposed hybrid models are built using non-dimensional information collected from previous studies.The proposed hybrid intelligent models are evaluated using several statistical performance metrics and graphical presentations.Besides,the uncertainty of models,variables,and data are inspected.Based on the achieved modeling results,adaptive neuro-fuzzy inference system-biogeographic based optimization(ANFIS-BBO)provides superior prediction accuracy compared to others,with a maximum correlation coefficient(R_(test)=0.923)and minimum root mean square error value(RMSE_(test)=0.0193).Thus,the proposed ANFIS-BBO is a capable cost-effective method for predicting long contraction scouring,thus,contributing to the base knowledge of hydraulic structure sustainability.展开更多
文摘In recent years, China's construction industry has been developing very rapidly. At the same time, many new construction technologies have emerged, among which the deep foundation pit supporting technology, as a construction technology with obvious advantages, plays a significant role in the foundation pit supporting construction. Foundation and various foundation constructions have an important impact on the overall quality of the project. Therefore, in order to fully guarantee the quality of foundation and foundation construction and the quality of the overall construction project, it is necessary to continuously strengthen the deep foundation pit support technology, select the appropriate construction technology scheme according to the actual situation of the project, and carry out detailed management on the key points of deep foundation pit support, so as to ensure the smooth development of the deep foundation pit support technology to the greatest extent and provide a solid and reliable guarantee for the quality of the whole project. Therefore, in this paper, we take the actual case as the basis to carry on the detailed analysis and the discussion to the construction project foundation pit support construction key point, for the reference.
文摘The increasing occurrence of sinkholes caused by water main bursts has attracted significant research attention in recent years.This study addresses the gap in evaluating soil blowout stability resulting from water main failures by investigating the three-dimensional stability of blowouts with circular,hemispherical,and spherical openings.Advanced finite element limit analysis(FELA)combined with adaptive meshing is employed to analyze critical factors,including soil cover depth,surcharge pressure,and internal water pressure,that contribute to blowout failure.In addition,dimensionless ratios are used throughout the paper to assess the influence of these factors.Numerical findings are rigorously validated,ensuring reliability and accuracy.Practical design charts are provided to accommodate a wide range of design scenarios,offering valuable guidance for engineers.This study introduces a pioneering sinkhole simulation methodology,leading to the understanding of three-dimensional blowout stability mechanisms.
文摘In this paper,Isogeometric analysis(IGA)is effectively integrated with machine learning(ML)to investigate the bearing capacity of strip footings in layered soil profiles,with a focus on a sand-over-clay configuration.The study begins with the generation of a comprehensive dataset of 10,000 samples from IGA upper bound(UB)limit analyses,facilitating an in-depth examination of various material and geometric conditions.A hybrid deep neural network,specifically the Whale Optimization Algorithm-Deep Neural Network(WOA-DNN),is then employed to utilize these 10,000 outputs for precise bearing capacity predictions.Notably,the WOA-DNN model outperforms conventional ML techniques,offering a robust and accurate prediction tool.This innovative approach explores a broad range of design parameters,including sand layer depth,load-to-soil unit weight ratio,internal friction angle,cohesion,and footing roughness.A detailed analysis of the dataset reveals the significant influence of these parameters on bearing capacity,providing valuable insights for practical foundation design.This research demonstrates the usefulness of data-driven techniques in optimizing the design of shallow foundations within layered soil profiles,marking a significant stride in geotechnical engineering advancements.
文摘In this paper,the dynamic response of a fixed offshore platform subjected to the underwater explosion(UNDEX)and probable events following it have been investigated.The pressure load due to UNDEX in a specified depth has been applied with a model that considers the effect of blast bubble fluctuations into account.The effect of water on the natural frequency and Fluid-Structure interaction has been modeled as equivalent added mass formulation.The effect of explosion distance on platform response is studied.In this regard,three cases of near,medium,and far-distance explosions are considered.For a case study,a real fixed offshore jacket platform,installed in the Persian Gulf,has been examined.Only the UNDEX pressure load is considered and other dynamic loads such as surface water waves and winds have been neglected.Dead loads,live loads and hydrostatic pressure has been considered in the static case based on the design codes.The results indicated that in near-distance explosions,the UNDEX pressure load can locally damage parts of the platform that are located at the same level as that of explosive material and it can destabilize the platform.In the medium to far distance explosion,a very large base shear was applied to the platform because more elements were exposed to the UNDEX load compared to the near-distance explosion.Therefore,precautionary measures against UNDEX such as risk assessment according to design codes are necessary.As a result of this,member strengthening against explosion may be required.
文摘Immunization and upgrading of structures are for the prevention of physical and financial losses due to earthquake. The importance of structures is not the same regarding the physical and financial losses caused by the earthquake damage, although the responsibility to improve and secure them in terms of providing financing according to the type of ownership is different. The formulation of rules, regulations and necessary letters, the supervision over the various stages of immunization, and the establishment of appropriate facilities are in accordance with the financial and executive capacity of the country, the prioritization and preparation of a major plan for the improvement and securing of government responsibilities. Old buildings in worn-out textures generally have a wall system without vertical and horizontal shafts. The experiences from Boijin Zahra, Tabas, Rudbar and Bam earthquakes indicate that the destruction of such buildings in the time of devastating shakes is definite. The importance of structures is not the same considering the physical and financial losses caused by the earthquake damage. The principal destruction and rehabilitation for prevention of physical and financial losses due to the earthquake in terms of providing financing and according to the type of ownership varies, and this requires a rebuild time and high costs for the employer. Therefore, it is recommended that according to the conditions of the buildings of the country, arrangements and decisions, whether for financial facilities, etc. are considered so that everyone can carry out the executive steps of the safe room according to their existing structures.
文摘We investigate the approximate solution of the Dirac equation for energy-dependent pseudoharmonic and Mie-type potentials under the pseudospin and spin symmetries using the supersymmetry quantum mechanics. We obtain the bound-state energy equation in an analytical manner and comment on the system behavior via various figures and tables.
基金the financial support from Australian Research Council(ARC)(Grant No.DP220100307).
文摘Polypropylene(PP) fibres have primarily used to control shrinkage cracks or mitigate explosive spalling in concrete structures exposed to fire or subjected to impact/blast loads, with limited investigations on capacity improvement. This study unveils the possibility of using PP micro-fibres to improve the impact behaviour of fibre-reinforced ultra-high-performance concrete(FRUHPC) columns. Results show that the addition of fibres significantly improves the impact behaviour of FRUHPC columns by shifting the failure mechanism from brittle shear to favourable flexural failure. The addition of steel or PP fibres affected the impact responses differently. Steel fibres considerably increased the peak impact force(up to 18%) while PP micro-fibres slightly increased the peak(3%-4%). FRUHPC significantly reduced the maximum midheight displacement by up to 30%(under 20°impact) and substantially improved the displacement recovery by up to 100%(under 20° impact). FRUHPC with steel fibres significantly improved the energy absorption while those with PP micro-fibres reduced the energy absorption, which is different from the effect of PP-macro fibre reported in the literature. The optimal fibre content for micro-PP fibres is 1% due to its minimal fibre usage and low peak and residual displacement. This study highlights the potential of FRUHPC as a promising material for impact-resistant structures by creating a more favourable flexural failure mechanism, enhancing ductility and toughness under impact loading, and advancing the understanding of the role of fibres in structural performance.
基金funded by the National Natural Science Foundation of China(Grant Nos.52308341 and 52178384).
文摘The excavation of deep foundation pits can cause variations in the displacement and stress fields of surrounding soils, which hence induces adverse effects on adjacent structures. This study presents a two-stage method to quantify the impact of the excavation of a deep foundation pit on the adjacent double-curved arch bridge in the historical city of Nanjing, Southeastern China. The entire process of the foundation pit excavation was simulated and the induced deformation of the arch foot was obtained in the first stage by hardening soil model with small-strain stiffness. Then, the obtained deformation of the arch foot was applied to the bridge structure as a displacement boundary in the second stage to calculate the internal forces and deformations of the double-curved arch bridge structure. The tensile strength of concrete is taken as the limit value of the tensile stress of the double-curved arch bridge. The limit values of arch foot displacement under four evaluation conditions are obtained by step loading calculation. The present results provide construction guidance and safety warning for the process of foundation pit excavation adjacent to double-curved arch bridges for historical preservation.
基金supported by the National Natural Science Foundation of China(Grant No.52476067)the Heilongjiang Province's Key Research and Development Project:“Leading the Charge with Open Competition”(Grant No.2023ZXJ06A04)。
文摘Concrete expansion and cracking at high altitudes present persistent challenges in construction,primarily due to extreme solar radiation and low night temperatures.Current mitigation strategies largely overlook energy regulation,relying instead on material modification and subsequent repair.However,these approaches fail to address the root cause of thermal cracking:Excessive temperature gradient within the concrete and constant temperature stress fluctuations.Recognizing that mitigating the excessive solar energy input at high altitudes is the key to solving this problem,this study introduces a highaltitude anti-cracking coating(HAAC)designed to leverage radiative cooling technology.The coating employs an innovative cooling strategy to reduce the temperature gradient and mitigate stress fluctuations in the concrete from the source successfully achieving zero-energy thermal protection for the concrete.Preliminary outdoor cooling tests,high-altitude concrete thermal protection tests,and thermal stress analyses were conducted on these materials.The results show that the application of HAAC to the concrete substrate reduced the maximum temperature by 9.9℃,decreased the day-night temperature differential by 10℃,lowered the surface thermal stress by 1.1 MPa,and limited the maximum thermal stress to only 1.9 MPa.Additionally,HAAC exhibited good weathering resistance,offering long-term thermal protection to concrete.These attributes make HAAC suitable for large-scale construction projects in high-altitude areas.
文摘Trenchless technology is often used in congested urban areas or river crossings to install underground pipelines to minimize disturbance to surface traffic or other activities.Pipe jacking is a typical technique applied to jack pipe segments between two working shafts.However,the design of the jacking force is usually implemented using empirical methods.It should be emphasized that the jacking force will change for each site,depending on the magnitude of overcut,lubricants,work stoppages,geology and misalignment.A particle method is proposed to estimate the jacking force along the pipe.The microparameters are calibrated for sandy soils in Shenyang,so that the macroscale material behavior can be reproduced using the particle model.Hence,the normal force around the pipe circumference can be derived in the particle model,after which the interface friction coefficient is applied to evaluate the friction resistance mobilized at the soil-pipe interface.A modified Protodyakonov’s arch model can be used to assess the magnitude of earth pressure acting on the shield face.In the end,the combination of friction resistance and face pressure provides the jacking force.The efficacy of the proposed particle method is demonstrated by comparing calculated jacking forces with those measured in the field for three types of jacking machines in sandy soils under the Hun River,Shenyang.
文摘We investigate the approximate solution of the Dirac equation for a combination of Mobius square and Mie type potentials under the pseudospin symmetry limit by using supersymmetry quantum mechanics. We obtain the bound-state energy equation and the corresponding spinor wave functions in an approximate analytical manner. We comment on the system via various useful figures and tables.
基金This research was funded by Vietnam National Foundation for Science and Technology Development(NAFOSTED)(No.107.01-2020.01).
文摘In sugar industries,the growing amount of sugarcane bagasse ash(SBA),a byproduct released after burning bagasse for producing electricity,is currently causing environmental pollution.The residual ash displays a pozzolanic potential;and hence,it has potential as a cement addictive.This study focuses on enhancing suitability of SBA through incorporating ground blast furnace slag(BFS)in manufacturing self-compacting concretes(SCCs).For this purpose,SBA was processed by burning at 700°C for 1 h,before being ground to the cement fineness of 4010 cm2/g.SCC mixtures were prepared by changing the proportions of SBA and BFS(i.e.,10%,20%,and 30%)in blended systems;and their performance was investigated.Test results showed that the presence of amorphous silica was detected for the processed SBA,revealing that the strength activity index was above 80%.The compressive strength of SCC containing SBA(without BFS)could reach 98%–127%of that of the control;combination of SBA and 30%BFS gets a similar strength to the control after 28 d.Regarding durability,the 10%SBA+30%BFS mix exhibited the lowest risk of corrosion.Moreover,the joint use of SBA and BFS enhanced significantly the SCC’s sulfate resistance.Finally,a hyperbolic formula for interpolating the compressive strength of the SBA-based SCC was proposed and validated with error range estimated within±10%.
文摘The scouring phenomenon is one of the major problems experienced in hydraulic engineering.In this study,an adaptive neuro-fuzzy inference system is hybridized with several evolutionary approaches,including the ant colony optimization,genetic algorithm,teaching-learning-based optimization,biogeographical-based optimization,and invasive weed optimization for estimating the long contraction scour depth.The proposed hybrid models are built using non-dimensional information collected from previous studies.The proposed hybrid intelligent models are evaluated using several statistical performance metrics and graphical presentations.Besides,the uncertainty of models,variables,and data are inspected.Based on the achieved modeling results,adaptive neuro-fuzzy inference system-biogeographic based optimization(ANFIS-BBO)provides superior prediction accuracy compared to others,with a maximum correlation coefficient(R_(test)=0.923)and minimum root mean square error value(RMSE_(test)=0.0193).Thus,the proposed ANFIS-BBO is a capable cost-effective method for predicting long contraction scouring,thus,contributing to the base knowledge of hydraulic structure sustainability.
