Login
Register
E-alert
2010 Vol. 40, No. 4
Display Method:
2010, 40(4): 1-4,16.
doi: 10.13204/j.gyjz201004001
Abstract:
Researchers all over the world have made a lot of experiments and theoretical studies on the overall performance and durability of concrete beams reinforced by FRP. But their studies mostly focused on the FRP such as CFRP and GFRP,there was little experiment study on the concrete structures reinforced by BFRP which has excellent cost performance. Based on the above factors ,a total of 18 concrete beams were tested respectively in nature environment and salt spray environment under the conditions of different initial loads,the result shows that different initial loads have little effect on beams reinforced by FRP, contrast with salt spray environment and nature environment it is found that the concrete beam reinforced by FRP has good resistance to salt spray corrosion.
Researchers all over the world have made a lot of experiments and theoretical studies on the overall performance and durability of concrete beams reinforced by FRP. But their studies mostly focused on the FRP such as CFRP and GFRP,there was little experiment study on the concrete structures reinforced by BFRP which has excellent cost performance. Based on the above factors ,a total of 18 concrete beams were tested respectively in nature environment and salt spray environment under the conditions of different initial loads,the result shows that different initial loads have little effect on beams reinforced by FRP, contrast with salt spray environment and nature environment it is found that the concrete beam reinforced by FRP has good resistance to salt spray corrosion.
2010, 40(4): 5-8,26.
doi: 10.13204/j.gyjz201004002
Abstract:
In order to investigate the law of properties' change for BFRP sheet under the condition of wet-dry cycling seawater,ageing tests were done for a total of 90 specimens impregnated by two different resins under the conditions of 3.5 times and 5 times concentration of artificial wet-dry cycling seawater. The results show that BFRP1 in 3.5times concentration seawater for 330 d,the tensile strength and extensibility are respectively dropped by 8.36% and 28.74% ,and the Young's modulus is increased by 1.68% ; BFRP1 in 5 times concentration seawater for 330 d,the tensile strength and extensibility are respectively dropped by 12.77% and 26.304% ,and the Young's modulus is increased by 3.24% ; BFRP2 in 3.5 times concentration seawater for 330 d,the tensile strength and extensibility are respectively dropped by 9.50% and 18.44% ,and the Young's modulus is increased by 0.43% ,BFRP2 in 5 times concentration seawater for 330 d,the tensile strength ,extensibility and the Young's modulus are respectively dropped by 8.53% ,20. 88% and 0.43% . Therefore,BFRP sheet has good resistance to seawater corrosion . Finally,contrast with other fiber sheets' aging experiment like CFRP,AFRP,GFRP and so on,it is shown that the basaltreinforced composite material has good resistance to seawater corrosion.
In order to investigate the law of properties' change for BFRP sheet under the condition of wet-dry cycling seawater,ageing tests were done for a total of 90 specimens impregnated by two different resins under the conditions of 3.5 times and 5 times concentration of artificial wet-dry cycling seawater. The results show that BFRP1 in 3.5times concentration seawater for 330 d,the tensile strength and extensibility are respectively dropped by 8.36% and 28.74% ,and the Young's modulus is increased by 1.68% ; BFRP1 in 5 times concentration seawater for 330 d,the tensile strength and extensibility are respectively dropped by 12.77% and 26.304% ,and the Young's modulus is increased by 3.24% ; BFRP2 in 3.5 times concentration seawater for 330 d,the tensile strength and extensibility are respectively dropped by 9.50% and 18.44% ,and the Young's modulus is increased by 0.43% ,BFRP2 in 5 times concentration seawater for 330 d,the tensile strength ,extensibility and the Young's modulus are respectively dropped by 8.53% ,20. 88% and 0.43% . Therefore,BFRP sheet has good resistance to seawater corrosion . Finally,contrast with other fiber sheets' aging experiment like CFRP,AFRP,GFRP and so on,it is shown that the basaltreinforced composite material has good resistance to seawater corrosion.
2010, 40(4): 9-12.
doi: 10.13204/j.gyjz201004003
Abstract:
As a complex material,infused resin is an important part of FRP. So durability of resin and fiber sheets may have straight influence on aging resistant capability of FRP. Two groups of resin and basalt fiber components are put into natural environment and salt fog environment respectively for 60 d. The strength and extensibility of resin had dropped. The strength,the Young's modulus and the extensibility of BFRP sheets hadn't changed.
As a complex material,infused resin is an important part of FRP. So durability of resin and fiber sheets may have straight influence on aging resistant capability of FRP. Two groups of resin and basalt fiber components are put into natural environment and salt fog environment respectively for 60 d. The strength and extensibility of resin had dropped. The strength,the Young's modulus and the extensibility of BFRP sheets hadn't changed.
2010, 40(4): 13-16.
doi: 10.13204/j.gyjz201004004
Abstract:
In order to study the durability of BFRP sheets under the conditions of ultraviolet light,ageing tests were done for a total of 70 BFRP sheets specimens impregnated by two different resins under the conditions of protection and without protection. The preliminary test results after 6464 h indicate that for BFRP1 under the conditions without protection,the tensile strength is decreased by 11.03% ,the extensibility is declined by 14.75% ,and Young's modulus is dropped by 5.23% ;while for BFRP2,the tensile strength is decreased by 2. 02% ,extensibility is declined by 13.73% ,and Young's modulus is increased by 0.34% ;under the conditions with protection,the tensile strength,extensibility and Young's modulus of BFRP1 is respectively dropped by 8.01% ,16.57% and 1.38% ; while the tensile strength,extensibility,and Young's modulus of BFRP2 are respectively dropped by 1.51% ,9.59% and 5.60%. Therefore,BFRP sheets have good durability under the ultraviolet light,protection has a protective effect on the properties of BFRP sheets.
In order to study the durability of BFRP sheets under the conditions of ultraviolet light,ageing tests were done for a total of 70 BFRP sheets specimens impregnated by two different resins under the conditions of protection and without protection. The preliminary test results after 6464 h indicate that for BFRP1 under the conditions without protection,the tensile strength is decreased by 11.03% ,the extensibility is declined by 14.75% ,and Young's modulus is dropped by 5.23% ;while for BFRP2,the tensile strength is decreased by 2. 02% ,extensibility is declined by 13.73% ,and Young's modulus is increased by 0.34% ;under the conditions with protection,the tensile strength,extensibility and Young's modulus of BFRP1 is respectively dropped by 8.01% ,16.57% and 1.38% ; while the tensile strength,extensibility,and Young's modulus of BFRP2 are respectively dropped by 1.51% ,9.59% and 5.60%. Therefore,BFRP sheets have good durability under the ultraviolet light,protection has a protective effect on the properties of BFRP sheets.
2010, 40(4): 17-21,38.
doi: 10.13204/j.gyjz201004005
Abstract:
Tension tests were carried out for a total of 39 basalt fiber reinforced polymer (BFRP) sheet specimens subjected to freeze-thaw cycles and freeze-thaw cycles-sodium chloride solution. The law of BFRP composites performance deterioration ,the effects of different environmental conditions and exposure time on durability of BFRP composites were studied. The experimental results indicate that tensile strength and elongation decrease and elastic modulus increases when subjected to the two test environments. Single environment shows more effect on BFRP tensile strength than compound environment. Compound environment shows more effect on BFRP elongation and elastic modulus than single environment. The result indicate that compound environment is more easier to cause material embrittlement than single environment. At last,a grey forecast model of BFRP relative tensile strength under environmental effect is presented.
Tension tests were carried out for a total of 39 basalt fiber reinforced polymer (BFRP) sheet specimens subjected to freeze-thaw cycles and freeze-thaw cycles-sodium chloride solution. The law of BFRP composites performance deterioration ,the effects of different environmental conditions and exposure time on durability of BFRP composites were studied. The experimental results indicate that tensile strength and elongation decrease and elastic modulus increases when subjected to the two test environments. Single environment shows more effect on BFRP tensile strength than compound environment. Compound environment shows more effect on BFRP elongation and elastic modulus than single environment. The result indicate that compound environment is more easier to cause material embrittlement than single environment. At last,a grey forecast model of BFRP relative tensile strength under environmental effect is presented.
2010, 40(4): 22-26.
doi: 10.13204/j.gyjz201004006
Abstract:
This paper makes an experiment research of mechanical performance of three kinds of CFRP (CS-1+RE-1,CS-1+RE-2,and CB-1) and two resins (RE-1 and RE-2) after three years aging in natural environment of southeast region. It can be inferred from the experiment result that the changing mechanical performance of CFRP is small and the durability is good,while the environment effects of two other resins are obvious,the deterioration is fast and the durability is poor. But the changing of resins' performance doesn't have a great effect on CFRP,because the mechanical performance of composite material is mainly depended on the carbon fiber sheets.
This paper makes an experiment research of mechanical performance of three kinds of CFRP (CS-1+RE-1,CS-1+RE-2,and CB-1) and two resins (RE-1 and RE-2) after three years aging in natural environment of southeast region. It can be inferred from the experiment result that the changing mechanical performance of CFRP is small and the durability is good,while the environment effects of two other resins are obvious,the deterioration is fast and the durability is poor. But the changing of resins' performance doesn't have a great effect on CFRP,because the mechanical performance of composite material is mainly depended on the carbon fiber sheets.
2010, 40(4): 27-32.
doi: 10.13204/j.gyjz201004007
Abstract:
The temperature-humidity cycle's action is one of major factors,which causing the deterioration of concrete structures,especially in the high temperature-humidity areas of the south of China. In this study,the influence of temperature-humidity cycles on mechanical behavior of concrete beams strengthened by carbon fiber reinforced plastics is explored,and crack phenomena are observed of concrete beams based on the fast temperaturehumidity tests. Moreover,the destructive pattern of concrete beams strengthened by CFRP with the temperaturehumidity cycle's action is analyzed. The test results are compared with experimental data under normal environmental condition,by which the deterioration mechanism of mechanical properties, and influenced degree of concrete structures strengthened by CFRP with temperature-humidity cycle's action are obtained.
The temperature-humidity cycle's action is one of major factors,which causing the deterioration of concrete structures,especially in the high temperature-humidity areas of the south of China. In this study,the influence of temperature-humidity cycles on mechanical behavior of concrete beams strengthened by carbon fiber reinforced plastics is explored,and crack phenomena are observed of concrete beams based on the fast temperaturehumidity tests. Moreover,the destructive pattern of concrete beams strengthened by CFRP with the temperaturehumidity cycle's action is analyzed. The test results are compared with experimental data under normal environmental condition,by which the deterioration mechanism of mechanical properties, and influenced degree of concrete structures strengthened by CFRP with temperature-humidity cycle's action are obtained.
2010, 40(4): 33-38.
doi: 10.13204/j.gyjz201004008
Abstract:
Based on the overall and times principle of design of re-constructed buildings in historic blocks,according to the role of the reconstructed buildings in historic blocks,the paper discussed the design elements including architectural patterns,architectural forms and construction technology. The paper put forward coordination of design strategy,variation of design strategy and integrated design strategy for the reconstructed buildings in historic blocks.
Based on the overall and times principle of design of re-constructed buildings in historic blocks,according to the role of the reconstructed buildings in historic blocks,the paper discussed the design elements including architectural patterns,architectural forms and construction technology. The paper put forward coordination of design strategy,variation of design strategy and integrated design strategy for the reconstructed buildings in historic blocks.
2010, 40(4): 39-41.
doi: 10.13204/j.gyjz201004009
Abstract:
It was expounded the design of the visiting space in a food products factory,which ernbodies the importance of a core place displaying corporation image and also disseminating corporation culture. It is expected that more and more architects would pay attention to the multivariate design of industrial architectures.
It was expounded the design of the visiting space in a food products factory,which ernbodies the importance of a core place displaying corporation image and also disseminating corporation culture. It is expected that more and more architects would pay attention to the multivariate design of industrial architectures.
2010, 40(4): 42-45.
doi: 10.13204/j.gyjz201004010
Abstract:
Response to thetwo-oriented society,this article proposes the goal of building and developing a city group which isenvironment-friendlyandresource conservational. Combining with the actual conditions of the project design,taking the advantage of theeco-architectureandappropriate technology,it is proposed a design frame platform of sustainable thinking,whose specific operations are explored initially.
Response to thetwo-oriented society,this article proposes the goal of building and developing a city group which isenvironment-friendlyandresource conservational. Combining with the actual conditions of the project design,taking the advantage of theeco-architectureandappropriate technology,it is proposed a design frame platform of sustainable thinking,whose specific operations are explored initially.
2010, 40(4): 46-50,83.
doi: 10.13204/j.gyjz201004011
Abstract:
With the development of the modern industry,abundant new type and high strength thin-walled shell structures were applied in most fields of military and civilized industry,therefore,it is necessary to enrich and perfect the theory for the calculation of the dynamic responses of the thin-walled shell under impact load. While the existing investigations on thin-walled shell are limited to staic situation based on numerical and approximate analytical methods,less researches were carried out on the dynamic responses of thin-walled shell under impact load. It is indicated that under the local action of the external impact,the radial oscillation of the thin-walled shell is nonperiodically,which agrees with its assumed frequency and periodicity. The stress state was also attenuated nonperiodically,which can be ordered by its extremes. The dynamic failure of the structure can be confirmed by two steps: Firstly, the strength properties of the structure were changed when the tension-compression plane wave propagated along the transverse direction. Secondly,the final failure of the structure occurred under the action of the flexure stresses.
With the development of the modern industry,abundant new type and high strength thin-walled shell structures were applied in most fields of military and civilized industry,therefore,it is necessary to enrich and perfect the theory for the calculation of the dynamic responses of the thin-walled shell under impact load. While the existing investigations on thin-walled shell are limited to staic situation based on numerical and approximate analytical methods,less researches were carried out on the dynamic responses of thin-walled shell under impact load. It is indicated that under the local action of the external impact,the radial oscillation of the thin-walled shell is nonperiodically,which agrees with its assumed frequency and periodicity. The stress state was also attenuated nonperiodically,which can be ordered by its extremes. The dynamic failure of the structure can be confirmed by two steps: Firstly, the strength properties of the structure were changed when the tension-compression plane wave propagated along the transverse direction. Secondly,the final failure of the structure occurred under the action of the flexure stresses.
2010, 40(4): 51-54,150.
doi: 10.13204/j.gyjz201004012
Abstract:
The performance-based seismic design is a developing trend of structure seismic design method. It is a revolution of the current seismic design procedures. This paper presents the performance objectives,performance levels,as well as the procedure to carry out the performance-based seismic design of mill building for conventional island of nuclear power plant. And seismic performance-based design method which is applied to mill building for conventional island of nuclear power plant is feasible according to a practical engineering case. The method and advice can be a reference to the engineering designers to design this kind of structures.
The performance-based seismic design is a developing trend of structure seismic design method. It is a revolution of the current seismic design procedures. This paper presents the performance objectives,performance levels,as well as the procedure to carry out the performance-based seismic design of mill building for conventional island of nuclear power plant. And seismic performance-based design method which is applied to mill building for conventional island of nuclear power plant is feasible according to a practical engineering case. The method and advice can be a reference to the engineering designers to design this kind of structures.
2010, 40(4): 55-59,74.
doi: 10.13204/j.gyjz201004013
Abstract:
TLD is an efficient passive control device for vibration energy-dissipating,whose rule and analysis design method have received much attention. Actually,the previous researches were mainly relied on?tests and have got fruitful achievements in the damping of vibration rule. Though the simplified analysis method of damping of vibration effect has also been developed based on those tests,its application has been greatly limited due to the rough models.Recently,with the development of computer technology,it is likely to do research into TLD numerical modeling analysis of fluid-structure interaction,which would become a valuable supplement. The fluid- structure interaction of general structural analysis software ADINA is applied to conduct the seismic response analysis of fluid-structure interaction in a high-rise frame structure controlled by installing TLD of roof tank. Meanwhile,earlier test rules and simplified methods are also compared and checked in this paper. Besides,the calculation and?modeling of fluidstructure interaction are initially explored and examined,whereby realizing the TLD numerical modeling of fluidstructures interaction as well as summarizing the TLD damping of vibration rule of high-rise frame structure.
TLD is an efficient passive control device for vibration energy-dissipating,whose rule and analysis design method have received much attention. Actually,the previous researches were mainly relied on?tests and have got fruitful achievements in the damping of vibration rule. Though the simplified analysis method of damping of vibration effect has also been developed based on those tests,its application has been greatly limited due to the rough models.Recently,with the development of computer technology,it is likely to do research into TLD numerical modeling analysis of fluid-structure interaction,which would become a valuable supplement. The fluid- structure interaction of general structural analysis software ADINA is applied to conduct the seismic response analysis of fluid-structure interaction in a high-rise frame structure controlled by installing TLD of roof tank. Meanwhile,earlier test rules and simplified methods are also compared and checked in this paper. Besides,the calculation and?modeling of fluidstructure interaction are initially explored and examined,whereby realizing the TLD numerical modeling of fluidstructures interaction as well as summarizing the TLD damping of vibration rule of high-rise frame structure.
2010, 40(4): 60-64.
doi: 10.13204/j.gyjz201004014
Abstract:
Four specimens of the T-shaped short-limbed shear wall were tested under low-frequency cyclic?lateral loading. The mechanical properties and failure modes of the T-shaped wall were analyzed based?on the experimental study. Nonlinear finite element analysis was carried out on T-shaped short-limbed shear wall through the finite element calculation software ANSYS. The calculated top force-displacement curves agree well with that of experiments,which indicate that the nonlinear FEA model is reasonable. The results show that?axial compression ratio and the reinforcement ratio of the web have remarkable effect on the short-limbed shear wall 's mechanical properties.Some researches are provided as a reference for the future design.
Four specimens of the T-shaped short-limbed shear wall were tested under low-frequency cyclic?lateral loading. The mechanical properties and failure modes of the T-shaped wall were analyzed based?on the experimental study. Nonlinear finite element analysis was carried out on T-shaped short-limbed shear wall through the finite element calculation software ANSYS. The calculated top force-displacement curves agree well with that of experiments,which indicate that the nonlinear FEA model is reasonable. The results show that?axial compression ratio and the reinforcement ratio of the web have remarkable effect on the short-limbed shear wall 's mechanical properties.Some researches are provided as a reference for the future design.
2010, 40(4): 65-69,41.
doi: 10.13204/j.gyjz201004015
Abstract:
Based on the laminated rubber bearing,the cellular laminated rubber bearing is the rubber bearing with holes. This article focuses on the cellular rubber bearings applied to Beijing Olympic Multifunctional Studio Tower.As a new type of rubber bearing,its vertical and horizontal stiffness have been studied through the mechanical properties experiments. At the same time,the finite element model of the cellular rubber bearing has been established and its mechanical properties have been analyzed with ANSYS. From this comparison,the finite element numerical simulation results agree with the experimental data in this study. Thus,it can provide reference for the design of cellular laminated rubber bearings.
Based on the laminated rubber bearing,the cellular laminated rubber bearing is the rubber bearing with holes. This article focuses on the cellular rubber bearings applied to Beijing Olympic Multifunctional Studio Tower.As a new type of rubber bearing,its vertical and horizontal stiffness have been studied through the mechanical properties experiments. At the same time,the finite element model of the cellular rubber bearing has been established and its mechanical properties have been analyzed with ANSYS. From this comparison,the finite element numerical simulation results agree with the experimental data in this study. Thus,it can provide reference for the design of cellular laminated rubber bearings.
2010, 40(4): 70-74.
doi: 10.13204/j.gyjz201004016
Abstract:
In order to investigate the seismic behavior of a concrete-filled GFRP (glass fiber reinforced polymer) tube structure,repeat low cycle loading tests are carried out on four concrete-filled GFRP tube columns and one RC column. The failure shape and hysteretic characteristics are researched,and factors such as concrete strength and the axial load ratio that affected ductility of the columns are analyzed. Researches show that the concrete-filled GFRP tube columns have excellent seismic behavior.
In order to investigate the seismic behavior of a concrete-filled GFRP (glass fiber reinforced polymer) tube structure,repeat low cycle loading tests are carried out on four concrete-filled GFRP tube columns and one RC column. The failure shape and hysteretic characteristics are researched,and factors such as concrete strength and the axial load ratio that affected ductility of the columns are analyzed. Researches show that the concrete-filled GFRP tube columns have excellent seismic behavior.
2010, 40(4): 75-78.
doi: 10.13204/j.gyjz201004017
Abstract:
Based on experimental research on plain concrete columns with high strength core,the formula to predict the bearing capacity of concrete columns with high strength core under axial compression load was brought forward in previous paper,in order to verify the formula whether right,axial compression tests including 3 concrete columns with high strength core and 1 general reinforced concrete column were completed in this paper, and the failure characteristic was analyzed additionally. According to experimental results,it can be shown that the failure modes of the concrete columns with high strength core are similar to those of general reinforced concrete columns,however,the bearing capacity of concrete columns with high strength core is significant high as compared with that of general reinforced concrete columns; the results of the bearing capacity obtained by the literature [3] was in good agreement with the experimental results.
Based on experimental research on plain concrete columns with high strength core,the formula to predict the bearing capacity of concrete columns with high strength core under axial compression load was brought forward in previous paper,in order to verify the formula whether right,axial compression tests including 3 concrete columns with high strength core and 1 general reinforced concrete column were completed in this paper, and the failure characteristic was analyzed additionally. According to experimental results,it can be shown that the failure modes of the concrete columns with high strength core are similar to those of general reinforced concrete columns,however,the bearing capacity of concrete columns with high strength core is significant high as compared with that of general reinforced concrete columns; the results of the bearing capacity obtained by the literature [3] was in good agreement with the experimental results.
2010, 40(4): 79-83.
doi: 10.13204/j.gyjz201004018
Abstract:
Based on load test of joint of shield tunneling lining,joint strength,force and deformation rule,the main influence factors of joint bending stiffness are studied. The results indicate that the segment joint local bearing capacity determines the integral bearing capacity of segment joint under positive eccentric load,the segment joint bearing capacity is sufficient and safe for negative eccentric load,and the joint displacement determines bearing capacity of segment joint for negative eccentric load. The eccentricity and axial force,the thickness of cushion and bolt pretension have great influence on joint bending stiffness of lining segment.
Based on load test of joint of shield tunneling lining,joint strength,force and deformation rule,the main influence factors of joint bending stiffness are studied. The results indicate that the segment joint local bearing capacity determines the integral bearing capacity of segment joint under positive eccentric load,the segment joint bearing capacity is sufficient and safe for negative eccentric load,and the joint displacement determines bearing capacity of segment joint for negative eccentric load. The eccentricity and axial force,the thickness of cushion and bolt pretension have great influence on joint bending stiffness of lining segment.
2010, 40(4): 84-87.
doi: 10.13204/j.gyjz201004019
Abstract:
According to the field test of caisson and rootstalk caisson under lateral static load,the behaviors of caisson and rootstalk foundation under lateral load are studied. At first,the caisson was loaded by the single cycle load holding method in the test. Then,the caisson was fitted on rootstalks and tested. The horizontal bearing capacities of the caisson and the rootstalk caisson were measured,and the deformation and caisson bending moment were obtained. The results of the experiment indicate that horizontal bearing capacity of the rootstalk caisson increased by nearly 60 percent. The effect of rootstalk is obvious when the horizontal force is great.
According to the field test of caisson and rootstalk caisson under lateral static load,the behaviors of caisson and rootstalk foundation under lateral load are studied. At first,the caisson was loaded by the single cycle load holding method in the test. Then,the caisson was fitted on rootstalks and tested. The horizontal bearing capacities of the caisson and the rootstalk caisson were measured,and the deformation and caisson bending moment were obtained. The results of the experiment indicate that horizontal bearing capacity of the rootstalk caisson increased by nearly 60 percent. The effect of rootstalk is obvious when the horizontal force is great.
2010, 40(4): 88-95.
doi: 10.13204/j.gyjz201004020
Abstract:
The consolidation of multi-layered sand drains foundation under single-drainage condition and doubledrainage condition was analyzed. Three types of variation patterns of the horizontal permeability of soil in the smear zone were considered,including the constant distribution pattern,the linear distribution pattern and the parabolic distribution pattern,and an analytical solution was obtained. The consolidation behavior of?double-layered sand drains foundation was investigated. The results show that the overall average degrees of consolidation of foundation in terms of pore pressure is equal to that in terms of strain only if compression modulus of every layer is equal to each other,otherwise the former is always larger than the later; the consolidation rate is at its maximum for the parabolic distribution pattern and is at its minimum for the constant distribution pattern whereas the?one for the linear distribution pattern is in the middle. The larger the smear zone is,the slower the consolidation rate is; the greater the disturbance magnitude is,the slower the consolidation rate is. Increasing compression modulus of any layer could accelerate the dissipation of pore pressure.
The consolidation of multi-layered sand drains foundation under single-drainage condition and doubledrainage condition was analyzed. Three types of variation patterns of the horizontal permeability of soil in the smear zone were considered,including the constant distribution pattern,the linear distribution pattern and the parabolic distribution pattern,and an analytical solution was obtained. The consolidation behavior of?double-layered sand drains foundation was investigated. The results show that the overall average degrees of consolidation of foundation in terms of pore pressure is equal to that in terms of strain only if compression modulus of every layer is equal to each other,otherwise the former is always larger than the later; the consolidation rate is at its maximum for the parabolic distribution pattern and is at its minimum for the constant distribution pattern whereas the?one for the linear distribution pattern is in the middle. The larger the smear zone is,the slower the consolidation rate is; the greater the disturbance magnitude is,the slower the consolidation rate is. Increasing compression modulus of any layer could accelerate the dissipation of pore pressure.
2010, 40(4): 96-99.
doi: 10.13204/j.gyjz201004021
Abstract:
A comparative test of foundation treatment using dynamic compaction of 18 000 kNm was carried out for the land backfill area and sea backfill area of a marine reclamation land in Guangdong Province. The geological conditions and design parameters were introduced in detail,The treatment effect was obtained by dynamic sounding test,Rayleigh wave test,standard penetration test and plate load test after compaction.
A comparative test of foundation treatment using dynamic compaction of 18 000 kNm was carried out for the land backfill area and sea backfill area of a marine reclamation land in Guangdong Province. The geological conditions and design parameters were introduced in detail,The treatment effect was obtained by dynamic sounding test,Rayleigh wave test,standard penetration test and plate load test after compaction.
2010, 40(4): 100-106，136.
doi: 10.13204/j.gyjz201004022
Abstract:
The axially compressive bearing capacity may be further enhanced,together with the plasticity and ductility also be improved by setting steel bars into circular concrete-filled steel tube column. Based on the limit equilibrium theory of concrete-filled steel tube column,the axially compressive static tests of 38 reinforced concretefilled steel tube short column specimens were carried out,in order to explore their bearing mechanism and failure modes. Some factors influencing the axial load-bearing capacity of the specimens are analyzed. The method of calculating the axial load-bearing capacity for this kind of short column is studied to provide a reference for the subsequent studies and the revision of correlative standards.
The axially compressive bearing capacity may be further enhanced,together with the plasticity and ductility also be improved by setting steel bars into circular concrete-filled steel tube column. Based on the limit equilibrium theory of concrete-filled steel tube column,the axially compressive static tests of 38 reinforced concretefilled steel tube short column specimens were carried out,in order to explore their bearing mechanism and failure modes. Some factors influencing the axial load-bearing capacity of the specimens are analyzed. The method of calculating the axial load-bearing capacity for this kind of short column is studied to provide a reference for the subsequent studies and the revision of correlative standards.
2010, 40(4): 107-111,99.
doi: 10.13204/j.gyjz201004023
Abstract:
To investigate how the welding situations of hidden seam and the loading hierarchy reversal of braces affect the structural performance of unstiffened overlapped circular hollow steel (CHS) KT-joints,three specimens were tested under monotonic loading. The test results show that: the mechanical behavior and failure mechanism of the overlapped KT-joints are different from that of simple gap KT-joints; the unwelded situation of hidden seam will decrease the ultimate capacity of KT-joints; the overlapped KT-joint with inclined compressive brace as through web member has lower load-carrying capacity compared with joint using vertical brace as through web member.
To investigate how the welding situations of hidden seam and the loading hierarchy reversal of braces affect the structural performance of unstiffened overlapped circular hollow steel (CHS) KT-joints,three specimens were tested under monotonic loading. The test results show that: the mechanical behavior and failure mechanism of the overlapped KT-joints are different from that of simple gap KT-joints; the unwelded situation of hidden seam will decrease the ultimate capacity of KT-joints; the overlapped KT-joint with inclined compressive brace as through web member has lower load-carrying capacity compared with joint using vertical brace as through web member.
2010, 40(4): 112-116,120.
doi: 10.13204/j.gyjz201004024
Abstract:
The damage constitutive law of concrete,which can better describe the mechanical characteristics of concrete,is introduced according to the continuum damage mechanics theory. Meanwhile,the damage constitutive law of steel is established by taking account of the plastic strain development and buckling effect of steel. Based on large numbers of the experimental results of pull-out specimens on bond-slip behaviors between steel and concrete,the relationship between bond strength and the value of slip is analyzed. A coupled interfacial bond damage -s model is established and the evolution characteristic equation of bond damage is put forward?through introducing a damage variable to consider the effect of bond degeneration between steel and concrete. Numerical results of SRC beam specimens analyzed by finite element numerical simulation are compared with experimental results and calculation results obtained by existing research. The results show the bond damage -s model herein established can better reflect the effect of interfacial bond degradation between steel and concrete for structural elements,so the numerical method is effective. All these may supply theoretical basis for the nonlinear numerical analysis of SRC composite structures under earthquake.
The damage constitutive law of concrete,which can better describe the mechanical characteristics of concrete,is introduced according to the continuum damage mechanics theory. Meanwhile,the damage constitutive law of steel is established by taking account of the plastic strain development and buckling effect of steel. Based on large numbers of the experimental results of pull-out specimens on bond-slip behaviors between steel and concrete,the relationship between bond strength and the value of slip is analyzed. A coupled interfacial bond damage -s model is established and the evolution characteristic equation of bond damage is put forward?through introducing a damage variable to consider the effect of bond degeneration between steel and concrete. Numerical results of SRC beam specimens analyzed by finite element numerical simulation are compared with experimental results and calculation results obtained by existing research. The results show the bond damage -s model herein established can better reflect the effect of interfacial bond degradation between steel and concrete for structural elements,so the numerical method is effective. All these may supply theoretical basis for the nonlinear numerical analysis of SRC composite structures under earthquake.
2010, 40(4): 117-120.
doi: 10.13204/j.gyjz201004025
Abstract:
In this paper,combining engineering design practice,light steel structure used in industrial plants of great column spacing grid is introduced through the aspects of design optimization and innovation from mechanical modeling,column foot shear keys setting,roof slope selection,value of snow load setting for roof,and etc. This article also describes the amount of steel for light steel structure used in industrial plants of great column spacing grid using a large number of engineering examples,which may be a reference for colleagues.
In this paper,combining engineering design practice,light steel structure used in industrial plants of great column spacing grid is introduced through the aspects of design optimization and innovation from mechanical modeling,column foot shear keys setting,roof slope selection,value of snow load setting for roof,and etc. This article also describes the amount of steel for light steel structure used in industrial plants of great column spacing grid using a large number of engineering examples,which may be a reference for colleagues.
2010, 40(4): 121-125.
doi: 10.13204/j.gyjz201004026
Abstract:
The concrete members strengthened with prestressed CFRP is an effective method. Through the theoretical analysis and summary of flexural failure of reinforce concrete beams strengthened with prestressed CFRP under sustaining load,the simplified calculation formulas of load carrying capacity are presented?and the influence of the sustaining loads and pre-stressed levels on ultimate load-carrying capacity are analyzed. The theoretical analysis results indicated that when the concrete in the compression zone is crushed,ultimate load-carrying capacity is decreasing with sustaining loads increasing,whereas ultimate load-carrying capacity is increasing with prestressed levels increasing and has extreme value. When CFRP sheet is ruptured,the change of ultimate?load-carrying capacity was completely contrary to that of the crushe concrete in compression zone. The effect of sustaining loads on ultimate load-carrying capacity isn't obvious and can be ignored. Finally control value on tensile strain of the CFRP is also given based on the ductility failure of the strengthened members.
The concrete members strengthened with prestressed CFRP is an effective method. Through the theoretical analysis and summary of flexural failure of reinforce concrete beams strengthened with prestressed CFRP under sustaining load,the simplified calculation formulas of load carrying capacity are presented?and the influence of the sustaining loads and pre-stressed levels on ultimate load-carrying capacity are analyzed. The theoretical analysis results indicated that when the concrete in the compression zone is crushed,ultimate load-carrying capacity is decreasing with sustaining loads increasing,whereas ultimate load-carrying capacity is increasing with prestressed levels increasing and has extreme value. When CFRP sheet is ruptured,the change of ultimate?load-carrying capacity was completely contrary to that of the crushe concrete in compression zone. The effect of sustaining loads on ultimate load-carrying capacity isn't obvious and can be ignored. Finally control value on tensile strain of the CFRP is also given based on the ductility failure of the strengthened members.
2010, 40(4): 126-130.
doi: 10.13204/j.gyjz201004027
Abstract:
BFRP sheet is a new type of complex material with outstanding performance. According to the static tests of 12 rectangular timber beams strengthened with basalt fiber reinforced polymer(BFRP) sheets,it is analyzed that the performance indexes such as the bearing capacity,deflection of reference beams and reinforced beams. The results show that BFRP sheets have a good strengthening effect for timber beam. Finally,the ANSYS software is applied to the numerical stimulation of the bending test of the timber beam reinforced by BFRP sheets. Then,the load-displacement curve and stress-strain nephogram of reinforced timber beam under vertical load are gained. Through the comparison of numerical result and experimental result,it verifies that using ANSYS software to the numerical stimulation of BFRP reinforced timber beam is feasible.
BFRP sheet is a new type of complex material with outstanding performance. According to the static tests of 12 rectangular timber beams strengthened with basalt fiber reinforced polymer(BFRP) sheets,it is analyzed that the performance indexes such as the bearing capacity,deflection of reference beams and reinforced beams. The results show that BFRP sheets have a good strengthening effect for timber beam. Finally,the ANSYS software is applied to the numerical stimulation of the bending test of the timber beam reinforced by BFRP sheets. Then,the load-displacement curve and stress-strain nephogram of reinforced timber beam under vertical load are gained. Through the comparison of numerical result and experimental result,it verifies that using ANSYS software to the numerical stimulation of BFRP reinforced timber beam is feasible.
2010, 40(4): 131-136.
doi: 10.13204/j.gyjz201004028
Abstract:
Combination strengthening RC beams with CFRP and steel plates is a new method. Through the test of one reference beam and six strengthened beams,it is indicated that the flexural capacity and ductility of combination strengthened beams are superior to carbon fiber strengthening and steel-bonded reinforecment and the initial load has not obvious effects on its load capacity. Furthermore,the failure mode and the increased limit value of the flexural capacity in combination strengthened beams are analyzed based on experimental results. The analysis shows that the increased limit value of combination strengthened beams is much more than 40% of concrete specifications,and combination strengthened statisfying the requirements for its service performance. Therefore if there is a need to both enhance bearing capacity to a greater extent and statisfy service performance of a flexural member,it is recommended that combination reinforcement should be used.
Combination strengthening RC beams with CFRP and steel plates is a new method. Through the test of one reference beam and six strengthened beams,it is indicated that the flexural capacity and ductility of combination strengthened beams are superior to carbon fiber strengthening and steel-bonded reinforecment and the initial load has not obvious effects on its load capacity. Furthermore,the failure mode and the increased limit value of the flexural capacity in combination strengthened beams are analyzed based on experimental results. The analysis shows that the increased limit value of combination strengthened beams is much more than 40% of concrete specifications,and combination strengthened statisfying the requirements for its service performance. Therefore if there is a need to both enhance bearing capacity to a greater extent and statisfy service performance of a flexural member,it is recommended that combination reinforcement should be used.
2010, 40(4): 137-141.
doi: 10.13204/j.gyjz201004029
Abstract:
In this paper,a siamesed structure with two-tower is analyzed. Structure plan of the library is optimized.Based on the computation result of some structure programs,several models of structure are analyzed under minor seisms. Pushover analysis is used for integral model. Selection of structure model,vibration characteristic and the final design measures are discussed. Seismic design based on performance is proposed. Siamesed structural members and supporting members are elastic under intermediate seisms,slippage is in control.
In this paper,a siamesed structure with two-tower is analyzed. Structure plan of the library is optimized.Based on the computation result of some structure programs,several models of structure are analyzed under minor seisms. Pushover analysis is used for integral model. Selection of structure model,vibration characteristic and the final design measures are discussed. Seismic design based on performance is proposed. Siamesed structural members and supporting members are elastic under intermediate seisms,slippage is in control.
2010, 40(4): 142-146.
doi: 10.13204/j.gyjz201004030
Abstract:
This issue mainly discuss the relation between contemporary old building renewal field and Mies's Architectural aesthetics. At first,demonstrate the influence of Mies's architectural aesthetics on old building renewal field by a historical analysis of this field. Then,indicate that the influences concretely are the aesthetics style in the design of glass with steel,the reduced geometrical figure and the architectural details. Finally,point out that research about thought history is directional for the development of this field in our country.
This issue mainly discuss the relation between contemporary old building renewal field and Mies's Architectural aesthetics. At first,demonstrate the influence of Mies's architectural aesthetics on old building renewal field by a historical analysis of this field. Then,indicate that the influences concretely are the aesthetics style in the design of glass with steel,the reduced geometrical figure and the architectural details. Finally,point out that research about thought history is directional for the development of this field in our country.
2010, 40(4): 147-150.
doi: 10.13204/j.gyjz201004031
Abstract:
According to the informative investigation，the paper tries to analyze and summarize of the color of Huizhou civil residence from outside to inside. It wants to sum up the fundamental causes and changes of the color,displaying the unique artistic effect. It also intends to stimulate the far－reaching cultural content and composition rules,which may be a reference for daih life.
According to the informative investigation，the paper tries to analyze and summarize of the color of Huizhou civil residence from outside to inside. It wants to sum up the fundamental causes and changes of the color,displaying the unique artistic effect. It also intends to stimulate the far－reaching cultural content and composition rules,which may be a reference for daih life.
