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2008 Vol. 38, No. 2
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2008, 38(2): 1-3.
doi: 10.13204/j.gyjz200802001
Abstract:
In order to investigate the law of changing property of CFRP fabric under different environments, 200 CFRP sheets under the environment of north China and northwest China were tested on natural aging. The results of two-year detection indicate that under the natural environment of west China and north China, the durability of CFRP can meet the engineering requirments.
In order to investigate the law of changing property of CFRP fabric under different environments, 200 CFRP sheets under the environment of north China and northwest China were tested on natural aging. The results of two-year detection indicate that under the natural environment of west China and north China, the durability of CFRP can meet the engineering requirments.
2008, 38(2): 4-6.
doi: 10.13204/j.gyjz200802002
Abstract:
Concrete structures reinforced by CFRP sheets are widely used in civil projects and much attention is paid to their durability. Studies and tests were done on the durability of common CFRP sheets. Influence to strength, extensibility and Young?? s modulus of CFRP sheets was investigated in nature aging environment of north China. Forty sheets were tested and the results indicate that as the increase of time, strength and extensibility of CFRP sheets will decrease slightly and Young?? s modulus will basically remain a constant.
Concrete structures reinforced by CFRP sheets are widely used in civil projects and much attention is paid to their durability. Studies and tests were done on the durability of common CFRP sheets. Influence to strength, extensibility and Young?? s modulus of CFRP sheets was investigated in nature aging environment of north China. Forty sheets were tested and the results indicate that as the increase of time, strength and extensibility of CFRP sheets will decrease slightly and Young?? s modulus will basically remain a constant.
2008, 38(2): 7-9.
doi: 10.13204/j.gyjz200802003
Abstract:
FRP strengthening is widely used in civil projects and more attention is paid to its durability. Studies and tests were done on the durability of common CFRP sheets. Influence to strength, extensibility and modulus of CFRP sheets was investigated in nature ag ing environment of northwest China. Forty sheets were tested and the results indicate that as the increase of time, extensibility of CFRP sheets will decrease and Young?? s modulus and tensile strength will basically remain a constant.
FRP strengthening is widely used in civil projects and more attention is paid to its durability. Studies and tests were done on the durability of common CFRP sheets. Influence to strength, extensibility and modulus of CFRP sheets was investigated in nature ag ing environment of northwest China. Forty sheets were tested and the results indicate that as the increase of time, extensibility of CFRP sheets will decrease and Young?? s modulus and tensile strength will basically remain a constant.
2008, 38(2): 10-12.
doi: 10.13204/j.gyjz200802004
Abstract:
As a complex material, infused resin is an important part of FRP. So durability of resin may have some influence on aging resistant capability of FRP. Tests and study were done on durability of resin common used in civil engineering, and some sheets were preserved. Influence of nature environment in north China to strength, extensibility and Young?? s modulus was investigated. Seven groups of sheets which are thirty-five sheets were tested in two years. The results indicates that property of sheets protected was better than the one unprotected.
As a complex material, infused resin is an important part of FRP. So durability of resin may have some influence on aging resistant capability of FRP. Tests and study were done on durability of resin common used in civil engineering, and some sheets were preserved. Influence of nature environment in north China to strength, extensibility and Young?? s modulus was investigated. Seven groups of sheets which are thirty-five sheets were tested in two years. The results indicates that property of sheets protected was better than the one unprotected.
STUDY ON THE INFLUENCE OF PROTECTION ON CFRP SHEETS DURALBILITY UNDER THE ENVIRONMENT OF NORTH CHINA
2008, 38(2): 13-14,12.
doi: 10.13204/j.gyjz200802005
Abstract:
The concrete structures strengthened by CFRP sheets are widely used in civil projects and much attentions is paid to their durability. Studies and tests were done on durability of common CFRP sheets in nature environment of north China. In order to investigate the influence of protection on strength, extensibility and Young?? s modulus of CFRP sheets, some sheets were protected. Each group includes five CFRP sheets and seven groups of sheets were tested up to now. Test results indicate that strength ability of sheets without protection declines badly then the one protected.
The concrete structures strengthened by CFRP sheets are widely used in civil projects and much attentions is paid to their durability. Studies and tests were done on durability of common CFRP sheets in nature environment of north China. In order to investigate the influence of protection on strength, extensibility and Young?? s modulus of CFRP sheets, some sheets were protected. Each group includes five CFRP sheets and seven groups of sheets were tested up to now. Test results indicate that strength ability of sheets without protection declines badly then the one protected.
THE INFLUENCE OF INFUSED RESIN ON DURABILITY OF CFRP SHEETS UNDER THE ENVIRONMENT OF NORTHWEST CHINA
2008, 38(2): 15-17,27.
doi: 10.13204/j.gyjz200802006
Abstract:
CFRP sheets strengthening is widely used in civil projects and much attentions is paid to their durability. Durability of two common CFRP sheets and resin were compared and studied under the nature environment of northwest China. Each group has 5 pieces of sheets and sixteen groups of sheets which are 80 sheets were tested in recent 2 years. The results indicate that durability of CFRP sheets has some relationship with durability of infused resin.
CFRP sheets strengthening is widely used in civil projects and much attentions is paid to their durability. Durability of two common CFRP sheets and resin were compared and studied under the nature environment of northwest China. Each group has 5 pieces of sheets and sixteen groups of sheets which are 80 sheets were tested in recent 2 years. The results indicate that durability of CFRP sheets has some relationship with durability of infused resin.
2008, 38(2): 18-20,6.
doi: 10.13204/j.gyjz200802007
Abstract:
Concrete structures reinforced by CFRP sheets are widely used in civil projects. As far as CFRP itself is concerned, environment takes little influence on its capability. However, as a complex material, capability of CFRP is influenced by the capability of resin. Durability of two common CFRP sheets and resin were compared and studied. Sixteen groups of sheets which are 80 sheets were tested in recent 2 years. Influence of nature environment on strength, extensibility and Young?? s modulus was investigated in north China. The results indicate that strength of CFRP sheets has relation to strength of infused resin, while durability has little influence on Young?? s modulus and extensibility.
Concrete structures reinforced by CFRP sheets are widely used in civil projects. As far as CFRP itself is concerned, environment takes little influence on its capability. However, as a complex material, capability of CFRP is influenced by the capability of resin. Durability of two common CFRP sheets and resin were compared and studied. Sixteen groups of sheets which are 80 sheets were tested in recent 2 years. Influence of nature environment on strength, extensibility and Young?? s modulus was investigated in north China. The results indicate that strength of CFRP sheets has relation to strength of infused resin, while durability has little influence on Young?? s modulus and extensibility.
2008, 38(2): 21-24.
doi: 10.13204/j.gyjz200802008
Abstract:
Due to intensified restraint of land, circumstance and energy, energy is becoming an important element in architecture design nowadays. Based on the theory of integration, the stratagems are put forward to integrate energy and architecture in a design progress with energy-oriented. And the aim is that energy is used effectively and the foundation is built up for ecology architecture.
Due to intensified restraint of land, circumstance and energy, energy is becoming an important element in architecture design nowadays. Based on the theory of integration, the stratagems are put forward to integrate energy and architecture in a design progress with energy-oriented. And the aim is that energy is used effectively and the foundation is built up for ecology architecture.
2008, 38(2): 25-27.
doi: 10.13204/j.gyjz200802009
Abstract:
It is analyzed that the traditional residences in southwest region, which adopt to local ecological characteristics, geographic climatic conditions, as well as their constructing mode of using local resources and acting according to circumstances. In the light of pollution and wastes from using energy, it is proposed that developing stratagem and study on technical canonical form of ecological energy-saving residences, thus realizing sustainable development of many villages and towns in southwest reg ions.
It is analyzed that the traditional residences in southwest region, which adopt to local ecological characteristics, geographic climatic conditions, as well as their constructing mode of using local resources and acting according to circumstances. In the light of pollution and wastes from using energy, it is proposed that developing stratagem and study on technical canonical form of ecological energy-saving residences, thus realizing sustainable development of many villages and towns in southwest reg ions.
2008, 38(2): 28-30.
doi: 10.13204/j.gyjz200802010
Abstract:
Energy consumption is influenced directly by the skylight of a atrium. Some models of the skylight of a atrium were assumed, the relation between energy consumption and skylight with different type, obliquity and orientation was also analyzed and discussed and initial result as achieved, which may provide experience for energy-saving design of a building in the future.
Energy consumption is influenced directly by the skylight of a atrium. Some models of the skylight of a atrium were assumed, the relation between energy consumption and skylight with different type, obliquity and orientation was also analyzed and discussed and initial result as achieved, which may provide experience for energy-saving design of a building in the future.
2008, 38(2): 31-34,58.
doi: 10.13204/j.gyjz200802011
Abstract:
It is researched 4 unbonded pos-t tensioned precast concrete beams under reversed cyclic loading. In this study there are some parameters that are taken into account, such as PT eccentric position, PT anchor length and initial pos-t tensioning load. Experiment shows that these beams used unbonded pos-t tensioned tendon have desirable seismic characteristics such as a sel-f centering capability and an ability to undergo large nonlinear displacements with little damage. Some seismic behaviors such as resilience, ductility, energy dissipation etc are analyzed. The objective of this test is to develop guidelines for precast structure in regions of earthquake zone.
It is researched 4 unbonded pos-t tensioned precast concrete beams under reversed cyclic loading. In this study there are some parameters that are taken into account, such as PT eccentric position, PT anchor length and initial pos-t tensioning load. Experiment shows that these beams used unbonded pos-t tensioned tendon have desirable seismic characteristics such as a sel-f centering capability and an ability to undergo large nonlinear displacements with little damage. Some seismic behaviors such as resilience, ductility, energy dissipation etc are analyzed. The objective of this test is to develop guidelines for precast structure in regions of earthquake zone.
2008, 38(2): 35-38,48.
doi: 10.13204/j.gyjz200802012
Abstract:
The hidden corbel is the vital supporting member in the dry beam-column connections in full precast concrete frame. The hidden corbel is analyzed with strut2and2tie model method and shear2friction theory, and corresponding design formulas are deduced. Some design advices are put forward. By the analyses of the hidden corbels with finite element software ANSYS, the design formula put forward in the paper is validated. This research has valuable information on designing analogical hidden corbels.
The hidden corbel is the vital supporting member in the dry beam-column connections in full precast concrete frame. The hidden corbel is analyzed with strut2and2tie model method and shear2friction theory, and corresponding design formulas are deduced. Some design advices are put forward. By the analyses of the hidden corbels with finite element software ANSYS, the design formula put forward in the paper is validated. This research has valuable information on designing analogical hidden corbels.
2008, 38(2): 39-42.
doi: 10.13204/j.gyjz200802013
Abstract:
An experimental study was carried out on the cross2section crack2resistant property of 5 steel fiber reinforced concrete shear walls and 1 reinforced concrete shear wall under cyclic reverse load. Through the theoretical analysis of crack modes,the calculation model of cross2section crack2resistant capacity was established. The calculation formulas of cross2 section crack2resistant capacity were deduced,which were connected with that of reinforced concrete shear walls. The calculated results agreed well with the test results.
An experimental study was carried out on the cross2section crack2resistant property of 5 steel fiber reinforced concrete shear walls and 1 reinforced concrete shear wall under cyclic reverse load. Through the theoretical analysis of crack modes,the calculation model of cross2section crack2resistant capacity was established. The calculation formulas of cross2 section crack2resistant capacity were deduced,which were connected with that of reinforced concrete shear walls. The calculated results agreed well with the test results.
2008, 38(2): 43-48.
doi: 10.13204/j.gyjz200802014
Abstract:
Isolation Structure is a new kind of structure, which has been used widely in recent years. This article uses SAP2000 program and finite element analysis method to apply the isolation technology to a real project-110kV switch building in 330kV Xibeijiao substation in Xian and gets the internal force caused by temperature stress. Its the first time to use isolation technology in electric systems and get wonderful effect. Besides this, the article discusses the temperature stress in isolation building and compares the results in different type of engineering.
Isolation Structure is a new kind of structure, which has been used widely in recent years. This article uses SAP2000 program and finite element analysis method to apply the isolation technology to a real project-110kV switch building in 330kV Xibeijiao substation in Xian and gets the internal force caused by temperature stress. Its the first time to use isolation technology in electric systems and get wonderful effect. Besides this, the article discusses the temperature stress in isolation building and compares the results in different type of engineering.
2008, 38(2): 49-52.
doi: 10.13204/j.gyjz200802015
Abstract:
There are some time-delay factors in the systems of active control for bridge.In order to explore the influence laws of time-delay on active control effect for bridge and time-delay compensation method, the bridge finite element model and the seismic mitigation control equation are set.With different lag time of control system, the active control seismic response calculation and analysis for a long-span continuous beam bridge are performed.The results indicate that time-delay can make the vibration-suppressed effectiveness of bridge active control systems worse with lag time longer.It can even make the seismic responses instable.Phase compensation for time-delay of bridge active control can get good control effect.The vibration-suppressed effectiveness of most seismic responses for the bridge with time-delay compensation can be close to the vibration-suppressed effectiveness without time-delay, and some can even exceed the vibration-suppressed effectiveness without time-delay.
There are some time-delay factors in the systems of active control for bridge.In order to explore the influence laws of time-delay on active control effect for bridge and time-delay compensation method, the bridge finite element model and the seismic mitigation control equation are set.With different lag time of control system, the active control seismic response calculation and analysis for a long-span continuous beam bridge are performed.The results indicate that time-delay can make the vibration-suppressed effectiveness of bridge active control systems worse with lag time longer.It can even make the seismic responses instable.Phase compensation for time-delay of bridge active control can get good control effect.The vibration-suppressed effectiveness of most seismic responses for the bridge with time-delay compensation can be close to the vibration-suppressed effectiveness without time-delay, and some can even exceed the vibration-suppressed effectiveness without time-delay.
2008, 38(2): 53-58.
doi: 10.13204/j.gyjz200802016
Abstract:
On the basis of saturated-unsaturated seepage model, by simulating transient seepage fields due to rainfall infiltration for Beijing Olympic Park Hill, the matric suction in the slope is analyzed. By the extendedMohr-Coulomb failure criterion, the slope stability is analyzed using limit equilibrium method. Therefore the factors of safety at different time during the rainfall are calculated. In addition, effects of different rainfall model on seepage fields distribution of unsaturated soil slope and the slope stability are analyzed in this paper. Then, the reliability of slope stability as the soil parameters varying is presented by means of probability method.
On the basis of saturated-unsaturated seepage model, by simulating transient seepage fields due to rainfall infiltration for Beijing Olympic Park Hill, the matric suction in the slope is analyzed. By the extendedMohr-Coulomb failure criterion, the slope stability is analyzed using limit equilibrium method. Therefore the factors of safety at different time during the rainfall are calculated. In addition, effects of different rainfall model on seepage fields distribution of unsaturated soil slope and the slope stability are analyzed in this paper. Then, the reliability of slope stability as the soil parameters varying is presented by means of probability method.
2008, 38(2): 59-63.
doi: 10.13204/j.gyjz200802017
Abstract:
Saturated sand is looked as soil2water two2medium, the fully coupled three2dimension effective2stress dynamic analysis procedure is developed on the base of Biot dynamic theory and the right of procedure was proved. Stone columns composite foundation is analyzed by the developed procedure, the influence of different soil layer and different additive pressure on anti2liquefaction characteristic of composite foundation is discussed. The research shows that the excess pore water press ratio in the soil around column is smaller than that of reinforcement before. With decreasing of input earthquake acceleration, the dissipation of excess pore water press is remarkable, the distance from stone columns is smaller, and the dissipation is more remarkable. Additive pressure can restrain the incensement of excess pore water pressure, this favourable factor should be considered in engineering design and the space of stone columns may be increscent.
Saturated sand is looked as soil2water two2medium, the fully coupled three2dimension effective2stress dynamic analysis procedure is developed on the base of Biot dynamic theory and the right of procedure was proved. Stone columns composite foundation is analyzed by the developed procedure, the influence of different soil layer and different additive pressure on anti2liquefaction characteristic of composite foundation is discussed. The research shows that the excess pore water press ratio in the soil around column is smaller than that of reinforcement before. With decreasing of input earthquake acceleration, the dissipation of excess pore water press is remarkable, the distance from stone columns is smaller, and the dissipation is more remarkable. Additive pressure can restrain the incensement of excess pore water pressure, this favourable factor should be considered in engineering design and the space of stone columns may be increscent.
2008, 38(2): 64-67.
doi: 10.13204/j.gyjz200802018
Abstract:
Field tests on pile2soil stress ratio of composite ground with cement2soil mixed pile under embankment filled with sand are carried out, the stresses on pile and surrounding soil are measured. Variations of pile2soil stress ratio of the composite ground with cement2soil mixed pile under embankment with flexible load and time are investigated. The measured results show that the variation of pile2soil stress ratio under embankment is quite different from that under rigid foundation, the measured pile2soil stress ratio is much more less than that under rigid foundation,it varies with embankment load from decrease to increase,its values are less than 2. 0,and changes hardly with time.
Field tests on pile2soil stress ratio of composite ground with cement2soil mixed pile under embankment filled with sand are carried out, the stresses on pile and surrounding soil are measured. Variations of pile2soil stress ratio of the composite ground with cement2soil mixed pile under embankment with flexible load and time are investigated. The measured results show that the variation of pile2soil stress ratio under embankment is quite different from that under rigid foundation, the measured pile2soil stress ratio is much more less than that under rigid foundation,it varies with embankment load from decrease to increase,its values are less than 2. 0,and changes hardly with time.
2008, 38(2): 68-72.
doi: 10.13204/j.gyjz200802019
Abstract:
In order to evaluate deformation capacity of corroded R. C. beams, factors affecting flexural stiffness of corroded R. C. beams are investigated, and a conclusion is reached that key factors affecting the establishment of calculation model are steel strain between cracks tending to uniformly distributed and steel strain lagging behind concrete strain for bond degrading due to steel corrosion. Throwing off conventional plane hypothesis, the section stiffness of flexural members with deteriorated bond strength is analyzed by means of stiffness analytic method. A comprehensive strain coefficient is adopted to reflect effects of both steel strain tending to uniformly distributed and lagging behind, and a calculation model of flexural stiffness of R. C. beams with corroded bars is established. By means of finite element analysis, the relationship between comprehensive strain coefficient and reduced coefficient of bond strength is built. The formula is used to analyze flexural stiffness of some tested members, and calculated results coincide with test results well.
In order to evaluate deformation capacity of corroded R. C. beams, factors affecting flexural stiffness of corroded R. C. beams are investigated, and a conclusion is reached that key factors affecting the establishment of calculation model are steel strain between cracks tending to uniformly distributed and steel strain lagging behind concrete strain for bond degrading due to steel corrosion. Throwing off conventional plane hypothesis, the section stiffness of flexural members with deteriorated bond strength is analyzed by means of stiffness analytic method. A comprehensive strain coefficient is adopted to reflect effects of both steel strain tending to uniformly distributed and lagging behind, and a calculation model of flexural stiffness of R. C. beams with corroded bars is established. By means of finite element analysis, the relationship between comprehensive strain coefficient and reduced coefficient of bond strength is built. The formula is used to analyze flexural stiffness of some tested members, and calculated results coincide with test results well.
2008, 38(2): 73-75,85.
doi: 10.13204/j.gyjz200802020
Abstract:
The effect of interaction between cycle loading and aggressive environment on corrosion fatigue of reinforced concrete beams was studied. The strain increase of the reinforcing bars was accelerated under simultaneous corrosion and fatigue loading from the experimental results. The effect of coupling action of corrosion fatigue was more serious than that of fatigue or corrosion and fatigue after corrosion on the deterioration of RC members. The coupling action was continuous with the strain increase until the RC members were destructed. The investigation shows that the corrosion fatigue is the main cause for the reinforced concrete beams to lose the durability. The experimental results may provide the reference for the durability design of reinforced concrete members and the protection measures of RC members in service.
The effect of interaction between cycle loading and aggressive environment on corrosion fatigue of reinforced concrete beams was studied. The strain increase of the reinforcing bars was accelerated under simultaneous corrosion and fatigue loading from the experimental results. The effect of coupling action of corrosion fatigue was more serious than that of fatigue or corrosion and fatigue after corrosion on the deterioration of RC members. The coupling action was continuous with the strain increase until the RC members were destructed. The investigation shows that the corrosion fatigue is the main cause for the reinforced concrete beams to lose the durability. The experimental results may provide the reference for the durability design of reinforced concrete members and the protection measures of RC members in service.
2008, 38(2): 76-80，90.
doi: 10.13204/j.gyjz200802021
Abstract:
Influences of water to cement ratio (w??c) and cement content on concrete durability are analyzed in detail based on experimental results. An initial chloride effective diffusion coefficient predicting model is proposed according to nonlinear least square method regression. This model can be used to evaluate the initial chloride effective diffusion coefficient which takes combination influences of w??c and cement content into consideration. At last, relevant validation experiments are executed to test the regression model.
Influences of water to cement ratio (w??c) and cement content on concrete durability are analyzed in detail based on experimental results. An initial chloride effective diffusion coefficient predicting model is proposed according to nonlinear least square method regression. This model can be used to evaluate the initial chloride effective diffusion coefficient which takes combination influences of w??c and cement content into consideration. At last, relevant validation experiments are executed to test the regression model.
2008, 38(2): 81-85.
doi: 10.13204/j.gyjz200802022
Abstract:
A three2dimensional finite element model is established,based on adiabatic temperature2rise experiment and the hydration heat of concrete effected by temperature, with which the temperature field of a mass concrete mock2up in 60 d is calculated and compared with data measured on site. The results show that the temperature rise inside the concrete is about 40 ℃, which is achieved between 5 and 7 d. The difference of temperatures between any two points is less than 25 ℃. The maximum of temperature gradients in the vertical direction is on both the top and bottom surfaces, which is attained at the beginning of cooling stage after the temperature rise.
A three2dimensional finite element model is established,based on adiabatic temperature2rise experiment and the hydration heat of concrete effected by temperature, with which the temperature field of a mass concrete mock2up in 60 d is calculated and compared with data measured on site. The results show that the temperature rise inside the concrete is about 40 ℃, which is achieved between 5 and 7 d. The difference of temperatures between any two points is less than 25 ℃. The maximum of temperature gradients in the vertical direction is on both the top and bottom surfaces, which is attained at the beginning of cooling stage after the temperature rise.
2008, 38(2): 86-90.
doi: 10.13204/j.gyjz200802023
Abstract:
An experimental study on ten full2size 550MPa high strength cold2formed thin2wall steel wall studs subjected to axial loads is carried out. The ultimate load carrying capacity and failure modes of all wall studs are obtained by tests. Based on the test, the finite element analysis model is established. A detailed parameter analysis is carried out after the finite element analysis model has been validated by test data. The parameter analysis results show that it doesnt have a significant effect on the ultimate load carrying capacity of high strength cold2formed steel wall studs under axial compression by changing the diameter and number of the self2drilling screws, altering the thickness and yield strength of the tracks and the wall stud spacing ; it is helpful to enhance the ultimate load carrying capacity of the wall studs by setting plate strips on both sides of the wall studs, but the ultimate load carrying capacity of the wall studs increase little when the plate strip spacing decreases below 1P4 the length of the wall stud.
An experimental study on ten full2size 550MPa high strength cold2formed thin2wall steel wall studs subjected to axial loads is carried out. The ultimate load carrying capacity and failure modes of all wall studs are obtained by tests. Based on the test, the finite element analysis model is established. A detailed parameter analysis is carried out after the finite element analysis model has been validated by test data. The parameter analysis results show that it doesnt have a significant effect on the ultimate load carrying capacity of high strength cold2formed steel wall studs under axial compression by changing the diameter and number of the self2drilling screws, altering the thickness and yield strength of the tracks and the wall stud spacing ; it is helpful to enhance the ultimate load carrying capacity of the wall studs by setting plate strips on both sides of the wall studs, but the ultimate load carrying capacity of the wall studs increase little when the plate strip spacing decreases below 1P4 the length of the wall stud.
2008, 38(2): 91-95113.
doi: 10.13204/j.gyjz200802024
Abstract:
Box section has the special features both its mass center and moment center unification as double symmetry coldformed section and its outstanding advantage in moment and torsion rigidity.According to which, it is put forward two new kinds of cold-formed box composite sections-flanges opposite welded box composite section and flanges lapped welded box composite section.On the basis of precise finite element model, nonlinear finite element method is adopted to study the static behaviors including buckling modes, deformed process, moment-curvature curves of two new kinds of section members under flexural loads.The buckling behaviors and static behaviors of the two kinds of sections are analyzed completely.It is compared every side of static behavior with those of channel sections that have the same dimensions.The two new type sections have some superior static behaviors including higher ultimate bending capacity, distortional buckling can escape and smaller local buckling in the member are verified.These two new kinds of sections can go deep into the experiment study as to be used in the practical engineering.
Box section has the special features both its mass center and moment center unification as double symmetry coldformed section and its outstanding advantage in moment and torsion rigidity.According to which, it is put forward two new kinds of cold-formed box composite sections-flanges opposite welded box composite section and flanges lapped welded box composite section.On the basis of precise finite element model, nonlinear finite element method is adopted to study the static behaviors including buckling modes, deformed process, moment-curvature curves of two new kinds of section members under flexural loads.The buckling behaviors and static behaviors of the two kinds of sections are analyzed completely.It is compared every side of static behavior with those of channel sections that have the same dimensions.The two new type sections have some superior static behaviors including higher ultimate bending capacity, distortional buckling can escape and smaller local buckling in the member are verified.These two new kinds of sections can go deep into the experiment study as to be used in the practical engineering.
2008, 38(2): 96-98.
doi: 10.13204/j.gyjz200802025
Abstract:
By large general finite element software, nine kinds of typical cable trusses are studied comparatively, which are used for the supporting structural system in large-span poin-t supported glass curtain wall. The impact of vertical cable on load-bearing behavior of cable truss are analyzed in detail.
By large general finite element software, nine kinds of typical cable trusses are studied comparatively, which are used for the supporting structural system in large-span poin-t supported glass curtain wall. The impact of vertical cable on load-bearing behavior of cable truss are analyzed in detail.
2008, 38(2): 99-102.
doi: 10.13204/j.gyjz200802026
Abstract:
An experiment study has been carried out on three types of joints, which are frequently used in the steel frame structure, employing fire-testing furnace. The types of joint include welded joint, welded flange bolted web joint and extended end-plate joint. Two welded joints and two welded flange bolted web joints are divided into column stiffened and column unstiffened. Two thicknesses, 12mm and 16mm, were taken into account in the four extended end-plate joints. Each-thickness-end-plate joints comprised two specimens and one was stiffened in column and the other was not stiffened. The experimental results indicate that the rib stiffener can greatly enhance the fire-resistance of welded joint and extended end-plate joint. Increasing the thickness of end-plate has not significantly effect on the fire-resistance of extended end-plate joint.
An experiment study has been carried out on three types of joints, which are frequently used in the steel frame structure, employing fire-testing furnace. The types of joint include welded joint, welded flange bolted web joint and extended end-plate joint. Two welded joints and two welded flange bolted web joints are divided into column stiffened and column unstiffened. Two thicknesses, 12mm and 16mm, were taken into account in the four extended end-plate joints. Each-thickness-end-plate joints comprised two specimens and one was stiffened in column and the other was not stiffened. The experimental results indicate that the rib stiffener can greatly enhance the fire-resistance of welded joint and extended end-plate joint. Increasing the thickness of end-plate has not significantly effect on the fire-resistance of extended end-plate joint.
2008, 38(2): 103-105.
doi: 10.13204/j.gyjz200802027
Abstract:
An overall detection of the main mill building structure for a steelmaking plant was carried out according to the technical reform. It was proposed that the feasible suggestions on conditions that could not meet the requirements of codes or those were not faverable for technical reform. The experience of the detection may be a reference for similar projects.
An overall detection of the main mill building structure for a steelmaking plant was carried out according to the technical reform. It was proposed that the feasible suggestions on conditions that could not meet the requirements of codes or those were not faverable for technical reform. The experience of the detection may be a reference for similar projects.
2008, 38(2): 106-108105.
doi: 10.13204/j.gyjz200802028
Abstract:
The sways of foundation piles, cushion caps and columns occurred due to unsuitable excavation of equipment foundations for a mill builging. The causes were analyzed. It was described emphatically the deviation-rectifying and strengthening technologies of the concrete columns for the mill building.
The sways of foundation piles, cushion caps and columns occurred due to unsuitable excavation of equipment foundations for a mill builging. The causes were analyzed. It was described emphatically the deviation-rectifying and strengthening technologies of the concrete columns for the mill building.
2008, 38(2): 109-113.
doi: 10.13204/j.gyjz200802029
Abstract:
After comprehensive assessing on seven static loading tests results of one failure piles engineering on mudstone subgrade in Nanning basin, the criterion, whose statistical value of axial single pile ultimate capacity adopts the average value after cancelling the peak value in turn until satisfy the condition that the relative difference between the peak value and minimum value won' t exceed 30 percent, is pointed that do not make enough use of piles potential bearing capacity.And it is a feasible way to treat the failure piles engineering problem by deformation control based on structural properties and loading and main factor of piles failure on the mudstone foundation is brought about by the decline of pile point capacity and pile side friction embedded in rock, which makes the piles bearing capacity deficient, which is also approved in the laboratory model test.Therefore, the success of boring pile will not only rely on adopting very low value of pile' s bearing capacity and pile side friction embedded in rock in piles foundation design.
After comprehensive assessing on seven static loading tests results of one failure piles engineering on mudstone subgrade in Nanning basin, the criterion, whose statistical value of axial single pile ultimate capacity adopts the average value after cancelling the peak value in turn until satisfy the condition that the relative difference between the peak value and minimum value won' t exceed 30 percent, is pointed that do not make enough use of piles potential bearing capacity.And it is a feasible way to treat the failure piles engineering problem by deformation control based on structural properties and loading and main factor of piles failure on the mudstone foundation is brought about by the decline of pile point capacity and pile side friction embedded in rock, which makes the piles bearing capacity deficient, which is also approved in the laboratory model test.Therefore, the success of boring pile will not only rely on adopting very low value of pile' s bearing capacity and pile side friction embedded in rock in piles foundation design.
2008, 38(2): 114-115118.
doi: 10.13204/j.gyjz200802030
Abstract:
Nowadays, environment protection and energy2saving become more and more important. Using solar energy in architecture design is a tendency of sustainable green buildings. The integral design of architecture with solar energy turns into a hot subject in construction society. Although there are many years of using solar energy, however, it is still in a discovery stage currently in the integral design of architecture with solar energy in China, which lacks experience and experience. This article tries to get some ideas and approach through discussion and case study on the integral design of architecture with solar energy.
Nowadays, environment protection and energy2saving become more and more important. Using solar energy in architecture design is a tendency of sustainable green buildings. The integral design of architecture with solar energy turns into a hot subject in construction society. Although there are many years of using solar energy, however, it is still in a discovery stage currently in the integral design of architecture with solar energy in China, which lacks experience and experience. This article tries to get some ideas and approach through discussion and case study on the integral design of architecture with solar energy.
2008, 38(2): 116-118.
doi: 10.13204/j.gyjz200802031
Abstract:
Through analysis of the traditional construction and structure feature of Mosuo people living at Lugu Lake, it is analyzed the existing problems of the traditional construction, and also explored how to buildMosuo tribe?? s new construction form, by combining the traditional construction with modern construction as well as selection of material and structure, and saving energy and so on.
Through analysis of the traditional construction and structure feature of Mosuo people living at Lugu Lake, it is analyzed the existing problems of the traditional construction, and also explored how to buildMosuo tribe?? s new construction form, by combining the traditional construction with modern construction as well as selection of material and structure, and saving energy and so on.
