Login
Register
E-alert
2009 Vol. 39, No. 9
Display Method:
2009, 39(9): 1-6.
doi: 10.13204/j.gyjz200909001
Abstract:
As a modification of common H-section,a new type of lipped H-section member is proposed.As an economic benefit profile,it will be used as beams and columns in portal frames and purlines in roof.Since the local buckling load of the flange of lipped H-section is increased greatly due to the lip's reinforcement,the flange of lipped H-section,unlike common H section,will go out of the limit of width to thickness ratio.Based on elastic numerical results obtained by FEM,local buckling behavior was studied by changing geometric parameters of the section.Accordingly,the effective length to width ratio was determined,and a reasonable range of the lip's width coefficient and the flange width to thickness ratio were obtained.
As a modification of common H-section,a new type of lipped H-section member is proposed.As an economic benefit profile,it will be used as beams and columns in portal frames and purlines in roof.Since the local buckling load of the flange of lipped H-section is increased greatly due to the lip's reinforcement,the flange of lipped H-section,unlike common H section,will go out of the limit of width to thickness ratio.Based on elastic numerical results obtained by FEM,local buckling behavior was studied by changing geometric parameters of the section.Accordingly,the effective length to width ratio was determined,and a reasonable range of the lip's width coefficient and the flange width to thickness ratio were obtained.
2009, 39(9): 7-14.
doi: 10.13204/j.gyjz200909002
Abstract:
As a new type of steel sections,lipped H-section members have excellent load-carrying efficiency and economic efficiency,compared with common H-section members.The load-carrying capacity of lipped H-members under axial load is studied by FEM,where with the large deformation,material elastic-plasticity, the geometric initial deflects and residual stress of the members taken into account,the influence of sectional geometric parameters and slenderness ratio on load-carrying capacity of the lipped H-section members are analyzed.Finally,based on a lot of FEA numerical results obtained,the design formulas are obtained for predicting load-carrying capacity of lipped H-members under axial loads.
As a new type of steel sections,lipped H-section members have excellent load-carrying efficiency and economic efficiency,compared with common H-section members.The load-carrying capacity of lipped H-members under axial load is studied by FEM,where with the large deformation,material elastic-plasticity, the geometric initial deflects and residual stress of the members taken into account,the influence of sectional geometric parameters and slenderness ratio on load-carrying capacity of the lipped H-section members are analyzed.Finally,based on a lot of FEA numerical results obtained,the design formulas are obtained for predicting load-carrying capacity of lipped H-members under axial loads.
2009, 39(9): 15-21.
doi: 10.13204/j.gyjz200909003
Abstract:
Lateral instability behavior of lipped H-section beams subjected to moments are investigated theoretically based on large deformation and material elastic-plasticity finite shell element analysis.Three possible failure modes will be involved in analysis,namely,plate local buckling,distortional buckling,overall buckling failure,and the interaction between them, in the case of lip's width coefficient of lipped H-section beams reaching an optimal value.The influence of both sectional geometric parameters and slenderness on lateral stability behavior of beams is analyzed systematically.Finally,based on the numbers of FEA numerical results obtained,the proposed formulas are given for predicting lateral stability capacity of lipped H-section beams under moments,which will be used in the further modification of Chinese code for steel structural design and that of engineering structures as well.
Lateral instability behavior of lipped H-section beams subjected to moments are investigated theoretically based on large deformation and material elastic-plasticity finite shell element analysis.Three possible failure modes will be involved in analysis,namely,plate local buckling,distortional buckling,overall buckling failure,and the interaction between them, in the case of lip's width coefficient of lipped H-section beams reaching an optimal value.The influence of both sectional geometric parameters and slenderness on lateral stability behavior of beams is analyzed systematically.Finally,based on the numbers of FEA numerical results obtained,the proposed formulas are given for predicting lateral stability capacity of lipped H-section beams under moments,which will be used in the further modification of Chinese code for steel structural design and that of engineering structures as well.
2009, 39(9): 22-27,14.
doi: 10.13204/j.gyjz200909004
Abstract:
As a new type of structural members,limit strength of lipped H-section members subjected to both compression and bending is studied.Failure modes of stubs subjected to local buckling interaction between plates are investigated theoretically,and the corresponding formula for predicting limit strength of stubs is obtained based on numbers of examples that are designed to evaluate the influence of section parameters of stubs.Further,with the numerical results and proposed formula of stubs,limit strength of lipped H-section members under both compression and bending is studied,considering slenderness ratio of members,and the proposed formula for predicting limit strength in plane and out of plane of members is given,respectively.
As a new type of structural members,limit strength of lipped H-section members subjected to both compression and bending is studied.Failure modes of stubs subjected to local buckling interaction between plates are investigated theoretically,and the corresponding formula for predicting limit strength of stubs is obtained based on numbers of examples that are designed to evaluate the influence of section parameters of stubs.Further,with the numerical results and proposed formula of stubs,limit strength of lipped H-section members under both compression and bending is studied,considering slenderness ratio of members,and the proposed formula for predicting limit strength in plane and out of plane of members is given,respectively.
2009, 39(9): 28-31.
doi: 10.13204/j.gyjz200909005
Abstract:
Lipped H-section members and common H-section members are compared in both stability capacity and economic performance.Firstly,different buckling modes of the two types of members are presented,and the difference of stability capacity between them can be seen clearly by the comparison of buckling coefficient of sections.Based on FE analysis considering large deformation and material elastic-plasticity,the economic performance is researched in two aspects: comparison of stability bearing capacity with the same steel consumption and comparison of steel consumption with the same stability bearing capacity.It is proved that lipped H-section members are more economic and effective than Hsection members.
Lipped H-section members and common H-section members are compared in both stability capacity and economic performance.Firstly,different buckling modes of the two types of members are presented,and the difference of stability capacity between them can be seen clearly by the comparison of buckling coefficient of sections.Based on FE analysis considering large deformation and material elastic-plasticity,the economic performance is researched in two aspects: comparison of stability bearing capacity with the same steel consumption and comparison of steel consumption with the same stability bearing capacity.It is proved that lipped H-section members are more economic and effective than Hsection members.
2009, 39(9): 32-35.
doi: 10.13204/j.gyjz200909006
Abstract:
The in-plane stability bearing capacity of lipped H-section tapered members under both compression and bending is studied,and corresponding calculation formula is also given based on the existing formula of current Chinese related technical codes.For tapered members,stability bearing capacity is seriously affected by tapering ratio,thereby a series of examples are designed to evaluate the influence of tapering ratio on stability bearing capacity of lipped H-section tapered members,meanwhile the accuracy and validity of the calculation formula proposed in the study is also confirmed.
The in-plane stability bearing capacity of lipped H-section tapered members under both compression and bending is studied,and corresponding calculation formula is also given based on the existing formula of current Chinese related technical codes.For tapered members,stability bearing capacity is seriously affected by tapering ratio,thereby a series of examples are designed to evaluate the influence of tapering ratio on stability bearing capacity of lipped H-section tapered members,meanwhile the accuracy and validity of the calculation formula proposed in the study is also confirmed.
2009, 39(9): 36-40.
doi: 10.13204/j.gyjz200909007
Abstract:
The accurate prediction of ultimate load-carrying capacity of welded box section subjected to local plate buckling has still not established in the current Chinese Code for Design of Steel Structure.This paper presents a direct strength method for predicting accurately ultimate load-carrying capacity of locally buckled box section under axial load,pure moment and their combination,respectively.A finite shell element is employed to exactly simulate the sectional geometric shape and boundary conditions,with incorporation of plate large displacement and elastic-plastic material.Based on numbers of numerical results,three simplified design formulas are respectively proposed to calculate the ultimate load-carrying capacity of the hollow section under the three load conditions mentioned above.The formulas are expressed directly with function of the component plate width-thickness ratio and section aspect ratio,and they are very convenient for designers,compared with the effective width method.
The accurate prediction of ultimate load-carrying capacity of welded box section subjected to local plate buckling has still not established in the current Chinese Code for Design of Steel Structure.This paper presents a direct strength method for predicting accurately ultimate load-carrying capacity of locally buckled box section under axial load,pure moment and their combination,respectively.A finite shell element is employed to exactly simulate the sectional geometric shape and boundary conditions,with incorporation of plate large displacement and elastic-plastic material.Based on numbers of numerical results,three simplified design formulas are respectively proposed to calculate the ultimate load-carrying capacity of the hollow section under the three load conditions mentioned above.The formulas are expressed directly with function of the component plate width-thickness ratio and section aspect ratio,and they are very convenient for designers,compared with the effective width method.
2009, 39(9): 41-48.
doi: 10.13204/j.gyjz200909008
Abstract:
Box-section columns are used widely for steel frame structures. The effective width concept employed by the current Chinese code for design of steel structure is not accurate enough for predicting their ultimate load-carrying capacity where the columns are subject to plate local buckling.This paper presents a direct strength method for accurately predicting the ultimate strength of locally buckled box-section columns.An accurate shell element is used in this study to not only simulate the local buckling exactly,but also incorporate the large displacement and the elastic-plastic material in the analysis.Numbers of numerical examples were obtained and they reveal the influences of plate is width to thickness ratio,section aspect ratio and member slenderness ratio on the ultimate strength of the hollow-section members subjected to plate local buckling.With those numerical results,three simplified design formulas are respectively proposed to estimate the ultimate strength of the hollow section columns that are subjected to centrally axial load,the pure moments and the combination between them,respectively.They will be helpful in the future modification of Chinese code for design of steel structure,and the design of hollow section columns as well.
Box-section columns are used widely for steel frame structures. The effective width concept employed by the current Chinese code for design of steel structure is not accurate enough for predicting their ultimate load-carrying capacity where the columns are subject to plate local buckling.This paper presents a direct strength method for accurately predicting the ultimate strength of locally buckled box-section columns.An accurate shell element is used in this study to not only simulate the local buckling exactly,but also incorporate the large displacement and the elastic-plastic material in the analysis.Numbers of numerical examples were obtained and they reveal the influences of plate is width to thickness ratio,section aspect ratio and member slenderness ratio on the ultimate strength of the hollow-section members subjected to plate local buckling.With those numerical results,three simplified design formulas are respectively proposed to estimate the ultimate strength of the hollow section columns that are subjected to centrally axial load,the pure moments and the combination between them,respectively.They will be helpful in the future modification of Chinese code for design of steel structure,and the design of hollow section columns as well.
2009, 39(9): 49-54,61.
doi: 10.13204/j.gyjz200909009
Abstract:
A parameter analysis of eight influencing factors of the shear performance of cold-formed steel framing walls is carried out after the finite element analysis model has been validated by test data.The analytic results show that it has little effect on the shear resistance of the wall by changing wall framing thickness,yield strength of wall framing,cross section of wall studs,vertical loading and altering the wall height in a certain range.The shear resistance of the wall can be improved effectively by thickening the wallboard;when the wall size is not changed,decreasing stud spacing is helpful to increase the shear resistance of the wall;the shear resistance of the wall and the deformation out of plane of the steel panel can be greatly improved by substituting the steel rib panel for the smooth plate,and with the increase of the steel rib height,the shear resistance of the wall is enhanced and the deformation out of plane of the steel panel is reduced.
A parameter analysis of eight influencing factors of the shear performance of cold-formed steel framing walls is carried out after the finite element analysis model has been validated by test data.The analytic results show that it has little effect on the shear resistance of the wall by changing wall framing thickness,yield strength of wall framing,cross section of wall studs,vertical loading and altering the wall height in a certain range.The shear resistance of the wall can be improved effectively by thickening the wallboard;when the wall size is not changed,decreasing stud spacing is helpful to increase the shear resistance of the wall;the shear resistance of the wall and the deformation out of plane of the steel panel can be greatly improved by substituting the steel rib panel for the smooth plate,and with the increase of the steel rib height,the shear resistance of the wall is enhanced and the deformation out of plane of the steel panel is reduced.
2009, 39(9): 55-57.
doi: 10.13204/j.gyjz200909010
Abstract:
It aims to realize a natural ventilation by building design,which not only improves a good indoor environment condition,but also saves the energy source and reduces the cost.It is described several technologies realizing a natural ventilation in building design,and researched the method and function of the building outline,building plan,building section and building component in realizing the building's natural ventilation.
It aims to realize a natural ventilation by building design,which not only improves a good indoor environment condition,but also saves the energy source and reduces the cost.It is described several technologies realizing a natural ventilation in building design,and researched the method and function of the building outline,building plan,building section and building component in realizing the building's natural ventilation.
2009, 39(9): 58-61.
doi: 10.13204/j.gyjz200909011
Abstract:
As a new way to build an ecological city,roof gardening receives more attention recently.There is a bright future in the development of roof garden projects.It has strategic meanings in the construction of ecological and sustainable cities to develop roof garden projects suitable to the national conditions of China.
As a new way to build an ecological city,roof gardening receives more attention recently.There is a bright future in the development of roof garden projects.It has strategic meanings in the construction of ecological and sustainable cities to develop roof garden projects suitable to the national conditions of China.
2009, 39(9): 62-66.
doi: 10.13204/j.gyjz200909012
Abstract:
For the dynamic performance of core-RC and composite frame structures, The space finite element models of a 30-storey hybrid structure are established,modal analysis and elastic time-history analysis are conducted.The results indicate that the connection between frame and core has obvious effect on mode shape and natural vibration periods.The inter-story displacement maximal angle occurs on the middle stories of the composite structure.There are two extremal regions of story acceleration along the height direction of the structure under earthquake. The ratios of the story shears of exterior frame are less,whereas the ratios of the story overturning moment of exterior frame are larger.the connection will lead to significant change in the deformation and distribution of internal force.
For the dynamic performance of core-RC and composite frame structures, The space finite element models of a 30-storey hybrid structure are established,modal analysis and elastic time-history analysis are conducted.The results indicate that the connection between frame and core has obvious effect on mode shape and natural vibration periods.The inter-story displacement maximal angle occurs on the middle stories of the composite structure.There are two extremal regions of story acceleration along the height direction of the structure under earthquake. The ratios of the story shears of exterior frame are less,whereas the ratios of the story overturning moment of exterior frame are larger.the connection will lead to significant change in the deformation and distribution of internal force.
2009, 39(9): 67-70.
doi: 10.13204/j.gyjz200909013
Abstract:
The problem of determining the allowable axial load ratio of concrete shear wall has not been completely solved.Through theoretical analysis and numerical calculation,the allowable axial load ratio of the rectangular crosssection shear wall without confined boundary elements has been studied.The results show that,to the given compressive ultimate strain of concrete,the aspect ratio and the target top displacement ratio are main factors which influence the allowable axial load ratio of the shear wall,the concrete strength,the strength and the ratio of vertical distribution reinforcement are less.Accordingly,a method of determining allowable axial load ratio in accordance with the aspect ratio and the target top displacement ratio is proposed.The method is simple and practical,it can also be used for revising the design code.
The problem of determining the allowable axial load ratio of concrete shear wall has not been completely solved.Through theoretical analysis and numerical calculation,the allowable axial load ratio of the rectangular crosssection shear wall without confined boundary elements has been studied.The results show that,to the given compressive ultimate strain of concrete,the aspect ratio and the target top displacement ratio are main factors which influence the allowable axial load ratio of the shear wall,the concrete strength,the strength and the ratio of vertical distribution reinforcement are less.Accordingly,a method of determining allowable axial load ratio in accordance with the aspect ratio and the target top displacement ratio is proposed.The method is simple and practical,it can also be used for revising the design code.
2009, 39(9): 71-73.
doi: 10.13204/j.gyjz200909014
Abstract:
Based on basic theory of pulsating wind and Davenport's power spectrum of wind pressure,a calculating method of wind-excited response of tall building structures in frequency domain is presented,the random vibrations analysis of tall building structures by power spectral density of the wind pressure is also carried out.The natural frequency,the mode and change in stresses after applying the wind pressure spectra to the structure are obtained by power spectral density based on ANSYS.The results indicate that analysis and treatment methods presented here are reasonable and feasible.
Based on basic theory of pulsating wind and Davenport's power spectrum of wind pressure,a calculating method of wind-excited response of tall building structures in frequency domain is presented,the random vibrations analysis of tall building structures by power spectral density of the wind pressure is also carried out.The natural frequency,the mode and change in stresses after applying the wind pressure spectra to the structure are obtained by power spectral density based on ANSYS.The results indicate that analysis and treatment methods presented here are reasonable and feasible.
2009, 39(9): 74-76,66.
doi: 10.13204/j.gyjz200909015
Abstract:
The structural design of a france beam can be done by PKPM after determining column grid layout and floor scheme.Overreinforced beams in reinforced concrete frame structures can be judged by TAT or SATWE analysis.The controlling factors of overreinforced beams are section size,input mode,preferred materials and TAT or SATWE parameters.Overreinforced beams can be avoided by reasonable parameters evaluation
The structural design of a france beam can be done by PKPM after determining column grid layout and floor scheme.Overreinforced beams in reinforced concrete frame structures can be judged by TAT or SATWE analysis.The controlling factors of overreinforced beams are section size,input mode,preferred materials and TAT or SATWE parameters.Overreinforced beams can be avoided by reasonable parameters evaluation
2009, 39(9): 77-80.
doi: 10.13204/j.gyjz200909016
Abstract:
Influences of concrete strength and steel fiber volume fraction on the ultimate bearing capacity of reinforced high-strength concrete square slabs subjected to punching shear are investigated through the experiments on six reinforced steel fiber reinforced high-strength concrete square slabs.The test results show that the deformation of slab before punching shear failure is caused by bending deformation and the steel fiber increases the ultimate bearing capacity of reinforced high-strength concrete square slabs.Finally,the formulas of ultimate bearing capacity are gotten based on the unified strength theory.
Influences of concrete strength and steel fiber volume fraction on the ultimate bearing capacity of reinforced high-strength concrete square slabs subjected to punching shear are investigated through the experiments on six reinforced steel fiber reinforced high-strength concrete square slabs.The test results show that the deformation of slab before punching shear failure is caused by bending deformation and the steel fiber increases the ultimate bearing capacity of reinforced high-strength concrete square slabs.Finally,the formulas of ultimate bearing capacity are gotten based on the unified strength theory.
2009, 39(9): 81-84.
doi: 10.13204/j.gyjz200909017
Abstract:
In the project of Shanghai Science Museum,the pre-stressing technology was used to control the cracking of the arc shaped ultra-long basement wall.The steel string type steel bar taseometer was installed in the wall in advance to examine the pre-stressing value.The measurement of the change of the pre-stressing value in the wall was lasted for eight month.The results indicated that the pre-stressing exerted on the wall has met the designed requirements.The changing of the pre-stressing value displays certain regularity in the time and the space.In the time,the performance is,the pre-stressing value of identical measuring point is firstly increasing gradually along with the time,finally tends to stability.In the space,the performance is: verticaly,in the wall,the pre-stressing value is small nearby the basement roof,then it will become the biggest at a place with some distance away from the basement roof,after that,it will reduce gradually.In crosswise,the pre-stressing value is biggest in both the tensile ends,it will then reduce gradually to the middle of the wall.Meanwhile,the crack monitoring instrument was used to monitor the cracks,the result showed that the concrete crack quantity and the scale finally were under control.The practice indicated that the pre-stressing technology is an ideal method to control the cracks of ultra-long concrete structures.
In the project of Shanghai Science Museum,the pre-stressing technology was used to control the cracking of the arc shaped ultra-long basement wall.The steel string type steel bar taseometer was installed in the wall in advance to examine the pre-stressing value.The measurement of the change of the pre-stressing value in the wall was lasted for eight month.The results indicated that the pre-stressing exerted on the wall has met the designed requirements.The changing of the pre-stressing value displays certain regularity in the time and the space.In the time,the performance is,the pre-stressing value of identical measuring point is firstly increasing gradually along with the time,finally tends to stability.In the space,the performance is: verticaly,in the wall,the pre-stressing value is small nearby the basement roof,then it will become the biggest at a place with some distance away from the basement roof,after that,it will reduce gradually.In crosswise,the pre-stressing value is biggest in both the tensile ends,it will then reduce gradually to the middle of the wall.Meanwhile,the crack monitoring instrument was used to monitor the cracks,the result showed that the concrete crack quantity and the scale finally were under control.The practice indicated that the pre-stressing technology is an ideal method to control the cracks of ultra-long concrete structures.
2009, 39(9): 85-89.
doi: 10.13204/j.gyjz200909018
Abstract:
The research is carried out in this paper about the effect of metro tunneling on the nearby underground pipeline.First of all,based on the elastic theory of Winkler's elastic beam,the equations for displacements of underground pipeline,rotation of underground pipeline,bending moment of underground pipeline,and shearing force of underground pipeline are established.Secondly,based on the proposed theories by authors,a case history is analyzed.Finally,the relationships such as he diffusion angle of the subgrade,and buried depth of the underground pipeline are obtained.According to the research,the maximum settlement of the underground pipeline is located in the pipeline's middle span of the settlement area,otherwise the maximum the bending moment of the underground pipeline and the maximum shearing force of the underground pipeline are located on the edge of the settlement area.The influence of the diffusion angle of the subgrade and the buried depth of the underground pipeline plays an important role.
The research is carried out in this paper about the effect of metro tunneling on the nearby underground pipeline.First of all,based on the elastic theory of Winkler's elastic beam,the equations for displacements of underground pipeline,rotation of underground pipeline,bending moment of underground pipeline,and shearing force of underground pipeline are established.Secondly,based on the proposed theories by authors,a case history is analyzed.Finally,the relationships such as he diffusion angle of the subgrade,and buried depth of the underground pipeline are obtained.According to the research,the maximum settlement of the underground pipeline is located in the pipeline's middle span of the settlement area,otherwise the maximum the bending moment of the underground pipeline and the maximum shearing force of the underground pipeline are located on the edge of the settlement area.The influence of the diffusion angle of the subgrade and the buried depth of the underground pipeline plays an important role.
2009, 39(9): 90-94.
doi: 10.13204/j.gyjz200909019
Abstract:
By the two-sided shearing experiments on concrete specimens strengthened by steel fiber cement mortar,the influence of surface treatment methods of old concrete,strength of steel fiber cement mortar on the interface bond strength between the mortar and the old concrete is investigated.The result demonstrates that the two factors have great influence on interface bond strength,and their interactive effect is not significant.Owing to the presence of steel fiber in the repair material,the interface bonding property has been enhanced to a certain extent.
By the two-sided shearing experiments on concrete specimens strengthened by steel fiber cement mortar,the influence of surface treatment methods of old concrete,strength of steel fiber cement mortar on the interface bond strength between the mortar and the old concrete is investigated.The result demonstrates that the two factors have great influence on interface bond strength,and their interactive effect is not significant.Owing to the presence of steel fiber in the repair material,the interface bonding property has been enhanced to a certain extent.
2009, 39(9): 95-98.
doi: 10.13204/j.gyjz200909020
Abstract:
It was studied the mechanical properties of polymer finishing mortar for external thermal insulation composite systems(ETICS) under weathering test.The experiment results indicated that the compression strength,the flexural strength and the bonding strength of polymer finishing mortar for ETICS all declined to different extent,but the flexural and compressive strength ratio of polymer finishing mortar increased.And it was also analyzed the damage mechanism of polymer finishing mortar under weathering test.
It was studied the mechanical properties of polymer finishing mortar for external thermal insulation composite systems(ETICS) under weathering test.The experiment results indicated that the compression strength,the flexural strength and the bonding strength of polymer finishing mortar for ETICS all declined to different extent,but the flexural and compressive strength ratio of polymer finishing mortar increased.And it was also analyzed the damage mechanism of polymer finishing mortar under weathering test.
2009, 39(9): 99-102.
doi: 10.13204/j.gyjz200909021
Abstract:
The effect of different wet curing period on carbonation resistance of grade 25 concretes including purified cement concrete A and three double-adding concretes(FA+SL) B,C and D was investigated under dry-cold climate via accelerated carbonation test.Liner equation between carbonation coefficient and different wetcuring period was proposed.The results show that in order to guarantee concrete service life of 50 years,A should be wet-cured for 11.2 d at least,and B,C and D should be wet-cured for 11.1 d,12.9 d and 14.5 d respectively.The more mineral admixture concrete contains,the longer the wet-curing period of concrete is for ensuring adequate carbonation resistance
The effect of different wet curing period on carbonation resistance of grade 25 concretes including purified cement concrete A and three double-adding concretes(FA+SL) B,C and D was investigated under dry-cold climate via accelerated carbonation test.Liner equation between carbonation coefficient and different wetcuring period was proposed.The results show that in order to guarantee concrete service life of 50 years,A should be wet-cured for 11.2 d at least,and B,C and D should be wet-cured for 11.1 d,12.9 d and 14.5 d respectively.The more mineral admixture concrete contains,the longer the wet-curing period of concrete is for ensuring adequate carbonation resistance
2009, 39(9): 103-106.
doi: 10.13204/j.gyjz200909022
Abstract:
This article aims to develop a new type of intelligence stress test sensor that can be used for double-intelligence control of the procedure of pretension and the prestressed reinforcement stress test after streching and anchoring,to cover the shortage on stress test and strech control of prestressed concrete construction.The primary operating principle and construction processing points were introduced in the paper.From the real efficency which verified in the engineering application instances,the technology is original,the contents are comprehensive and the results are accurate with regard to intelligence detection,because of this technology,the construction quality is assured and the generalization prospect is extensive.
This article aims to develop a new type of intelligence stress test sensor that can be used for double-intelligence control of the procedure of pretension and the prestressed reinforcement stress test after streching and anchoring,to cover the shortage on stress test and strech control of prestressed concrete construction.The primary operating principle and construction processing points were introduced in the paper.From the real efficency which verified in the engineering application instances,the technology is original,the contents are comprehensive and the results are accurate with regard to intelligence detection,because of this technology,the construction quality is assured and the generalization prospect is extensive.
2009, 39(9): 107-109,116.
doi: 10.13204/j.gyjz200909023
Abstract:
Dihao Super Tall Building in Shanghai is a higher synthetically building.In which the rectangular concrete filled steel tubular columns are adopted as frame columns.The self-compacting concrete is used.The 7.3.7 item in Technical Specification Applied to Self-Compacting Concrete shows that stipulation of the free drop height of concrete is not over 5 m.And this stipulation is broken,a short leading pipe is used to pour concrete into steel tube,then the work efficiency is raised.As well as,some effective measures are adopted to decrease the air bubbles under partitions to guarantee the construction quality.
Dihao Super Tall Building in Shanghai is a higher synthetically building.In which the rectangular concrete filled steel tubular columns are adopted as frame columns.The self-compacting concrete is used.The 7.3.7 item in Technical Specification Applied to Self-Compacting Concrete shows that stipulation of the free drop height of concrete is not over 5 m.And this stipulation is broken,a short leading pipe is used to pour concrete into steel tube,then the work efficiency is raised.As well as,some effective measures are adopted to decrease the air bubbles under partitions to guarantee the construction quality.
2009, 39(9): 110-113.
doi: 10.13204/j.gyjz200909024
Abstract:
The development of structural reliability theory was summarized and analyzed.It was described in detail the various stages of development and the advantages and disadvantages of the development process;and the methods and countermeasures of ensuring structural reliability were presented,which can provide a development way to enhance the level of research on the structural reliability.
The development of structural reliability theory was summarized and analyzed.It was described in detail the various stages of development and the advantages and disadvantages of the development process;and the methods and countermeasures of ensuring structural reliability were presented,which can provide a development way to enhance the level of research on the structural reliability.
2009, 39(9): 114-116.
doi: 10.13204/j.gyjz200909025
Abstract:
According to the actual uses of projects,it is described the difference in the calculation of wind speed and basic wind pressure as well as conversion methods between the Chinese GB 500092001 Construction Structure Load Standard and the American ASCE 705 Minimum Design Loads for Buildings and Other Structures.
According to the actual uses of projects,it is described the difference in the calculation of wind speed and basic wind pressure as well as conversion methods between the Chinese GB 500092001 Construction Structure Load Standard and the American ASCE 705 Minimum Design Loads for Buildings and Other Structures.
2009, 39(9): 117-120.
doi: 10.13204/j.gyjz200909026
Abstract:
A new main factory building is adjacent to the existing main factory building.A corner column of the new main factory building located among two existing auxiliary buildings is unable to be set.The analysis and comparison are made to solve the problems,including calculation unit of the bent frame without low-corner column,setting of the up-corner column,connection schemes between existing building and joists,etc.According to the above result,a better scheme is selected to make use of the side column of existed building to support the new up-corner column.This scheme can meet the commands of current national codes.In this scheme,the joists and supports are designed as simple-structure which is convenient for construction,safe and reasonable.
A new main factory building is adjacent to the existing main factory building.A corner column of the new main factory building located among two existing auxiliary buildings is unable to be set.The analysis and comparison are made to solve the problems,including calculation unit of the bent frame without low-corner column,setting of the up-corner column,connection schemes between existing building and joists,etc.According to the above result,a better scheme is selected to make use of the side column of existed building to support the new up-corner column.This scheme can meet the commands of current national codes.In this scheme,the joists and supports are designed as simple-structure which is convenient for construction,safe and reasonable.
2009, 39(9): 121-123,98.
doi: 10.13204/j.gyjz200909027
Abstract:
Based on the collapse of the high scaffolding for bracing forms,the cause of collapse was analyzed;it was that the constructional requirements of standard were not met.The importance of vertical cross bridging of the scaffolding was analyzed by the rigid-connected and the hinged models respectively.It was found that variable geometry system had become the invariable one for the hinged model when the cross bridging was added to the scaffolding;on the other hand for the rigid-connected model,the axle force of the vertical bar was reduced by more than 25% compared with that of the one without the cross bridging.The removing scheme was discussed.The secure line was set up before the removal work began; for the collapsed in zone Ⅰ part,the concrete plate was removed firstly.At the same time the main beam and the mesh reinforcement were remained to keep the force balance.The steel wire netting was set up on the surface of the deforming scaffolding in zone VII to strengthen the scaffolding.At last,the removal sequence of the whole structure was determined and the collapsed part was removed smoothly.
Based on the collapse of the high scaffolding for bracing forms,the cause of collapse was analyzed;it was that the constructional requirements of standard were not met.The importance of vertical cross bridging of the scaffolding was analyzed by the rigid-connected and the hinged models respectively.It was found that variable geometry system had become the invariable one for the hinged model when the cross bridging was added to the scaffolding;on the other hand for the rigid-connected model,the axle force of the vertical bar was reduced by more than 25% compared with that of the one without the cross bridging.The removing scheme was discussed.The secure line was set up before the removal work began; for the collapsed in zone Ⅰ part,the concrete plate was removed firstly.At the same time the main beam and the mesh reinforcement were remained to keep the force balance.The steel wire netting was set up on the surface of the deforming scaffolding in zone VII to strengthen the scaffolding.At last,the removal sequence of the whole structure was determined and the collapsed part was removed smoothly.
2009, 39(9): 124-126.
doi: 10.13204/j.gyjz200909028
Abstract:
It is introduced an critical potential safety hazard of a tower crane for project during lifting operation in Shenzhen.It is the derailment of the lifting hoop frame's guide wheel,which made the upper structure of the tower crane incline that caused the accident;then emergency treatments of raising,tying,strengthening and dismantling were conducted to resolve the accident effectively and timely.In the end,the causes of the accident and precautionary measures for similar incidents are analyzed and summarized.
It is introduced an critical potential safety hazard of a tower crane for project during lifting operation in Shenzhen.It is the derailment of the lifting hoop frame's guide wheel,which made the upper structure of the tower crane incline that caused the accident;then emergency treatments of raising,tying,strengthening and dismantling were conducted to resolve the accident effectively and timely.In the end,the causes of the accident and precautionary measures for similar incidents are analyzed and summarized.
2009, 39(9): 127-130.
doi: 10.13204/j.gyjz200909029
Abstract:
The original supporting design of the south side of this foundation pit is earthnail retaining wall.During construction of the earthnail retaining wall a poor drainage was caused by continuous rainfall,rain water entered back the earthnail retaining wall through the underground drains near the foundation pit's southern slope,together with non-standard construction methods,hence large areas of collapse have occurred in quite a few earthnail retaining wall and slope under construction.It was carried out a detailed analysis of the project incidents.After determining the cause of the accident,it was adjusted the original design scheme i.e.the scheme of anchor and brick wall composite structure was used.And a few of advice is provided for the construction of the earthnail retaining wall in loess region,such as attention to drainage,standard and informational construction,dynamic design.
The original supporting design of the south side of this foundation pit is earthnail retaining wall.During construction of the earthnail retaining wall a poor drainage was caused by continuous rainfall,rain water entered back the earthnail retaining wall through the underground drains near the foundation pit's southern slope,together with non-standard construction methods,hence large areas of collapse have occurred in quite a few earthnail retaining wall and slope under construction.It was carried out a detailed analysis of the project incidents.After determining the cause of the accident,it was adjusted the original design scheme i.e.the scheme of anchor and brick wall composite structure was used.And a few of advice is provided for the construction of the earthnail retaining wall in loess region,such as attention to drainage,standard and informational construction,dynamic design.
2009, 39(9): 131-134.
doi: 10.13204/j.gyjz200909030
Abstract:
Based on the accident to a composite foundation using ram-compacted piles with bearing base,the accident causes were analyzed from design and construction.Through the static loading testing and low strain testing,the accident causes of composited foundation were found out,and the measures were put forwarded,the scheme of treatment and testing as well as acceptance was also supplied,finally the quality accident had been solved out successfully.
Based on the accident to a composite foundation using ram-compacted piles with bearing base,the accident causes were analyzed from design and construction.Through the static loading testing and low strain testing,the accident causes of composited foundation were found out,and the measures were put forwarded,the scheme of treatment and testing as well as acceptance was also supplied,finally the quality accident had been solved out successfully.
2009, 39(9): 135-137.
doi: 10.13204/j.gyjz200909031
Abstract:
Tangwu is an integral part of a house,there is a profound cultural origin,but with the impact of globalization and urbanization process accelerated,few people have touched the core of their culture.Know these,I do not know why they are so since makes the destruction of the vitality of the national culture,and the urbanization lacks national identity.From the sacred and affinity two parts it is analyzed the cultural essence of Tangwu,as well as its position and role in a house of Zhenshan village,which is applied to the practice of constructions.
Tangwu is an integral part of a house,there is a profound cultural origin,but with the impact of globalization and urbanization process accelerated,few people have touched the core of their culture.Know these,I do not know why they are so since makes the destruction of the vitality of the national culture,and the urbanization lacks national identity.From the sacred and affinity two parts it is analyzed the cultural essence of Tangwu,as well as its position and role in a house of Zhenshan village,which is applied to the practice of constructions.
2009, 39(9): 138-141.
doi: 10.13204/j.gyjz200909032
Abstract:
Based on the analysis of British architect Zaha Hadid's creative central thoughts,it was analyzed thoroughly Hadid's classic work,Contemporary Arts Centre,Cincinnati in America.In order to show the dynamic composing design skill in the usage of architecture,and realize the polysemy and the illegibility of architectural design,the formation cause,characteristics and vision impression of the building modality are researched,according to the modern design view.This design breaks limit of the notion of the traditional space form,thus developing a pioneer field of architecture design in the future.
Based on the analysis of British architect Zaha Hadid's creative central thoughts,it was analyzed thoroughly Hadid's classic work,Contemporary Arts Centre,Cincinnati in America.In order to show the dynamic composing design skill in the usage of architecture,and realize the polysemy and the illegibility of architectural design,the formation cause,characteristics and vision impression of the building modality are researched,according to the modern design view.This design breaks limit of the notion of the traditional space form,thus developing a pioneer field of architecture design in the future.
