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2012 Vol. 42, No. 11
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2012, 42(11): 1-5.
doi: 10.13204/j.gyjz201211001
Abstract:
On the basis of the C120 concrete with ultra-high strength,polypropylene fibre was added and such tests were taken for concrete as early shrinkage,breaking performance,splitting and tensile strength,brittleness cracking under high temperature．It turned out that the development of concrete crack was limited by polypropylene fiber|as the increases of fiber volume fraction,the toughness of concrete was improved．The splitting and tensile strength and the ratio of tension and pressure were also increased for C120 polypropylene fiber concrete,the brittleness of concrete was improved obviously．The high temperature embrittlement of explosion had been overcome,which made C120 ultra-high strength concrete obtain high performance．
On the basis of the C120 concrete with ultra-high strength,polypropylene fibre was added and such tests were taken for concrete as early shrinkage,breaking performance,splitting and tensile strength,brittleness cracking under high temperature．It turned out that the development of concrete crack was limited by polypropylene fiber|as the increases of fiber volume fraction,the toughness of concrete was improved．The splitting and tensile strength and the ratio of tension and pressure were also increased for C120 polypropylene fiber concrete,the brittleness of concrete was improved obviously．The high temperature embrittlement of explosion had been overcome,which made C120 ultra-high strength concrete obtain high performance．
2012, 42(11): 6-10,15.
doi: 10.13204/j.gyjz201211002
Abstract:
Self-compacting ultra-high performance steel fiber reinforced concrete has the advantages in high strength,high toughness,high fluidity and durability.However,its tensile strength is still far below the compressive strength.In this experiment,superfine fiber and end-bend fiber with steel fiber volume ratio of 2% are mixed at a proportion of 3:1 in the concrete with a matrix strength higher than C100,to be applied into the ultrahigh performance fiber concrete beam of 550 MPa tensile reinforcement.Six beams with shear span ratio of 2.5 and 3 are studied in this experiment through the method of static loading tests.The results show that at compare with beams without fiber,the imitial crack load of ultra-high performance reinforced concrete beams with steel bar and hybrid steel fiber is increased by 25%～180%,the load of 0.2mm crack width is increased 73%～18%,the ultimate load is increased by 68%～317%,the ductility is increased by 3.2～4.4 times.
Self-compacting ultra-high performance steel fiber reinforced concrete has the advantages in high strength,high toughness,high fluidity and durability.However,its tensile strength is still far below the compressive strength.In this experiment,superfine fiber and end-bend fiber with steel fiber volume ratio of 2% are mixed at a proportion of 3:1 in the concrete with a matrix strength higher than C100,to be applied into the ultrahigh performance fiber concrete beam of 550 MPa tensile reinforcement.Six beams with shear span ratio of 2.5 and 3 are studied in this experiment through the method of static loading tests.The results show that at compare with beams without fiber,the imitial crack load of ultra-high performance reinforced concrete beams with steel bar and hybrid steel fiber is increased by 25%～180%,the load of 0.2mm crack width is increased 73%～18%,the ultimate load is increased by 68%～317%,the ductility is increased by 3.2～4.4 times.
2012, 42(11): 11-15.
doi: 10.13204/j.gyjz201211003
Abstract:
In order to study the shear performance of high-strength concrete and HRBF500 steel beams without web reinforcement,6 beams with different shear span ratio were tested under the concentrated load.The whole process from the appearance of cracks to breakage of the beams was observed,the strain of main reinforcement,deflection and shear capacity were analyzed.Then,the test results were compared with the shear strengths predicted by the code (GB 50010－2010) .The results showed that the shear strengths of beams of smaller span-to-depth ratios and larger span-to-depth ratios significantly differed between calculation results and the experimental results．
In order to study the shear performance of high-strength concrete and HRBF500 steel beams without web reinforcement,6 beams with different shear span ratio were tested under the concentrated load.The whole process from the appearance of cracks to breakage of the beams was observed,the strain of main reinforcement,deflection and shear capacity were analyzed.Then,the test results were compared with the shear strengths predicted by the code (GB 50010－2010) .The results showed that the shear strengths of beams of smaller span-to-depth ratios and larger span-to-depth ratios significantly differed between calculation results and the experimental results．
2012, 42(11): 16-21.
doi: 10.13204/j.gyjz201211004
Abstract:
The beams were cast with self-compacting UHPFRC and cured in normal temperature．The flexural behaviors of 8 UHPFRC beams with different reinforcement ratio were tested by static loading．The results showed that the bearing capacities of ultra-high performance concrete beams reinforced with steel bars and hybrid-fiber were increased by 13%,the ductility factors were increased by 158% ,as compared with beams with the same strength of the matrix and reinforcement ratio．Comparing with the beams without fiber,the initial crack load,and load of 0.1mm crack width of beams with fiber when the load is accounted for the proportion of the ultimate load greatly improved,but the load of 0.2 mm crack width was not very different．Comparing with beams with reinforcement ratio of 0.86% ,the flexural capacities of beams were increased by 72% and 113% respectively when the reinforcement ratios of beams were 1.52% and 2.38% ．The calculating methods of the flexural capacities of UHPFRC beams reinforced with tensile steel bars and hybrid-fiber were proposed according to the document．The calculated results corresponded well with the experimental data．
The beams were cast with self-compacting UHPFRC and cured in normal temperature．The flexural behaviors of 8 UHPFRC beams with different reinforcement ratio were tested by static loading．The results showed that the bearing capacities of ultra-high performance concrete beams reinforced with steel bars and hybrid-fiber were increased by 13%,the ductility factors were increased by 158% ,as compared with beams with the same strength of the matrix and reinforcement ratio．Comparing with the beams without fiber,the initial crack load,and load of 0.1mm crack width of beams with fiber when the load is accounted for the proportion of the ultimate load greatly improved,but the load of 0.2 mm crack width was not very different．Comparing with beams with reinforcement ratio of 0.86% ,the flexural capacities of beams were increased by 72% and 113% respectively when the reinforcement ratios of beams were 1.52% and 2.38% ．The calculating methods of the flexural capacities of UHPFRC beams reinforced with tensile steel bars and hybrid-fiber were proposed according to the document．The calculated results corresponded well with the experimental data．
2012, 42(11): 22-26,48.
doi: 10.13204/j.gyjz201211005
Abstract:
Seismic behavior of the prestressed high strength concrete beams was studied based on the low-cycle reversed load test of three prestressed concrete beams,for which the strength grade of the concrete,mild steel and prestressing strand were C80,HRBF500 and 1 860 MPa separately.The test results indicated that the main failure mode of the specimens was that the compression concrete at the top side crushed severely,while the tension reinforcing bars and prestressing strands were not broken; crushing of the high strength concrete was more sudden,inducing that strength decrease of the specimens was relatively rapid; the load-deflection hysteresis loops were fatter,and the specimens had enough energy dissipation capacity; The yielding and ultimate strength of the specimens increased with the reinforcing ratio,while the ductility factor was just the opposite; with the medium conversion reinforcing ratio,the test specimens had certain deformation capacity under reversed load; the prestressed high strength concrete beams had preferable displacement restoring capacity.Reducing the prestressed intensity was helpful to increase the energy dissipation capacity of the prestressed high strength concrete beams．
Seismic behavior of the prestressed high strength concrete beams was studied based on the low-cycle reversed load test of three prestressed concrete beams,for which the strength grade of the concrete,mild steel and prestressing strand were C80,HRBF500 and 1 860 MPa separately.The test results indicated that the main failure mode of the specimens was that the compression concrete at the top side crushed severely,while the tension reinforcing bars and prestressing strands were not broken; crushing of the high strength concrete was more sudden,inducing that strength decrease of the specimens was relatively rapid; the load-deflection hysteresis loops were fatter,and the specimens had enough energy dissipation capacity; The yielding and ultimate strength of the specimens increased with the reinforcing ratio,while the ductility factor was just the opposite; with the medium conversion reinforcing ratio,the test specimens had certain deformation capacity under reversed load; the prestressed high strength concrete beams had preferable displacement restoring capacity.Reducing the prestressed intensity was helpful to increase the energy dissipation capacity of the prestressed high strength concrete beams．
2012, 42(11): 27-31.
doi: 10.13204/j.gyjz201211006
Abstract:
Eight HRBF500 and fiber reinforced cementitious composites hollow columns under eccentric loading were tested to study the effects of experimental parameters,such as eccentricity distance,reinforcement ratio and fiber types,the load-deflection curves,the load-strain curves of the steel bar,the load-strain curves of the cementitious materials and failure characters;and the plane cross-section assumption was verified．The results showed that HRBF500 and fiber reinforced cementitious composites hollow columns had good deformation capacity and high bearing capacity under eccentric loads．Their design method was generally consistent with normal high strength concrete columns,satisfying the requirements of current code GB 50010－2010．
Eight HRBF500 and fiber reinforced cementitious composites hollow columns under eccentric loading were tested to study the effects of experimental parameters,such as eccentricity distance,reinforcement ratio and fiber types,the load-deflection curves,the load-strain curves of the steel bar,the load-strain curves of the cementitious materials and failure characters;and the plane cross-section assumption was verified．The results showed that HRBF500 and fiber reinforced cementitious composites hollow columns had good deformation capacity and high bearing capacity under eccentric loads．Their design method was generally consistent with normal high strength concrete columns,satisfying the requirements of current code GB 50010－2010．
2012, 42(11): 32-35,40.
doi: 10.13204/j.gyjz201211007
Abstract:
In order to research the anti-crack bearing capacity of steel reinforced high-strength concrete short-leg shear wall joint,4 steel reinforced high-strength concrete short-leg shear wall joints and 1 high-strength concrete short-leg shear wall joint are designed for the low cycle loading test,taking account of the variable parameters of steel type,axial compression ratio and beam type．Test results show that the whole failure process of joints experiences first-crack,full-crack, ultimate and failure successively.First-crack loading is approximately from 30 to 40 percentage of ultimate loading．Different steel type has the obvious influence on the anti-crack bearing capacity．Increasing axial compression ratio can improve the anti-crack bearing capacity of joints.Based on experimental research,the anti-crack bearing capacity formula of joint is proposed,calculated results agree well with test results．
In order to research the anti-crack bearing capacity of steel reinforced high-strength concrete short-leg shear wall joint,4 steel reinforced high-strength concrete short-leg shear wall joints and 1 high-strength concrete short-leg shear wall joint are designed for the low cycle loading test,taking account of the variable parameters of steel type,axial compression ratio and beam type．Test results show that the whole failure process of joints experiences first-crack,full-crack, ultimate and failure successively.First-crack loading is approximately from 30 to 40 percentage of ultimate loading．Different steel type has the obvious influence on the anti-crack bearing capacity．Increasing axial compression ratio can improve the anti-crack bearing capacity of joints.Based on experimental research,the anti-crack bearing capacity formula of joint is proposed,calculated results agree well with test results．
2012, 42(11): 36-40.
doi: 10.13204/j.gyjz201211008
Abstract:
To achieve the housing industry is based on the premise of the standardization of residential design．And to implement the module coordination and integrate the industrial chain resources are key task in the standardization of residential design．Therefore,with the graphical method under the modulus co-ordination principle,it was proposed the basic concept of combined unit of rural residence by analyzing the life content of the principal room,wing room,kitchen and bathroom．Then,the graphic of standard units'combination was created by the unit concept,and the standard grid of columns was created by the graphic of standard units'combination．Finally,the modulus relationship of the standard design was established．Based on the standard combination of units and the standard grid of column,it was discussed the compound mode and its spatial characteristics of the standard components．Which would solve the contradiction between standardization and diversity．
To achieve the housing industry is based on the premise of the standardization of residential design．And to implement the module coordination and integrate the industrial chain resources are key task in the standardization of residential design．Therefore,with the graphical method under the modulus co-ordination principle,it was proposed the basic concept of combined unit of rural residence by analyzing the life content of the principal room,wing room,kitchen and bathroom．Then,the graphic of standard units'combination was created by the unit concept,and the standard grid of columns was created by the graphic of standard units'combination．Finally,the modulus relationship of the standard design was established．Based on the standard combination of units and the standard grid of column,it was discussed the compound mode and its spatial characteristics of the standard components．Which would solve the contradiction between standardization and diversity．
THE ECOLOGICAL DESIGN STRATEGY OF THE ICE HOCKEY GYMNASIUM IN HARBIN INSTITUTE OF PHYSICAL EDUCATION
2012, 42(11): 41-44.
doi: 10.13204/j.gyjz201211009
Abstract:
Aiming at the common phenomenon that the development of sports building for ice games in cold regions is faced with various environment pressures,through analyzing the characteristics of the sports buildings for ice games and the different ecological hierarchies of their surroundings,as well as combining with the practical project of ice hockey gymnasium in Harbin Institute of Physical Education,it is then proposed ecological design methods of the sports buildings for ice games in cold regions,so as to realize the harmonious development between the sprorts buildings for ice games and the ecological environment．
Aiming at the common phenomenon that the development of sports building for ice games in cold regions is faced with various environment pressures,through analyzing the characteristics of the sports buildings for ice games and the different ecological hierarchies of their surroundings,as well as combining with the practical project of ice hockey gymnasium in Harbin Institute of Physical Education,it is then proposed ecological design methods of the sports buildings for ice games in cold regions,so as to realize the harmonious development between the sprorts buildings for ice games and the ecological environment．
2012, 42(11): 45-48.
doi: 10.13204/j.gyjz201211010
Abstract:
It analyses the comprehensive planning sight design and the conception of corporation brandculture construction of Guanghua Garden．The garden is not only organic component of city public space,but also a carrier of the corporation culture,which will embody its social responsibility and value by a positive and constructive conception．
It analyses the comprehensive planning sight design and the conception of corporation brandculture construction of Guanghua Garden．The garden is not only organic component of city public space,but also a carrier of the corporation culture,which will embody its social responsibility and value by a positive and constructive conception．
2012, 42(11): 49-52.
doi: 10.13204/j.gyjz201211011
Abstract:
Along with the social economy unceasing development,China has entered the period of quickening urbanization.The industrial parks,and economic development zones emerge in large numbers,hence the landscape construction of the attracted parks in our country has become the important subject of building the future city.Taking the landscape design of the multifuction park in Zhangzhou Gulei Economic Development Zone for example,it is analysed the park design ideas and principles,park design characteristics and expression of local culture in landscape design,and explored the development zone park iandscape design ideas．
Along with the social economy unceasing development,China has entered the period of quickening urbanization.The industrial parks,and economic development zones emerge in large numbers,hence the landscape construction of the attracted parks in our country has become the important subject of building the future city.Taking the landscape design of the multifuction park in Zhangzhou Gulei Economic Development Zone for example,it is analysed the park design ideas and principles,park design characteristics and expression of local culture in landscape design,and explored the development zone park iandscape design ideas．
2012, 42(11): 53-55,86.
doi: 10.13204/j.gyjz201211012
Abstract:
Through the research on the Northwest Henan natural climate and geographical location as well as the status of enerty-saving of urban villages under villages under construction,it was analysed building energy-saving issues of urban villages in the northwest of Henan Province.On the design stage a comprehensive evaluation index system of building energy-saving for the said urban villages was set up．
Through the research on the Northwest Henan natural climate and geographical location as well as the status of enerty-saving of urban villages under villages under construction,it was analysed building energy-saving issues of urban villages in the northwest of Henan Province.On the design stage a comprehensive evaluation index system of building energy-saving for the said urban villages was set up．
2012, 42(11): 56-59.
doi: 10.13204/j.gyjz201211013
Abstract:
Eco-composite wall acting as the main bearing member of an eco-composite wall structure is consisted of concealed frame and eco-composite slab．The ultimate capacity analysis of eco-composite wall is the main contents of the analysis of the structural ultimate bearing capacity and seismic performance evaluation．According to the mechanical behavior and failure process of the wall,shear resistant mechanism of eco-composite wall under limit state of bearing capacity was proposed．The calculating equations for ultimate strength were provided from shear resistant mechanism and equilibrium conditions,and at the same time it was analyzed the ultimate bearing capacity of the preliminary research walls．Theoretical researches and experimental analysis show that the model can better reflect the ultimate strength properties of the ecological composite wall,can be applied to check the ultimate strength under different load conditions of the ecological composite wall．
Eco-composite wall acting as the main bearing member of an eco-composite wall structure is consisted of concealed frame and eco-composite slab．The ultimate capacity analysis of eco-composite wall is the main contents of the analysis of the structural ultimate bearing capacity and seismic performance evaluation．According to the mechanical behavior and failure process of the wall,shear resistant mechanism of eco-composite wall under limit state of bearing capacity was proposed．The calculating equations for ultimate strength were provided from shear resistant mechanism and equilibrium conditions,and at the same time it was analyzed the ultimate bearing capacity of the preliminary research walls．Theoretical researches and experimental analysis show that the model can better reflect the ultimate strength properties of the ecological composite wall,can be applied to check the ultimate strength under different load conditions of the ecological composite wall．
2012, 42(11): 60-67,126.
doi: 10.13204/j.gyjz201211014
Abstract:
The multi-tower-connected structure with enlarged base is a new type of structure．Twenty analysis models were established with ETABS finite element analysis software,and vibration model response spectrum method was used to analyse the seismic response of double-tower-connected structure with enlarged base and transfer story．It was discussed the following respectively:1)The seismic response analysis of the equal height double-tower-connected and the equal height multi-tower(unconnected)structure with enlarged base and transfer story;2)The seismic response analysis of the equal height and unequal height double-tower-connected structure with enlarged base and transfer story;3)The effect of podium stories on the seismic response of the double-tower-connected structure with enlarged base and transfer story;4)The effect of transfer stories on the seismic response of the double-tower-connected structure with enlarged base and transfer story;5)The effect of connection(the position change of connection,the story change of connection,the connection mode change)on the seismic response of the double-tower-connected structure with enlarged base and transfer story．Finally the design analysis method and design suggestions of actual engineering were put forward．
The multi-tower-connected structure with enlarged base is a new type of structure．Twenty analysis models were established with ETABS finite element analysis software,and vibration model response spectrum method was used to analyse the seismic response of double-tower-connected structure with enlarged base and transfer story．It was discussed the following respectively:1)The seismic response analysis of the equal height double-tower-connected and the equal height multi-tower(unconnected)structure with enlarged base and transfer story;2)The seismic response analysis of the equal height and unequal height double-tower-connected structure with enlarged base and transfer story;3)The effect of podium stories on the seismic response of the double-tower-connected structure with enlarged base and transfer story;4)The effect of transfer stories on the seismic response of the double-tower-connected structure with enlarged base and transfer story;5)The effect of connection(the position change of connection,the story change of connection,the connection mode change)on the seismic response of the double-tower-connected structure with enlarged base and transfer story．Finally the design analysis method and design suggestions of actual engineering were put forward．
2012, 42(11): 68-73,96.
doi: 10.13204/j.gyjz201211015
Abstract:
This paper was based on experimental research on shear capacity of concrete members confined with highstrength stirrups．The experimental result indicates that concrete members with high-strength stirrups have good seismic performances．The truss-arch model derived in this paper was used to calculate the shear capacity of concrete members confined with high-strength stirrups．The calculation results were comparable with the experimental results,and shear calculation formula of the practical theory for concrete members confined with high-strength stirrups was proposed in this paper．
This paper was based on experimental research on shear capacity of concrete members confined with highstrength stirrups．The experimental result indicates that concrete members with high-strength stirrups have good seismic performances．The truss-arch model derived in this paper was used to calculate the shear capacity of concrete members confined with high-strength stirrups．The calculation results were comparable with the experimental results,and shear calculation formula of the practical theory for concrete members confined with high-strength stirrups was proposed in this paper．
2012, 42(11): 74-77,110.
doi: 10.13204/j.gyjz201211016
Abstract:
Due to rapid industrialization and increased urbanization,the contamination of soils with heavy metals have become a serious environmental problem in many parts of the world．The contamination of soils by toxic heavy metals,such as lead,zinc and copper,may lead to the change in soil engineering properties．Solidification and stabilization is one of the most effective methods of dealing with heavy metal contaminated sites．It was investigated the engineering properties of solidified and stabilized heavy metal contaminated soils．Test results showed that the shear strength of stabilized soils decreased when contaminated by heavy metal．The shear strength of solidified and stabilized contaminated soils increased with the increase in curing age and added cement content．The results also indicated that the presence of lower concentration heavy metal ions could promote the improvement of the shear strength of cement stabilized soil．
Due to rapid industrialization and increased urbanization,the contamination of soils with heavy metals have become a serious environmental problem in many parts of the world．The contamination of soils by toxic heavy metals,such as lead,zinc and copper,may lead to the change in soil engineering properties．Solidification and stabilization is one of the most effective methods of dealing with heavy metal contaminated sites．It was investigated the engineering properties of solidified and stabilized heavy metal contaminated soils．Test results showed that the shear strength of stabilized soils decreased when contaminated by heavy metal．The shear strength of solidified and stabilized contaminated soils increased with the increase in curing age and added cement content．The results also indicated that the presence of lower concentration heavy metal ions could promote the improvement of the shear strength of cement stabilized soil．
2012, 42(11): 78-81.
doi: 10.13204/j.gyjz201211017
Abstract:
A series of tests and Proctor compaction test were carried out to study the compaction characteristics of Malan Losses．Analysis were made of the influence of water content on compaction effect and compaction effect of single or the new combination technology．The reference index of physical and mechanical property of compact Malan Losses were gained,and it was also given reference value of ground bearing capacity and modulus of deformation．The results of the tests showed that compact Malan losses had strong water susceptibility,and water content controlling was the key factor of compaction effect;the scope of water content controlling in-situ was 12%～14% and maximum dry density was 1.85～1.89g/cm3 ．The vibrating-dynamic combination technology was best for compacting Malan Losses,and the construction speed of this technology was rapid and compliance was good,and it best for gully fill construction．
A series of tests and Proctor compaction test were carried out to study the compaction characteristics of Malan Losses．Analysis were made of the influence of water content on compaction effect and compaction effect of single or the new combination technology．The reference index of physical and mechanical property of compact Malan Losses were gained,and it was also given reference value of ground bearing capacity and modulus of deformation．The results of the tests showed that compact Malan losses had strong water susceptibility,and water content controlling was the key factor of compaction effect;the scope of water content controlling in-situ was 12%～14% and maximum dry density was 1.85～1.89g/cm3 ．The vibrating-dynamic combination technology was best for compacting Malan Losses,and the construction speed of this technology was rapid and compliance was good,and it best for gully fill construction．
2012, 42(11): 82-86.
doi: 10.13204/j.gyjz201211018
Abstract:
The magnifying coefficient of earthquake acceleration peak value could be obtained,using numeric calculation method to analyze the earthquake response and compare inner points with ground reference ones in earthquake for a certain slope model．The most dangerous stress state of the slope could be obtained,using numeric calculation to multiply the acceleration magnifying coefficient by ground designed acceleration as the level acceleration of a point．In order to estimate the earthquake dynamic stability of a slope,the potential sliding faces were enacted and their safety factors were analyzed．
The magnifying coefficient of earthquake acceleration peak value could be obtained,using numeric calculation method to analyze the earthquake response and compare inner points with ground reference ones in earthquake for a certain slope model．The most dangerous stress state of the slope could be obtained,using numeric calculation to multiply the acceleration magnifying coefficient by ground designed acceleration as the level acceleration of a point．In order to estimate the earthquake dynamic stability of a slope,the potential sliding faces were enacted and their safety factors were analyzed．
2012, 42(11): 87-91.
doi: 10.13204/j.gyjz201211019
Abstract:
The model of the interaction of tall building-thick raft foundation-soil was set up according to the typical ground soils of Beijing and general structure．The differential settlement and inclination of different positions between main building and podiums was analyzed under different structural style．The results were reference to design an integral raft foundation and control diffrential settlements．
The model of the interaction of tall building-thick raft foundation-soil was set up according to the typical ground soils of Beijing and general structure．The differential settlement and inclination of different positions between main building and podiums was analyzed under different structural style．The results were reference to design an integral raft foundation and control diffrential settlements．
2012, 42(11): 92-96.
doi: 10.13204/j.gyjz201211020
Abstract:
In order to colligate the virtue of bonding-anchor and wedge-anchor,the wedge-bond anchorage for CFRP tendons was investigated,which was made by bonding and wedge parts, working in parallel．Based on the characteristics of exiting CFRP tendon anchors and according to a series of static load tests,it was studied the bonding property of colloid,and the influence of bond length,colloids thickness on the performance of straight pipe bonding anchorage．The static load test of wedge-bond anchorage was conducted to investigate its failure mode,ultimate load,slip deformation,etc．Transport mechanism of anchorage stress is preliminarily analysed according to variation of actual stress in the anchorage zone．The influences of variation in specific parameters,such as wedge slope,angular differential,presetting load,on the internal stress of the anchorage were simulated by using finite element method．And the suggested design parameters were offered．Which can provide academic reference for the optimization of wedge-bond anchorage．
In order to colligate the virtue of bonding-anchor and wedge-anchor,the wedge-bond anchorage for CFRP tendons was investigated,which was made by bonding and wedge parts, working in parallel．Based on the characteristics of exiting CFRP tendon anchors and according to a series of static load tests,it was studied the bonding property of colloid,and the influence of bond length,colloids thickness on the performance of straight pipe bonding anchorage．The static load test of wedge-bond anchorage was conducted to investigate its failure mode,ultimate load,slip deformation,etc．Transport mechanism of anchorage stress is preliminarily analysed according to variation of actual stress in the anchorage zone．The influences of variation in specific parameters,such as wedge slope,angular differential,presetting load,on the internal stress of the anchorage were simulated by using finite element method．And the suggested design parameters were offered．Which can provide academic reference for the optimization of wedge-bond anchorage．
2012, 42(11): 97-101,144.
doi: 10.13204/j.gyjz201211021
Abstract:
Through the CFRP anchor bond performance test after acid,alkali,salt,freeze-thaw cycle environmental impact,fitting different environment bond-slip relational expression and also based on the test parameters,CFRP anchor bond unit was simulated with nonlinear spring element Combin 39 of ANSYS．The fit -s curve was used for determining F-S relation parameters of the spring unit．The comparison between the simulation analysis and experimental results showed that the fit bond-slip relation curve could reflect well the CFRP reinforcement and epoxy mortar performance changes after acid,alkali,salt,freeze-thaw cycle environmental impact．Which provided a theoretical basis for performance analysis,design theory and engineering application of CFRP anchor under special environment,also provided a reference for compiling and perfecting relevant norms．
Through the CFRP anchor bond performance test after acid,alkali,salt,freeze-thaw cycle environmental impact,fitting different environment bond-slip relational expression and also based on the test parameters,CFRP anchor bond unit was simulated with nonlinear spring element Combin 39 of ANSYS．The fit -s curve was used for determining F-S relation parameters of the spring unit．The comparison between the simulation analysis and experimental results showed that the fit bond-slip relation curve could reflect well the CFRP reinforcement and epoxy mortar performance changes after acid,alkali,salt,freeze-thaw cycle environmental impact．Which provided a theoretical basis for performance analysis,design theory and engineering application of CFRP anchor under special environment,also provided a reference for compiling and perfecting relevant norms．
2012, 42(11): 102-105.
doi: 10.13204/j.gyjz201211022
Abstract:
In order to study the damage after concrete cracking,the influence of the combined use of steel fiber and carbon fiber on the conductivity and crack resistance of concrete beam under flexural loading were investigated．Carbon fiber and steel fiber were added as diphasic conductive materials to produce the electric conductive and ductile concrete.It was reported the experimental and analytical work associated with establishing the crack width in relation to the fractional change in resistance of electric conductive concrete．After cracking,the electrical resistance change was found to correlate linearly with the crack width on the tension side of concrete beam．
In order to study the damage after concrete cracking,the influence of the combined use of steel fiber and carbon fiber on the conductivity and crack resistance of concrete beam under flexural loading were investigated．Carbon fiber and steel fiber were added as diphasic conductive materials to produce the electric conductive and ductile concrete.It was reported the experimental and analytical work associated with establishing the crack width in relation to the fractional change in resistance of electric conductive concrete．After cracking,the electrical resistance change was found to correlate linearly with the crack width on the tension side of concrete beam．
2012, 42(11): 106-110.
doi: 10.13204/j.gyjz201211023
Abstract:
Tianjin Cihai Bridge is a hybrid structure of new cable-stayed bridge with giant wheel．Three wind tunnel models of hybrid structure were established in order to comprehensively understand and judge the structure's dynamic characteristics of wind action,and to study the vibration phenomenon by air wake．With tunnel test,wind force coefficients from different wind angel between the directions of bridge axis were acquired,and through the experimental observation and data analysis the phenomenon of vibration by air wake was judged.The result shows that the phenomenon of vibration by air wake will not occur after completion of the overall structure,but in the construction of the main tower only,if the design wind speed is close to the resonant wind speed the phenomenon of vibration by air wake will occur．The measure of setting partitions between the inverted Y towers can be used to improve the stiffness of the main tower,and then to avoid the occurrence of unstable vibration by air wake．
Tianjin Cihai Bridge is a hybrid structure of new cable-stayed bridge with giant wheel．Three wind tunnel models of hybrid structure were established in order to comprehensively understand and judge the structure's dynamic characteristics of wind action,and to study the vibration phenomenon by air wake．With tunnel test,wind force coefficients from different wind angel between the directions of bridge axis were acquired,and through the experimental observation and data analysis the phenomenon of vibration by air wake was judged.The result shows that the phenomenon of vibration by air wake will not occur after completion of the overall structure,but in the construction of the main tower only,if the design wind speed is close to the resonant wind speed the phenomenon of vibration by air wake will occur．The measure of setting partitions between the inverted Y towers can be used to improve the stiffness of the main tower,and then to avoid the occurrence of unstable vibration by air wake．
2012, 42(11): 111-114.
doi: 10.13204/j.gyjz201211024
Abstract:
In this paper,eight top and seat angle connections were selected for parameters analysis with ANSYS 10.0,based on three-parameter power model which was fit for structural analysis．The results were testified with prevenient test data and others M－ curves were got．The suggested value of shape coefficient(n)was got by numerical analysis method of these curves．The research indicated that numerical curves is fitted with test curves and FEA curves perfectly,and the shape coefficient(n)value of those numerical curves have small difference．By contrast of the initial stiffness and ultimate bending moment and those fitting curves,it was suggested that the value of the shape coefficient(n)of top and seat angle connections should be 1.9．
In this paper,eight top and seat angle connections were selected for parameters analysis with ANSYS 10.0,based on three-parameter power model which was fit for structural analysis．The results were testified with prevenient test data and others M－ curves were got．The suggested value of shape coefficient(n)was got by numerical analysis method of these curves．The research indicated that numerical curves is fitted with test curves and FEA curves perfectly,and the shape coefficient(n)value of those numerical curves have small difference．By contrast of the initial stiffness and ultimate bending moment and those fitting curves,it was suggested that the value of the shape coefficient(n)of top and seat angle connections should be 1.9．
2012, 42(11): 115-120.
doi: 10.13204/j.gyjz201211025
Abstract:
Truss string structure is applied more and more to platform canopy of railway stations．Taking truss string structure of Beijing North Railway Station for example,the relationship between mechanical behavior and structural parameters are researched,from which it has been found that vertical distance and axial stiffness of the cable can greatly improve the structural mechanical properties under dead-load．Compared to dead-load,truss string structure is more sensitive to wind-load,research show that structural wind-resistance performance can be optimized through changing the vector high,cable-vertical distance and sectional area,etc．Based on the results of the structural performance research,the optimization design method for truss string structure is proposed,and this method has been applied to the canopy of Beijing North Railway Station successfully．
Truss string structure is applied more and more to platform canopy of railway stations．Taking truss string structure of Beijing North Railway Station for example,the relationship between mechanical behavior and structural parameters are researched,from which it has been found that vertical distance and axial stiffness of the cable can greatly improve the structural mechanical properties under dead-load．Compared to dead-load,truss string structure is more sensitive to wind-load,research show that structural wind-resistance performance can be optimized through changing the vector high,cable-vertical distance and sectional area,etc．Based on the results of the structural performance research,the optimization design method for truss string structure is proposed,and this method has been applied to the canopy of Beijing North Railway Station successfully．
2012, 42(11): 121-126.
doi: 10.13204/j.gyjz201211026
Abstract:
Analyses of structural form selection of a gymnasium in the Philippines were carried out．The maximum wind speed for design is 215 km/h,the wind force is 17 level and it belongs to hurricane．Therefore,the designs of long-span roof become especially difficult．The lower natatorium roof was used to be the top roof's supports and stand．The top roof was a long-span space steel truss structure which had a span dimension of 130.0m31.0m．Considering the characteristics such as roof being large span and its overall structure being super-long,the plane pipe truss was used in top roof and the spatial triangle pipe truss structure was used in the lower roof and stands．Due to comparison and selection of different structure schemes,pipe truss structure,space truss structure set with pulling up and down prestressed cable,space truss structure with pulling up prestressed cable and self-balance steel-tube filled with concrete were selected．Analyses models were built and the nonlinear analyses were performed．Structural deflection,members dimension,structural materials,and construction difficulties were investigated,it was found that scheme 3 had a good economy and structural performance,which was suitable for long-span structures under hurricane．The research results can be referenced by designing other similar long-span structures．
Analyses of structural form selection of a gymnasium in the Philippines were carried out．The maximum wind speed for design is 215 km/h,the wind force is 17 level and it belongs to hurricane．Therefore,the designs of long-span roof become especially difficult．The lower natatorium roof was used to be the top roof's supports and stand．The top roof was a long-span space steel truss structure which had a span dimension of 130.0m31.0m．Considering the characteristics such as roof being large span and its overall structure being super-long,the plane pipe truss was used in top roof and the spatial triangle pipe truss structure was used in the lower roof and stands．Due to comparison and selection of different structure schemes,pipe truss structure,space truss structure set with pulling up and down prestressed cable,space truss structure with pulling up prestressed cable and self-balance steel-tube filled with concrete were selected．Analyses models were built and the nonlinear analyses were performed．Structural deflection,members dimension,structural materials,and construction difficulties were investigated,it was found that scheme 3 had a good economy and structural performance,which was suitable for long-span structures under hurricane．The research results can be referenced by designing other similar long-span structures．
2012, 42(11): 127-130,120.
doi: 10.13204/j.gyjz201211027
Abstract:
With consideration of the intermediate principal stress,the calculation formula of bearing capacity of RPC filled steel tube columns under axial compression was deduced based on the twin shear unified strength theory．Combining with the bond-slip theory,new ultimate bearing capacity formula was derived with the highest regard for bond stress．Compared with the theoretical result and the experimental data,good agreement could be found．The results show that unified strength theory and the bond-slip theory are versatile in theoretical analysis of the column．The analysis results can provide a theoretical basis for the optimum design of RPC filled steel tube and the solution has an important practical value for engineering application．
With consideration of the intermediate principal stress,the calculation formula of bearing capacity of RPC filled steel tube columns under axial compression was deduced based on the twin shear unified strength theory．Combining with the bond-slip theory,new ultimate bearing capacity formula was derived with the highest regard for bond stress．Compared with the theoretical result and the experimental data,good agreement could be found．The results show that unified strength theory and the bond-slip theory are versatile in theoretical analysis of the column．The analysis results can provide a theoretical basis for the optimum design of RPC filled steel tube and the solution has an important practical value for engineering application．
2012, 42(11): 131-149.
doi: 10.13204/j.gyjz201211028
Abstract:
It was introduced a new type air-cooling tower,which was built up with triangular lattice structural system and horizontal stiffened rings．Under actions of dead ＆ live loads,earthquake,temperature and wind loads,modeling and calculating work was done by STAAD software．Statical features and spatial performance of this structural system were discussed|distribution regularities of internal forces were analyzed for all kinds of members．And by changing stiffened rings quantities and diameter-to-camber ratio,the differences were achieved．Conclusion shows that this system has good structural integrity,bigger lateral stiffness and wind resisting capacity|it is suitable for construction of air-cooling tower．
It was introduced a new type air-cooling tower,which was built up with triangular lattice structural system and horizontal stiffened rings．Under actions of dead ＆ live loads,earthquake,temperature and wind loads,modeling and calculating work was done by STAAD software．Statical features and spatial performance of this structural system were discussed|distribution regularities of internal forces were analyzed for all kinds of members．And by changing stiffened rings quantities and diameter-to-camber ratio,the differences were achieved．Conclusion shows that this system has good structural integrity,bigger lateral stiffness and wind resisting capacity|it is suitable for construction of air-cooling tower．
2012, 42(11): 136-139.
doi: 10.13204/j.gyjz201211029
Abstract:
To promote the technology of externally prestressed concrete structures,especially in the reinforcement of low-strength concrete beams．Twelve externally prestressed concrete beams were tested with static load．Combining with the study of bending performance of model beam,it was analyzed the affect of the stress increment of tendon on flexural capacity．Test results show that the stress increment is the important factor influencing accuracy of bending capacity of externally prestressed concrete beams,and is significantly lower,and the value of the stress increment specified as 100 MPa in JGJ 92 it is suggested that this value should be 170 MPa．
To promote the technology of externally prestressed concrete structures,especially in the reinforcement of low-strength concrete beams．Twelve externally prestressed concrete beams were tested with static load．Combining with the study of bending performance of model beam,it was analyzed the affect of the stress increment of tendon on flexural capacity．Test results show that the stress increment is the important factor influencing accuracy of bending capacity of externally prestressed concrete beams,and is significantly lower,and the value of the stress increment specified as 100 MPa in JGJ 92 it is suggested that this value should be 170 MPa．
2012, 42(11): 140-144.
doi: 10.13204/j.gyjz201211030
Abstract:
Based on the flexural experimental research on RC concrete beams strengthened with NSM CFRP tendons,the reliability index before and after reinforced concrete beams strengthened with the amount of CFRP tendons was studied．The reliability analysis of different amount of RC concrete beams strengthened with NSM CFRP tendons was discussed．The results showed that the reliability index could be enhanced maximally by 79.52%,which not only made full use of the intensity of the CFRP tendons,but also improved observably the reliability of the reinforced beams．The reinforcement effect with two NSM CFRP tendons was better than the others．
Based on the flexural experimental research on RC concrete beams strengthened with NSM CFRP tendons,the reliability index before and after reinforced concrete beams strengthened with the amount of CFRP tendons was studied．The reliability analysis of different amount of RC concrete beams strengthened with NSM CFRP tendons was discussed．The results showed that the reliability index could be enhanced maximally by 79.52%,which not only made full use of the intensity of the CFRP tendons,but also improved observably the reliability of the reinforced beams．The reinforcement effect with two NSM CFRP tendons was better than the others．
2012, 42(11): 145-150.
doi: 10.13204/j.gyjz201211031
Abstract:
It was presented that the aseismic appraisal method and checck on the original structure,overall calculation and feasibility analysis of story-adding structure,by taking the story-adding reform of a hotel．It was also given the structure of the story-adding concrete columns,detail of the joints between the added steel structure and the original concrete column and beam,as well as the methods to ensure the integrity and reliability between the new and old members．Angle steel-encasing,steel plate-gluing and section-increasing were used for the framed column and framed beam with insufficient capacities respectively in the original structure．The method to strengthen the joints,and matters needing attention during comstruction were presented．The project was completed in 2010 and was decorated into a five-star hotel,which has been used so far and excellent effect has been got．
It was presented that the aseismic appraisal method and checck on the original structure,overall calculation and feasibility analysis of story-adding structure,by taking the story-adding reform of a hotel．It was also given the structure of the story-adding concrete columns,detail of the joints between the added steel structure and the original concrete column and beam,as well as the methods to ensure the integrity and reliability between the new and old members．Angle steel-encasing,steel plate-gluing and section-increasing were used for the framed column and framed beam with insufficient capacities respectively in the original structure．The method to strengthen the joints,and matters needing attention during comstruction were presented．The project was completed in 2010 and was decorated into a five-star hotel,which has been used so far and excellent effect has been got．
APPLICATION OF PVA FIBER SHRINKAGE-COMPENSATING CONCRETE ABOUT LARGE-SCALE UNDERGROUND INDUSTRY TANK
2012, 42(11): 151-153,150.
doi: 10.13204/j.gyjz201211032
Abstract:
On the basis of experimental research about PVA fiber shrinkage-compensating concrete,combined with the technology measures such as expansive reinforce tape,improvement of horizontal bar,construction quality monitoring,the jointless design and construction is successfully carried out for an large-scale underground industry tank．The water storage test results show that practical water leakages of each tank grid accounted for only permits water leakage 56%～60% ,the impermeability can meet the design requirements,and achieved the desired effect．
On the basis of experimental research about PVA fiber shrinkage-compensating concrete,combined with the technology measures such as expansive reinforce tape,improvement of horizontal bar,construction quality monitoring,the jointless design and construction is successfully carried out for an large-scale underground industry tank．The water storage test results show that practical water leakages of each tank grid accounted for only permits water leakage 56%～60% ,the impermeability can meet the design requirements,and achieved the desired effect．
2012, 42(11): 154-157.
doi: 10.13204/j.gyjz201211033
Abstract:
In order to meet the rapid changes in the personal,social and environmental needs,architects have been looking for the best combination of up-to-date technology and architecture,to realize the adaptive dynamic architecture．In this paper,according to the time order,the dynamic architectures were divided into four categories:The mobile architecture based on nomadic complex;the changeable architecture based on the dynamic technology;the intelligent architecture based on sustainable technology;and the interactive architecture based on interactive technology,which were analyzed in order to get the panorama of the mrodern dynamic architectures．
In order to meet the rapid changes in the personal,social and environmental needs,architects have been looking for the best combination of up-to-date technology and architecture,to realize the adaptive dynamic architecture．In this paper,according to the time order,the dynamic architectures were divided into four categories:The mobile architecture based on nomadic complex;the changeable architecture based on the dynamic technology;the intelligent architecture based on sustainable technology;and the interactive architecture based on interactive technology,which were analyzed in order to get the panorama of the mrodern dynamic architectures．
2012, 42(11): 158-162.
doi: 10.13204/j.gyjz201211034
Abstract:
On the background of rapid development of digital design in China,this article discussed the principle of computer-aided architecture design (CAAD ) through showing a comprehensive view of the root and technical strategies of CAAD．With the CAAD influence index (CAADII) proposed,different influential extent of each CAAD strategy to the design process was analyzed,and the future development of CAAD was proposed．
On the background of rapid development of digital design in China,this article discussed the principle of computer-aided architecture design (CAAD ) through showing a comprehensive view of the root and technical strategies of CAAD．With the CAAD influence index (CAADII) proposed,different influential extent of each CAAD strategy to the design process was analyzed,and the future development of CAAD was proposed．
