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2012 Vol. 42, No. 12
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2012, 42(12): 1-4.
doi: 10.13204/j.gyjz201212001
Abstract:
The establishing of sustainable residential district is critical to the sustainable development of the whole society.Currently,rapid progress has been made in the construction of such districts,however there are still some problems needed to solve urgently.It was analyzed the feature and background of these problems first,then from the design mode of ecovillage studied the effectiveness of applying such design mode to resolve these problems,and it was also proposed some specific design methods suitable for the condition of China.
The establishing of sustainable residential district is critical to the sustainable development of the whole society.Currently,rapid progress has been made in the construction of such districts,however there are still some problems needed to solve urgently.It was analyzed the feature and background of these problems first,then from the design mode of ecovillage studied the effectiveness of applying such design mode to resolve these problems,and it was also proposed some specific design methods suitable for the condition of China.
2012, 42(12): 5-8.
doi: 10.13204/j.gyjz201212002
Abstract:
The sustainable reuse of historic industrial buildings hasn't been a brand new topic.Since the day when these buildings were completed,the ways of use and reuse are keeping on changing.But this kind of reuse is also based on the industrial process while the reuse based on the conservation and non-industrial purposes hasn't begun until 1950s.In the field of conservation and adaptive reuse of industrial buildings,west Europe is no-doubt ahead of others in the world.From the apocalypse of the reuse of industrial building heritages in Britain and some relevant cases in Germany and France,and by the contract of that in Britain and in China,the situation and the patterns of conservation and adaptive reuse of industrial buildings in China were discussed.
The sustainable reuse of historic industrial buildings hasn't been a brand new topic.Since the day when these buildings were completed,the ways of use and reuse are keeping on changing.But this kind of reuse is also based on the industrial process while the reuse based on the conservation and non-industrial purposes hasn't begun until 1950s.In the field of conservation and adaptive reuse of industrial buildings,west Europe is no-doubt ahead of others in the world.From the apocalypse of the reuse of industrial building heritages in Britain and some relevant cases in Germany and France,and by the contract of that in Britain and in China,the situation and the patterns of conservation and adaptive reuse of industrial buildings in China were discussed.
2012, 42(12): 9-12.
doi: 10.13204/j.gyjz201212003
Abstract:
Critical regionalism emphasizes the close connection of the building with the local natural environment,the background of culture and local building materials.Through analyzing Tiantai Museum,it was interpreted that the characteristics and the meaning of existence of critical regionalism construction,and tapped the positive guidance function of critical regionalism concepts in the practice of a modern architectural design.And then analyzing the idea of designing,the using regional elements,and creative strategies of Tiantai Museum.Finally it was summarized the creatives strategies and thinkings of the critical regionalism architectures.
Critical regionalism emphasizes the close connection of the building with the local natural environment,the background of culture and local building materials.Through analyzing Tiantai Museum,it was interpreted that the characteristics and the meaning of existence of critical regionalism construction,and tapped the positive guidance function of critical regionalism concepts in the practice of a modern architectural design.And then analyzing the idea of designing,the using regional elements,and creative strategies of Tiantai Museum.Finally it was summarized the creatives strategies and thinkings of the critical regionalism architectures.
2012, 42(12): 13-16,52.
doi: 10.13204/j.gyjz201212004
Abstract:
The rapid development of urban construction often requires the removal of the building in a short time.In order to meet the needs of the city's fast development,usually,the mechanical removal of the houses is used in China and creates a lot of garbages at the same time.Which caused the contradictory and problems in the building activities.This paper presented the design ideas and suggestions of the building dismantling,through the introduction of foreign advanced theories and experience,and also analysed of the related steps of the building dismantling and the reuse of old building materials.In the design stage the building detachability and the full use of the old building materials should be considered,and it was explored the development in future of China in the building dismantling and the reuse of old building materials.
The rapid development of urban construction often requires the removal of the building in a short time.In order to meet the needs of the city's fast development,usually,the mechanical removal of the houses is used in China and creates a lot of garbages at the same time.Which caused the contradictory and problems in the building activities.This paper presented the design ideas and suggestions of the building dismantling,through the introduction of foreign advanced theories and experience,and also analysed of the related steps of the building dismantling and the reuse of old building materials.In the design stage the building detachability and the full use of the old building materials should be considered,and it was explored the development in future of China in the building dismantling and the reuse of old building materials.
2012, 42(12): 17-20,66.
doi: 10.13204/j.gyjz201212005
Abstract:
It was put forward a new type of beam consisting of ultra toughness concrete,high strength steels and low yield point steels to improve seismic performance of normal RC beams.Based on contrast experiments of ultra toughness concrete beam with different yield poins steels and a normal RC beam under low reversed cyclic loading,crack propagation,failure pattern,hysteresis curves,framework curve,energy dissipation,ductility,etc.were studied systematically.The studies showed that ultra toughness concrete beam with different yield poins steels had better seismic performance.
It was put forward a new type of beam consisting of ultra toughness concrete,high strength steels and low yield point steels to improve seismic performance of normal RC beams.Based on contrast experiments of ultra toughness concrete beam with different yield poins steels and a normal RC beam under low reversed cyclic loading,crack propagation,failure pattern,hysteresis curves,framework curve,energy dissipation,ductility,etc.were studied systematically.The studies showed that ultra toughness concrete beam with different yield poins steels had better seismic performance.
2012, 42(12): 21-24,40.
doi: 10.13204/j.gyjz201212006
Abstract:
Based on the test of 5 steel reinforced high performance concrete(SRHSHPC) beam specimens under low cycle reversed loading,the failure model,hysteretic curves,skeleton curves,ductility and energy dissipation capacity of frame beams with different design parameters were studied.The seismic performance of the beams was analyzed.The results indicate that the reasonably designed SRHSHPC beams subjected to low cycle reversed loading produce flexure failure normally,and possess of good ductility and energy dissipation capacity.
Based on the test of 5 steel reinforced high performance concrete(SRHSHPC) beam specimens under low cycle reversed loading,the failure model,hysteretic curves,skeleton curves,ductility and energy dissipation capacity of frame beams with different design parameters were studied.The seismic performance of the beams was analyzed.The results indicate that the reasonably designed SRHSHPC beams subjected to low cycle reversed loading produce flexure failure normally,and possess of good ductility and energy dissipation capacity.
2012, 42(12): 25-29.
doi: 10.13204/j.gyjz201212007
Abstract:
Two assembled monolithic RC columns with precast external shell and cast-in-place core concrete and one cast-in-place RC column were fabricated.Their bending capacities were tested.The failure process and failure modes of the columns were studied.Besides,the load deflection relation,the strain developments of main bars were compared.Also the cracking load and ultimate capacity were investigated.It can be concluded that the new-type assembled monolithic RC columns have good flexural behavior as the same as the cast-in-place RC column.Based on the test results,a calculation method is provided,it can be referred for the design of this kind of columns
Two assembled monolithic RC columns with precast external shell and cast-in-place core concrete and one cast-in-place RC column were fabricated.Their bending capacities were tested.The failure process and failure modes of the columns were studied.Besides,the load deflection relation,the strain developments of main bars were compared.Also the cracking load and ultimate capacity were investigated.It can be concluded that the new-type assembled monolithic RC columns have good flexural behavior as the same as the cast-in-place RC column.Based on the test results,a calculation method is provided,it can be referred for the design of this kind of columns
2012, 42(12): 30-34.
doi: 10.13204/j.gyjz201212008
Abstract:
The influence of concentrated load position,concrete strength and FRP bars ratio on punching performance of two-way slabs were investigated by the test of 7 concrete two-way slabs reinforced with FRP bars subjected to punching shear loading.The test results showed that concentrated load position,concrete strength and FRP bars ratio were the main factors influencing the punching shear performance of concrete two-way slabs reinforced with FRP bars.Along with the increase of concrete strength and FRP bars ratio,the strain of concrete and FRP bars decreased gradually in same loading level,but the increase rate expedited gradually after cracking.The influence of concrete strength on the cracking load and the ultimate punching capacity of the test slabs was larger than FRP bars ratio.The concrete two-way slabs reinforced with FRP bars under concentrated loading exhibited brittle local punching failure.
The influence of concentrated load position,concrete strength and FRP bars ratio on punching performance of two-way slabs were investigated by the test of 7 concrete two-way slabs reinforced with FRP bars subjected to punching shear loading.The test results showed that concentrated load position,concrete strength and FRP bars ratio were the main factors influencing the punching shear performance of concrete two-way slabs reinforced with FRP bars.Along with the increase of concrete strength and FRP bars ratio,the strain of concrete and FRP bars decreased gradually in same loading level,but the increase rate expedited gradually after cracking.The influence of concrete strength on the cracking load and the ultimate punching capacity of the test slabs was larger than FRP bars ratio.The concrete two-way slabs reinforced with FRP bars under concentrated loading exhibited brittle local punching failure.
2012, 42(12): 35-40.
doi: 10.13204/j.gyjz201212009
Abstract:
The evolutionary power spectrum reflecting the earthquake energy contribution characteristics on time-frequency plane was estimated by the Hilbert-Huang Transform(HHT),and with reference to the experiential statistical method,an evolutionary spectrum prediction model for given earthquake magnitude and distance was established based on the 121 near-source acceleration records at rock surface with large magnitude from the ground motion database of western U S.The pseudo excitation method was adopted to acquire the solution for linear structural random response under specific non-stationary seismic excitation and structural dynamic reliability was discussed based on the first-excursion failure criterion.The results demonstrated that the non-stationary contents included in seismic excitation would increase greatly the random response and failure probability of structure in comparison with strength non-strationary excitation.
The evolutionary power spectrum reflecting the earthquake energy contribution characteristics on time-frequency plane was estimated by the Hilbert-Huang Transform(HHT),and with reference to the experiential statistical method,an evolutionary spectrum prediction model for given earthquake magnitude and distance was established based on the 121 near-source acceleration records at rock surface with large magnitude from the ground motion database of western U S.The pseudo excitation method was adopted to acquire the solution for linear structural random response under specific non-stationary seismic excitation and structural dynamic reliability was discussed based on the first-excursion failure criterion.The results demonstrated that the non-stationary contents included in seismic excitation would increase greatly the random response and failure probability of structure in comparison with strength non-strationary excitation.
2012, 42(12): 41-45.
doi: 10.13204/j.gyjz201212010
Abstract:
Soil-water characteristics play roles in engineering behaviors of undisturbed and unsaturated expansive clays.Based on SEM and other experiments,microstructures and shrinkage-swelling properties were discussed for the unsaturated expansive clays in the area of Xinqiao International Airport in Hefei.Moreover,soil-water characteristic curves(SWCCs) during drying and wetting process were measured by means of GDS triaxial stress path system,and numerical simulations and comparisons were conducted for the corresponding SWCC,relative hydraulic conductivity and soil-water diffusivity.The results showed that the measured SWCCs during wetting process behaved hysteresis with reference to that during drying process.The simulation SWCC using Fredlund model was in good agreement with the measured curve.These results provided a certain basis for making a rational foundation treatment plan for the Xinqiao International Airport founded on expansive clays.
Soil-water characteristics play roles in engineering behaviors of undisturbed and unsaturated expansive clays.Based on SEM and other experiments,microstructures and shrinkage-swelling properties were discussed for the unsaturated expansive clays in the area of Xinqiao International Airport in Hefei.Moreover,soil-water characteristic curves(SWCCs) during drying and wetting process were measured by means of GDS triaxial stress path system,and numerical simulations and comparisons were conducted for the corresponding SWCC,relative hydraulic conductivity and soil-water diffusivity.The results showed that the measured SWCCs during wetting process behaved hysteresis with reference to that during drying process.The simulation SWCC using Fredlund model was in good agreement with the measured curve.These results provided a certain basis for making a rational foundation treatment plan for the Xinqiao International Airport founded on expansive clays.
2012, 42(12): 46-52.
doi: 10.13204/j.gyjz201212011
Abstract:
Based on the design method of soil nailing in the current codes for excavation support,the need of global stability checking and local stability checking for soil nailing in design was discussed.It was shown that only global stability checking was necessary when the failure of the soil nailing obeyed the law of elastic-perfectly plastic or hardening.However,local stability checking could make the design more reasonable.Global stability checking were local stability checking were both needed when the failure of the soil nailing possessed of a softening nature.But local stability checking was sufficient when the cohesion of the soil was relatively large.
Based on the design method of soil nailing in the current codes for excavation support,the need of global stability checking and local stability checking for soil nailing in design was discussed.It was shown that only global stability checking was necessary when the failure of the soil nailing obeyed the law of elastic-perfectly plastic or hardening.However,local stability checking could make the design more reasonable.Global stability checking were local stability checking were both needed when the failure of the soil nailing possessed of a softening nature.But local stability checking was sufficient when the cohesion of the soil was relatively large.
2012, 42(12): 53-57,103.
doi: 10.13204/j.gyjz201212012
Abstract:
By utilizing an integrated method of field tests and numerical modeling the law of force distribution in second lining,it was studied the effect of the adjacent construction of following tunnel on the existing tunnel with different spacing of a eight-lane twin highway tunnel with a big section and a samll separation on the Shenzhen Nanping Expressway(Stage Ⅱ).The research results showed that the axial force and bending moment values of each measuring point in second lining were much small.It was possible to be a smaller tension in vault,the side wall away from the intermediate rock specimen and the arch foot of the intermediate rock specimen,attention should be paid to preventing the concrete cracking.The influence scope of the following tunnel excavation on the existing tunnel reinforcement force under the condition of 30 m spacing and IV surrounding rock was within 40 m at the rear of the tunnel face,and the better the surrounding rock the smaller the influence scope.Only the principal stress in vault was subjected to tension,and the other parts were under pressure,of which the maximum principal stress was on in the left and right arch foot.With the spacing gradually increasing,the tensile stress and compressive stress values changed little,there was no consistent trend of increase or decrease,the effect of spacing changes on the supporting stress was not obvious.
By utilizing an integrated method of field tests and numerical modeling the law of force distribution in second lining,it was studied the effect of the adjacent construction of following tunnel on the existing tunnel with different spacing of a eight-lane twin highway tunnel with a big section and a samll separation on the Shenzhen Nanping Expressway(Stage Ⅱ).The research results showed that the axial force and bending moment values of each measuring point in second lining were much small.It was possible to be a smaller tension in vault,the side wall away from the intermediate rock specimen and the arch foot of the intermediate rock specimen,attention should be paid to preventing the concrete cracking.The influence scope of the following tunnel excavation on the existing tunnel reinforcement force under the condition of 30 m spacing and IV surrounding rock was within 40 m at the rear of the tunnel face,and the better the surrounding rock the smaller the influence scope.Only the principal stress in vault was subjected to tension,and the other parts were under pressure,of which the maximum principal stress was on in the left and right arch foot.With the spacing gradually increasing,the tensile stress and compressive stress values changed little,there was no consistent trend of increase or decrease,the effect of spacing changes on the supporting stress was not obvious.
2012, 42(12): 58-61,90.
doi: 10.13204/j.gyjz201212013
Abstract:
According to the circular tunnel double layer and three-layer composite lining structure,based on hollow circular cylinder elastic solution,the stress deformation elastic solution for different lining layers were deduced,including the lining layer elastic stress,radial displacement and tangential displacement.The study results could provide a refaremce for the design of composite lining structure.
According to the circular tunnel double layer and three-layer composite lining structure,based on hollow circular cylinder elastic solution,the stress deformation elastic solution for different lining layers were deduced,including the lining layer elastic stress,radial displacement and tangential displacement.The study results could provide a refaremce for the design of composite lining structure.
2012, 42(12): 63-66.
doi: 10.13204/j.gyjz201212014
Abstract:
In order to investigate the size effect of concrete flexural strength,a series of four-point bending tests were performed on a total of 54 group specimens.The flexural strengths of concrete specimens with three different dimensions including 70 mm70 mm310 mm,100 mm100 mm400 mm,150 mm150 mm550 mm and three different strength levels including 20,40,60 MPa were obtained.Based on the test results,the flexural strengths of specimens with different strength level and specimen size were investigated.Furthermore,the test data were analyzed by Bazant's size effect theory.The results indicated that the higher the strength level,the more obvious the size effect.Also the size effects of concrete specimens were much more notable than the cement specimens and motar specimens with the same strength level.The amended size effect law could be used to predict the size effect of the flexural stength of concrete.
In order to investigate the size effect of concrete flexural strength,a series of four-point bending tests were performed on a total of 54 group specimens.The flexural strengths of concrete specimens with three different dimensions including 70 mm70 mm310 mm,100 mm100 mm400 mm,150 mm150 mm550 mm and three different strength levels including 20,40,60 MPa were obtained.Based on the test results,the flexural strengths of specimens with different strength level and specimen size were investigated.Furthermore,the test data were analyzed by Bazant's size effect theory.The results indicated that the higher the strength level,the more obvious the size effect.Also the size effects of concrete specimens were much more notable than the cement specimens and motar specimens with the same strength level.The amended size effect law could be used to predict the size effect of the flexural stength of concrete.
2012, 42(12): 67-71,95.
doi: 10.13204/j.gyjz201212015
Abstract:
The durability failure mechanism of damaged concrete induced by mechanical load was analyzed firstly in this paper.Then through the chloride penetration test and freezing-thawing test of concrete specimens after direct uniaxial tensile or compressive loading,the load-induced damage influence on the long-term durability of concrete was investigated.The results indicated that concrete changed from reversible phase,irreversible phase to accelerated degradation phase under the action of compressive load.But the concrete under tension load experienced continuous degradation.When the uniaxial tensile load level reached the 65% and 75% of ultimate capacity,the apparent chloride diffusion coefficient of concrete increased by 6.4% and 34%,and the surface chloride concentration increased by 10% and 40% respectively,which showed the negative effect.But with the increasing of uniaxial compressive load level,the influence on frost resistance of concrete experienced from a positive effectto a negative effect transformation.
The durability failure mechanism of damaged concrete induced by mechanical load was analyzed firstly in this paper.Then through the chloride penetration test and freezing-thawing test of concrete specimens after direct uniaxial tensile or compressive loading,the load-induced damage influence on the long-term durability of concrete was investigated.The results indicated that concrete changed from reversible phase,irreversible phase to accelerated degradation phase under the action of compressive load.But the concrete under tension load experienced continuous degradation.When the uniaxial tensile load level reached the 65% and 75% of ultimate capacity,the apparent chloride diffusion coefficient of concrete increased by 6.4% and 34%,and the surface chloride concentration increased by 10% and 40% respectively,which showed the negative effect.But with the increasing of uniaxial compressive load level,the influence on frost resistance of concrete experienced from a positive effectto a negative effect transformation.
2012, 42(12): 72-75.
doi: 10.13204/j.gyjz201212016
Abstract:
A long-span complex steel grid structure was monitored closely during the construction process,including stress change monitoring for sensitive and important steel components in hoisting procedure,and supporting point deformation monitoring for demolishment of temporary support structure,and welding ring deformation monitoring for ascent of the whole welding ball.Monitoring results demonstrated that stress and deformation were in reasonable range,and eventually stabilized to a value,and the monitoring effect was fine.The steel grid structure was conducted with finite element simulation analysis on stress and deformation of various working conditions during construction course.The measured stress and deformation values were compared with those of finite element analysis,and substantial agreement was obtained,which demonstrated that finite element analysis simulated the change of stress and deformation in construction process satisfactorily.
A long-span complex steel grid structure was monitored closely during the construction process,including stress change monitoring for sensitive and important steel components in hoisting procedure,and supporting point deformation monitoring for demolishment of temporary support structure,and welding ring deformation monitoring for ascent of the whole welding ball.Monitoring results demonstrated that stress and deformation were in reasonable range,and eventually stabilized to a value,and the monitoring effect was fine.The steel grid structure was conducted with finite element simulation analysis on stress and deformation of various working conditions during construction course.The measured stress and deformation values were compared with those of finite element analysis,and substantial agreement was obtained,which demonstrated that finite element analysis simulated the change of stress and deformation in construction process satisfactorily.
2012, 42(12): 76-80,108.
doi: 10.13204/j.gyjz201212017
Abstract:
In recent years,the high-rise buildings have been emerging in China,from previous Shenzhen Diwang Mansion,Shanghai Jinmao Mansion,Shanghai Global Financial Center,to today's Shenzhen Kingkey Finance Center,Shanghai Center,Wuhan Greenland Center,etc.It is well-known that the key for restricting high-rise building's construction is the vertical transportation equipment's limit,while tower crane is the most important vertical transportation equipment.Therefore,scientific choice and rational layout of tower cranes are the key to ensuring the qulity,safety and progress of construction.By way of discussion on tower crane's selection and arrangement in high-rise building's construction with some constructed and constructing high-rise buildings,some rational opinions are proposed.
In recent years,the high-rise buildings have been emerging in China,from previous Shenzhen Diwang Mansion,Shanghai Jinmao Mansion,Shanghai Global Financial Center,to today's Shenzhen Kingkey Finance Center,Shanghai Center,Wuhan Greenland Center,etc.It is well-known that the key for restricting high-rise building's construction is the vertical transportation equipment's limit,while tower crane is the most important vertical transportation equipment.Therefore,scientific choice and rational layout of tower cranes are the key to ensuring the qulity,safety and progress of construction.By way of discussion on tower crane's selection and arrangement in high-rise building's construction with some constructed and constructing high-rise buildings,some rational opinions are proposed.
2012, 42(12): 81-85.
doi: 10.13204/j.gyjz201212018
Abstract:
It was presented a model experimental study on the shuttle-shape columns for the main building of the phase Ⅱ expansion project T3A terminal of Xianyang International Airport.Three SXZ models with a scale of 1/2 were tested under axial loading until failure.Their ultimate load-carrying capacities and failure mechanism were obtained and observed.Its ultimate bearing capacity was greater than 2 times its designed load,which could meet the requirements for design of the column.The results of test were compared with those obtained by FEM involved in ultimate load-carrying capacities,destruction modes and the load-displacement curves,and a good agreement was observed between them.In addition,based on FE model,it was analysed the effect of taper ratio and length ratio on the ultimate bearing capacity,and the formula between and Pu was presented.
It was presented a model experimental study on the shuttle-shape columns for the main building of the phase Ⅱ expansion project T3A terminal of Xianyang International Airport.Three SXZ models with a scale of 1/2 were tested under axial loading until failure.Their ultimate load-carrying capacities and failure mechanism were obtained and observed.Its ultimate bearing capacity was greater than 2 times its designed load,which could meet the requirements for design of the column.The results of test were compared with those obtained by FEM involved in ultimate load-carrying capacities,destruction modes and the load-displacement curves,and a good agreement was observed between them.In addition,based on FE model,it was analysed the effect of taper ratio and length ratio on the ultimate bearing capacity,and the formula between and Pu was presented.
2012, 42(12): 86-90.
doi: 10.13204/j.gyjz201212019
Abstract:
An experimental research on 5 steel tube columns filled with steel-reinforced concrete subjected to compression-flexure loading was carried out.Ultimate bearing capacity and deformation were studied corresponding to different ratio of axial compression and loading direction.It was deeply analyzed the influence of double confining on bearing capacity,which was between the steel skeleton and steel tube,and distributing regularity of double confining in tensile region and compressive region.Contrasting with the experimental results,the practical formula of compression-flexure was built by N-M relationship,and a good agreement was obtained between the calculated results and the experimental results.
An experimental research on 5 steel tube columns filled with steel-reinforced concrete subjected to compression-flexure loading was carried out.Ultimate bearing capacity and deformation were studied corresponding to different ratio of axial compression and loading direction.It was deeply analyzed the influence of double confining on bearing capacity,which was between the steel skeleton and steel tube,and distributing regularity of double confining in tensile region and compressive region.Contrasting with the experimental results,the practical formula of compression-flexure was built by N-M relationship,and a good agreement was obtained between the calculated results and the experimental results.
2012, 42(12): 91-95.
doi: 10.13204/j.gyjz201212020
Abstract:
Based on axially compressive tests of 6 recycled concrete filled steel tube short columns and 3 common concrete filled steel tube short columns,the influence of replacement percentages of recycled aggregate and longitude to diameter ratio on compressive capacity was studied in this paper.The test results demonstrated that the recycled concrete-filled steel tube short column and common concrete-filled steel tube short column had similar deformation and failure mode.The greater the longitude to diameter ratio and replacement percentages of the recycled aggregate,the lower the compressive capacity of specimens;the formula for the calculation of the ultimate compressive capacity of common concrete filled steel tube short column was also applicable to recycled concrete filled steel tube short column.
Based on axially compressive tests of 6 recycled concrete filled steel tube short columns and 3 common concrete filled steel tube short columns,the influence of replacement percentages of recycled aggregate and longitude to diameter ratio on compressive capacity was studied in this paper.The test results demonstrated that the recycled concrete-filled steel tube short column and common concrete-filled steel tube short column had similar deformation and failure mode.The greater the longitude to diameter ratio and replacement percentages of the recycled aggregate,the lower the compressive capacity of specimens;the formula for the calculation of the ultimate compressive capacity of common concrete filled steel tube short column was also applicable to recycled concrete filled steel tube short column.
2012, 42(12): 96-103.
doi: 10.13204/j.gyjz201212021
Abstract:
Super high-rise steel structure building with concrete filled steel tubular column is a commonly used structure type.the beam connecting with concrete filled steel tubular column has several types,as steel beam,reinforced concrete beam,concrete beams,etc.There are less researches for joints between steel tubular concrete column and steel reinforced concrete beam.In this paper,the 1:2 scale experimental study for bracket-type joints of steel tubular concrete column and reinforced concrete beam was executed,at the same time these joints were designed by ANSYS finite element analysis software.Combined the experimental results with those of finite element analysis,the stress characteristics of these joints were also analyzed,the results showed that the joint had good ultimate bearing capacity and seismic performance.
Super high-rise steel structure building with concrete filled steel tubular column is a commonly used structure type.the beam connecting with concrete filled steel tubular column has several types,as steel beam,reinforced concrete beam,concrete beams,etc.There are less researches for joints between steel tubular concrete column and steel reinforced concrete beam.In this paper,the 1:2 scale experimental study for bracket-type joints of steel tubular concrete column and reinforced concrete beam was executed,at the same time these joints were designed by ANSYS finite element analysis software.Combined the experimental results with those of finite element analysis,the stress characteristics of these joints were also analyzed,the results showed that the joint had good ultimate bearing capacity and seismic performance.
2012, 42(12): 104-108.
doi: 10.13204/j.gyjz201212022
Abstract:
By means of ANSYS parametric design language(APDL),cast steel joints of steel truss in Chongqing Jiangbei International Airport were modeled with a set of parameters.Through probabilistic design system(PDS)module in ANSYS programme,a numerical simulation techniqueresponse surface method(RSM) based on probability theory was adopted to analyze solid structure such as cast steel joints.According to single calculation results of finite element analysis,different failure stress was selected as the strength limit to obtain corresponding failure probability and reliability index of cast steel joint,and it was shown that the working status of cast steel joints was safe and reliable.From correlation coefficient and effect degree ratio of different variables,the significance of influencing factors of cast steel joints was revealed.Finally it was discussed some principles of failure mode selection for similar nodes.
By means of ANSYS parametric design language(APDL),cast steel joints of steel truss in Chongqing Jiangbei International Airport were modeled with a set of parameters.Through probabilistic design system(PDS)module in ANSYS programme,a numerical simulation techniqueresponse surface method(RSM) based on probability theory was adopted to analyze solid structure such as cast steel joints.According to single calculation results of finite element analysis,different failure stress was selected as the strength limit to obtain corresponding failure probability and reliability index of cast steel joint,and it was shown that the working status of cast steel joints was safe and reliable.From correlation coefficient and effect degree ratio of different variables,the significance of influencing factors of cast steel joints was revealed.Finally it was discussed some principles of failure mode selection for similar nodes.
2012, 42(12): 109-112,132.
doi: 10.13204/j.gyjz201212023
Abstract:
Based on the unified strength theory,the mechanical behavior of circular tubed steel reinforced concrete(CTSRC) short columns was analyzed.The calculation formula of bearing capacity of the CTSRC short columns under axial compression was deduced with consideration of the restriction effect of steel tube on SRC by using the unified strength theory solution of thickness cylinder.Parametric studies were carried out to evaluate the effects of influence factors on the bearing capacity of the column.A reasonable match was reached by comparing the results calculated by the formulas with the test results.It was concluded that the unified strength theory was versatile in theoretical analyses of the CTSRC short columns.
Based on the unified strength theory,the mechanical behavior of circular tubed steel reinforced concrete(CTSRC) short columns was analyzed.The calculation formula of bearing capacity of the CTSRC short columns under axial compression was deduced with consideration of the restriction effect of steel tube on SRC by using the unified strength theory solution of thickness cylinder.Parametric studies were carried out to evaluate the effects of influence factors on the bearing capacity of the column.A reasonable match was reached by comparing the results calculated by the formulas with the test results.It was concluded that the unified strength theory was versatile in theoretical analyses of the CTSRC short columns.
2012, 42(12): 113-115,142.
doi: 10.13204/j.gyjz201212024
Abstract:
The joint of concrete filled steel pipe transition truss support is the key joint of a structure,and the stress state is complex.Combined with the example of Central Bank Building of Kuwait,the capacity of this joint to the shear wall was analysed with the finite element analysis software ANSYS,considering the material nonlinearity,the complex stress characteristics were explored,it puts forward the design scheme of the connection joint between the transfer truss,concrete shear wall and the concrete filled steel tube columns,which provided a reference for the staff to design such joints.
The joint of concrete filled steel pipe transition truss support is the key joint of a structure,and the stress state is complex.Combined with the example of Central Bank Building of Kuwait,the capacity of this joint to the shear wall was analysed with the finite element analysis software ANSYS,considering the material nonlinearity,the complex stress characteristics were explored,it puts forward the design scheme of the connection joint between the transfer truss,concrete shear wall and the concrete filled steel tube columns,which provided a reference for the staff to design such joints.
2012, 42(12): 116-120.
doi: 10.13204/j.gyjz201212025
Abstract:
A new type of plain steel-plate-concrete composite hollow slab is composed of common steel plate,internal hollow model and concrete connected with steel PBL shear connection.Due to the using of plain steel plate and internal hollow model,the composite slab has lots of advantage such as light-weight,sound-proofing and easy construction without bottom forms,therefore,this type of composite slab has wide prospect for projects.Experiments of six specimens of such composite slabs were conducted to study the mechanical behaviors.Based on the experimental results,the influences of the nominal shear-span of the slabs were studied.During the experimental process,the failure modes,concrete strains,types of cracking,interface slippage and bearing capacity of the decks were focused.From the experimental results,it could be found that no obvious slippage on the interface of between the steel plate and concrete were measured in the composite hollow decks,which result in big flexural rigidity,good ductility as well as good bearing capacity,indicating that the strengths of both the bottom steel plate and the top concrete were fully utilized.Calculation methods for the bend-bearing capacity of the composite decks were proposed.It could be concluded that this type of composite hollow slab was advantageous in mechanical behaviors,and should be more widely studied and applied.
A new type of plain steel-plate-concrete composite hollow slab is composed of common steel plate,internal hollow model and concrete connected with steel PBL shear connection.Due to the using of plain steel plate and internal hollow model,the composite slab has lots of advantage such as light-weight,sound-proofing and easy construction without bottom forms,therefore,this type of composite slab has wide prospect for projects.Experiments of six specimens of such composite slabs were conducted to study the mechanical behaviors.Based on the experimental results,the influences of the nominal shear-span of the slabs were studied.During the experimental process,the failure modes,concrete strains,types of cracking,interface slippage and bearing capacity of the decks were focused.From the experimental results,it could be found that no obvious slippage on the interface of between the steel plate and concrete were measured in the composite hollow decks,which result in big flexural rigidity,good ductility as well as good bearing capacity,indicating that the strengths of both the bottom steel plate and the top concrete were fully utilized.Calculation methods for the bend-bearing capacity of the composite decks were proposed.It could be concluded that this type of composite hollow slab was advantageous in mechanical behaviors,and should be more widely studied and applied.
2012, 42(12): 121-125.
doi: 10.13204/j.gyjz201212026
Abstract:
The minimum field inspection sample number for concrete carbonation inspection is discussed at the present work.The fib Model Code is chosen to develop a method to calculate minimum inspection sample number using Monte-Carlo simulation.The relationship between the sample number and the accuracy expected at different conditions is discussed according to such an approach.The minimum sample numbers at some given accuracies are obtained and validated by a set of data from some long-term exposed beams.
The minimum field inspection sample number for concrete carbonation inspection is discussed at the present work.The fib Model Code is chosen to develop a method to calculate minimum inspection sample number using Monte-Carlo simulation.The relationship between the sample number and the accuracy expected at different conditions is discussed according to such an approach.The minimum sample numbers at some given accuracies are obtained and validated by a set of data from some long-term exposed beams.
2012, 42(12): 126-128,138.
doi: 10.13204/j.gyjz201212027
Abstract:
Combining the static displacement curvature assurance coefficient used for damage identification with artificial neural network technology,the system of structural damage identification based on the grey network was set up.Using the system to judge the location and extent of structural damage on cantilever beam,it can be seen that this method is very effective,and the calculation on the static displacement curvature assurance coefficient is simple,the accuracy is high,and it also has a highly parallel computing power and good fault tolerance.
Combining the static displacement curvature assurance coefficient used for damage identification with artificial neural network technology,the system of structural damage identification based on the grey network was set up.Using the system to judge the location and extent of structural damage on cantilever beam,it can be seen that this method is very effective,and the calculation on the static displacement curvature assurance coefficient is simple,the accuracy is high,and it also has a highly parallel computing power and good fault tolerance.
2012, 42(12): 129-132.
doi: 10.13204/j.gyjz201212028
Abstract:
Data fusion techniques were used to do single-damage and multi-damage identification of truss structures.By studying the structural damage theory based on frequency,it was analysed the relation between the normalized frequency and location of damage;and the wavelet probabilistic neural network algorithm was used to modify decision fusion,thus establishing a data fusion model of structural damage identification based on wavelet probabilistic neural network.The structural calculation software was used to calculate the frequency of a typical truss structure,which was integrated into an input feature vector of the wavelet probabilistic neural network algorithm,and a damage identification was done for the truss structure model example.Through truss damage of different locations to verify the effectiveness of the method was verified,and the problems needing attention during engineering uses was proposed.The results showed that data fusion technology based on wavelet probabilistic neural network algorithm was a more reliable damage identification method,and had good prospects for engineering applications.
Data fusion techniques were used to do single-damage and multi-damage identification of truss structures.By studying the structural damage theory based on frequency,it was analysed the relation between the normalized frequency and location of damage;and the wavelet probabilistic neural network algorithm was used to modify decision fusion,thus establishing a data fusion model of structural damage identification based on wavelet probabilistic neural network.The structural calculation software was used to calculate the frequency of a typical truss structure,which was integrated into an input feature vector of the wavelet probabilistic neural network algorithm,and a damage identification was done for the truss structure model example.Through truss damage of different locations to verify the effectiveness of the method was verified,and the problems needing attention during engineering uses was proposed.The results showed that data fusion technology based on wavelet probabilistic neural network algorithm was a more reliable damage identification method,and had good prospects for engineering applications.
2012, 42(12): 133-138.
doi: 10.13204/j.gyjz201212029
Abstract:
The deterioration of the main structure of the RC building of a colliery and the changes of coal preparation technology to heavy medium technology demand a reliability test of the main building,and an assessment of its safety,usability and level of reliability.It was carried out that respective tests on the main building's structural role,working environment,foundation bearing capacity and deformation,apparent quality and cracks of construction members,carbonation and the strength of concrete of construction members,steel corrosion rate,steel distribution and thickness of the protective layer,and the dynamic performances of construction members.And the safety of the building was reevaluated according to the test results.On the basis of which,the level of safety of the building was determined,and relevant suggestions of maintenance,repair and reinforcement were proposed.
The deterioration of the main structure of the RC building of a colliery and the changes of coal preparation technology to heavy medium technology demand a reliability test of the main building,and an assessment of its safety,usability and level of reliability.It was carried out that respective tests on the main building's structural role,working environment,foundation bearing capacity and deformation,apparent quality and cracks of construction members,carbonation and the strength of concrete of construction members,steel corrosion rate,steel distribution and thickness of the protective layer,and the dynamic performances of construction members.And the safety of the building was reevaluated according to the test results.On the basis of which,the level of safety of the building was determined,and relevant suggestions of maintenance,repair and reinforcement were proposed.
2012, 42(12): 139-142.
doi: 10.13204/j.gyjz201212030
Abstract:
The main teaching building of a middle school in Shanghai is the masonry structure,founded in 1985,following the expansion of the laboratory building and the corridor in 1991.The original design of earthquake-proofing of the original design was classified as Class C,with an earthquake fortification intensity of 6 degree.A comprehensive structural seismic evaluation of teaching building was done based on current norms.The evaluation results showed that the number of constructional columns was inadequate,mortar strength was much lower than the normal value,most of the vertical walls' antiseism and compressive bearing capacity were insufficient,thus,the overall seismic performance could not meet the requirements of current seismic code regulations.In accordance with the results of the evaluation,the strengthening method was put forward to achieve fortification class seismic standards and follow-up using period of 40 years for the teaching building.
The main teaching building of a middle school in Shanghai is the masonry structure,founded in 1985,following the expansion of the laboratory building and the corridor in 1991.The original design of earthquake-proofing of the original design was classified as Class C,with an earthquake fortification intensity of 6 degree.A comprehensive structural seismic evaluation of teaching building was done based on current norms.The evaluation results showed that the number of constructional columns was inadequate,mortar strength was much lower than the normal value,most of the vertical walls' antiseism and compressive bearing capacity were insufficient,thus,the overall seismic performance could not meet the requirements of current seismic code regulations.In accordance with the results of the evaluation,the strengthening method was put forward to achieve fortification class seismic standards and follow-up using period of 40 years for the teaching building.
2012, 42(12): 143-145,160.
doi: 10.13204/j.gyjz201212031
Abstract:
Two piers and a girder of a high speed railway bridge were damaged to some extent after fire.It was presented the detection and analysis process of the damaged area,including judgement of fired temperature,carbonization depth,strength detection,the detection of the affected depth by elastic waves etc.It was finally proposed the repair sugestions on the damaged piers and girder after the initial and detailed evaluations.
Two piers and a girder of a high speed railway bridge were damaged to some extent after fire.It was presented the detection and analysis process of the damaged area,including judgement of fired temperature,carbonization depth,strength detection,the detection of the affected depth by elastic waves etc.It was finally proposed the repair sugestions on the damaged piers and girder after the initial and detailed evaluations.
2012, 42(12): 146-150.
doi: 10.13204/j.gyjz201212032
Abstract:
Combining with the case of percussion drilling bored piles for tall buildings in Guangxi karst area,it was analyzed the factors influencing the quality of such piles in the karst area and detection methods and comprehensively compared the advantages and disadvantages of low strain reflection wave method,ultrasonic transmission method and the drilling pumping core.According to the different situation of percussion drilling bored piles,it was put forward how to comprehensively use the different combinations of low strain reflected wave method,ultrasonic transmission method and borehole core,it was carried out testing and analysis of the quality of punching perfusion pile located in karst zone.In addition,According to the defective piles,it was put forward effective treatment plan of high pressure grouting method,and the treated piles were detected using ultrasonic detector test again,the effect was ideal.
Combining with the case of percussion drilling bored piles for tall buildings in Guangxi karst area,it was analyzed the factors influencing the quality of such piles in the karst area and detection methods and comprehensively compared the advantages and disadvantages of low strain reflection wave method,ultrasonic transmission method and the drilling pumping core.According to the different situation of percussion drilling bored piles,it was put forward how to comprehensively use the different combinations of low strain reflected wave method,ultrasonic transmission method and borehole core,it was carried out testing and analysis of the quality of punching perfusion pile located in karst zone.In addition,According to the defective piles,it was put forward effective treatment plan of high pressure grouting method,and the treated piles were detected using ultrasonic detector test again,the effect was ideal.
2012, 42(12): 151-155.
doi: 10.13204/j.gyjz201212033
Abstract:
The paper briefly introduces the characteristics of the structure with staggered stories,and taking a high-rise shear wall structure with staggered stories for example,according to the requirements of the relevant specification,an analysis was done using different structure analysis softwares,which was checked by the elastic time history analysis.According to above analysis results,it was put forward the matters needing attention in the design process of high-rise shear wall structure with staggered stories,and combined with standard,the corresponding a seismic measures were taken,and the optimization design was done under the premise of safety,which reduced project cost.It was expected to be a reference for future similar projects.
The paper briefly introduces the characteristics of the structure with staggered stories,and taking a high-rise shear wall structure with staggered stories for example,according to the requirements of the relevant specification,an analysis was done using different structure analysis softwares,which was checked by the elastic time history analysis.According to above analysis results,it was put forward the matters needing attention in the design process of high-rise shear wall structure with staggered stories,and combined with standard,the corresponding a seismic measures were taken,and the optimization design was done under the premise of safety,which reduced project cost.It was expected to be a reference for future similar projects.
2012, 42(12): 156-160.
doi: 10.13204/j.gyjz201212034
Abstract:
Based on the analysis of the cultural contents and elements of architecture forms,it was analyzed the cultural inheritance and innovation of modern architecture forms in Suzhou from solid material factors and non-solid material factors.It was found that the expression of solid material factors were mainly reflected in the inheritance and innovation of architectural space and architectural forms,the appearance of non-solid material factors in the deduction and expression of traditional culture and the construction and expression of existential space.
Based on the analysis of the cultural contents and elements of architecture forms,it was analyzed the cultural inheritance and innovation of modern architecture forms in Suzhou from solid material factors and non-solid material factors.It was found that the expression of solid material factors were mainly reflected in the inheritance and innovation of architectural space and architectural forms,the appearance of non-solid material factors in the deduction and expression of traditional culture and the construction and expression of existential space.
2012, 42(12): 161-163.
doi: 10.13204/j.gyjz201212035
Abstract:
By analysing the region,the humanities,and the climate factors,it was comprehensively elaborated the planning and design of local characteristics housing projects in Libya,North-Africa from the point view of planning.
By analysing the region,the humanities,and the climate factors,it was comprehensively elaborated the planning and design of local characteristics housing projects in Libya,North-Africa from the point view of planning.
