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2012 Vol. 42, No. 3
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2012, 42(3): 1-6,11.
doi: 10.13204/j.gyjz201203001
Abstract:
In order to investigate the rule of elasto-plastic torsional response of the eccentric frame-shear wall structure under earthquake action,a group of fine finite element models of actual frame-shear wall structure designed according to China code with different eccentricity were established for a comparative study in terms of their structural elasto-plastic seismic responses,such as the storey drift angle and torsional angle,distribution of plastic hinge,ductility coefficient,etc,using dynamic time-history analysis with many different seismic waves.The analysis results showed that the rule of elasto-plastic storey drift angle and interlayer torsional angle is consistent with the previous research using macroscopic model,and the storey drift angle satisfy the seismic requirements of code;the ductility demand of the rigid side elements is about 2~3 times large than that of the flexible side elements;the ductility demand of the rigid side elements of the frame-shear wall structure with rigid foundation assumption under artificial rare earthquake action is too large,which should be paid attention to.
In order to investigate the rule of elasto-plastic torsional response of the eccentric frame-shear wall structure under earthquake action,a group of fine finite element models of actual frame-shear wall structure designed according to China code with different eccentricity were established for a comparative study in terms of their structural elasto-plastic seismic responses,such as the storey drift angle and torsional angle,distribution of plastic hinge,ductility coefficient,etc,using dynamic time-history analysis with many different seismic waves.The analysis results showed that the rule of elasto-plastic storey drift angle and interlayer torsional angle is consistent with the previous research using macroscopic model,and the storey drift angle satisfy the seismic requirements of code;the ductility demand of the rigid side elements is about 2~3 times large than that of the flexible side elements;the ductility demand of the rigid side elements of the frame-shear wall structure with rigid foundation assumption under artificial rare earthquake action is too large,which should be paid attention to.
2012, 42(3): 7-11,6.
doi: 10.13204/j.gyjz201203002
Abstract:
The response of RC(reinforced concrete)shear wall with different shear span ratios and axial compression ratios under quasi-static load and dynamic load with high strain rate is studied using finite element software ABAQUS.Then the results are compared with the results calculated according to codes after considering strain rate effect,to obtain the influence of strain rates on aseismic capacity of RC shear wall.Through comparing the failure mode and bearing capacity of shear wall under various shear span ratios,axial compression ratios and strain rates,it can be concluded that: with the increasing of strain rate,the seismic bearing capacity of shear wall will increase if the shear span ratios and axial compression ratios of shear walls are the same.So the strain rate effect should be taken into account properly in the seismic analysis of RC shear wall.
The response of RC(reinforced concrete)shear wall with different shear span ratios and axial compression ratios under quasi-static load and dynamic load with high strain rate is studied using finite element software ABAQUS.Then the results are compared with the results calculated according to codes after considering strain rate effect,to obtain the influence of strain rates on aseismic capacity of RC shear wall.Through comparing the failure mode and bearing capacity of shear wall under various shear span ratios,axial compression ratios and strain rates,it can be concluded that: with the increasing of strain rate,the seismic bearing capacity of shear wall will increase if the shear span ratios and axial compression ratios of shear walls are the same.So the strain rate effect should be taken into account properly in the seismic analysis of RC shear wall.
2012, 42(3): 12-19.
doi: 10.13204/j.gyjz201203003
Abstract:
Six RC box piers samples were designed and studied under the constant the axial force and reversed horizontal load.The effect of the reversed horizontal load direction and the stirrup ratio on the seismic performance of RC box pier was studied.Such seismic performance as ductility,hysteresis curve,skeleton curve,etc.of RC box piers is studied by pseudo-static test on six RC box piers.The simulation results show that RC box piers exist excellent performance of resisting seismic force,the direction of horizontal load and the stirrup ratio are the main factors affecting that performance.
Six RC box piers samples were designed and studied under the constant the axial force and reversed horizontal load.The effect of the reversed horizontal load direction and the stirrup ratio on the seismic performance of RC box pier was studied.Such seismic performance as ductility,hysteresis curve,skeleton curve,etc.of RC box piers is studied by pseudo-static test on six RC box piers.The simulation results show that RC box piers exist excellent performance of resisting seismic force,the direction of horizontal load and the stirrup ratio are the main factors affecting that performance.
2012, 42(3): 20-24,63.
doi: 10.13204/j.gyjz201203004
Abstract:
According to the Wenchuan Earthquake and the seismic resistance of an infilled frame under strong earthquakes,the main reasons for earthquakes damage to infilled frame structures are analyzed.Infilled wall is simplified into equivalent double compressive strut model.An investigation has been conducted to study the influence of infill walls on the performance of the framework subjected to earthquake(dynamic)loading.The study shows that masonry infill walls improve the structure's lateral stiffness and strength,and also have a capacity of dissipating energy when subjected to earthquake(dynamic)loading.
According to the Wenchuan Earthquake and the seismic resistance of an infilled frame under strong earthquakes,the main reasons for earthquakes damage to infilled frame structures are analyzed.Infilled wall is simplified into equivalent double compressive strut model.An investigation has been conducted to study the influence of infill walls on the performance of the framework subjected to earthquake(dynamic)loading.The study shows that masonry infill walls improve the structure's lateral stiffness and strength,and also have a capacity of dissipating energy when subjected to earthquake(dynamic)loading.
2012, 42(3): 25-32,171.
doi: 10.13204/j.gyjz201203005
Abstract:
Lessons learned from the Wenchuan Earthquake on May 12,2008 indicate that in addition to possessing sufficient collapse prevention capacity,the brick masonry structures should be able to collapse in such a reasonable pattern that the collapses of different structural components can follow expected sequence and the structural components enclosing particular spaces of the structure can be restrained from collapse for the maximum protection of human lives and properties when the collapse is unavoidable under the attack of a mega earthquake that largely exceeds the local seismic fortification intensity specified the code.The equivalent diagonal strut model is introduced to establish the load transfer path and the interaction between tie columns and brick walls.There seismic collapse patterns as well as the corresponding calculation methods are discussed.A confinement coefficient and a collapse prevention index are defined to reflect the confining capacity of the tie columns and tie beams and the collapse prevention capacity of brick walls.Finally,several fundamental measures for the improvement of seismic collapse prevention capacity of the brick masonry buildings confined by tie columns and tie beams are suggested.
Lessons learned from the Wenchuan Earthquake on May 12,2008 indicate that in addition to possessing sufficient collapse prevention capacity,the brick masonry structures should be able to collapse in such a reasonable pattern that the collapses of different structural components can follow expected sequence and the structural components enclosing particular spaces of the structure can be restrained from collapse for the maximum protection of human lives and properties when the collapse is unavoidable under the attack of a mega earthquake that largely exceeds the local seismic fortification intensity specified the code.The equivalent diagonal strut model is introduced to establish the load transfer path and the interaction between tie columns and brick walls.There seismic collapse patterns as well as the corresponding calculation methods are discussed.A confinement coefficient and a collapse prevention index are defined to reflect the confining capacity of the tie columns and tie beams and the collapse prevention capacity of brick walls.Finally,several fundamental measures for the improvement of seismic collapse prevention capacity of the brick masonry buildings confined by tie columns and tie beams are suggested.
2012, 42(3): 33-38,48.
doi: 10.13204/j.gyjz201203006
Abstract:
Friction pendulum system(FPS)is a type of seismic isolator with spherical sliding surface that is intended for protecting large engineering structures from damages of earthquake.In recent years,large space buildings have been developed significantly.To improve the seismic performance of such buildings,the FPS is installed between the roof and substructure to form a sliding isolation mechanism to reduce the seismic response of the structure.A sliding isolation study is performed for steel lattice grid roof structures with substructures.The 3-D structural models are implemented by using the ABAQUS general-purpose finite element program.In the FE models,the FPS and structural components are simulated respectively with contact surface and beam elements to capture the nonlinear behavior of the structure.Nonlinear time-history analyses are executed to investigate the feasibility and effectiveness of the FPS under different parameters.
Friction pendulum system(FPS)is a type of seismic isolator with spherical sliding surface that is intended for protecting large engineering structures from damages of earthquake.In recent years,large space buildings have been developed significantly.To improve the seismic performance of such buildings,the FPS is installed between the roof and substructure to form a sliding isolation mechanism to reduce the seismic response of the structure.A sliding isolation study is performed for steel lattice grid roof structures with substructures.The 3-D structural models are implemented by using the ABAQUS general-purpose finite element program.In the FE models,the FPS and structural components are simulated respectively with contact surface and beam elements to capture the nonlinear behavior of the structure.Nonlinear time-history analyses are executed to investigate the feasibility and effectiveness of the FPS under different parameters.
2012, 42(3): 39-42,132.
doi: 10.13204/j.gyjz201203007
Abstract:
Recently,the serial isolation system,i.e.the laminated rubber bearing is on the top of RC columns the basement,is widely applied in the base isolation building,it helps to underground space utilization.However,in the earthquake,the performance of laminated rubber bearings is affected by vertical gravity load and both horizontal and vertical seismic force and lower constraint.In this case,the stress and the deformation of laminated rubber bearings is affected and remains to be analyzed.Three models of serial isolation system are analyzed for this problem on the paper.Compared with the results,it indicates that the stiffness of RC column has the great influence in the stress and the deformation of laminated rubber bearing.With the increasing of stiffness the corner of the bottom of the laminated rubber bearings is smaller and the displacement is larger when the plastic stress occuts.
Recently,the serial isolation system,i.e.the laminated rubber bearing is on the top of RC columns the basement,is widely applied in the base isolation building,it helps to underground space utilization.However,in the earthquake,the performance of laminated rubber bearings is affected by vertical gravity load and both horizontal and vertical seismic force and lower constraint.In this case,the stress and the deformation of laminated rubber bearings is affected and remains to be analyzed.Three models of serial isolation system are analyzed for this problem on the paper.Compared with the results,it indicates that the stiffness of RC column has the great influence in the stress and the deformation of laminated rubber bearing.With the increasing of stiffness the corner of the bottom of the laminated rubber bearings is smaller and the displacement is larger when the plastic stress occuts.
2012, 42(3): 49-51.
doi: 10.13204/j.gyjz201203009
Abstract:
The humanization design of an industrial building focuses on a person-centered rather than object-centered.First,it is analyzed the deficiencies of the object-centered design,second analyzes the strategy of the humanization design of an industrial building,it is concluded four points for attention: firstly,the most important point is paying attention to humanbeing;secondly,attention should be paid to the diversity rational arrangement of the spatial functions,providing the diversity rather than a single production space;thirdly,the industrial building design should be from the closing to the opening,becoming an opening and closing humanization sapce;finally,the humanization design of an industrial building should be embodied in the details.
The humanization design of an industrial building focuses on a person-centered rather than object-centered.First,it is analyzed the deficiencies of the object-centered design,second analyzes the strategy of the humanization design of an industrial building,it is concluded four points for attention: firstly,the most important point is paying attention to humanbeing;secondly,attention should be paid to the diversity rational arrangement of the spatial functions,providing the diversity rather than a single production space;thirdly,the industrial building design should be from the closing to the opening,becoming an opening and closing humanization sapce;finally,the humanization design of an industrial building should be embodied in the details.
2012, 42(3): 52-55,75.
doi: 10.13204/j.gyjz201203010
Abstract:
Industrial heritage is an important part of urban cultural heritages,which has historic,cultural,scientific technical,aesthetic and ecological value.In the paper,the actual problems of creative industrial parks in Shanghai are analyzed.On the base of which,the actuality and measures of protecting industrial heritage are further researched.
Industrial heritage is an important part of urban cultural heritages,which has historic,cultural,scientific technical,aesthetic and ecological value.In the paper,the actual problems of creative industrial parks in Shanghai are analyzed.On the base of which,the actuality and measures of protecting industrial heritage are further researched.
2012, 42(3): 56-59.
doi: 10.13204/j.gyjz201203011
Abstract:
As the center of culture,economic,transport of Paris,the buildings and public gardens of Les Halles,which were built in 1970s,have been unable to adapt to urban development and the pressures arising from population growth.In 2004,an international completion gave this place a chance to rebirth.6 years later,the new plan came out with interconnected strategy for the renovation of commercial buildings,public gardens and the underground interchange.
As the center of culture,economic,transport of Paris,the buildings and public gardens of Les Halles,which were built in 1970s,have been unable to adapt to urban development and the pressures arising from population growth.In 2004,an international completion gave this place a chance to rebirth.6 years later,the new plan came out with interconnected strategy for the renovation of commercial buildings,public gardens and the underground interchange.
2012, 42(3): 60-63,24.
doi: 10.13204/j.gyjz201203012
Abstract:
Science and technology have become the main factor of social development,and the technical representation has also become the primary means of architectural creation.But the practice of the old building renevation is different from that of a new construction,which is an organic integration result of old and new systems.This endows the technology selection and technology application of old buildings with its own characteristics.This article tries to analyze the technical self-value and logical characteristics in the renovation of old buildings,summarizes the means of technology application,which would be useful for the practice of old building renovation.
Science and technology have become the main factor of social development,and the technical representation has also become the primary means of architectural creation.But the practice of the old building renevation is different from that of a new construction,which is an organic integration result of old and new systems.This endows the technology selection and technology application of old buildings with its own characteristics.This article tries to analyze the technical self-value and logical characteristics in the renovation of old buildings,summarizes the means of technology application,which would be useful for the practice of old building renovation.
2012, 42(3): 64-67,70.
doi: 10.13204/j.gyjz201203013
Abstract:
It was analyzed the gap between Tianjin township industrial buildings and green building rating standards,and was also proposed the idea of implementing green building design of Tianjin township industrial buildings;and it was put forward the green design strategies suitable for such buildings in Tianjin by way of planning and architectural design.
It was analyzed the gap between Tianjin township industrial buildings and green building rating standards,and was also proposed the idea of implementing green building design of Tianjin township industrial buildings;and it was put forward the green design strategies suitable for such buildings in Tianjin by way of planning and architectural design.
2012, 42(3): 68-70,67.
doi: 10.13204/j.gyjz201203014
Abstract:
The model of ecological construction development is one of the main ways which coordinates deepening contradictions between economic development and ecological environment.The actual state of related research subjects both at home and abroad is analyzed systematically.Only looking at this problem from the angel of the union of subject consciousness and object and the most vast scope of material range(cosmic whole matter energy movement)and establishing the model of ecological construction development that can meet the essential requirements of construction,can get a suitable living and ideal settlement environment,which will be the trend of future urban and rural planning and construction development in China.
The model of ecological construction development is one of the main ways which coordinates deepening contradictions between economic development and ecological environment.The actual state of related research subjects both at home and abroad is analyzed systematically.Only looking at this problem from the angel of the union of subject consciousness and object and the most vast scope of material range(cosmic whole matter energy movement)and establishing the model of ecological construction development that can meet the essential requirements of construction,can get a suitable living and ideal settlement environment,which will be the trend of future urban and rural planning and construction development in China.
2012, 42(3): 71-75,55.
doi: 10.13204/j.gyjz201203015
Abstract:
In order to make full use of the high-strength performance of CFRP tendons,the different prestress was applied to 7 mm diameter CFRP tendons put on to 20 mm20 mm grooves opened on the concrete surface of the tensile region of concrete beams.Flexural behavior of nine RC beams strengthened with prestressed near surface mounted CFRP tendons applied different levels of prestress and that of one unstrengthened RC beam were studied.In these tests,stiffness,characteristic load,crack development and ductility of test specimens were carried out.Experimental results show that the high-strength performance of CFRP is fully used,the stiffness of strengthened beams is risen notably,the maximal crack load is increased by 303.17%,the maximal ultimate load is increased by 237.92%,the ductility of beams can approximately meet the requirements of anti-earthquake design,and failure has three expressional forms.
In order to make full use of the high-strength performance of CFRP tendons,the different prestress was applied to 7 mm diameter CFRP tendons put on to 20 mm20 mm grooves opened on the concrete surface of the tensile region of concrete beams.Flexural behavior of nine RC beams strengthened with prestressed near surface mounted CFRP tendons applied different levels of prestress and that of one unstrengthened RC beam were studied.In these tests,stiffness,characteristic load,crack development and ductility of test specimens were carried out.Experimental results show that the high-strength performance of CFRP is fully used,the stiffness of strengthened beams is risen notably,the maximal crack load is increased by 303.17%,the maximal ultimate load is increased by 237.92%,the ductility of beams can approximately meet the requirements of anti-earthquake design,and failure has three expressional forms.
2012, 42(3): 76-79,112.
doi: 10.13204/j.gyjz201203016
Abstract:
It was studied the influence of Turpan natural environment on bending behavior of FRP strengthened RC beams.Eight pieces of experimental beams were made,4 beams for indoor test;the others placed outdoor,after 1 881 d natural aging,bending test was done,and the bending performances of FRP strengthened RC beams between indoor and outdoor environment were compared.The test results show that after the effects of environment,the bearing capacity,ductility and stiffness of strengthened beams have little change,damage forms are the partial peeling of GFRP U-hoops and the break of FRP tensile.Which shows that influence on the bending performance of FRP strengthened RC beams is small in Xinjiang Turpan natural conditions,where large temperature difference and strong ultraviolet ray exist.
It was studied the influence of Turpan natural environment on bending behavior of FRP strengthened RC beams.Eight pieces of experimental beams were made,4 beams for indoor test;the others placed outdoor,after 1 881 d natural aging,bending test was done,and the bending performances of FRP strengthened RC beams between indoor and outdoor environment were compared.The test results show that after the effects of environment,the bearing capacity,ductility and stiffness of strengthened beams have little change,damage forms are the partial peeling of GFRP U-hoops and the break of FRP tensile.Which shows that influence on the bending performance of FRP strengthened RC beams is small in Xinjiang Turpan natural conditions,where large temperature difference and strong ultraviolet ray exist.
2012, 42(3): 80-83,158.
doi: 10.13204/j.gyjz201203017
Abstract:
To establish reasonable deep excavation multi-point displacement monitoring model,radial basis function artificial neural network(RBF)was taken as frame.Its input layer came from displacement mechanical theory,and output layer was formed by interrelated multi-point displacement.Considering excavation and displacement characteristics,special preselecting RBF centers and Fuzzy C-means Algorithm(FCM)were used together to confirm RBF centers.Instances showed that these methods were more reasonable and possed good training and forecasting results.
To establish reasonable deep excavation multi-point displacement monitoring model,radial basis function artificial neural network(RBF)was taken as frame.Its input layer came from displacement mechanical theory,and output layer was formed by interrelated multi-point displacement.Considering excavation and displacement characteristics,special preselecting RBF centers and Fuzzy C-means Algorithm(FCM)were used together to confirm RBF centers.Instances showed that these methods were more reasonable and possed good training and forecasting results.
2012, 42(3): 84-87,137.
doi: 10.13204/j.gyjz201203018
Abstract:
Mechanical behavior of pile-soil interface is an important project in the research field of pile-soil interaction.Using the digital image correlation method,the model tests of pile-soil interface mechanism characteristics were carried out in dense sand.The load transfer characteristics,the distribution regularities of shear displacement field and strain field were analyzed from the view of mesomechanics.The study results indicated that the relationship between pile shaft resistance and settlement presented softening behavior,and the settlement for ultimate shaft resistance was about three percent of pile side length.The shear sliding zone was restricted to the limited range around pile side.The maximum shear strain first appeared in pile top and pile tip,and then developed to the central part of pile.The distribution pattern of maximum shear strain along the pile shaft under ultimate load performed as big at both ends and small in the middle.These test results provided some useful references for determining reasonable pile-soil interface model and relevant numerical calculations.
Mechanical behavior of pile-soil interface is an important project in the research field of pile-soil interaction.Using the digital image correlation method,the model tests of pile-soil interface mechanism characteristics were carried out in dense sand.The load transfer characteristics,the distribution regularities of shear displacement field and strain field were analyzed from the view of mesomechanics.The study results indicated that the relationship between pile shaft resistance and settlement presented softening behavior,and the settlement for ultimate shaft resistance was about three percent of pile side length.The shear sliding zone was restricted to the limited range around pile side.The maximum shear strain first appeared in pile top and pile tip,and then developed to the central part of pile.The distribution pattern of maximum shear strain along the pile shaft under ultimate load performed as big at both ends and small in the middle.These test results provided some useful references for determining reasonable pile-soil interface model and relevant numerical calculations.
2012, 42(3): 88-92,116.
doi: 10.13204/j.gyjz201203019
Abstract:
The vibration of impact drilling was tested to evaluate the impact on surrounding buildings.The main test items included: acceleration on ground surface,acceleration in deep layers,and soil layer deposition.The vibration attenuation rules,wave propagation rules and deposition near the building in different formations caused by vibration were analyzed,and the engineering measures were taken to ensure the building safety.The result showed that the vibration would be generated in foundation obviously during impacting drilling.And the rate of vibration attenuation was higher on ground surface and in the inner formation.The waves caused by vibration propagate in two ways.Vibration amplitude was mainly distributed in relatively lower frequency range in the silt layer near the ground surface.Using method of every hole piling and limiting the number of drilling could reduce the impact of vibration on surround buildings effectively.
The vibration of impact drilling was tested to evaluate the impact on surrounding buildings.The main test items included: acceleration on ground surface,acceleration in deep layers,and soil layer deposition.The vibration attenuation rules,wave propagation rules and deposition near the building in different formations caused by vibration were analyzed,and the engineering measures were taken to ensure the building safety.The result showed that the vibration would be generated in foundation obviously during impacting drilling.And the rate of vibration attenuation was higher on ground surface and in the inner formation.The waves caused by vibration propagate in two ways.Vibration amplitude was mainly distributed in relatively lower frequency range in the silt layer near the ground surface.Using method of every hole piling and limiting the number of drilling could reduce the impact of vibration on surround buildings effectively.
2012, 42(3): 93-96.
doi: 10.13204/j.gyjz201203020
Abstract:
Based on hyperbolic fitting method,two equations describing the relationship between the settlement rate and the residual settlement,and that between the residual settlement and the post-construction settlement,were established.The settlement rate standard and the unloading time prediction method under the conditions of equal loading were proposed.These formulas reveal that settlement rate was directly proportional to square of residual settlement,the ratio of post-construction settlement to the residual settlement depended on not only the consolidation rate of soil,but also the preloading duration with equal loading and the design working life of pavement,but the preloading duration had little effect on the settlement rate standard.Allowed settlement rates were a power function of the controlled post-construction settlements.An analysis of a case history showed that the settlement rate standards provided by the technical specifications and some local engineering experiences were suitable only for the embankment behind abutment,it took too long reloading time for the standards to be applied to common embankment and the embankment adjacent to structures such as culvert.
Based on hyperbolic fitting method,two equations describing the relationship between the settlement rate and the residual settlement,and that between the residual settlement and the post-construction settlement,were established.The settlement rate standard and the unloading time prediction method under the conditions of equal loading were proposed.These formulas reveal that settlement rate was directly proportional to square of residual settlement,the ratio of post-construction settlement to the residual settlement depended on not only the consolidation rate of soil,but also the preloading duration with equal loading and the design working life of pavement,but the preloading duration had little effect on the settlement rate standard.Allowed settlement rates were a power function of the controlled post-construction settlements.An analysis of a case history showed that the settlement rate standards provided by the technical specifications and some local engineering experiences were suitable only for the embankment behind abutment,it took too long reloading time for the standards to be applied to common embankment and the embankment adjacent to structures such as culvert.
2012, 42(3): 97-101,142.
doi: 10.13204/j.gyjz201203021
Abstract:
This subject studies a simplified design method of the long-span spatial arch structure.The internal force analysis models of the most common form-prestressed tie rod are established and a systemic design theory about the long-span spatial arch space structure is formed.Based on the mutual effect between the upper structure and the foundation the basic requirements and major steps for the design are pointed out.The formulas in everyt stage of design are given.The entire design process is improved.This subject fills the research gap in the foundation design of the long-span spatial arch structure.
This subject studies a simplified design method of the long-span spatial arch structure.The internal force analysis models of the most common form-prestressed tie rod are established and a systemic design theory about the long-span spatial arch space structure is formed.Based on the mutual effect between the upper structure and the foundation the basic requirements and major steps for the design are pointed out.The formulas in everyt stage of design are given.The entire design process is improved.This subject fills the research gap in the foundation design of the long-span spatial arch structure.
2012, 42(3): 102-106.
doi: 10.13204/j.gyjz201203022
Abstract:
Strain hardening cementitious composites(SHCC) varied with mix proportion were preparated with common engineering material in this area,experimental research on tensile performance of dumbbell specimens was carried out by using uniaxial tensile test at different ages,and tensile stress versus strain curves and crack development of different SHCC were obtained.The results showed that different SHCC all had strain-hardening and multiple-cracking characteristics obviously,among them,ultimate tensile strain of A and C type SHCC could exceed 0.03.Steady SHCC having excellent tensile performance were preparated based on common river sand and not silica sand,which would reduce project cost and be a theoretic basis for the application of SHCC in practical projects.
Strain hardening cementitious composites(SHCC) varied with mix proportion were preparated with common engineering material in this area,experimental research on tensile performance of dumbbell specimens was carried out by using uniaxial tensile test at different ages,and tensile stress versus strain curves and crack development of different SHCC were obtained.The results showed that different SHCC all had strain-hardening and multiple-cracking characteristics obviously,among them,ultimate tensile strain of A and C type SHCC could exceed 0.03.Steady SHCC having excellent tensile performance were preparated based on common river sand and not silica sand,which would reduce project cost and be a theoretic basis for the application of SHCC in practical projects.
2012, 42(3): 107-112,79.
doi: 10.13204/j.gyjz201203023
Abstract:
By testing flexural strength and compressive strength of different size samples during the corrosion age,it was studied the size effect values among steel fiber reinforced concrete samples with different size.According to the calculation method by definition,it was also studied the compressive strength size effect and the flexural strength size effect under the environment of different solutions.The results show that the compressive strength size conversion coefficient is the same between the non-standard sizes steel fiber reinforced concrete specimens and the standard steel fiber reinforced concrete specimens;the compressive strength size effect values are 0.94、0.86 and 1.00 from the non-standard specimens to the standard specimens;the flexural strength size effect values are 0.73、0.77 and 1.05.Thus a reliable theoretic basis could be provided for using the small size specimen instead of standard size specimen in corrosion tests.
By testing flexural strength and compressive strength of different size samples during the corrosion age,it was studied the size effect values among steel fiber reinforced concrete samples with different size.According to the calculation method by definition,it was also studied the compressive strength size effect and the flexural strength size effect under the environment of different solutions.The results show that the compressive strength size conversion coefficient is the same between the non-standard sizes steel fiber reinforced concrete specimens and the standard steel fiber reinforced concrete specimens;the compressive strength size effect values are 0.94、0.86 and 1.00 from the non-standard specimens to the standard specimens;the flexural strength size effect values are 0.73、0.77 and 1.05.Thus a reliable theoretic basis could be provided for using the small size specimen instead of standard size specimen in corrosion tests.
2012, 42(3): 113-116,92.
doi: 10.13204/j.gyjz201203024
Abstract:
The scheme of manufacturing and handing by sections,and high altitude splicing in field was used for a project of the ultra high industrial plant.It was introduced the splicing of columns,support installation and erection of steel beams,and it was expounded mainly the steel structure hoisting process,assembly sequence,key points of installation,quality control measures.The practice has proved that this installation scheme has solved the problems of the high plant transport and installation,shortened construction period,reduced the cost of the project,improved the quality of installation.
The scheme of manufacturing and handing by sections,and high altitude splicing in field was used for a project of the ultra high industrial plant.It was introduced the splicing of columns,support installation and erection of steel beams,and it was expounded mainly the steel structure hoisting process,assembly sequence,key points of installation,quality control measures.The practice has proved that this installation scheme has solved the problems of the high plant transport and installation,shortened construction period,reduced the cost of the project,improved the quality of installation.
2012, 42(3): 117-122,167.
doi: 10.13204/j.gyjz201203025
Abstract:
The Shouguang Stadium is a long-span cable-suspended space structure.The inner of roof is suspended by cable from the mast,and the outer of the roof is placed on the concrete column of the stands.The roof is a joint-and-girder space truss system.It was introduced the structure system,the load distribution,the design method of two key aspects(cable and sliding support),it was also compared the design controlling data to the monitoring data during construction.The results show that the preloading force of cable and the displacement of the sliding support.For the cable-suspended structure,the preloading force should be applied to avoid the inactivation of the cable under the wind loading.For long-span space structure,the seismic performance can be improved and the cost be saved by changing the restraint mode of the support and selecting the force-transferred path appropriated.
The Shouguang Stadium is a long-span cable-suspended space structure.The inner of roof is suspended by cable from the mast,and the outer of the roof is placed on the concrete column of the stands.The roof is a joint-and-girder space truss system.It was introduced the structure system,the load distribution,the design method of two key aspects(cable and sliding support),it was also compared the design controlling data to the monitoring data during construction.The results show that the preloading force of cable and the displacement of the sliding support.For the cable-suspended structure,the preloading force should be applied to avoid the inactivation of the cable under the wind loading.For long-span space structure,the seismic performance can be improved and the cost be saved by changing the restraint mode of the support and selecting the force-transferred path appropriated.
2012, 42(3): 123-127,146.
doi: 10.13204/j.gyjz201203026
Abstract:
According to unique architectural style of Wenchuan Gymnasium,it is introduced that the concrete frame,space grid structure of the roof and elliptic cylinder shell,which are applied to achieve the architectural style.It is mainly introduced that characteristic technology of energy-consuming joint that achieves the strong nodes,weak component design concept of connection between column bracing and embedded parts,large-diameter spherical joint substitution and buckling restrained components.As carefully designed,the project has gained comprehensive benefits of security,application,economy and beauty.
According to unique architectural style of Wenchuan Gymnasium,it is introduced that the concrete frame,space grid structure of the roof and elliptic cylinder shell,which are applied to achieve the architectural style.It is mainly introduced that characteristic technology of energy-consuming joint that achieves the strong nodes,weak component design concept of connection between column bracing and embedded parts,large-diameter spherical joint substitution and buckling restrained components.As carefully designed,the project has gained comprehensive benefits of security,application,economy and beauty.
2012, 42(3): 128-132,42.
doi: 10.13204/j.gyjz201203027
Abstract:
Experiment on three 1∶5 specimens of the plant column with web opening subjected to eccentric loading is carried out to study the failure mode,the strain,deformation and bearing capacity.The experimental results exhibit that the capacity and the deformation mode are deeply suffering from the influence of web openings,The effect of improving the mechanical behavior of the column by setting the stiffeners surrounding the opening is quite limited,but evidently by setting both stiffeners and thickening the web,the local shear deformation character is presented in the opening area.The works in this paper could be a reference for the design of congener structural components.
Experiment on three 1∶5 specimens of the plant column with web opening subjected to eccentric loading is carried out to study the failure mode,the strain,deformation and bearing capacity.The experimental results exhibit that the capacity and the deformation mode are deeply suffering from the influence of web openings,The effect of improving the mechanical behavior of the column by setting the stiffeners surrounding the opening is quite limited,but evidently by setting both stiffeners and thickening the web,the local shear deformation character is presented in the opening area.The works in this paper could be a reference for the design of congener structural components.
2012, 42(3): 133-137,87.
doi: 10.13204/j.gyjz201203028
Abstract:
The mechanical behavior and horizontal bearing capacity of the connection joint between steel roof and reinforced concrete structure under earthquake were investigated.According to the experimental studies on three 1/2 scaled models of the real connection joint between the steel roof and the concrete structure under low cyclic reversed loading,the failure process and patterns were obtained and load-carrying capacity,ductility and energy dissipation were analyzed.Results show that the bearing capacity of the connection joint is less than the yielding capacity of the connecting bolts alone.The final damage reason of the connection joint is the crack of the concrete structure around the anchor bolts.The hysteresis curve of the connection joint with strong capability of energy was full.According to the comparative analysis of test results and theoretical calculations,the formulas of the bearing capacity of the connection joint between steel roof and reinforced concrete structure were presented,the calculated results agree well with those of the test.
The mechanical behavior and horizontal bearing capacity of the connection joint between steel roof and reinforced concrete structure under earthquake were investigated.According to the experimental studies on three 1/2 scaled models of the real connection joint between the steel roof and the concrete structure under low cyclic reversed loading,the failure process and patterns were obtained and load-carrying capacity,ductility and energy dissipation were analyzed.Results show that the bearing capacity of the connection joint is less than the yielding capacity of the connecting bolts alone.The final damage reason of the connection joint is the crack of the concrete structure around the anchor bolts.The hysteresis curve of the connection joint with strong capability of energy was full.According to the comparative analysis of test results and theoretical calculations,the formulas of the bearing capacity of the connection joint between steel roof and reinforced concrete structure were presented,the calculated results agree well with those of the test.
2012, 42(3): 138-142,101.
doi: 10.13204/j.gyjz201203029
Abstract:
At present,pre-stressed cable structure and pre-stressed rod structure are two important structures which have been widely used in long-span structures.So it is an important issue to select right form of structure in actual project,if the wrong structure is selected,it may lead to large stress and deformation in the upper part of structure.More seriously,the irrational selection will cause major accident during the process of construction.Integrated with an international convention and exhibition centre logging hall project,it is calculated the displacement of foot arch in the different tension program and different structure forms(mainly refers to the cable structure and the rod structure),then the best tension program and structure form are compared and selected.
At present,pre-stressed cable structure and pre-stressed rod structure are two important structures which have been widely used in long-span structures.So it is an important issue to select right form of structure in actual project,if the wrong structure is selected,it may lead to large stress and deformation in the upper part of structure.More seriously,the irrational selection will cause major accident during the process of construction.Integrated with an international convention and exhibition centre logging hall project,it is calculated the displacement of foot arch in the different tension program and different structure forms(mainly refers to the cable structure and the rod structure),then the best tension program and structure form are compared and selected.
2012, 42(3): 143-146,127.
doi: 10.13204/j.gyjz201203030
Abstract:
A 120 m high chimney structure design is elaborated,which is located at a power plant in Longkou City,Shandong Province.Through the comparative analysis,a type of super elevation steel-concrete composite chimney is presented.It is expounded how to compare and select a better one between steel chimney and steel-concrete chimney,and how to design it.
A 120 m high chimney structure design is elaborated,which is located at a power plant in Longkou City,Shandong Province.Through the comparative analysis,a type of super elevation steel-concrete composite chimney is presented.It is expounded how to compare and select a better one between steel chimney and steel-concrete chimney,and how to design it.
2012, 42(3): 147-153,163.
doi: 10.13204/j.gyjz201203031
Abstract:
In this thesis,some simple analytical FEA(finite element analysis) models are developed and utilized to determine the shear strain and seismic capacity of the frame joints of continued projects strengthened by two different methods,bonding steel and CFRP(carbon fiber reinforced plastic).The shear mechanism,failure mode,deformation capacity,bearing capacity and the reliability of the reinforced models and un-reinforced model are gathered to determine the influence produced by the reinforcements.Results of FEA show that both strengthening methods have significant influences on their failure capacity and seismic capacity.From some mechanical aspects,bonding steel proves more suitable for better engineering performance.
In this thesis,some simple analytical FEA(finite element analysis) models are developed and utilized to determine the shear strain and seismic capacity of the frame joints of continued projects strengthened by two different methods,bonding steel and CFRP(carbon fiber reinforced plastic).The shear mechanism,failure mode,deformation capacity,bearing capacity and the reliability of the reinforced models and un-reinforced model are gathered to determine the influence produced by the reinforcements.Results of FEA show that both strengthening methods have significant influences on their failure capacity and seismic capacity.From some mechanical aspects,bonding steel proves more suitable for better engineering performance.
2012, 42(3): 154-158,83.
doi: 10.13204/j.gyjz201203032
Abstract:
In this paper,a floating underground garage,which connects with two multi rise residential buildings,was researched because concrete cracks or crushes occurred on the main members.Through monitoring and investigation on site,the reasons which caused the accidents and the failure mechanism were found that firstly,anti floating design was not carried out due to the wrong peak value of underground water level,which was less than bottom elevation of basement floor;secondly,because the progress of project wasn't completed on schedule,the benefit additional mass was not placed at the correct locations on time so as to make the damage of the members more seriously.Based on the results of monitoring and analysis,the combination of lowering the water level and adding additional mass was applied to deal with the incident,simultaneously,the damaged members were strengthened with RC and externally bonded steel plate.After the reinforced treatment was carried out,the performance of underground garage was good.The experience can be useful for similar projects.
In this paper,a floating underground garage,which connects with two multi rise residential buildings,was researched because concrete cracks or crushes occurred on the main members.Through monitoring and investigation on site,the reasons which caused the accidents and the failure mechanism were found that firstly,anti floating design was not carried out due to the wrong peak value of underground water level,which was less than bottom elevation of basement floor;secondly,because the progress of project wasn't completed on schedule,the benefit additional mass was not placed at the correct locations on time so as to make the damage of the members more seriously.Based on the results of monitoring and analysis,the combination of lowering the water level and adding additional mass was applied to deal with the incident,simultaneously,the damaged members were strengthened with RC and externally bonded steel plate.After the reinforced treatment was carried out,the performance of underground garage was good.The experience can be useful for similar projects.
2012, 42(3): 159-163,153.
doi: 10.13204/j.gyjz201203033
Abstract:
Chizhou Zhongxiang International Hotel is a special irregular and complex high-rise structure,modal response spectrum method and time-history analysis method are used to do elastic static analysis,the limit indicators are under control through optimized adjustment.At the same time,according to the above results and the elastic-plastic overall verification calculation,the final comparative analysis results show that the seismic design of structure can meet the requirements of earthquake resistance standard.
Chizhou Zhongxiang International Hotel is a special irregular and complex high-rise structure,modal response spectrum method and time-history analysis method are used to do elastic static analysis,the limit indicators are under control through optimized adjustment.At the same time,according to the above results and the elastic-plastic overall verification calculation,the final comparative analysis results show that the seismic design of structure can meet the requirements of earthquake resistance standard.
2012, 42(3): 164-167,122.
doi: 10.13204/j.gyjz201203034
Abstract:
During the construction process of photo and text center project,to make up the pile is needed,because the space has been excavated,a large height difference exists inside and outside and no retreat from the field,therefore the original static play equipment can not be used.According to site conditions,three schemes to make up the pile are proposed: hand-dug piles,bored piles,pile hammer.After a detailed study on engineering geology and the technique,duration,economy of 3 schemes,the way of hammer piling is adopted.The testing of the added pile proves pile integrity of the surrounding soil is not disturbed,and the results of sampling show that the pile ultimate bearing capacity can meet the design requirements.
During the construction process of photo and text center project,to make up the pile is needed,because the space has been excavated,a large height difference exists inside and outside and no retreat from the field,therefore the original static play equipment can not be used.According to site conditions,three schemes to make up the pile are proposed: hand-dug piles,bored piles,pile hammer.After a detailed study on engineering geology and the technique,duration,economy of 3 schemes,the way of hammer piling is adopted.The testing of the added pile proves pile integrity of the surrounding soil is not disturbed,and the results of sampling show that the pile ultimate bearing capacity can meet the design requirements.
2012, 42(3): 168-171.
doi: 10.13204/j.gyjz201203035
Abstract:
With the swift development of the national economy,the housing comfortableness needed by people and humanization request are also getting higher and higher.Lots of researches on design of dwelling size and facade etc have been conducted by experts and scholars,but less attention has been paid to the housing entrance.The housing entrance as the transition space of the achievement connecting the indoor outer space plays the vital role is the first space,in which people enters.Whether a housing entrance design is reasonable or not,influences the impression of people on the building.So it has the vital practical significance of the research on the housing entrance space.Moreover,because the housing entrance space often receives the restriction of the transportation core,it is put forward several kinds of designs of the housing entrance space according to several kinds of typical transportation cores of the high-rise residence.
With the swift development of the national economy,the housing comfortableness needed by people and humanization request are also getting higher and higher.Lots of researches on design of dwelling size and facade etc have been conducted by experts and scholars,but less attention has been paid to the housing entrance.The housing entrance as the transition space of the achievement connecting the indoor outer space plays the vital role is the first space,in which people enters.Whether a housing entrance design is reasonable or not,influences the impression of people on the building.So it has the vital practical significance of the research on the housing entrance space.Moreover,because the housing entrance space often receives the restriction of the transportation core,it is put forward several kinds of designs of the housing entrance space according to several kinds of typical transportation cores of the high-rise residence.
