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2010 Vol. 40, No. 3
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2010, 40(3): 1-3.
doi: 10.13204/j.gyjz201003001
Abstract:
Reacting to severe global warming climate,energy conservation and zero carbon become the general trend of future buildings. This paper expounds the meaning and the international trends of zero carbon buildings,and makes an analysis of the famous zero carbon buildings both at home and abroad. It also brings forword some tentative ideas of the development of zero carbon buildings in China.
Reacting to severe global warming climate,energy conservation and zero carbon become the general trend of future buildings. This paper expounds the meaning and the international trends of zero carbon buildings,and makes an analysis of the famous zero carbon buildings both at home and abroad. It also brings forword some tentative ideas of the development of zero carbon buildings in China.
2010, 40(3): 4-7.
doi: 10.13204/j.gyjz201003002
Abstract:
For a realenergy-saving and land-conservationhouse,it is necessary to tap every link that can save the resources. In this paper,on the basis of the original energy-saving and land-conservation strategy,it is conducted a full range of research on energy-saving design and land-conservation design,re-examined the planning and designing process,proposed energy-saving strategy in group planning,and also put forward the land-conservation measures for monomer design of a building. By overall coordination,the real implementation and application ofenergy-saving and land-conservation housescan be realized.
For a realenergy-saving and land-conservationhouse,it is necessary to tap every link that can save the resources. In this paper,on the basis of the original energy-saving and land-conservation strategy,it is conducted a full range of research on energy-saving design and land-conservation design,re-examined the planning and designing process,proposed energy-saving strategy in group planning,and also put forward the land-conservation measures for monomer design of a building. By overall coordination,the real implementation and application ofenergy-saving and land-conservation housescan be realized.
2010, 40(3): 8-11.
doi: 10.13204/j.gyjz201003003
Abstract:
There are many problems in the energy-saving renovation of urban existing residential building in China. It would be a great help to solving these problems if industrial prefabrication schemes are used to replace the traditional site constructions. It is proposed that the tentative ideas of the research on the industrial prefabrication schemes of energy-saving renovation in China according to the European relevant subject(ANNEX 50).
There are many problems in the energy-saving renovation of urban existing residential building in China. It would be a great help to solving these problems if industrial prefabrication schemes are used to replace the traditional site constructions. It is proposed that the tentative ideas of the research on the industrial prefabrication schemes of energy-saving renovation in China according to the European relevant subject(ANNEX 50).
2010, 40(3): 12-15.
doi: 10.13204/j.gyjz201003004
Abstract:
According to the investigation on uses of solar water-heating projects of residential buildings in hot summer and cold winter areas,the paper analyzes application problems of integrative technology of residential buildings and solar energy from the view of suitability,and proposes operation method and way for integrative design of solar energy and residential buildings.
According to the investigation on uses of solar water-heating projects of residential buildings in hot summer and cold winter areas,the paper analyzes application problems of integrative technology of residential buildings and solar energy from the view of suitability,and proposes operation method and way for integrative design of solar energy and residential buildings.
2010, 40(3): 16-19.
doi: 10.13204/j.gyjz201003005
Abstract:
Solar water heaters have been used largely,but their combination with a building has not been solved perfectly. This paper provides three solutions from the architectural point of view: such ascentralized typetwo-part typeaverage type . It analyzes their specific method from the form of system,collector installation,water tank setting,conduit shaft setting,and analyzes the advantages and disadvantages of them.
Solar water heaters have been used largely,but their combination with a building has not been solved perfectly. This paper provides three solutions from the architectural point of view: such ascentralized typetwo-part typeaverage type . It analyzes their specific method from the form of system,collector installation,water tank setting,conduit shaft setting,and analyzes the advantages and disadvantages of them.
2010, 40(3): 20-22.
doi: 10.13204/j.gyjz201003006
Abstract:
To implement energy-saving reconstruction of the existing residential buildings,a technical scheme must be worked out according to their characteristics and the energy conservation requests,and the outstanding problems of projects or key spot structures must be well resolved.
To implement energy-saving reconstruction of the existing residential buildings,a technical scheme must be worked out according to their characteristics and the energy conservation requests,and the outstanding problems of projects or key spot structures must be well resolved.
2010, 40(3): 23-25,22.
doi: 10.13204/j.gyjz201003007
Abstract:
Energy conservation of buildings has become a world-concerned issue. The thermal behavior of building enclosures is the first important problem of ameliorating indoor heat environment. This article analysed the features of climate and building environment in south areas of China and explored EPS panel insulation structural technology of residential buildings in the said areas and their project examples.
Energy conservation of buildings has become a world-concerned issue. The thermal behavior of building enclosures is the first important problem of ameliorating indoor heat environment. This article analysed the features of climate and building environment in south areas of China and explored EPS panel insulation structural technology of residential buildings in the said areas and their project examples.
2010, 40(3): 26-29.
doi: 10.13204/j.gyjz201003008
Abstract:
A new socialist countryside residential design is an important component of residential construction. Due to increasing scarce in todays global resources,it is of great urgency to construct green houses in a socialist new countryside,namely,energy-saving and land-savinghousings will be constructed,which adapts to Chinas national conditions; realizing sustainable development of housing construction is an urgent need for establishing the harmonious society. In this paper,on the basis of summarizing the theory of previous studies,it is expounded that concepts,features,and implementation approach of green houses in the new socialist countryside. It is expected that a contribution will be made to the sustainable development of the residential construction of the new countryside in China.
A new socialist countryside residential design is an important component of residential construction. Due to increasing scarce in todays global resources,it is of great urgency to construct green houses in a socialist new countryside,namely,energy-saving and land-savinghousings will be constructed,which adapts to Chinas national conditions; realizing sustainable development of housing construction is an urgent need for establishing the harmonious society. In this paper,on the basis of summarizing the theory of previous studies,it is expounded that concepts,features,and implementation approach of green houses in the new socialist countryside. It is expected that a contribution will be made to the sustainable development of the residential construction of the new countryside in China.
2010, 40(3): 30-33.
doi: 10.13204/j.gyjz201003009
Abstract:
Taking an energy-saving renovation project in Xuzhou for example,and through the analysis of external and internal insulation systems for outer walls,it has been found out that the external insulation system for an outer wall is more suitable for existing public buildings in the northern area of Jiangsu Province. Renovation studies on roof,outer window,sun-shading and transparent curtain wall have also been carried out. Then,technical measures of energy-saving renovation of the enclosures suitable for the said areas climate conditions have been put forward,and they can be referred by design and construction of energy-saving renovation projects.
Taking an energy-saving renovation project in Xuzhou for example,and through the analysis of external and internal insulation systems for outer walls,it has been found out that the external insulation system for an outer wall is more suitable for existing public buildings in the northern area of Jiangsu Province. Renovation studies on roof,outer window,sun-shading and transparent curtain wall have also been carried out. Then,technical measures of energy-saving renovation of the enclosures suitable for the said areas climate conditions have been put forward,and they can be referred by design and construction of energy-saving renovation projects.
2010, 40(3): 34-36,11.
doi: 10.13204/j.gyjz201003010
Abstract:
Based on the existing public buildings in northern area of Jiangsu Province,combining with specific region,climate and architecture form,investigations have been carried out. Energy consumption structures of existing buildings in this area have been studied initially,and the reasons leading to high energy consumption have been figured out. At last,the integrated technologies of energy-saving renovation of existing buildings in this area which can be referred by designers and builders have been put forward.
Based on the existing public buildings in northern area of Jiangsu Province,combining with specific region,climate and architecture form,investigations have been carried out. Energy consumption structures of existing buildings in this area have been studied initially,and the reasons leading to high energy consumption have been figured out. At last,the integrated technologies of energy-saving renovation of existing buildings in this area which can be referred by designers and builders have been put forward.
2010, 40(3): 37-43.
doi: 10.13204/j.gyjz201003011
Abstract:
Nine continuous concrete beams reinforced with unbonded CFRP tendon were fabricated. Static load tests were carried out for these beams. A new method for CFRP tendon was presented before test to explore the anchorage method of CFRP tendon,whose feasibility was verified through test. Based on test data,it was studied stress of CFRP tendon,distribution of zone of plastic hinge,redistribution of internal force and so on. Then the calculation formula of length of equivalent plastic hinge and that of moment modification were presented respectively.
Nine continuous concrete beams reinforced with unbonded CFRP tendon were fabricated. Static load tests were carried out for these beams. A new method for CFRP tendon was presented before test to explore the anchorage method of CFRP tendon,whose feasibility was verified through test. Based on test data,it was studied stress of CFRP tendon,distribution of zone of plastic hinge,redistribution of internal force and so on. Then the calculation formula of length of equivalent plastic hinge and that of moment modification were presented respectively.
2010, 40(3): 44-46,59.
doi: 10.13204/j.gyjz201003012
Abstract:
The controlling factors of section size of frame columns are axial compression ratio and story drift angle and shear compression ratio. In the design process,section size of frame columns should be estimated and aseismic grade of the frame structure should be determined firstly. And trial calculation is performed by PKPM. And then section size of frame columns are updated according to the corresponding limited value of controlling factors. By above method,better technical and economic indexes are obtained.
The controlling factors of section size of frame columns are axial compression ratio and story drift angle and shear compression ratio. In the design process,section size of frame columns should be estimated and aseismic grade of the frame structure should be determined firstly. And trial calculation is performed by PKPM. And then section size of frame columns are updated according to the corresponding limited value of controlling factors. By above method,better technical and economic indexes are obtained.
2010, 40(3): 47-51.
doi: 10.13204/j.gyjz201003013
Abstract:
Based on the method of the time-history data of strain,the damage identification of a cantilever beam is studied in this paper. By using the method of strain mode curvature difference,this index is affected by vibration mode and exciting force and cant satisfy the request of damage identification. By using the energy method based on strain which is identified to avoid the effect of vibration mode and exciting force,the effect of the damage identification has been greatly improved,especially after amplifying processing with a magnification factors k which is proposed in this paper.
Based on the method of the time-history data of strain,the damage identification of a cantilever beam is studied in this paper. By using the method of strain mode curvature difference,this index is affected by vibration mode and exciting force and cant satisfy the request of damage identification. By using the energy method based on strain which is identified to avoid the effect of vibration mode and exciting force,the effect of the damage identification has been greatly improved,especially after amplifying processing with a magnification factors k which is proposed in this paper.
2010, 40(3): 52-59.
doi: 10.13204/j.gyjz201003014
Abstract:
This paper deals with the limit analysis of structure system under the combined action of constant loadings and live loadings. An efficient algorithm based on the elastic compensation finite element method ( ECFEM),is presented,in which the action of constant loadings to limit analysis is considered. In the algorithm,the iteration process of ECFEM is improved,which keeps the action of constant loadings unchanged while acquires the result of limit analysis. Contrastive analysis of some classical examples and analysis of influence factors show that the results using the algorithm are convergent,accurate and stabilizing.
This paper deals with the limit analysis of structure system under the combined action of constant loadings and live loadings. An efficient algorithm based on the elastic compensation finite element method ( ECFEM),is presented,in which the action of constant loadings to limit analysis is considered. In the algorithm,the iteration process of ECFEM is improved,which keeps the action of constant loadings unchanged while acquires the result of limit analysis. Contrastive analysis of some classical examples and analysis of influence factors show that the results using the algorithm are convergent,accurate and stabilizing.
2010, 40(3): 60-65.
doi: 10.13204/j.gyjz201003015
Abstract:
Based on the test results of eight eccentric in-plane beam-thin wall joints,combined with the nonlinear finite element parametric analyses,the mechanical behavior and force-transferring mechanism of the joint were analyzed. Then,the macro force and strut-and-tie transfer models of eccentric in-plane beam-thin wall joints were proposed. Based on the above research,the calculation and design methods were derived,which are effective and practical,compared with the test results.
Based on the test results of eight eccentric in-plane beam-thin wall joints,combined with the nonlinear finite element parametric analyses,the mechanical behavior and force-transferring mechanism of the joint were analyzed. Then,the macro force and strut-and-tie transfer models of eccentric in-plane beam-thin wall joints were proposed. Based on the above research,the calculation and design methods were derived,which are effective and practical,compared with the test results.
2010, 40(3): 66-70.
doi: 10.13204/j.gyjz201003016
Abstract:
Experiment was carried out on crack width of 15 concrete beams reinforced with HRB500 steel bars. Crack properties of specimens were studied; and the calculating method of crack width in GB 500102002Code for Design of Concrete Structureswas analyzed. The results indicate that the parallel relationship of sm-s is true for HRB500 steel bars. It is proper to take 0. 87 for coefficient of internal force arm. Test results of crack spacing and crack width is smaller than that calculated by the formula from GB 500102002. Adjusting bond coefficient of HRB500 steel bars to 1. 2 can improve the accuracy of the formula. Crack calculating mode of GB 500102002 is practical while the calculated maximum crack width is conservative.
Experiment was carried out on crack width of 15 concrete beams reinforced with HRB500 steel bars. Crack properties of specimens were studied; and the calculating method of crack width in GB 500102002Code for Design of Concrete Structureswas analyzed. The results indicate that the parallel relationship of sm-s is true for HRB500 steel bars. It is proper to take 0. 87 for coefficient of internal force arm. Test results of crack spacing and crack width is smaller than that calculated by the formula from GB 500102002. Adjusting bond coefficient of HRB500 steel bars to 1. 2 can improve the accuracy of the formula. Crack calculating mode of GB 500102002 is practical while the calculated maximum crack width is conservative.
2010, 40(3): 71-76.
doi: 10.13204/j.gyjz201003017
Abstract:
The influence of loading rate on stress-strain behaviors of rockfill under isotropic compression condition was analyzed. Based on the research achievements of particle crushing for rockfill,the time dependent constitutive relationship was generalized from isotropic to shearing condition,and a constitutive model considering particle crushing and time-effect was proposed further. The comparison of predicted and tested results indicate that the proposed model can not only consider the influence of particle crushing and time-effect on deformation while loading reasonably,but also describe well the deformation with time increasing during holding the load.
The influence of loading rate on stress-strain behaviors of rockfill under isotropic compression condition was analyzed. Based on the research achievements of particle crushing for rockfill,the time dependent constitutive relationship was generalized from isotropic to shearing condition,and a constitutive model considering particle crushing and time-effect was proposed further. The comparison of predicted and tested results indicate that the proposed model can not only consider the influence of particle crushing and time-effect on deformation while loading reasonably,but also describe well the deformation with time increasing during holding the load.
2010, 40(3): 77-81,76.
doi: 10.13204/j.gyjz201003018
Abstract:
In this paper,the limit state function of a reinforced clay foundation,which was used in reliability analysis was obtained. At same time,the modification of the uncertainty of Hassan formula was done: the average value from Hassan formula was equal to the average value of limit bearing capacity obtained in site test. The selfcorrelation of soil character parameter and commutative correlation between soil character parameters were considered in the calculation of capacity reliability of reinforced clay foundation,with which the reliability of the foundation was increased. It was considered that the uncertainties of material parameters,load factors and calculation models. Finally,it is pointed out that a further study on the calculation methed of this sort of foundation is needed.
In this paper,the limit state function of a reinforced clay foundation,which was used in reliability analysis was obtained. At same time,the modification of the uncertainty of Hassan formula was done: the average value from Hassan formula was equal to the average value of limit bearing capacity obtained in site test. The selfcorrelation of soil character parameter and commutative correlation between soil character parameters were considered in the calculation of capacity reliability of reinforced clay foundation,with which the reliability of the foundation was increased. It was considered that the uncertainties of material parameters,load factors and calculation models. Finally,it is pointed out that a further study on the calculation methed of this sort of foundation is needed.
2010, 40(3): 82-87.
doi: 10.13204/j.gyjz201003019
Abstract:
With the development of urban construction,tension piles are widely used for resisting uplift loads of underground structures. However,there are few research achievements of tension piles. Most of study achievements of tension piles are centralized at the uplift capacity,but the study on analytic methods of the deformation of tension piles is very few. The elastic-plastic load-transfer functions of pile shaft are adopted in the analysis of deformation of tension piles. The lateral soil strength is regarded as constant or increasing linearly along the depth. On this basis,a series of expressions of deformation and the value of the axial load at a certain depth from the ground surface of tension pile are deduced. The comparison of the load-settlement responses of the model experiment to the results of shows that this method can predict well the nonlinear deformation of the tension piles.
With the development of urban construction,tension piles are widely used for resisting uplift loads of underground structures. However,there are few research achievements of tension piles. Most of study achievements of tension piles are centralized at the uplift capacity,but the study on analytic methods of the deformation of tension piles is very few. The elastic-plastic load-transfer functions of pile shaft are adopted in the analysis of deformation of tension piles. The lateral soil strength is regarded as constant or increasing linearly along the depth. On this basis,a series of expressions of deformation and the value of the axial load at a certain depth from the ground surface of tension pile are deduced. The comparison of the load-settlement responses of the model experiment to the results of shows that this method can predict well the nonlinear deformation of the tension piles.
2010, 40(3): 88-93.
doi: 10.13204/j.gyjz201003020
Abstract:
In this paper,a 3-D numerical analysis is used to simulate the soil arching effect surrounding anti-slide pile with FLAC3D,which is the main manner of the soil-pile interaction. The analytic results show that there are two kinds of stress arches behind the anti-slide pile and in the soil between piles,the soil arching effect will increase with the depth of the soil,and different soil property leads to different soil arching shape. The effecting factors on the behavior of soil arching effect are studied,such as the magnitude of load,the spacing between adjacent piles,the cohesion and internal friction angle of soil,the modulus of elasticity ratio of soil to pile,Poisson ratio,pile-soil interface behavior,etc.
In this paper,a 3-D numerical analysis is used to simulate the soil arching effect surrounding anti-slide pile with FLAC3D,which is the main manner of the soil-pile interaction. The analytic results show that there are two kinds of stress arches behind the anti-slide pile and in the soil between piles,the soil arching effect will increase with the depth of the soil,and different soil property leads to different soil arching shape. The effecting factors on the behavior of soil arching effect are studied,such as the magnitude of load,the spacing between adjacent piles,the cohesion and internal friction angle of soil,the modulus of elasticity ratio of soil to pile,Poisson ratio,pile-soil interface behavior,etc.
2010, 40(3): 94-97.
doi: 10.13204/j.gyjz201003021
Abstract:
High-Performance CFRP tendon is a nonmetal fiber polymer reinforcement,which has the characteristic of high strength,lightweight,corrosion resistance,etc. So it is one of the best choices,in which CFRP tendons are substitute for the ordinary and prestressing reinforcements in the corrosion circumstances and meeting the using requirements of the special structures. A meliorative test method of the compression performance of the CFRP tendons is put forward in this paper. The compression performance of the domestic and imported CFRP tendons is tested by the meliorative test method,and the influence of the seawater corrosion on the CFRP tendons is studied. The results show that the CFRP tendons have the performance of the high strength and the large ultimate strain of compression, and the stress strain curve expresses as approximate lines. The influence of the artificial seawater corrosion on the tension performance of CFRP tendons is very little,but it is obvious on the compression performance.
High-Performance CFRP tendon is a nonmetal fiber polymer reinforcement,which has the characteristic of high strength,lightweight,corrosion resistance,etc. So it is one of the best choices,in which CFRP tendons are substitute for the ordinary and prestressing reinforcements in the corrosion circumstances and meeting the using requirements of the special structures. A meliorative test method of the compression performance of the CFRP tendons is put forward in this paper. The compression performance of the domestic and imported CFRP tendons is tested by the meliorative test method,and the influence of the seawater corrosion on the CFRP tendons is studied. The results show that the CFRP tendons have the performance of the high strength and the large ultimate strain of compression, and the stress strain curve expresses as approximate lines. The influence of the artificial seawater corrosion on the tension performance of CFRP tendons is very little,but it is obvious on the compression performance.
2010, 40(3): 98-101.
doi: 10.13204/j.gyjz201003022
Abstract:
This paper studied three key issues relating to the use of recycled aggregate concrete (RAC) as structural materialthe statistical variation characteristics of the compressive strength,the bond behavior between RAC and rebar,and the thermal expansion coefficient of RAC. Three types of recycled concrete aggregates (RCA) were used to investigate their influence on the statistical characteristics of the concrete compressive strength. The test results indicate that the coefficient of variation of the compressive strength of RAC is similar to that of normal concrete, irrespective of the types of the RCA used. Normal distribution can be used to describe the probability distribution of concrete with various RCAs. The bond-slip curves of RAC and deformed steel rebar are similar to that of normal concrete; the bond strength of RAC with deformed steel rebar is slightly lower than that of normal concrete and the thermal expansion coefficient of RAC does not differ much from that of normal concrete.
This paper studied three key issues relating to the use of recycled aggregate concrete (RAC) as structural materialthe statistical variation characteristics of the compressive strength,the bond behavior between RAC and rebar,and the thermal expansion coefficient of RAC. Three types of recycled concrete aggregates (RCA) were used to investigate their influence on the statistical characteristics of the concrete compressive strength. The test results indicate that the coefficient of variation of the compressive strength of RAC is similar to that of normal concrete, irrespective of the types of the RCA used. Normal distribution can be used to describe the probability distribution of concrete with various RCAs. The bond-slip curves of RAC and deformed steel rebar are similar to that of normal concrete; the bond strength of RAC with deformed steel rebar is slightly lower than that of normal concrete and the thermal expansion coefficient of RAC does not differ much from that of normal concrete.
2010, 40(3): 102-106,138.
doi: 10.13204/j.gyjz201003023
Abstract:
Through incorporating different amount of fly ash (FA) and air entraining agent (AEA) to thermal insulating mortar blended with vitrified microsphere (VM),the influence of fly ash (FA) and air entraining agent (AEA) on properties like consistency,wet apparent density,dry apparent density,compressive strength and thermal conductivity of the thermal insulating mortar was investigated systematically. The results indicate that,when incorporating fly ash lonely,thermal insulating mortars consistency increased first and then reduced. However,wet apparent density,dry apparent density,compressive strength and thermal conductivity were all declined first and then rised,mortars drying shrinkage was inhibited to some extent simultaneously. Taking integrated performance of thermal insulating mortar into account,there exist optimal incorporating amount of AEA for the mortar mixing both FA and AEA. In addition,for thermal insulating mortar blended with VM,the properties were acceptable for incorporating 20 kg/m3 FA and 0. 1% AEA.
Through incorporating different amount of fly ash (FA) and air entraining agent (AEA) to thermal insulating mortar blended with vitrified microsphere (VM),the influence of fly ash (FA) and air entraining agent (AEA) on properties like consistency,wet apparent density,dry apparent density,compressive strength and thermal conductivity of the thermal insulating mortar was investigated systematically. The results indicate that,when incorporating fly ash lonely,thermal insulating mortars consistency increased first and then reduced. However,wet apparent density,dry apparent density,compressive strength and thermal conductivity were all declined first and then rised,mortars drying shrinkage was inhibited to some extent simultaneously. Taking integrated performance of thermal insulating mortar into account,there exist optimal incorporating amount of AEA for the mortar mixing both FA and AEA. In addition,for thermal insulating mortar blended with VM,the properties were acceptable for incorporating 20 kg/m3 FA and 0. 1% AEA.
2010, 40(3): 107-110,127.
doi: 10.13204/j.gyjz201003024
Abstract:
According to the site characteristic and operation requirement of dry coal shed of Dagang Power Station in Tianjin,several schemes were put forward respectively for the roof bearing structure,lateral load-resisted structure and the bearing column structure. Through comparison of these presented structural schemes,a new-type structure system:hybrid structure of large-span portal frame and cable supported barrel vault was proposed and used in this project. Analysis of the new-type structure was completed under different load case and combination,and the static and dynamic behaviors were acquired. The result shows that this structure has clear constitution and distinct load- transmitting way,whose internal force and deformation meet the requirements of relevant codes,which is suitable for actual conditions of this project.
According to the site characteristic and operation requirement of dry coal shed of Dagang Power Station in Tianjin,several schemes were put forward respectively for the roof bearing structure,lateral load-resisted structure and the bearing column structure. Through comparison of these presented structural schemes,a new-type structure system:hybrid structure of large-span portal frame and cable supported barrel vault was proposed and used in this project. Analysis of the new-type structure was completed under different load case and combination,and the static and dynamic behaviors were acquired. The result shows that this structure has clear constitution and distinct load- transmitting way,whose internal force and deformation meet the requirements of relevant codes,which is suitable for actual conditions of this project.
2010, 40(3): 111-115,134.
doi: 10.13204/j.gyjz201003025
Abstract:
Corrugated steel sheets are mounted on purlins either through self-drilled nails or through specially designed splints. The steel sheets exert torsional restraints on purlins when the latter buckles laterally. The present paper reports on an analysis of this torsional restraints on purlins by FEM. HXY-478 roof system developed by Hangxiao Steel Corp. is used in the analysis. Two formulas,one for purlins in positive bending,the other for negative bending moments,are developed for determing the restraints for buckling analysis of purlins.
Corrugated steel sheets are mounted on purlins either through self-drilled nails or through specially designed splints. The steel sheets exert torsional restraints on purlins when the latter buckles laterally. The present paper reports on an analysis of this torsional restraints on purlins by FEM. HXY-478 roof system developed by Hangxiao Steel Corp. is used in the analysis. Two formulas,one for purlins in positive bending,the other for negative bending moments,are developed for determing the restraints for buckling analysis of purlins.
2010, 40(3): 116-123.
doi: 10.13204/j.gyjz201003026
Abstract:
Referencing to the load conditions of steel frame column members in meizoseismal area and aiming at engineering application of profiled bar combination under active international code,this paper designed a total of 36 calculation models of steel specially shaped columns with cruciform section of different flange width-thickness ratio and web depth-thickness ratio under different axial compression ratio,which were equal-stress and 1∶ 2 scale. These models were analyzed by the numbers under low cyclic loading and constant axial compression considering their initial imperfection and material nonlinearity. The paper simulated the entire process of their forcing,deformation and destruction,studied their seismic performance such as bearing capacity,rotational performance,hysteretic behavior, energy dissipation capacity,destruction mode and so on,also analyzed the influencing rule of flange width-thickness ratio,web depth-thickness ratio and axial compression ratio on the seismic performance,and evaluated the holistic seismic behavior of these models. Finally,based on the requirements of seismatic bearing capacity and holistic seismic performance,the paper proposed the limit values of flange width-thickness ratio and web depth-thickness ratio under different axial compression ratio for application of steel specially shaped columns with cruciform section in meizoseismal area,and provided theoretical foundation for practical engineering applications and the compilations of Technical Specification for Steel Structures with Specially Shaped Columns.
Referencing to the load conditions of steel frame column members in meizoseismal area and aiming at engineering application of profiled bar combination under active international code,this paper designed a total of 36 calculation models of steel specially shaped columns with cruciform section of different flange width-thickness ratio and web depth-thickness ratio under different axial compression ratio,which were equal-stress and 1∶ 2 scale. These models were analyzed by the numbers under low cyclic loading and constant axial compression considering their initial imperfection and material nonlinearity. The paper simulated the entire process of their forcing,deformation and destruction,studied their seismic performance such as bearing capacity,rotational performance,hysteretic behavior, energy dissipation capacity,destruction mode and so on,also analyzed the influencing rule of flange width-thickness ratio,web depth-thickness ratio and axial compression ratio on the seismic performance,and evaluated the holistic seismic behavior of these models. Finally,based on the requirements of seismatic bearing capacity and holistic seismic performance,the paper proposed the limit values of flange width-thickness ratio and web depth-thickness ratio under different axial compression ratio for application of steel specially shaped columns with cruciform section in meizoseismal area,and provided theoretical foundation for practical engineering applications and the compilations of Technical Specification for Steel Structures with Specially Shaped Columns.
2010, 40(3): 124-127.
doi: 10.13204/j.gyjz201003027
Abstract:
In this paper,the first four modal parameters of polymer filled steel tubes are determined with the application of the identification of performance parameters theory and the modal test method of hammer impact. And their proportional damping coefficients are determined by means of the method of least squares. The damping ratios of them are also determined with the test method of free vibration. By comparing with empty steel tubes, the results show that the damping ratios and the damping proportional coefficients of polymer filled steel tubes enhance remarkably,and they have very good damping properties.
In this paper,the first four modal parameters of polymer filled steel tubes are determined with the application of the identification of performance parameters theory and the modal test method of hammer impact. And their proportional damping coefficients are determined by means of the method of least squares. The damping ratios of them are also determined with the test method of free vibration. By comparing with empty steel tubes, the results show that the damping ratios and the damping proportional coefficients of polymer filled steel tubes enhance remarkably,and they have very good damping properties.
2010, 40(3): 128-134.
doi: 10.13204/j.gyjz201003028
Abstract:
An overall housing tilt to the northeast occurred on a 11-story reinforced concrete building,due to uneven settlement of its foundation,and the maximum cumulative settlement amount of 111. 33 mm occurred at the northeast point of the building,maximum tilt amount was 6 ,which could not meet the requirements of the code,so a tilt- correction was needed. In conjunction with geologic conditions of the housing and the situation of superstructure,a certain number of static bolt-pressing piles were set on the north side to stabilize the housing settlement; then the disturbing holes were arranged on south side of the building to disturb the gravel layer at the bottom of the raft foundation,so that housing south was forced to lower,so as to achieve the purpose of correcting tilt,after returning to the design value of the building,the pressure grouting was used to reinforce the foundation. In this paper,analysis of the causes of the housing tilt,tilt correction program selection and correct operation,as well as its design and construction were described in detail.
An overall housing tilt to the northeast occurred on a 11-story reinforced concrete building,due to uneven settlement of its foundation,and the maximum cumulative settlement amount of 111. 33 mm occurred at the northeast point of the building,maximum tilt amount was 6 ,which could not meet the requirements of the code,so a tilt- correction was needed. In conjunction with geologic conditions of the housing and the situation of superstructure,a certain number of static bolt-pressing piles were set on the north side to stabilize the housing settlement; then the disturbing holes were arranged on south side of the building to disturb the gravel layer at the bottom of the raft foundation,so that housing south was forced to lower,so as to achieve the purpose of correcting tilt,after returning to the design value of the building,the pressure grouting was used to reinforce the foundation. In this paper,analysis of the causes of the housing tilt,tilt correction program selection and correct operation,as well as its design and construction were described in detail.
2010, 40(3): 135-138.
doi: 10.13204/j.gyjz201003029
Abstract:
Twin jet-grouting technology with dual-rod (TDR) is a useful approach to solidify the soft soil instantly, in which accelerator is used to mixing with cement slurry. The main equipments of twin jet-grouting include a high pressure cement pump,a accelerator pump,a diverter,a drilling rod,a drill rig,and a multifunctional injection monitor with two nozzles,through which the high pressure cement slurry is jetted out from the upper nozzle,eroding soil,and the accelerator shrouded the high pressure cement slurry is jetted from the lower nozzle,mixing with the eroded soil. Therefore,the admixture can gel within several seconds. TDR has the possibility of wide applications for its instant solidification of soft sandy soil with much groundwater.
Twin jet-grouting technology with dual-rod (TDR) is a useful approach to solidify the soft soil instantly, in which accelerator is used to mixing with cement slurry. The main equipments of twin jet-grouting include a high pressure cement pump,a accelerator pump,a diverter,a drilling rod,a drill rig,and a multifunctional injection monitor with two nozzles,through which the high pressure cement slurry is jetted out from the upper nozzle,eroding soil,and the accelerator shrouded the high pressure cement slurry is jetted from the lower nozzle,mixing with the eroded soil. Therefore,the admixture can gel within several seconds. TDR has the possibility of wide applications for its instant solidification of soft sandy soil with much groundwater.
2010, 40(3): 139-143,87.
doi: 10.13204/j.gyjz201003030
Abstract:
Taking the construction of mass concrete basement of a plant for example,this paper studies control technology of temperature crack at early age of the mass concrete from aspects of optimization of mix proportion, casting by layer,adding of admixtures of crack resistant fibres and cement-based crystal water-proof agent,and strengthening of temperature monitoring and curing of concrete etc,and calculates temperature,temperature stress and maximum pouring length of concrete by using related formulae of temperature calculation,which achieves a good effect. It also describes law of temperature variation,application of adding technology of admixture in crack resistance and seepage protecting,and researches the control mechanism of shrinkage crack from aspects of construction conditions,raw materials etc.
Taking the construction of mass concrete basement of a plant for example,this paper studies control technology of temperature crack at early age of the mass concrete from aspects of optimization of mix proportion, casting by layer,adding of admixtures of crack resistant fibres and cement-based crystal water-proof agent,and strengthening of temperature monitoring and curing of concrete etc,and calculates temperature,temperature stress and maximum pouring length of concrete by using related formulae of temperature calculation,which achieves a good effect. It also describes law of temperature variation,application of adding technology of admixture in crack resistance and seepage protecting,and researches the control mechanism of shrinkage crack from aspects of construction conditions,raw materials etc.
2010, 40(3): 144-148,70.
doi: 10.13204/j.gyjz201003031
Abstract:
The controls of materials,pouring and temperature are used for mass concrete construction for cushion cap and column base of Shanghai Yangtze River Tunnel and Bridge. Among them,temperature control is the critical technology to control the mass concrete cracking,and to ensure the quality of concrete?construction,while burying cooling water pipe in concrete is the effective measure to lower the temperature of concrete hydration heat at early age. Better results are got during construction,which provides a reference for similar projects.
The controls of materials,pouring and temperature are used for mass concrete construction for cushion cap and column base of Shanghai Yangtze River Tunnel and Bridge. Among them,temperature control is the critical technology to control the mass concrete cracking,and to ensure the quality of concrete?construction,while burying cooling water pipe in concrete is the effective measure to lower the temperature of concrete hydration heat at early age. Better results are got during construction,which provides a reference for similar projects.
2010, 40(3): 149-152.
doi: 10.13204/j.gyjz201003032
Abstract:
The needs of mentality by people are increasing with a rapid development of cities. As a pattern of the consideration and perception for architectures,phenomenology is forming a new architectural concept; and site mentalityis also becoming gradually a hot spot concerned by building circles. According to the architectural design of Walker Cultural and Commercial Street in Haolishan District of Taian,it is explored how to tap the intension and historical atmosphere of site culture during the design,and architectural language is used to explain the site mentality.
The needs of mentality by people are increasing with a rapid development of cities. As a pattern of the consideration and perception for architectures,phenomenology is forming a new architectural concept; and site mentalityis also becoming gradually a hot spot concerned by building circles. According to the architectural design of Walker Cultural and Commercial Street in Haolishan District of Taian,it is explored how to tap the intension and historical atmosphere of site culture during the design,and architectural language is used to explain the site mentality.
