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2012 Vol. 42, No. 5
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2012, 42(5): 1-11.
doi: 10.13204/j.gyjz2011205001
Abstract:
Stainless steels have unique properties such as favorable corrosion resistance and durability,which could be a satisfactory solution to the corrosion problem of ordinary steel structures.Naturally,service lives of structures are able to get prolonged while the maintenance cost can be reduced provided that stainless steel structural members are adopted in building structures.On account of nonlinear material properties,the stiffness of stainless steel structural members would degenerate with the growth of stresses.Meanwhile,high material cost necessitates more economic design comparing with ordinary steel structures.Consequently,special attention should be paid to the stability of stainless steel structural members.This paper presents status quo and advances of stability research on stainless steel structural members,and analyzes current design provisions in foreign countries.Based upon the recent research and design development,recommendations are made on related research activities regarding the deficiency of experimental results and design provisions in China．
Stainless steels have unique properties such as favorable corrosion resistance and durability,which could be a satisfactory solution to the corrosion problem of ordinary steel structures.Naturally,service lives of structures are able to get prolonged while the maintenance cost can be reduced provided that stainless steel structural members are adopted in building structures.On account of nonlinear material properties,the stiffness of stainless steel structural members would degenerate with the growth of stresses.Meanwhile,high material cost necessitates more economic design comparing with ordinary steel structures.Consequently,special attention should be paid to the stability of stainless steel structural members.This paper presents status quo and advances of stability research on stainless steel structural members,and analyzes current design provisions in foreign countries.Based upon the recent research and design development,recommendations are made on related research activities regarding the deficiency of experimental results and design provisions in China．
2012, 42(5): 12-20.
doi: 10.13204/j.gyjz2011205002
Abstract:
ANSYS is employed to study the overall buckling properties of stainless steel cold formed tubular columns under axial load.Non-linear property of material,the effect of cold-formed,local and overall imperfection as well as the residual stress are considered in this model.The comparisons between test results and the calculated results are performed in order to verify the FEM model.Comparisons indicate that the developed FEM model could represent the test exactly and the deviations in average are limited in 5%. Then the influences of varieties of factor are valued.The results of parameterized analysis conclude that: the influence of the increase strength in the corner region,the parameters variation of the material property and the amplitude of the overall imperfection could cause considerable changes in the buckling strength of stainless columns; shifts in section types almost do not influence the buckling strength.The conclusion could be regarded as the foundation of the design method for cold-formed stainless steel columns．
ANSYS is employed to study the overall buckling properties of stainless steel cold formed tubular columns under axial load.Non-linear property of material,the effect of cold-formed,local and overall imperfection as well as the residual stress are considered in this model.The comparisons between test results and the calculated results are performed in order to verify the FEM model.Comparisons indicate that the developed FEM model could represent the test exactly and the deviations in average are limited in 5%. Then the influences of varieties of factor are valued.The results of parameterized analysis conclude that: the influence of the increase strength in the corner region,the parameters variation of the material property and the amplitude of the overall imperfection could cause considerable changes in the buckling strength of stainless columns; shifts in section types almost do not influence the buckling strength.The conclusion could be regarded as the foundation of the design method for cold-formed stainless steel columns．
2012, 42(5): 21-28.
doi: 10.13204/j.gyjz2011205003
Abstract:
Test results of the stainless steel material property indicate that: considerable difference exists among different states of the same type stainless steel and also exists among varieties of type.However this difference is not directly considered in the typical design codes existing in the world.Based on the verified FEM model,total 30 column curves are calculated that covered the range of material properties in common use.The concept of modification slenderness ratio is utilized to modify the Perry formula and the K＆R formula; at last,new design formula is obtained for calculating the buckling strength of stainless steel columns.Comparisons between the available test result and the proposed approach are conducted.The comparisons indicated that the proposed approach could fit the test results well.This approach could be used as a reference for the first version of stainless steel design code of China．
Test results of the stainless steel material property indicate that: considerable difference exists among different states of the same type stainless steel and also exists among varieties of type.However this difference is not directly considered in the typical design codes existing in the world.Based on the verified FEM model,total 30 column curves are calculated that covered the range of material properties in common use.The concept of modification slenderness ratio is utilized to modify the Perry formula and the K＆R formula; at last,new design formula is obtained for calculating the buckling strength of stainless steel columns.Comparisons between the available test result and the proposed approach are conducted.The comparisons indicated that the proposed approach could fit the test results well.This approach could be used as a reference for the first version of stainless steel design code of China．
2012, 42(5): 29-32.
doi: 10.13204/j.gyjz2011205004
Abstract:
In order to investigate the inelastic deformation behavior of stainless steel beams,4 stainless steel welded beams under pure bending and concentrated loading were performed.The tested material was austenitic stainless steel 316. The relationship between load and deflection was discussed and comparison between test results and results obtained by finite element method was made.The results showed that the deformation behavior of stainless steel performed non-linear load-deflection relationship because of the influence of nonlinear material properties; when yield load reached,the plastic deflection was about half of total one; plastic deflection increased remarkably when out-of- plane displacement took place.The test results can provide a basis for the deflection calculation of the domestic stainless steel I-beams．
In order to investigate the inelastic deformation behavior of stainless steel beams,4 stainless steel welded beams under pure bending and concentrated loading were performed.The tested material was austenitic stainless steel 316. The relationship between load and deflection was discussed and comparison between test results and results obtained by finite element method was made.The results showed that the deformation behavior of stainless steel performed non-linear load-deflection relationship because of the influence of nonlinear material properties; when yield load reached,the plastic deflection was about half of total one; plastic deflection increased remarkably when out-of- plane displacement took place.The test results can provide a basis for the deflection calculation of the domestic stainless steel I-beams．
2012, 42(5): 33-40.
doi: 10.13204/j.gyjz2011205005
Abstract:
Test investigation was performed on the stainless steel flexural members with sections consist of SHS,RHS and welding H section.The flexural members were made in austenitic stainless steel type 304. The test included 39 flexural members totally with 11differernt size sections.The test demonstrated that the simply supported SHS and RHS beams mainly have three different failure modes with different constraint to web and different load methods: flexural failure,web crippling and the combination of flexural failure and web crippling.On the other hand,the beams with welding H-sections were liable to flexural-torsional buckling.Then the test results were compared to the results obtained by EN1993-1-4 and SEI/ASCE 8-02 in the following aspects: the flexural capacity,the nonlinear deflection and the stability coefficient of the welding H-beam.These comparisons indicate that: test results of flexural strength and flexural-torsional buckling strength were higher than those predictions using above design codes; deflections predicted using above design codes were smaller than tests results．
Test investigation was performed on the stainless steel flexural members with sections consist of SHS,RHS and welding H section.The flexural members were made in austenitic stainless steel type 304. The test included 39 flexural members totally with 11differernt size sections.The test demonstrated that the simply supported SHS and RHS beams mainly have three different failure modes with different constraint to web and different load methods: flexural failure,web crippling and the combination of flexural failure and web crippling.On the other hand,the beams with welding H-sections were liable to flexural-torsional buckling.Then the test results were compared to the results obtained by EN1993-1-4 and SEI/ASCE 8-02 in the following aspects: the flexural capacity,the nonlinear deflection and the stability coefficient of the welding H-beam.These comparisons indicate that: test results of flexural strength and flexural-torsional buckling strength were higher than those predictions using above design codes; deflections predicted using above design codes were smaller than tests results．
2012, 42(5): 41-44.
doi: 10.13204/j.gyjz2011205006
Abstract:
Design methods about stainless beam-columns that are buckling about the axis of the bending in three typical stainless design codes,Code of America (SEI/ASCE 8-02),Eurocode (EN 1993-1-4: 2006) and Code of Japan (2002) are compared.A design method of beam-columns based on the Technical Code of Cold-Formed Thin- Wall Steel Structures (GB 500182002) and the previous research achievements in columns is proposed. Comparisons among three specifications and experiment results indicated that the calculated results by the proposed method have similar accuracy with those of these specifications and are conservative on average.Some improvements to this method in the future are given in the end.Conclusion can be used as a reference for the first version for stainless steel design code of China．
Design methods about stainless beam-columns that are buckling about the axis of the bending in three typical stainless design codes,Code of America (SEI/ASCE 8-02),Eurocode (EN 1993-1-4: 2006) and Code of Japan (2002) are compared.A design method of beam-columns based on the Technical Code of Cold-Formed Thin- Wall Steel Structures (GB 500182002) and the previous research achievements in columns is proposed. Comparisons among three specifications and experiment results indicated that the calculated results by the proposed method have similar accuracy with those of these specifications and are conservative on average.Some improvements to this method in the future are given in the end.Conclusion can be used as a reference for the first version for stainless steel design code of China．
2012, 42(5): 45-50,44.
doi: 10.13204/j.gyjz2011205007
Abstract:
The applications of stainless steel in construction increase gradually,including the stainless steel roof structure,the stainless steel bridge,the stainless steel wall etc.Nowadays there are few researches on the mechanical property of stainless steel,of which the residual stress from welding is an important aspect of the welding effect on stainless steel components,while the distribution law of residual stress for stainless steel becomes an urgent subject. In this paper an experimental study on the residual stress of the Austenitic stainless steel 316(06Cr17Ni12Mo2) is conducted including 6 types of sections.Through the analysis of the test results,the value and the distribution law of the residual stress are given,serving a base for further study on the effect of the residual stress on stainless steel components．
The applications of stainless steel in construction increase gradually,including the stainless steel roof structure,the stainless steel bridge,the stainless steel wall etc.Nowadays there are few researches on the mechanical property of stainless steel,of which the residual stress from welding is an important aspect of the welding effect on stainless steel components,while the distribution law of residual stress for stainless steel becomes an urgent subject. In this paper an experimental study on the residual stress of the Austenitic stainless steel 316(06Cr17Ni12Mo2) is conducted including 6 types of sections.Through the analysis of the test results,the value and the distribution law of the residual stress are given,serving a base for further study on the effect of the residual stress on stainless steel components．
2012, 42(5): 51-54.
doi: 10.13204/j.gyjz2011205008
Abstract:
The influence of residual stress on stainless steel beams is to cause premature yield and loss of flexural stiffness.The influences of magnitudes and distribution of residual stress on the lateral buckling are therefore important for stainless steel welded I-beams.The influencing factors analysis on the inelastic lateral buckling behavior of the beams was presented by adopting the widely approval model of residual stress.This paper improves the investigation on the overall buckling behavior and the results show that the amplitude of compression stress in flange performs the significant effect．
The influence of residual stress on stainless steel beams is to cause premature yield and loss of flexural stiffness.The influences of magnitudes and distribution of residual stress on the lateral buckling are therefore important for stainless steel welded I-beams.The influencing factors analysis on the inelastic lateral buckling behavior of the beams was presented by adopting the widely approval model of residual stress.This paper improves the investigation on the overall buckling behavior and the results show that the amplitude of compression stress in flange performs the significant effect．
2012, 42(5): 55-62,54.
doi: 10.13204/j.gyjz2011205009
Abstract:
Stainless steel enjoys better popularity in spatial structure construction for its endurance,anti-corrosion, fire-resistance,low temperature resistance,its attractive appearance and the low cost for repair.Recent researches on mechanical property of stainless steel are still limited and the relevant standard is under composition.Under the basic introduction of its material characteristics and classification,this paper summarized the research status about the mechanical property of the material and the uniaxial bearing members at home and abroad.The paper summarized the welding performance and the node bearing capacity of stainless steel welded hollow spherical joints as well as the relevant research findings of the stainless steel bolted spherical joint,especially the engineering application in spatial structure.The mechanical property of tetrahedron tensegrity structure made of stainless steel in Tianjin University is analyzed at the end of this article.Its promising future in space grid structure application is referred as well．
Stainless steel enjoys better popularity in spatial structure construction for its endurance,anti-corrosion, fire-resistance,low temperature resistance,its attractive appearance and the low cost for repair.Recent researches on mechanical property of stainless steel are still limited and the relevant standard is under composition.Under the basic introduction of its material characteristics and classification,this paper summarized the research status about the mechanical property of the material and the uniaxial bearing members at home and abroad.The paper summarized the welding performance and the node bearing capacity of stainless steel welded hollow spherical joints as well as the relevant research findings of the stainless steel bolted spherical joint,especially the engineering application in spatial structure.The mechanical property of tetrahedron tensegrity structure made of stainless steel in Tianjin University is analyzed at the end of this article.Its promising future in space grid structure application is referred as well．
A COMPARISION OF CONNECTION DESIGN IN STAINLESS STEEL STRUCTURES BETWEEN AMERICAN AND EUROPEAN CODES
2012, 42(5): 63-66.
doi: 10.13204/j.gyjz2011205010
Abstract:
Stainless steel has been widely used as load-bearing members in various engineering structures because of its good anti-rust performance,but the lack of design code affects the usage of stainless steel in China.The American stainless steel code (SEI/ASCE 8-02) and the European steel structures (Eurocode 3) on the basic design rules, the calculation of welded connections and the design of bolted connections in stainless steel are compared and analyzed.The result can be a reference for the design of structures as well as for drafting the Chinese design code of stainless steel structures．
Stainless steel has been widely used as load-bearing members in various engineering structures because of its good anti-rust performance,but the lack of design code affects the usage of stainless steel in China.The American stainless steel code (SEI/ASCE 8-02) and the European steel structures (Eurocode 3) on the basic design rules, the calculation of welded connections and the design of bolted connections in stainless steel are compared and analyzed.The result can be a reference for the design of structures as well as for drafting the Chinese design code of stainless steel structures．
2012, 42(5): 67-70,164.
doi: 10.13204/j.gyjz2011205011
Abstract:
Current situations and energy-consumption structure of 400 existing rural residential buildings in 43 typical villages in cold regions of Jiangsu Province have been investigated and analyzed.In addition,the comfort level of rural residential buildings is also discussed.At last,the energy saving proper technology for rural residential buildings in this area has been proposed,which can provide references for the related designs and constructions．
Current situations and energy-consumption structure of 400 existing rural residential buildings in 43 typical villages in cold regions of Jiangsu Province have been investigated and analyzed.In addition,the comfort level of rural residential buildings is also discussed.At last,the energy saving proper technology for rural residential buildings in this area has been proposed,which can provide references for the related designs and constructions．
2012, 42(5): 71-75.
doi: 10.13204/j.gyjz2011205012
Abstract:
This paper summarizes the characteristics of high-rise office building energy consumption in cold areas, analyzes the common problems in passive energy-saving design.On this basis,as an example of taking the scientific research office building for Xi' an Road Institute,for example,this paper introduces the passiveenergy-saving design scheme of high-rise office building in cold areas,and verifies the effect of passive design,finally calculates quantitatively the energy-saving rate of a passive design．
This paper summarizes the characteristics of high-rise office building energy consumption in cold areas, analyzes the common problems in passive energy-saving design.On this basis,as an example of taking the scientific research office building for Xi' an Road Institute,for example,this paper introduces the passiveenergy-saving design scheme of high-rise office building in cold areas,and verifies the effect of passive design,finally calculates quantitatively the energy-saving rate of a passive design．
2012, 42(5): 76-78,83.
doi: 10.13204/j.gyjz2011205013
Abstract:
The article divides the ecological residence into three types: the green residence,sustainable residence and health residence,according to the relationship between ecological residence with nature,and society with people. Based on which the design cruces of the ecological residence are explained and analyzed．
The article divides the ecological residence into three types: the green residence,sustainable residence and health residence,according to the relationship between ecological residence with nature,and society with people. Based on which the design cruces of the ecological residence are explained and analyzed．
2012, 42(5): 79-83.
doi: 10.13204/j.gyjz2011205014
Abstract:
The construction of model villages,in famous towns and villages is the major move of building livable urban and rural areas in Cruangdong Province.In this paper,taking Liantang Village in Jiulong Town of Guangzhou Luogang District for example,for a rural arrangement of Lingnan Culture,in line with the principle of local conditions,a village (town) a policy of flexible mechanisms,it is put forward the concept of Sangji ponds ecological planning model to create a model village effect in famous town and village having genuine sense,but also to avoid the monotony of new faces in rural areas．
The construction of model villages,in famous towns and villages is the major move of building livable urban and rural areas in Cruangdong Province.In this paper,taking Liantang Village in Jiulong Town of Guangzhou Luogang District for example,for a rural arrangement of Lingnan Culture,in line with the principle of local conditions,a village (town) a policy of flexible mechanisms,it is put forward the concept of Sangji ponds ecological planning model to create a model village effect in famous town and village having genuine sense,but also to avoid the monotony of new faces in rural areas．
2012, 42(5): 84-89,28.
doi: 10.13204/j.gyjz2011205015
Abstract:
It was conducted an experimental investigation on four steel fiber reinforced high-strength concrete frame exterior joints under the low cycle loading,and discussed the influence of steel fiber volume ratio and stirrup ratio on seismic capacity of the joint of this type.The result shows that with the increase of the steel fiber volume ratio and stirrup ratio,the restriction role to the concrete of the core area of the joint was enhanced; the shearing-resistance capacity of the core area of the joint was increased; the degeneration degree of shearing-resistance capacity and rigidity was mitigated; joint core area shearing deformation was reduced; the joint ductility was increased and the energy dissipation capacity of the joint was improved．
It was conducted an experimental investigation on four steel fiber reinforced high-strength concrete frame exterior joints under the low cycle loading,and discussed the influence of steel fiber volume ratio and stirrup ratio on seismic capacity of the joint of this type.The result shows that with the increase of the steel fiber volume ratio and stirrup ratio,the restriction role to the concrete of the core area of the joint was enhanced; the shearing-resistance capacity of the core area of the joint was increased; the degeneration degree of shearing-resistance capacity and rigidity was mitigated; joint core area shearing deformation was reduced; the joint ductility was increased and the energy dissipation capacity of the joint was improved．
2012, 42(5): 90-93,97.
doi: 10.13204/j.gyjz2011205016
Abstract:
Under low cyclic loading,6 interior frame nodes of Z-shaped concrete columns with 1 /2 scale were tested.The fracture morphology of frame nodes of Z-shaped columns was obtained.The limits of shear capacity of frame node core zone were measured,and the check values of shear capacity of node core zone were calculated by the formulas in current related standards.Through the analysis of comparison between test values and standard calculation values,the deviations of shear capacity of node core zone of Z-shaped columns calculated by current standard were obtained.The conclusion may be a reference for the design and calculation of Z-shaped concrete columns in practical projects．
Under low cyclic loading,6 interior frame nodes of Z-shaped concrete columns with 1 /2 scale were tested.The fracture morphology of frame nodes of Z-shaped columns was obtained.The limits of shear capacity of frame node core zone were measured,and the check values of shear capacity of node core zone were calculated by the formulas in current related standards.Through the analysis of comparison between test values and standard calculation values,the deviations of shear capacity of node core zone of Z-shaped columns calculated by current standard were obtained.The conclusion may be a reference for the design and calculation of Z-shaped concrete columns in practical projects．
2012, 42(5): 94-97.
doi: 10.13204/j.gyjz2011205017
Abstract:
Based on the traditional mechanical model of straight beam,the paper makes a systematic analysis and research on the pre-twisted Euler beam finite element numerical model.The paper uses two-node model of 12 degrees of freedom,axial displacement interpolation function using 2-node Lagrange interpolation function,beam transverse bending displacements (u and v) still use the cubic displacement,bending with torsion angle displacement function using cubic polynomial displacement function.Firstly,based on the author previous literature on the flexure strain relationship,the paper deduces the element stiffness matrix of the pre-twisted beam.Finally,by calculating the pre- twisted rectangle section beam example,and contrasting three-dimensional solid finite element using ANSYS,the comparative analysis results show that pre-twisted Euler beam element stiffness matrix has good accuracy．
Based on the traditional mechanical model of straight beam,the paper makes a systematic analysis and research on the pre-twisted Euler beam finite element numerical model.The paper uses two-node model of 12 degrees of freedom,axial displacement interpolation function using 2-node Lagrange interpolation function,beam transverse bending displacements (u and v) still use the cubic displacement,bending with torsion angle displacement function using cubic polynomial displacement function.Firstly,based on the author previous literature on the flexure strain relationship,the paper deduces the element stiffness matrix of the pre-twisted beam.Finally,by calculating the pre- twisted rectangle section beam example,and contrasting three-dimensional solid finite element using ANSYS,the comparative analysis results show that pre-twisted Euler beam element stiffness matrix has good accuracy．
2012, 42(5): 98-101,105.
doi: 10.13204/j.gyjz2011205018
Abstract:
Grid frame structure with phosphogypsum as the wall is a new type structure,which can be designed by the existing structure software.The conversion formula of the thickness of the equivalent shear wall is established according to the principle of the same top displacement under horizontal loads.The error between the calculated value and the finite element analysis of grid frame structure with phosphogypsum as the wall is only 0. 4% ,which is 8. 59% as compared with the equivalent shear wall.The error of finite element analysis of the equivalent shear wall is caused by not considering the impact of the hole weakening the cross-sectional area and stiffness.Overall,the theoretical calculation values and finite element analysis results agree well,the conversion formula of equivalent shear wall thickness is consistent with the actual conditions,which may provide a reference for engineering design reference．
Grid frame structure with phosphogypsum as the wall is a new type structure,which can be designed by the existing structure software.The conversion formula of the thickness of the equivalent shear wall is established according to the principle of the same top displacement under horizontal loads.The error between the calculated value and the finite element analysis of grid frame structure with phosphogypsum as the wall is only 0. 4% ,which is 8. 59% as compared with the equivalent shear wall.The error of finite element analysis of the equivalent shear wall is caused by not considering the impact of the hole weakening the cross-sectional area and stiffness.Overall,the theoretical calculation values and finite element analysis results agree well,the conversion formula of equivalent shear wall thickness is consistent with the actual conditions,which may provide a reference for engineering design reference．
2012, 42(5): 102-105.
doi: 10.13204/j.gyjz2011205019
Abstract:
The foundation with symmetric double batter piles is the main type,which is used for buildings and structure.The model experiments were done.The angles of the batter piles were 0,5,10,15,and 20 separately.The characteristics of the vertical bearing capacity were analyzed.The study indicated that under the vertical load as the angle of the batter pile was between 5 and 10,the vertical bearing capacity of the foundation was more than the one with vertical group piles.When the angle was more than 10,the vertical bearing capacity of the foundation decreased and even less than the one with vertical group piles．
The foundation with symmetric double batter piles is the main type,which is used for buildings and structure.The model experiments were done.The angles of the batter piles were 0,5,10,15,and 20 separately.The characteristics of the vertical bearing capacity were analyzed.The study indicated that under the vertical load as the angle of the batter pile was between 5 and 10,the vertical bearing capacity of the foundation was more than the one with vertical group piles.When the angle was more than 10,the vertical bearing capacity of the foundation decreased and even less than the one with vertical group piles．
2012, 42(5): 106-114.
doi: 10.13204/j.gyjz2011205020
Abstract:
By using the finite element software of Plaxis,the geosynthetic-reinforced and pile-supported earth platform resting on oversized deep soft soil in Chaoshan Railway Station of Xiamen-Shenzhen High Speed Railway was simulated.The settlement of subgrade,variation of earth pressure,and tensile force distribution of geogrid and so on were investigated.The results showed that the varying law of layers settlement with fill height appeared to be intermittent,and the settlement mainly occured in the underlying stratum; the earth pressure changed gradually and rectified its value throughout the entire construction period; the axial ultimate force of the piles occured on the top of the muddy clay layer in the vertical direction,and the moment and shear of pile body increased from the subgrade center outside in the horizontal direction; the maximum tension of geogrid occured at the edge of caps and the settings of caps contributed to balance the tension in geogrid to avoid stress concentration; the excess pore water pressure increased with increased fill height,which indicated that the upper loads could be effectively transferred from pile body to deep stratum,thus controlling foundation settlement well．
By using the finite element software of Plaxis,the geosynthetic-reinforced and pile-supported earth platform resting on oversized deep soft soil in Chaoshan Railway Station of Xiamen-Shenzhen High Speed Railway was simulated.The settlement of subgrade,variation of earth pressure,and tensile force distribution of geogrid and so on were investigated.The results showed that the varying law of layers settlement with fill height appeared to be intermittent,and the settlement mainly occured in the underlying stratum; the earth pressure changed gradually and rectified its value throughout the entire construction period; the axial ultimate force of the piles occured on the top of the muddy clay layer in the vertical direction,and the moment and shear of pile body increased from the subgrade center outside in the horizontal direction; the maximum tension of geogrid occured at the edge of caps and the settings of caps contributed to balance the tension in geogrid to avoid stress concentration; the excess pore water pressure increased with increased fill height,which indicated that the upper loads could be effectively transferred from pile body to deep stratum,thus controlling foundation settlement well．
2012, 42(5): 115-118,114.
doi: 10.13204/j.gyjz2011205021
Abstract:
MMP pile is an improved method of deep mixing cement-soil columns,and driving pile affects the surrounding soil of the pile.By using the finite element software ABAQUS,the process of MMP pile driven at a site near a railway foundation in Shanghai was simulated based on the theory of Biot consolidation and modified Cam-Clay constitutive model.The changes in the excess pore pressure and the lateral earth pressure were obtained.Comparison of computed and measured results in situ showed that the computed excess pore water pressure and lateral earth pressure were consistency with those measured from in situ．
MMP pile is an improved method of deep mixing cement-soil columns,and driving pile affects the surrounding soil of the pile.By using the finite element software ABAQUS,the process of MMP pile driven at a site near a railway foundation in Shanghai was simulated based on the theory of Biot consolidation and modified Cam-Clay constitutive model.The changes in the excess pore pressure and the lateral earth pressure were obtained.Comparison of computed and measured results in situ showed that the computed excess pore water pressure and lateral earth pressure were consistency with those measured from in situ．
2012, 42(5): 119-121.
doi: 10.13204/j.gyjz2011205022
Abstract:
Tensile tests were conducted for 320 groups of carbon fiber sheets in order to determinate mechanical properties of tensile strength,elastic modulus,elongation,etc.According to the experimental results,the values of mechanical properties were determined, which provided a reference for further research．
Tensile tests were conducted for 320 groups of carbon fiber sheets in order to determinate mechanical properties of tensile strength,elastic modulus,elongation,etc.According to the experimental results,the values of mechanical properties were determined, which provided a reference for further research．
2012, 42(5): 122-125.
doi: 10.13204/j.gyjz2011205023
Abstract:
A prestressed steel trussed arch structure with a span of 286 m is used for Costa Rica National Stadium. The steel truss was fixed by bracing structures and the grading process for removing temperary supports was also used removing temporary supports.During removing temporary supports,the wireless stress monitoring system was used to monitor the steel awning stress and the intelligent total station was used to monitor the steel awning deformation, which could technically guarantee removing temporary supports successfully.The result showed that the results of monitoring are in good agreement with the results of theoretical calculation during the removing temporary supports. Which displays that removing temporary supports of steel awning structure is successful．
A prestressed steel trussed arch structure with a span of 286 m is used for Costa Rica National Stadium. The steel truss was fixed by bracing structures and the grading process for removing temperary supports was also used removing temporary supports.During removing temporary supports,the wireless stress monitoring system was used to monitor the steel awning stress and the intelligent total station was used to monitor the steel awning deformation, which could technically guarantee removing temporary supports successfully.The result showed that the results of monitoring are in good agreement with the results of theoretical calculation during the removing temporary supports. Which displays that removing temporary supports of steel awning structure is successful．
2012, 42(5): 126-128.
doi: 10.13204/j.gyjz2011205024
Abstract:
Henan Broadcast TV Tower belongs to super-high structures,it has narrow high workspace and large risks.According to the actual situation of this project,this paper introduces the steel columns lifting,tower columns installation and the construction of inner flanges of eucalyptus leaves shape section steel column.What' s more,the appropriate safety precautions are made.Practice shows that these measures meet the site construction and lifting need,providing a secure platform for workers,which can solve the problems of the narrow high workspace and security protection.So far,there has no security problems during construction of the project and a good protective effect is got．
Henan Broadcast TV Tower belongs to super-high structures,it has narrow high workspace and large risks.According to the actual situation of this project,this paper introduces the steel columns lifting,tower columns installation and the construction of inner flanges of eucalyptus leaves shape section steel column.What' s more,the appropriate safety precautions are made.Practice shows that these measures meet the site construction and lifting need,providing a secure platform for workers,which can solve the problems of the narrow high workspace and security protection.So far,there has no security problems during construction of the project and a good protective effect is got．
2012, 42(5): 129-133.
doi: 10.13204/j.gyjz2011205025
Abstract:
Since March 15,2011, the burning performance requirements of civil construction exterior insulation materials should be upto A-level.As a non-combustible inorganic material,the mineral wool panels with small thermal conductivity,high thermal insulation properties,good permeability,etc.are widely used in exterior insulation. However,because of high density,easy to deform and warp,mineral wool panels are mainly used for curtain walls, the thin plaster system applied in super high-rise building is extremely rare.Combining with project examples,based on theoretical calculations,it is described wind pressure,shear,the number of anchor bolts,and other problems when applying the thin plaster miner wool panels in super high-rise building exterior insulation.Then it is analysed the system's technical difficulties,proposed solutions,testing and project acceptance by entity meet the design requirements,which provides a reference for similar projects．
Since March 15,2011, the burning performance requirements of civil construction exterior insulation materials should be upto A-level.As a non-combustible inorganic material,the mineral wool panels with small thermal conductivity,high thermal insulation properties,good permeability,etc.are widely used in exterior insulation. However,because of high density,easy to deform and warp,mineral wool panels are mainly used for curtain walls, the thin plaster system applied in super high-rise building is extremely rare.Combining with project examples,based on theoretical calculations,it is described wind pressure,shear,the number of anchor bolts,and other problems when applying the thin plaster miner wool panels in super high-rise building exterior insulation.Then it is analysed the system's technical difficulties,proposed solutions,testing and project acceptance by entity meet the design requirements,which provides a reference for similar projects．
2012, 42(5): 134-138,156.
doi: 10.13204/j.gyjz2011205026
Abstract:
This paper presents a review of advances in research on fire resistance and high temperature properties of high-strength concrete (HSC) and ultra-high-strength concrete (UHSC).Further research needs in the near future on UHSC,especially on reactive powder concrete (RPC),are also discussed.It is commonly recognized that HSC suffers strength loss in a manner basically similar to that of normal strength concrete.But the main problem of HSC is explosive spalling under high temperature,which can be solved by employing either polymer fiber or steel fiber.The objectives of fire resistance research are to restrain explosive spalling and minimizing spalling probability,so as to ensure satisfactory fire resistance of RPC.It is expected that in-depth research will be carried out on fracture properties,and micro-structure,resulting in establishment of a mechanism for improving fire resistance of RPC as well as technical measures．
This paper presents a review of advances in research on fire resistance and high temperature properties of high-strength concrete (HSC) and ultra-high-strength concrete (UHSC).Further research needs in the near future on UHSC,especially on reactive powder concrete (RPC),are also discussed.It is commonly recognized that HSC suffers strength loss in a manner basically similar to that of normal strength concrete.But the main problem of HSC is explosive spalling under high temperature,which can be solved by employing either polymer fiber or steel fiber.The objectives of fire resistance research are to restrain explosive spalling and minimizing spalling probability,so as to ensure satisfactory fire resistance of RPC.It is expected that in-depth research will be carried out on fracture properties,and micro-structure,resulting in establishment of a mechanism for improving fire resistance of RPC as well as technical measures．
2012, 42(5): 139-145.
doi: 10.13204/j.gyjz2011205027
Abstract:
The seismic behavior of frame side joints of the steel high-strength reinforced concrete with dog-bone type weakening has been investigated based on the experiment and analysis of nine joint specimens,under cyclic loading. The test results show that well designed HSRC frame joint with dog-bone type weakening has good displacement ductility and hysteretic behavior.The joint,whose axial compression ratio is small,hysteretic curve is full and skeleton curve is gentle,has a better ductility and energy dissipation.In condition of the same or close axial compression ratio,the seismic performance,including the ductility and energy dissipation capacity of the joint with dog-bone type weakening is clearly superior to that of the ordinary joint,and the displacement ductile coefficient is increased by 10% to 25%. When the dog-bone type weakening is taken on the flanges of the steel at the beam end near the joint,the plastic hinge of the beam may be transferred from the root of beam end to the weakened position, thus the seismic behavior of the joints may be improved effectively and the ductile design can be realized．
The seismic behavior of frame side joints of the steel high-strength reinforced concrete with dog-bone type weakening has been investigated based on the experiment and analysis of nine joint specimens,under cyclic loading. The test results show that well designed HSRC frame joint with dog-bone type weakening has good displacement ductility and hysteretic behavior.The joint,whose axial compression ratio is small,hysteretic curve is full and skeleton curve is gentle,has a better ductility and energy dissipation.In condition of the same or close axial compression ratio,the seismic performance,including the ductility and energy dissipation capacity of the joint with dog-bone type weakening is clearly superior to that of the ordinary joint,and the displacement ductile coefficient is increased by 10% to 25%. When the dog-bone type weakening is taken on the flanges of the steel at the beam end near the joint,the plastic hinge of the beam may be transferred from the root of beam end to the weakened position, thus the seismic behavior of the joints may be improved effectively and the ductile design can be realized．
2012, 42(5): 146-150,160.
doi: 10.13204/j.gyjz2011205028
Abstract:
To study the seismic performance of brick masonry wall strengthened with strand mesh reinforcing polymer mortar overlay,and to develop its nonlinear analysis method,experimental study on seismic performance of brick masonry wall strengthened with strand mesh reinforcing polymer mortar overlay was carried out,and then the special experimental study on interface peeling behavior was executed.Experimental results show that the strengthened walls exhibit good seismic performance and ductility.However,there is peeling phenomena between the strengthening overlay and the masonry matrix,leading to the low stress of stand mesh,which is far less than it's ultimate tension strength.Based on the experimental studies,nonlinear static analysis method for the strengthened brick wall is presented.The load-displacement curve can be obtained with the proposed method,and the trend of analytical results show the good agreement with experimental results．
To study the seismic performance of brick masonry wall strengthened with strand mesh reinforcing polymer mortar overlay,and to develop its nonlinear analysis method,experimental study on seismic performance of brick masonry wall strengthened with strand mesh reinforcing polymer mortar overlay was carried out,and then the special experimental study on interface peeling behavior was executed.Experimental results show that the strengthened walls exhibit good seismic performance and ductility.However,there is peeling phenomena between the strengthening overlay and the masonry matrix,leading to the low stress of stand mesh,which is far less than it's ultimate tension strength.Based on the experimental studies,nonlinear static analysis method for the strengthened brick wall is presented.The load-displacement curve can be obtained with the proposed method,and the trend of analytical results show the good agreement with experimental results．
2012, 42(5): 151-156.
doi: 10.13204/j.gyjz2011205029
Abstract:
The experimental investigation concerning the flexional behavior of 36 cylindrical wood beams reinforced with FRP sheets were conducted.The work mechanism and failure modes of the specimens were discussed in details. The parameters of the specimens were number,types and the location of FRP sheets.The effect of design parameters of the specimens on the carrying capacity and deflection of beams was analyzed.The results show that FRP in the tension zone of the wood beam can improve the capacity effectively.The capacity of wood beam is increased by 30. 61% with one layer sheet of CFRP in tension zone.The lateral FRP wound in the pure flexion zone can improve the behavior of the compression zone of wood beam,and increase its flexional capacity effectively.The increased extent is related with the number of FRP sheets.The failure of reinforced wood beam presents the folded fiber in the compressive zone and broken wood fiber in the tension zone.The effect of FRP in the compression zone on the bending capacity of timber beam is related to the strengthened forms.The reinforcement effect of the lateral FRP wound in the compression zone is the best,but little effect is found along the longitudinal FRP．
The experimental investigation concerning the flexional behavior of 36 cylindrical wood beams reinforced with FRP sheets were conducted.The work mechanism and failure modes of the specimens were discussed in details. The parameters of the specimens were number,types and the location of FRP sheets.The effect of design parameters of the specimens on the carrying capacity and deflection of beams was analyzed.The results show that FRP in the tension zone of the wood beam can improve the capacity effectively.The capacity of wood beam is increased by 30. 61% with one layer sheet of CFRP in tension zone.The lateral FRP wound in the pure flexion zone can improve the behavior of the compression zone of wood beam,and increase its flexional capacity effectively.The increased extent is related with the number of FRP sheets.The failure of reinforced wood beam presents the folded fiber in the compressive zone and broken wood fiber in the tension zone.The effect of FRP in the compression zone on the bending capacity of timber beam is related to the strengthened forms.The reinforcement effect of the lateral FRP wound in the compression zone is the best,but little effect is found along the longitudinal FRP．
2012, 42(5): 157-160.
doi: 10.13204/j.gyjz2011205030
Abstract:
Because of the change in building functions of a public building of Rizao City,a large span cantilever beam(1. 8 m) of post-installed fastenings needs to be casted,and other horizontal components'bearing capacity is insufficient due to loads increasing by the new beam.The method of the design and the main points of construction are introducted.The paper emphasizes the application of the double insurance in the design.The project completion and acceptance shows that,the two-insurance design and construction model in the large-span cantilevered beam has a good application prospect．
Because of the change in building functions of a public building of Rizao City,a large span cantilever beam(1. 8 m) of post-installed fastenings needs to be casted,and other horizontal components'bearing capacity is insufficient due to loads increasing by the new beam.The method of the design and the main points of construction are introducted.The paper emphasizes the application of the double insurance in the design.The project completion and acceptance shows that,the two-insurance design and construction model in the large-span cantilevered beam has a good application prospect．
2012, 42(5): 161-164.
doi: 10.13204/j.gyjz2011205031
Abstract:
North Anhui is a region with long history and cultural richness.Existing architectures of large variety and high level are precious gifts from history.This article deeply analyzes the types and patterns of existing traditional architectures in this region based on field reconnaissance and survey,it is expected to make some contributions to the protection,inherence,and innovation of traditional architectures．
North Anhui is a region with long history and cultural richness.Existing architectures of large variety and high level are precious gifts from history.This article deeply analyzes the types and patterns of existing traditional architectures in this region based on field reconnaissance and survey,it is expected to make some contributions to the protection,inherence,and innovation of traditional architectures．
