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2004 Vol. 34, No. 5
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2004, 34(5): 1-3,10.
doi: 10.13204/j.gyjz200405001
Abstract:
There are few experiments of PC structures under salt fog corrosion environments at home and abroad.The authors expatiate the corrosion rules of PC structure under the coaction of stress and salt fog according to the research results of durability tests. Which will provide suggestions for working out durability codes of PC structures.
There are few experiments of PC structures under salt fog corrosion environments at home and abroad.The authors expatiate the corrosion rules of PC structure under the coaction of stress and salt fog according to the research results of durability tests. Which will provide suggestions for working out durability codes of PC structures.
2004, 34(5): 4-6,14.
doi: 10.13204/j.gyjz200405002
Abstract:
The state-of-the-art of research and application of desalted sea sand are introduced, 12 groups(three specimens in each group)of specimens with Ф10050 are fabricated with strength grade of C60 and C80.The fine aggregated used in high performance concrete includes sea sand, desalted sea sand and river sand.According to ASTM C1202 specification, tests on chloride ion permeability are carried out.The effects of curing age, admixture and strength grade are investigated and the test results show that the permeability of concrete with desalted sea sand is very low.Finally, it is concluded that high performance concrete with desalted sea sand up to standard has fine durability.
The state-of-the-art of research and application of desalted sea sand are introduced, 12 groups(three specimens in each group)of specimens with Ф10050 are fabricated with strength grade of C60 and C80.The fine aggregated used in high performance concrete includes sea sand, desalted sea sand and river sand.According to ASTM C1202 specification, tests on chloride ion permeability are carried out.The effects of curing age, admixture and strength grade are investigated and the test results show that the permeability of concrete with desalted sea sand is very low.Finally, it is concluded that high performance concrete with desalted sea sand up to standard has fine durability.
2004, 34(5): 7-10.
doi: 10.13204/j.gyjz200405003
Abstract:
According to the primary channels and source of chloride penetrating into concrete, the mechanism is expounded.The kinds and their limitations of the existing calculating models are analyzed.After taking account of the effects on chloride diffusion coefficient of cement kind, mixed ratio, temperature, relative humidity and time, a calculating model of chloride penetrating into concrete based on finite difference is established.The model is better to reflect the actual situation, which has proper theoretical and practical value.
According to the primary channels and source of chloride penetrating into concrete, the mechanism is expounded.The kinds and their limitations of the existing calculating models are analyzed.After taking account of the effects on chloride diffusion coefficient of cement kind, mixed ratio, temperature, relative humidity and time, a calculating model of chloride penetrating into concrete based on finite difference is established.The model is better to reflect the actual situation, which has proper theoretical and practical value.
2004, 34(5): 11-14.
doi: 10.13204/j.gyjz200405004
Abstract:
Through the analysis of the corrosion mechanism of reinforcement and its influencing factors, using the relation between the macroscopical phenomenon and micro mechanism and the theory of anodic control/cathodic control, two experimental devices were designed.Through the relationship of the corrosion current and the corrosion rate, the effect of ambient temperature on the corrosion rate of the reinforcement can be got.
Through the analysis of the corrosion mechanism of reinforcement and its influencing factors, using the relation between the macroscopical phenomenon and micro mechanism and the theory of anodic control/cathodic control, two experimental devices were designed.Through the relationship of the corrosion current and the corrosion rate, the effect of ambient temperature on the corrosion rate of the reinforcement can be got.
2004, 34(5): 15-17.
doi: 10.13204/j.gyjz200405005
Abstract:
Reinforcing steel provides strength and ductility only through bond and anchorage to the concrete.The effectiveness of such connection can be reduced through corrosion of the reinforcing steel.Corrosion of reinforcement leads to a volume increase, causing splitting stresses in the concrete.Therefore, there is a close interaction between corrosion and bond.In order to evaluate the effect of different degrees of reinforcement corrosion on the bond degradation, the tests were designed to provide data required to assess the bond properties including the ultimate bond strength and free-end slip for various degrees of corrosion under pull-out loads.The results of the tests and analyses may supply a valuable reference for durability forecast of concrete structures.
Reinforcing steel provides strength and ductility only through bond and anchorage to the concrete.The effectiveness of such connection can be reduced through corrosion of the reinforcing steel.Corrosion of reinforcement leads to a volume increase, causing splitting stresses in the concrete.Therefore, there is a close interaction between corrosion and bond.In order to evaluate the effect of different degrees of reinforcement corrosion on the bond degradation, the tests were designed to provide data required to assess the bond properties including the ultimate bond strength and free-end slip for various degrees of corrosion under pull-out loads.The results of the tests and analyses may supply a valuable reference for durability forecast of concrete structures.
2004, 34(5): 18-20,43.
doi: 10.13204/j.gyjz200405006
Abstract:
It is the phenomenon that concrete structures in salted contaminated environments suffer premature deterioration from chloride induced reinforcing corrosion.The method of applying cathodic polarization to the existing concrete structures for controlling corrosion is called cathodic protection.The method of applying cathodic polarization to the new concrete structures for preventing corrosion is called cathodic prevention.It is introduced that the construction method, status and development of cathodic protection and cathodic prevention for concrete.
It is the phenomenon that concrete structures in salted contaminated environments suffer premature deterioration from chloride induced reinforcing corrosion.The method of applying cathodic polarization to the existing concrete structures for controlling corrosion is called cathodic protection.The method of applying cathodic polarization to the new concrete structures for preventing corrosion is called cathodic prevention.It is introduced that the construction method, status and development of cathodic protection and cathodic prevention for concrete.
2004, 34(5): 21-23.
doi: 10.13204/j.gyjz200405007
Abstract:
Because of corroded by saturated saltwater, a salt-pot-pool will destroy in a short period when using ordinary concrete.The antiseawater corrosive concrete with a great proportion of ground granulated blast-furnace slag has a higher resistance to chlorides, so it is suitable for a project suffering from chlorides.Through optimizing materials and mixture proportion of a concrete, the antiseawater corrosive concrete with a great proportion of ground granulated blast-furnace slag is used successfully in the salt-pot-pool project of Jiangmen Electrochemical Factory.
Because of corroded by saturated saltwater, a salt-pot-pool will destroy in a short period when using ordinary concrete.The antiseawater corrosive concrete with a great proportion of ground granulated blast-furnace slag has a higher resistance to chlorides, so it is suitable for a project suffering from chlorides.Through optimizing materials and mixture proportion of a concrete, the antiseawater corrosive concrete with a great proportion of ground granulated blast-furnace slag is used successfully in the salt-pot-pool project of Jiangmen Electrochemical Factory.
2004, 34(5): 24-26,29.
doi: 10.13204/j.gyjz200405008
Abstract:
It is put forward that the design of sunshading and heat-insulating of west walls for residential buildings, to settle the problem of uncomfortable indoor environment due to facing west according to the characteristics of regions of hot in summer and cold in winter.
It is put forward that the design of sunshading and heat-insulating of west walls for residential buildings, to settle the problem of uncomfortable indoor environment due to facing west according to the characteristics of regions of hot in summer and cold in winter.
2004, 34(5): 27-29.
doi: 10.13204/j.gyjz200405009
Abstract:
Much energy must be consumed by an atrium due to its glass envelope of a large area.The thermal performance of different glasses is discussed and the glass shall be selected reasonably in the light of zones with different climates and atriums orientation, which achieves the aim of energy -saving.
Much energy must be consumed by an atrium due to its glass envelope of a large area.The thermal performance of different glasses is discussed and the glass shall be selected reasonably in the light of zones with different climates and atriums orientation, which achieves the aim of energy -saving.
2004, 34(5): 30-33,49.
doi: 10.13204/j.gyjz200405010
Abstract:
The development stategy and implementing methods of a water front are expounded from space landscape, regional climate, functional organ, land value, human value, social publicity etc, by combining current urban economy and society etc, and analyzing the systematicness, complexity, sensitivity, compatibility, sharing and character etc, according to the changes of history of a water front. The urban strategy target of sustainable development is realized through renewing and integrating water fronts to promote urban economic development baded on establishing an effective developing mechanism.
The development stategy and implementing methods of a water front are expounded from space landscape, regional climate, functional organ, land value, human value, social publicity etc, by combining current urban economy and society etc, and analyzing the systematicness, complexity, sensitivity, compatibility, sharing and character etc, according to the changes of history of a water front. The urban strategy target of sustainable development is realized through renewing and integrating water fronts to promote urban economic development baded on establishing an effective developing mechanism.
2004, 34(5): 34-36.
doi: 10.13204/j.gyjz200405011
Abstract:
It is discussed that the basic principles of the analytic methods of the structure system reliability based on some functions. It is also given that the theoretical calculation formulas and the approximate calculation methods, which may be a reference for persons concerned.
It is discussed that the basic principles of the analytic methods of the structure system reliability based on some functions. It is also given that the theoretical calculation formulas and the approximate calculation methods, which may be a reference for persons concerned.
WIND-INDUCED VIBRATION RESPONSE ANALYSIS AND STRUCTURAL SCHEME APPRAISAL FOR A THREE-PIPE RC CHIMNEY
2004, 34(5): 37-39.
doi: 10.13204/j.gyjz200405012
Abstract:
Three structural schemes for a three-pipe reinforced concrete (RC) lattice chimney are developed.Taking wind load as a stochastic loading, the dynamical characteristics analysis and wind-induced vibration response analysis for the three structural schemes are carried out.Comparisons between the responses of the three structural schemes due to wind loading given by the Davenport spectrum are emphasized and their appraisals are performed at the same time.
Three structural schemes for a three-pipe reinforced concrete (RC) lattice chimney are developed.Taking wind load as a stochastic loading, the dynamical characteristics analysis and wind-induced vibration response analysis for the three structural schemes are carried out.Comparisons between the responses of the three structural schemes due to wind loading given by the Davenport spectrum are emphasized and their appraisals are performed at the same time.
2004, 34(5): 40-43.
doi: 10.13204/j.gyjz200405013
Abstract:
The observation results of the bridge head experimental site of Jialichen Bridge are analyzed such as vacuum degree, ground water table, flowrate, pore water pressure and surface settlement.The combined mechanism of vacuum combined with surcharge preloading is discussed.It is not the way of the vacuum loading combined with surcharge loading but the the way of pore water pressure difference caused by vacuum preloading combined with the the pore water pressure difference caused by surcharge loading.The testing results show that soft foundation treated by vacuum combined with surcharge preloading is very effective.
The observation results of the bridge head experimental site of Jialichen Bridge are analyzed such as vacuum degree, ground water table, flowrate, pore water pressure and surface settlement.The combined mechanism of vacuum combined with surcharge preloading is discussed.It is not the way of the vacuum loading combined with surcharge loading but the the way of pore water pressure difference caused by vacuum preloading combined with the the pore water pressure difference caused by surcharge loading.The testing results show that soft foundation treated by vacuum combined with surcharge preloading is very effective.
2004, 34(5): 44-49.
doi: 10.13204/j.gyjz200405014
Abstract:
Based on the results of cyclic traxial test, it is presented that an analysis of earthquake resistance of several subway stations which are located in sandy soils and clayey soils in Shanghai.The method of FE dynamic effective stress analysis and reliability analysis is used in the analysis.In order to consider the influence of input earthquake motion, six different recorded earthquake motions selected from both home and aboard are used in the calculations.The results of dynamic response analysis, include the dynamic stresses of subway stations and surrounding soils, pore water pressures and settlements of surrounding soils.The dynamic reliability of subway and surrounding soil is also given.The results of the analysis improve the seismic analysis level of the subway stations surrounded by soft soil, and it is helpful for the aseismic design of underground structures.
Based on the results of cyclic traxial test, it is presented that an analysis of earthquake resistance of several subway stations which are located in sandy soils and clayey soils in Shanghai.The method of FE dynamic effective stress analysis and reliability analysis is used in the analysis.In order to consider the influence of input earthquake motion, six different recorded earthquake motions selected from both home and aboard are used in the calculations.The results of dynamic response analysis, include the dynamic stresses of subway stations and surrounding soils, pore water pressures and settlements of surrounding soils.The dynamic reliability of subway and surrounding soil is also given.The results of the analysis improve the seismic analysis level of the subway stations surrounded by soft soil, and it is helpful for the aseismic design of underground structures.
2004, 34(5): 50-53,61.
doi: 10.13204/j.gyjz200405015
Abstract:
In order to solve the problems of settlement and resistance of soft soil foundation, a lot of 2-D FEM programs based on Biot consolidation theory are written.The mesh needs to be densified to get accuracy.In this paper a practical local mesh densification method, which can deal with the problems in 2-D FEM of Biot consolidation theory that usually interface element and multi-loads are included, is given.At last, the authors write a mesh densification program which shows the method is correct and very useful for a real project.
In order to solve the problems of settlement and resistance of soft soil foundation, a lot of 2-D FEM programs based on Biot consolidation theory are written.The mesh needs to be densified to get accuracy.In this paper a practical local mesh densification method, which can deal with the problems in 2-D FEM of Biot consolidation theory that usually interface element and multi-loads are included, is given.At last, the authors write a mesh densification program which shows the method is correct and very useful for a real project.
2004, 34(5): 54-56.
doi: 10.13204/j.gyjz200405016
Abstract:
Through analyzing the problems of reforming pedestrian streets in China at the present, and summarizing relevant theoretical researches, it is pointed out that a systematical theory shall be used to study the pedestrian streets systematically.Based on which a theoretical game framework is also proposed.
Through analyzing the problems of reforming pedestrian streets in China at the present, and summarizing relevant theoretical researches, it is pointed out that a systematical theory shall be used to study the pedestrian streets systematically.Based on which a theoretical game framework is also proposed.
2004, 34(5): 57-58,87.
doi: 10.13204/j.gyjz200405017
Abstract:
Plate-hinge support, as a new kind of hinge support of steel structure, is based on the theory of the simple is the best.The integral structural concept of a breathing system for the plate-hinge support was introduced; its load transfer mechanism and deformability were researched, and finally the application cases of relevant projects were also described.
Plate-hinge support, as a new kind of hinge support of steel structure, is based on the theory of the simple is the best.The integral structural concept of a breathing system for the plate-hinge support was introduced; its load transfer mechanism and deformability were researched, and finally the application cases of relevant projects were also described.
2004, 34(5): 59-61.
doi: 10.13204/j.gyjz200405018
Abstract:
It is very difficult for longitudinal braces to find a place for some mill buildings because below certain elevation the space is occupied by production lines.This paper studies the buckling of columns for which no brace is provided below certain level, but above this level there exists cross-bracing.Three types of bracing layouts are analyzed, and tables of the column effective length coefficients are given, and approximate formulas are also suggested, which may be a reference for designers.
It is very difficult for longitudinal braces to find a place for some mill buildings because below certain elevation the space is occupied by production lines.This paper studies the buckling of columns for which no brace is provided below certain level, but above this level there exists cross-bracing.Three types of bracing layouts are analyzed, and tables of the column effective length coefficients are given, and approximate formulas are also suggested, which may be a reference for designers.
2004, 34(5): 62-64,23.
doi: 10.13204/j.gyjz200405019
Abstract:
The steel-concrete composite beam has been widely used in China, yet there have not been similar reports on its applications in equipment foundations at home and abroad.In order to understand its use for foundations the characteristics of its use for equipment foundations are expounded, as well as the ordinary design methods, the design requirements and structural measures for special positions are introduced according to its application examples.
The steel-concrete composite beam has been widely used in China, yet there have not been similar reports on its applications in equipment foundations at home and abroad.In order to understand its use for foundations the characteristics of its use for equipment foundations are expounded, as well as the ordinary design methods, the design requirements and structural measures for special positions are introduced according to its application examples.
2004, 34(5): 65-66,82.
doi: 10.13204/j.gyjz200405020
Abstract:
A dynamic measurement method is used to conduct a real-time monitoring of a crane beam, collect great amount of strain-time diagram and deflection-time diagram in actual use and identify the modal parameters.This measurement and the result by the analysis provide certain evidence of the study of vibration and fatigue character of the crane beam, of the drawing up of crane beam load effect spectrum, and of the safety monitoring of the crane beam.
A dynamic measurement method is used to conduct a real-time monitoring of a crane beam, collect great amount of strain-time diagram and deflection-time diagram in actual use and identify the modal parameters.This measurement and the result by the analysis provide certain evidence of the study of vibration and fatigue character of the crane beam, of the drawing up of crane beam load effect spectrum, and of the safety monitoring of the crane beam.
2004, 34(5): 67-69.
doi: 10.13204/j.gyjz200405021
Abstract:
The influence of dimensions of earthquake waves and damping ratio on the response time-history analysis of mega steel frame is studied through analysis of calculation examples.The result shows that earthquake waves should be inputted from three directions even for symmetrical structures.It also shows that influence of damping ratio on elastoplastic response time-history analysis is great and it is better to determine the damping ratio of steel structures by pilot calculation.
The influence of dimensions of earthquake waves and damping ratio on the response time-history analysis of mega steel frame is studied through analysis of calculation examples.The result shows that earthquake waves should be inputted from three directions even for symmetrical structures.It also shows that influence of damping ratio on elastoplastic response time-history analysis is great and it is better to determine the damping ratio of steel structures by pilot calculation.
2004, 34(5): 70-72.
doi: 10.13204/j.gyjz200405022
Abstract:
Reinforced concrete arbitrary cross-sections are analyzed with concrete constitutive relations of China code and CEB model code.The cross-sections are analyzed under the action of biaxial bending and compression.The differences of ultimade bearing capacities analyzed with two constitutive relations are small.The ascendant segments of moment-curvature diagram are nearly overlapped.There are some differences in the descendant segments of the diagrams.The analyzed ultimate bearing capacity are corresponding well with experiment data.
Reinforced concrete arbitrary cross-sections are analyzed with concrete constitutive relations of China code and CEB model code.The cross-sections are analyzed under the action of biaxial bending and compression.The differences of ultimade bearing capacities analyzed with two constitutive relations are small.The ascendant segments of moment-curvature diagram are nearly overlapped.There are some differences in the descendant segments of the diagrams.The analyzed ultimate bearing capacity are corresponding well with experiment data.
2004, 34(5): 73-75.
doi: 10.13204/j.gyjz200405023
Abstract:
The forced behavior of RC beams strengthened with CFRP is studied, whose forced characteristics and also proposed.It is discussed that the effects of various factors subjected to secondary loading on the ultimate bearing capacity of the strengthened RC bemas, which may be a reference for designing actual projects.
The forced behavior of RC beams strengthened with CFRP is studied, whose forced characteristics and also proposed.It is discussed that the effects of various factors subjected to secondary loading on the ultimate bearing capacity of the strengthened RC bemas, which may be a reference for designing actual projects.
2004, 34(5): 76-77,90.
doi: 10.13204/j.gyjz200405024
Abstract:
By summarizing various experiments and researches, the paper applies the mature theory of calculating the bearing capacity of a bending normal section of the RC beam with rectangular section is used, and the computational formula of the bearing capacity of the bending normal section of single rebar RC beam with rectangular section strengthened by CFRP, which meets the requirements of experiments results.It may be a reference for engineering design.
By summarizing various experiments and researches, the paper applies the mature theory of calculating the bearing capacity of a bending normal section of the RC beam with rectangular section is used, and the computational formula of the bearing capacity of the bending normal section of single rebar RC beam with rectangular section strengthened by CFRP, which meets the requirements of experiments results.It may be a reference for engineering design.
2004, 34(5): 78-79,84.
doi: 10.13204/j.gyjz200405025
Abstract:
An overall checkout has been carried out for the main mill building of a steelworks.A strengthening design has been brought forward for the structure. It can be concluded from the calculation that there are not enough load combinations to find out the most dangerous internal force in usual design manual and design procedure. A practical calcuation method of residual fatigue life of the crane girder is also put forward in the paper.
An overall checkout has been carried out for the main mill building of a steelworks.A strengthening design has been brought forward for the structure. It can be concluded from the calculation that there are not enough load combinations to find out the most dangerous internal force in usual design manual and design procedure. A practical calcuation method of residual fatigue life of the crane girder is also put forward in the paper.
2004, 34(5): 80-82.
doi: 10.13204/j.gyjz200405026
Abstract:
Soil removal by water jetting in sinking wells and drawing out soil in drilling holes were used respectively in rectification of two inclined houses in a dwelling district.Both bases were reinforced with static bolt-pressing piles.These two methods are compared, including operation mechanism, construction process, rectifying speed and settlement velocity after construction.The study shows soil removal by water jetting in sinking wells can rectify the inclined building more quickly with a lower settlement rate after construction than that of drawing out soil in drilling holes. And this method is especially suitable for rectifying inclined buildings on soft soil foundation with thin sole plate and upside structure of poor integral rigidity.
Soil removal by water jetting in sinking wells and drawing out soil in drilling holes were used respectively in rectification of two inclined houses in a dwelling district.Both bases were reinforced with static bolt-pressing piles.These two methods are compared, including operation mechanism, construction process, rectifying speed and settlement velocity after construction.The study shows soil removal by water jetting in sinking wells can rectify the inclined building more quickly with a lower settlement rate after construction than that of drawing out soil in drilling holes. And this method is especially suitable for rectifying inclined buildings on soft soil foundation with thin sole plate and upside structure of poor integral rigidity.
2004, 34(5): 83-84.
doi: 10.13204/j.gyjz200405027
Abstract:
There has been a rapid development in translation of integral houses recently, yet there are few cases where houses should be rotated with a certain angle during their translation. It is introduced that a tap water companys multipurpose building is translated successfully with a rotation of 60.
There has been a rapid development in translation of integral houses recently, yet there are few cases where houses should be rotated with a certain angle during their translation. It is introduced that a tap water companys multipurpose building is translated successfully with a rotation of 60.
2004, 34(5): 85-87.
doi: 10.13204/j.gyjz200405028
Abstract:
An engineering example of a buildings uneven settlement was introduced.The causes of uneven settlement, consolidation and treatment scheme and monitoring results were recommended in detail.After consolidation, the building was safe in use and the anticipative aims were achieved.
An engineering example of a buildings uneven settlement was introduced.The causes of uneven settlement, consolidation and treatment scheme and monitoring results were recommended in detail.After consolidation, the building was safe in use and the anticipative aims were achieved.
2004, 34(5): 88-90.
doi: 10.13204/j.gyjz200405029
Abstract:
The application of an iterative method in building strucrures is explored, especially involiving in three efficient and characteristic iterative methods in finding solutions to large system of linear equations, large system of non-linear equations and equations of higher degree.
The application of an iterative method in building strucrures is explored, especially involiving in three efficient and characteristic iterative methods in finding solutions to large system of linear equations, large system of non-linear equations and equations of higher degree.
