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2004 Vol. 34, No. 6
Display Method:
2004, 34(6): 1-3.
doi: 10.13204/j.gyjz200406001
Abstract:
Structural design and technical detailings adopted in the strengthening and renovating of the Art Gallery of China are presented, which would be useful for similar projects.
Structural design and technical detailings adopted in the strengthening and renovating of the Art Gallery of China are presented, which would be useful for similar projects.
2004, 34(6): 4-6,12.
doi: 10.13204/j.gyjz200406002
Abstract:
It is fully explored that the lectotype of top structure and foundation for an outer-jacketing frame storey-adding structural system, through a project of changing two 3-storey brick-concrete buildings(that have been used for over 40 years)into two 7-storey dormitories .The reliable and practical information is also provided for perfecting the design method of the outer-jacketing frame storey-adding structural system according to the experimental study on load bearing characteristics of excavated pedestal piles.
It is fully explored that the lectotype of top structure and foundation for an outer-jacketing frame storey-adding structural system, through a project of changing two 3-storey brick-concrete buildings(that have been used for over 40 years)into two 7-storey dormitories .The reliable and practical information is also provided for perfecting the design method of the outer-jacketing frame storey-adding structural system according to the experimental study on load bearing characteristics of excavated pedestal piles.
2004, 34(6): 7-9.
doi: 10.13204/j.gyjz200406003
Abstract:
The original design of Haitian Building in Beian is a five-story frame building .When the second story was being constructed, the function of the top story needs to be changed and several columns of the top story need to be removed .It is introduced that the design idea of removing columns, design of the prestressed concrete frame after removing columns,checking and strengthening of relative columns and relative single-foundations in the original design .It can serve as reference in modifying the design of homogeneous structures.
The original design of Haitian Building in Beian is a five-story frame building .When the second story was being constructed, the function of the top story needs to be changed and several columns of the top story need to be removed .It is introduced that the design idea of removing columns, design of the prestressed concrete frame after removing columns,checking and strengthening of relative columns and relative single-foundations in the original design .It can serve as reference in modifying the design of homogeneous structures.
2004, 34(6): 10-12.
doi: 10.13204/j.gyjz200406004
Abstract:
In a design of reconstructing a stair into an escalator, the headroom of the escalator should be thought over when the escalator is decided to be disposed in cross or parallel. In order to support the escalator, rebar-implanting should be done at the upper end of the frame girder, which is used as a bracket; a new beam should also be added to the lower end of it. In order to anchor steel bar of the new beam, section area of the frame g irder bottom should be enlarged. On the join of the girder and the beam, a hoop should be added.
In a design of reconstructing a stair into an escalator, the headroom of the escalator should be thought over when the escalator is decided to be disposed in cross or parallel. In order to support the escalator, rebar-implanting should be done at the upper end of the frame girder, which is used as a bracket; a new beam should also be added to the lower end of it. In order to anchor steel bar of the new beam, section area of the frame g irder bottom should be enlarged. On the join of the girder and the beam, a hoop should be added.
2004, 34(6): 13-14.
doi: 10.13204/j.gyjz200406005
Abstract:
During the reconstruction of an office building, the load transfer path of the original girders and foundation had been changed by composite column and composite foundation, which could meet the needs of architectural function and save the investment.
During the reconstruction of an office building, the load transfer path of the original girders and foundation had been changed by composite column and composite foundation, which could meet the needs of architectural function and save the investment.
2004, 34(6): 15-17,27.
doi: 10.13204/j.gyjz200406006
Abstract:
As strengthening a flexural member with method of increasing section and setting support, messures should be taken to ensure the integral working and loading of new-old concrete structures; at the same time, the unloading ratio should also be increased, which has possibly a remarkable effect on raising the bearing capacity of the strengthened member.
As strengthening a flexural member with method of increasing section and setting support, messures should be taken to ensure the integral working and loading of new-old concrete structures; at the same time, the unloading ratio should also be increased, which has possibly a remarkable effect on raising the bearing capacity of the strengthened member.
2004, 34(6): 18-20.
doi: 10.13204/j.gyjz200406007
Abstract:
Based on Technical Specification for Strengthening Concrete Structures(CECS 25:90), the basic calculating theory of strengthening RC flexural member with enlarging cross-section was introduced, design process was coded and software development was also realized using Visual Basic 60 software. Strengthening model and calculating method of enlarging cross-section of flexural member in SEU-DEEP was further given; finally an example was used to show this course.
Based on Technical Specification for Strengthening Concrete Structures(CECS 25:90), the basic calculating theory of strengthening RC flexural member with enlarging cross-section was introduced, design process was coded and software development was also realized using Visual Basic 60 software. Strengthening model and calculating method of enlarging cross-section of flexural member in SEU-DEEP was further given; finally an example was used to show this course.
2004, 34(6): 21-23.
doi: 10.13204/j.gyjz200406008
Abstract:
Energy-saving and environment protection are the design concept of a modern green building .Ground source heat pump technique is a energy-saving, environmental protective method of energy development, which can use fully the function of saving energy between shallow earth ground.This method will offer a new mode to design buildings and has a bright future of application and development.
Energy-saving and environment protection are the design concept of a modern green building .Ground source heat pump technique is a energy-saving, environmental protective method of energy development, which can use fully the function of saving energy between shallow earth ground.This method will offer a new mode to design buildings and has a bright future of application and development.
2004, 34(6): 24-27.
doi: 10.13204/j.gyjz200406009
Abstract:
The planning and design of the ecoenergy for Jiangnan Ecological Garden consist of ecoenergy overall utilization system, ecoenergy scenery system and ecoenergy experienced system. According to the local conditions, photothermal system, photovotaic system, wind-power system, geothermal system, optic illumination system and methane system are mainly used for the ecoenergy, which is over 10% of the total energy consumption of the garden (about 3, 500kW) . The value of the residential area is raised greatly by the planning and design of the garden, which provides a guide and demonstration to the design and construction of domestic ecological gardens, and brings about a great deal of economic benefit.
The planning and design of the ecoenergy for Jiangnan Ecological Garden consist of ecoenergy overall utilization system, ecoenergy scenery system and ecoenergy experienced system. According to the local conditions, photothermal system, photovotaic system, wind-power system, geothermal system, optic illumination system and methane system are mainly used for the ecoenergy, which is over 10% of the total energy consumption of the garden (about 3, 500kW) . The value of the residential area is raised greatly by the planning and design of the garden, which provides a guide and demonstration to the design and construction of domestic ecological gardens, and brings about a great deal of economic benefit.
2004, 34(6): 28-30.
doi: 10.13204/j.gyjz200406010
Abstract:
Today many new ideas and techniques appear in the design of the exterior inhabitable environment form, such as space form design, space system composition, interface scale series and the conception of environment scene, we try to discover them by analysing the environmental form characterstic and use them as valuable deisgn experiences to make our inhabitable environment more colorful and more beautiful.
Today many new ideas and techniques appear in the design of the exterior inhabitable environment form, such as space form design, space system composition, interface scale series and the conception of environment scene, we try to discover them by analysing the environmental form characterstic and use them as valuable deisgn experiences to make our inhabitable environment more colorful and more beautiful.
2004, 34(6): 31-34.
doi: 10.13204/j.gyjz200406011
Abstract:
The basic requirements of high efficiency hea-t insulating materials for an energy-saving building are expounded and the overall behaviours of traditional heat insulating materials are compared, and the construction way that uses a new inorganic composite silicate hea-t insulating material as a cladding heat insulation and its techno-economic analysis are also introduced.
The basic requirements of high efficiency hea-t insulating materials for an energy-saving building are expounded and the overall behaviours of traditional heat insulating materials are compared, and the construction way that uses a new inorganic composite silicate hea-t insulating material as a cladding heat insulation and its techno-economic analysis are also introduced.
2004, 34(6): 35-38.
doi: 10.13204/j.gyjz200406012
Abstract:
The temperature effects of super-long tall buildings under the difference in temperature resulted from day to night are studied. According to the characteristics of the environmentcs temperature change caused by the subrogation from day to night, using the linearity distributing method to calculate the temperature load, the whole temperature effects of the Second Lon-g Distance Telecom Hinge in Zhengzhou are calculated and analyzed through running the current finite element application. Consequently, the whole structural deformation and the scope and the distribution of the internal force or stress of each kind component under such a temperature case have been provided; as compared with the effects under the seasonal descending-temperature case, the reasons in that different temperature cases causing the differences of temperature effects on the super-long tall buildings are given, and the disadvantageous effects caused by the difference in temperature resulted from day to night are summarized. These results may be a references for the design and construction of the project.
The temperature effects of super-long tall buildings under the difference in temperature resulted from day to night are studied. According to the characteristics of the environmentcs temperature change caused by the subrogation from day to night, using the linearity distributing method to calculate the temperature load, the whole temperature effects of the Second Lon-g Distance Telecom Hinge in Zhengzhou are calculated and analyzed through running the current finite element application. Consequently, the whole structural deformation and the scope and the distribution of the internal force or stress of each kind component under such a temperature case have been provided; as compared with the effects under the seasonal descending-temperature case, the reasons in that different temperature cases causing the differences of temperature effects on the super-long tall buildings are given, and the disadvantageous effects caused by the difference in temperature resulted from day to night are summarized. These results may be a references for the design and construction of the project.
2004, 34(6): 39-41.
doi: 10.13204/j.gyjz200406013
Abstract:
The analysis of moments to prestressed concrete statically indeterminate beams is examined. The second moments of two-span and three-span prestressed continuous beams should be calculated under the uniform loads and concentrated loads. The locations of prestressed reinforcements arrangement should be obtained, which will satisfy the demands on cracking resisting of pretensioned area for prestressed concrete members in the condition of construction stage based on concrete structure design code, which also provides a basis for arrang ing the prestressing reinforcements of such sort of beams.
The analysis of moments to prestressed concrete statically indeterminate beams is examined. The second moments of two-span and three-span prestressed continuous beams should be calculated under the uniform loads and concentrated loads. The locations of prestressed reinforcements arrangement should be obtained, which will satisfy the demands on cracking resisting of pretensioned area for prestressed concrete members in the condition of construction stage based on concrete structure design code, which also provides a basis for arrang ing the prestressing reinforcements of such sort of beams.
2004, 34(6): 42-43,41.
doi: 10.13204/j.gyjz200406014
Abstract:
The bearing mechanism of soil-cement pile is studied by means of the transfer function method, the development of the skin friction of the pile and the influencing factors of the bearing capacity are also discussed. The conclusion is significant to the soil-cement pile research and the engineering practice.
The bearing mechanism of soil-cement pile is studied by means of the transfer function method, the development of the skin friction of the pile and the influencing factors of the bearing capacity are also discussed. The conclusion is significant to the soil-cement pile research and the engineering practice.
2004, 34(6): 44-47.
doi: 10.13204/j.gyjz200406015
Abstract:
The relative between stress ratio of pile-soil and the thickness of cushion is researched by experimental and theoretical analyses. 7 experiments were conducted, including tests on 3 piles and single-pile composite-foundations. The distribution of stress and deformation in the composite-foundation were measured. The thickness of the cushion for test of 3 piles was 20cm and the test loading was 2 times of the designed one. When loading toe the designed load the pressure between the piles was 230kPa which is 160kPa higher than the bearing capacity of the original soil. The stress ratio of pilesoil was 14. 3, much less than the assumed stress ratio.When the thickness of cushion was suitable, the stress ratio is near to the assumed ratio. According to these measurements, when the thickness of cushion was 5cm, the deformation was less than the one of 20cm.Which was favorable for controlling settlement.
The relative between stress ratio of pile-soil and the thickness of cushion is researched by experimental and theoretical analyses. 7 experiments were conducted, including tests on 3 piles and single-pile composite-foundations. The distribution of stress and deformation in the composite-foundation were measured. The thickness of the cushion for test of 3 piles was 20cm and the test loading was 2 times of the designed one. When loading toe the designed load the pressure between the piles was 230kPa which is 160kPa higher than the bearing capacity of the original soil. The stress ratio of pilesoil was 14. 3, much less than the assumed stress ratio.When the thickness of cushion was suitable, the stress ratio is near to the assumed ratio. According to these measurements, when the thickness of cushion was 5cm, the deformation was less than the one of 20cm.Which was favorable for controlling settlement.
2004, 34(6): 48-51,14.
doi: 10.13204/j.gyjz200406016
Abstract:
There is a local large deformation in the peripheral foundation soil of the compacting spots,so the mechanical derivation of infinitesimal strain can't eliminate the effect of a rigid displacement,and the large deformation theory must be used to analyze the impact course of dynamic consolidation to foundation soil.The improved artificial boundary conditions are applied to simulate waves propagation at the boundary.Liquefaction element is used in the calculation program for ensuring the mesh stability of the model.Finally,an engineering example is discussed to verify the reliability of this model.
There is a local large deformation in the peripheral foundation soil of the compacting spots,so the mechanical derivation of infinitesimal strain can't eliminate the effect of a rigid displacement,and the large deformation theory must be used to analyze the impact course of dynamic consolidation to foundation soil.The improved artificial boundary conditions are applied to simulate waves propagation at the boundary.Liquefaction element is used in the calculation program for ensuring the mesh stability of the model.Finally,an engineering example is discussed to verify the reliability of this model.
2004, 34(6): 52-54.
doi: 10.13204/j.gyjz200406017
Abstract:
Based on reliability theory, using the JC method and the end-off JC method, different factors which affects underground pipelines' reliability index are analyzed. Moreover the effect of large ground displacement caused by earthquake liquefaction on underground pipeline is also analyzed, its result is almost the same as that of a finite element analysis, which proves the result's correctness. At the same time, it offers a reference to underground pipeline's burying which gets through a liquefaction zone.
Based on reliability theory, using the JC method and the end-off JC method, different factors which affects underground pipelines' reliability index are analyzed. Moreover the effect of large ground displacement caused by earthquake liquefaction on underground pipeline is also analyzed, its result is almost the same as that of a finite element analysis, which proves the result's correctness. At the same time, it offers a reference to underground pipeline's burying which gets through a liquefaction zone.
2004, 34(6): 55-57.
doi: 10.13204/j.gyjz200406018
Abstract:
When precast piles are installed into the ground, the same volume of soil should be displaced. Then, the excess pore pressure will be developed around the piles. That will result in the influence on the surrounding soil and nearby structures. Based on the field monitoring for the construction of piling in deep soft soil foundation, the influences of pile driving in clay are examined,with emphasis on the excess pore pressure and the lateral displacement etc. It is shown that the adoption of holes to relax stress is an effective measure against soil-squeezing during pile-driving. The conclusion provides a reference for the design and construction of similar projects.
When precast piles are installed into the ground, the same volume of soil should be displaced. Then, the excess pore pressure will be developed around the piles. That will result in the influence on the surrounding soil and nearby structures. Based on the field monitoring for the construction of piling in deep soft soil foundation, the influences of pile driving in clay are examined,with emphasis on the excess pore pressure and the lateral displacement etc. It is shown that the adoption of holes to relax stress is an effective measure against soil-squeezing during pile-driving. The conclusion provides a reference for the design and construction of similar projects.
2004, 34(6): 59-60,30.
doi: 10.13204/j.gyjz200406019
Abstract:
Damping ratio is the main index representing the property of materials in reducing vibration. Free vibration method is employed to measure the damping ratio. A batch of fundamental data for the damping ratio of polypropylene fibre concrete in small deformation is obtained. The analyses of experimental results conclude that the testing method and procedure for damping ratio are reliable; for concrete in the same class, the damping ratio changes slightly with increasing polypropylene fibre; and Young's modulus decreases with increasing polypropylene fibre.
Damping ratio is the main index representing the property of materials in reducing vibration. Free vibration method is employed to measure the damping ratio. A batch of fundamental data for the damping ratio of polypropylene fibre concrete in small deformation is obtained. The analyses of experimental results conclude that the testing method and procedure for damping ratio are reliable; for concrete in the same class, the damping ratio changes slightly with increasing polypropylene fibre; and Young's modulus decreases with increasing polypropylene fibre.
2004, 34(6): 61-64.
doi: 10.13204/j.gyjz200406020
Abstract:
Large amounts of research achievements and modeling of concrete chloride ingress are reviewed. Progress and new development trend of chloride diffusion equation in marine concrete are summarized. Reference and suggestions are provided for modeling of chloride ingress under combined action of factors for functional service life prediction of marine concrete and durability design of similar concrete structure engineering in China.
Large amounts of research achievements and modeling of concrete chloride ingress are reviewed. Progress and new development trend of chloride diffusion equation in marine concrete are summarized. Reference and suggestions are provided for modeling of chloride ingress under combined action of factors for functional service life prediction of marine concrete and durability design of similar concrete structure engineering in China.
2004, 34(6): 65-67,58.
doi: 10.13204/j.gyjz200406021
Abstract:
The hollow steel tubes of concrete filled steel tubular(CFST) structure are suffered vertical construction loads during construction as they are vertical support frame.The steel tubes will suffer initial stress before they can work together with concrete infilled.On the other hand,they are also subjected to horizontal hydrostatic loads of inner wet concrete as well as axial loads during concrete pouring because they play the formwork.The design of CFST that should be divided into two stages,and the design method and mechanical analysis at its construction stage are explored.It is possible and available way to solve the problem by FEM.The research method of civil engineering construction mechanics is also discussed.
The hollow steel tubes of concrete filled steel tubular(CFST) structure are suffered vertical construction loads during construction as they are vertical support frame.The steel tubes will suffer initial stress before they can work together with concrete infilled.On the other hand,they are also subjected to horizontal hydrostatic loads of inner wet concrete as well as axial loads during concrete pouring because they play the formwork.The design of CFST that should be divided into two stages,and the design method and mechanical analysis at its construction stage are explored.It is possible and available way to solve the problem by FEM.The research method of civil engineering construction mechanics is also discussed.
2004, 34(6): 68-70,83.
doi: 10.13204/j.gyjz200406022
Abstract:
Three ways to calculate bearing capacities of steel composite beams are introduced, and then the shortcomings of them are pointed out. After that modified ways are provided and they are verified by test data, which is executed on a cantilever composite beams with web opening . It is evident that the modified ways are feasible. In the end other aspects of designing the composite beams with web opening are specified in a simple way.
Three ways to calculate bearing capacities of steel composite beams are introduced, and then the shortcomings of them are pointed out. After that modified ways are provided and they are verified by test data, which is executed on a cantilever composite beams with web opening . It is evident that the modified ways are feasible. In the end other aspects of designing the composite beams with web opening are specified in a simple way.
2004, 34(6): 71-73,64.
doi: 10.13204/j.gyjz200406023
Abstract:
It is pointed out that a cold- formed processing consists of plastic deformation and elastic recovery.We can get residual stress of cold-formed member through adding stress field produced by each course. There are clear differences in distribution of residual stress between the ex isting research and that by the analysis. A vertical residual stress is distributed along thickness of slab, displaying that residual stress is increasing from inside layer to neutral layer. It is pointed out in the ex isting literatures that residual stress is linear distribution that is disadvantageous to stability of structure, because it can clearly reduce effective thickness of slab in bended zone under outer load. Vertical residual tensile stress of outer layer in bended zone is slightly bigger than vertical residual compressive stress of inside layer. The calculated result of cold-formed residual strain is equivalent to that of field measurement.
It is pointed out that a cold- formed processing consists of plastic deformation and elastic recovery.We can get residual stress of cold-formed member through adding stress field produced by each course. There are clear differences in distribution of residual stress between the ex isting research and that by the analysis. A vertical residual stress is distributed along thickness of slab, displaying that residual stress is increasing from inside layer to neutral layer. It is pointed out in the ex isting literatures that residual stress is linear distribution that is disadvantageous to stability of structure, because it can clearly reduce effective thickness of slab in bended zone under outer load. Vertical residual tensile stress of outer layer in bended zone is slightly bigger than vertical residual compressive stress of inside layer. The calculated result of cold-formed residual strain is equivalent to that of field measurement.
2004, 34(6): 74-76.
doi: 10.13204/j.gyjz200406024
Abstract:
Through comparison and analysis on design and test results of two steel beam-to-column connections with cantilever beam splicing under cyclic-loading, it is pointed out that the slip between faying surfaces and the bearing of bolts to hole surfaces can be used to improve seismic behavior of the whole connection.Design suggestions based on test results are presented.
Through comparison and analysis on design and test results of two steel beam-to-column connections with cantilever beam splicing under cyclic-loading, it is pointed out that the slip between faying surfaces and the bearing of bolts to hole surfaces can be used to improve seismic behavior of the whole connection.Design suggestions based on test results are presented.
2004, 34(6): 77-78,87.
doi: 10.13204/j.gyjz200406025
Abstract:
It has been discussed that the values of section effective depth in shear??bearing capacity calculation of concrete oblique section, effective compression flange width of beams in cast??in??situ concrete ribbed floor and the relative depth of compression zone of concrete members in bending in bending and compression; and some corresponding suggestions are presented.These can be acted as reference for structures design.
It has been discussed that the values of section effective depth in shear??bearing capacity calculation of concrete oblique section, effective compression flange width of beams in cast??in??situ concrete ribbed floor and the relative depth of compression zone of concrete members in bending in bending and compression; and some corresponding suggestions are presented.These can be acted as reference for structures design.
2004, 34(6): 79-83.
doi: 10.13204/j.gyjz200406026
Abstract:
The material and the technology used for membrane structure are different from the traditional structure. Usually,the specialized membrane structure company involves the construction in the design proposal stage. This lecture focuses on the knowledge of the conceptual proposal, including structure system determination, the fabric choice, the cost estimating and so on.
The material and the technology used for membrane structure are different from the traditional structure. Usually,the specialized membrane structure company involves the construction in the design proposal stage. This lecture focuses on the knowledge of the conceptual proposal, including structure system determination, the fabric choice, the cost estimating and so on.
2004, 34(6): 84-87.
doi: 10.13204/j.gyjz200406027
Abstract:
A kind of amended ar ithmetic which solves maximum moment of reinforced concrete isosceles trapezoid slab is introduced. Presently, calculation method of a reinforced concrete isosceles trapezoid slab is experiential arithmetic with which the isosceles trapezoid slab is simplified into an equivalent rectangled slab. It has been verified by analyzing that the relative error of the experiential arithmetic is larger and does not conform to the requirements of engineering design. Based on experiential arithmetic, we use simplified arithmetic of perimeter fixed strut rectangled slab to calculate isosceles trapezoid slab. After amended the error, we acquired satisfactory result. The amended arithmetic features high accuracy, good practicality and convenient calculation.
A kind of amended ar ithmetic which solves maximum moment of reinforced concrete isosceles trapezoid slab is introduced. Presently, calculation method of a reinforced concrete isosceles trapezoid slab is experiential arithmetic with which the isosceles trapezoid slab is simplified into an equivalent rectangled slab. It has been verified by analyzing that the relative error of the experiential arithmetic is larger and does not conform to the requirements of engineering design. Based on experiential arithmetic, we use simplified arithmetic of perimeter fixed strut rectangled slab to calculate isosceles trapezoid slab. After amended the error, we acquired satisfactory result. The amended arithmetic features high accuracy, good practicality and convenient calculation.
