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2014 Vol. 44, No. 07
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2014, 44(07): 1-6.
Abstract:
In the circumstances of dynamic loading，the reinforced concrete beam-column joint exhibits different properties with those presented in the case of quasi-static loads，due to the effect of strain rate． The majority of previous studies were focused more on the beam-column joint model as well as axial load ratio，concrete strength， longitudinal reinforced ratio etc，but less on the strain rate effect on the beam-column joint performance． Considering the strain rate effect，three beam-column joint specimens with displacement control loading were studied，respectively at the beam-end loading speed of 0. 4 mm/s，4 mm/s and 40 mm/s． Comparing the impact of different loading rates， the failure mode，carrying capacity，stiffness degradation and energy dissipation of the joint are discussed in detail． The results show that with the increasing of the strain rate，the failure mode of the beam-column joint does not changed essentially，but the number of crack within the joint continues to decline with the tendency to a single main crack damage． The higher the strain rate，the higher the yield carrying capacity and ultimate carrying capacity of the joint，and the degree of yield carrying capacity improvement is more obvious than that of ultimate carrying capacity． Within a certain range，the carrying capacity，stiffness and energy dissipation capacity of the joint are enhanced with the increase of strain rate． Beyond a certain range，the carrying capacity and stiffness decline sharply，and energy dissipation capacity is reduced as well，then the increase of strain rate will have adverse affect． Therefore，in the practical design，it is significant to consider the effect of strain rate on the beam-column joint．
In the circumstances of dynamic loading，the reinforced concrete beam-column joint exhibits different properties with those presented in the case of quasi-static loads，due to the effect of strain rate． The majority of previous studies were focused more on the beam-column joint model as well as axial load ratio，concrete strength， longitudinal reinforced ratio etc，but less on the strain rate effect on the beam-column joint performance． Considering the strain rate effect，three beam-column joint specimens with displacement control loading were studied，respectively at the beam-end loading speed of 0. 4 mm/s，4 mm/s and 40 mm/s． Comparing the impact of different loading rates， the failure mode，carrying capacity，stiffness degradation and energy dissipation of the joint are discussed in detail． The results show that with the increasing of the strain rate，the failure mode of the beam-column joint does not changed essentially，but the number of crack within the joint continues to decline with the tendency to a single main crack damage． The higher the strain rate，the higher the yield carrying capacity and ultimate carrying capacity of the joint，and the degree of yield carrying capacity improvement is more obvious than that of ultimate carrying capacity． Within a certain range，the carrying capacity，stiffness and energy dissipation capacity of the joint are enhanced with the increase of strain rate． Beyond a certain range，the carrying capacity and stiffness decline sharply，and energy dissipation capacity is reduced as well，then the increase of strain rate will have adverse affect． Therefore，in the practical design，it is significant to consider the effect of strain rate on the beam-column joint．
2014, 44(07): 7-10.
Abstract:
In order to study the seismic behavior of steel plate hoop-bolt prefabricated column by high-strength composite spiral stirrups，the low cyclic loading tests were carried out． Four long column specimens were designed． Cracking，yield，destroyed process and destroyed state of specimens were observed in the tests，and the loaddisplacement hysteretic curves and skeleton curves of each specimen were also obtained． Comparative study on carrying capacity，ductility and energy dissipation capacity of each specimen was conducted，and analysis of the reliability of steel plate hoop-bolt connection was done． The test proves that steel plate hoop-bolt prefabricated column confined by high-strength composite spiral stirrups has about the same bearing capacity and seismic capacity as compared with cast-in-place column，and the prefabricated column can be used to replace the cast-in-place column in project in case of secure connections．
In order to study the seismic behavior of steel plate hoop-bolt prefabricated column by high-strength composite spiral stirrups，the low cyclic loading tests were carried out． Four long column specimens were designed． Cracking，yield，destroyed process and destroyed state of specimens were observed in the tests，and the loaddisplacement hysteretic curves and skeleton curves of each specimen were also obtained． Comparative study on carrying capacity，ductility and energy dissipation capacity of each specimen was conducted，and analysis of the reliability of steel plate hoop-bolt connection was done． The test proves that steel plate hoop-bolt prefabricated column confined by high-strength composite spiral stirrups has about the same bearing capacity and seismic capacity as compared with cast-in-place column，and the prefabricated column can be used to replace the cast-in-place column in project in case of secure connections．
2014, 44(07): 11-15.
Abstract:
A new kind of precast concrete segmental columns has been put forward in this paper． Its core concrete is constrainted by high-strength compound spiral stirrups and the exterior steel plate hoop penetrated by the bolt bar used for the connection area． It is compared the three assembled long columns under different width of the exterior steel plate hoop and axial pressure ratio to the one cast-in-place long column． It is proved that the new kind of precast concrete segmental columns is better for the anti-seismic capacity and safe in the node connection area so that the cast-in-place long column can be replaced． ANSYS FEM software is used to take contrastive analysis for the column of hysteretic behavior based on the width of the exterior steel plate hoop and axial pressure ratio，the results show that numerical simulation meets well with the experiment， the ANSYS numerical analysis model of precast concrete segmental columns is feasible and correct． The ANSYS FEM can be used for the numerical simulation and the analysis of mechanical performance study of the assembled column structures．
A new kind of precast concrete segmental columns has been put forward in this paper． Its core concrete is constrainted by high-strength compound spiral stirrups and the exterior steel plate hoop penetrated by the bolt bar used for the connection area． It is compared the three assembled long columns under different width of the exterior steel plate hoop and axial pressure ratio to the one cast-in-place long column． It is proved that the new kind of precast concrete segmental columns is better for the anti-seismic capacity and safe in the node connection area so that the cast-in-place long column can be replaced． ANSYS FEM software is used to take contrastive analysis for the column of hysteretic behavior based on the width of the exterior steel plate hoop and axial pressure ratio，the results show that numerical simulation meets well with the experiment， the ANSYS numerical analysis model of precast concrete segmental columns is feasible and correct． The ANSYS FEM can be used for the numerical simulation and the analysis of mechanical performance study of the assembled column structures．
2014, 44(07): 16-20.
Abstract:
To study the seismic behavior of sprayed concrete sandwich shear walls with low shear-span ratio，quasistatic tests on 3 specimens were carried out． The test results indicated that the concrete sprayed on both surfaces of the steel wire mesh framed by expanded polystyrene panel and the boundary elements work together as a unit． The wall specimens failed in bending-shear． The boundary elements enhanced the elastic-plastic deformation capacity and energy dissipation capacity of the specimen obviously．
To study the seismic behavior of sprayed concrete sandwich shear walls with low shear-span ratio，quasistatic tests on 3 specimens were carried out． The test results indicated that the concrete sprayed on both surfaces of the steel wire mesh framed by expanded polystyrene panel and the boundary elements work together as a unit． The wall specimens failed in bending-shear． The boundary elements enhanced the elastic-plastic deformation capacity and energy dissipation capacity of the specimen obviously．
2014, 44(07): 21-24.
Abstract:
Under the low cyclic loading，4 steel and polypropylene fiber reiforced special-shaped column edge nodes were tested，and the bearing capacity，displacement ductility，the restoring force characteristics of each node were analyzed，including hysteresis curves，energy dissipation and stiffness degradation curve，it was compared seismic indicators of steel framed reinforced edge node，fiber reinforced edge node and ordinary node． The research shows that the steel and polypropylene fiber reinforcement can all improve the shear crack form，increase the cracking load and deformation ability of the nodes，delay node rigidity degradation in later stage，especially in the deformation capacity，steel reinforced node has a more obvious superiority．
Under the low cyclic loading，4 steel and polypropylene fiber reiforced special-shaped column edge nodes were tested，and the bearing capacity，displacement ductility，the restoring force characteristics of each node were analyzed，including hysteresis curves，energy dissipation and stiffness degradation curve，it was compared seismic indicators of steel framed reinforced edge node，fiber reinforced edge node and ordinary node． The research shows that the steel and polypropylene fiber reinforcement can all improve the shear crack form，increase the cracking load and deformation ability of the nodes，delay node rigidity degradation in later stage，especially in the deformation capacity，steel reinforced node has a more obvious superiority．
2014, 44(07): 25-30.
Abstract:
In order to investigate the seismic behavior of the damaged ＲC frames retrofitted with Y-eccentrically steel brace under low reversed cyclic loading，two one-bay，one-story test specimens of one-third scale were built and tested． The hysteretic behavior，stiffness degradation，plastic deformation capacity，ductility and energy dissipation capacity were analyzed． The results indicate that test specimens show large lateral stiffness and lateral strength，and also have good energy dissipation capacity． With the increase of the height of energy dissipation link webs，the lateral bearing capacity of the test specimens increased． However，the ductility and energy dissipation capacity decreased slightly．
In order to investigate the seismic behavior of the damaged ＲC frames retrofitted with Y-eccentrically steel brace under low reversed cyclic loading，two one-bay，one-story test specimens of one-third scale were built and tested． The hysteretic behavior，stiffness degradation，plastic deformation capacity，ductility and energy dissipation capacity were analyzed． The results indicate that test specimens show large lateral stiffness and lateral strength，and also have good energy dissipation capacity． With the increase of the height of energy dissipation link webs，the lateral bearing capacity of the test specimens increased． However，the ductility and energy dissipation capacity decreased slightly．
2014, 44(07): 31-36.
Abstract:
Four 700mm × 700mm reinforced concrete columns were tested under monotonic horizontal loading and low cycle reversed loading with high axial load ratio． Their bearing capacity，failure characteristic and hysteretic behavior were discussed． The axial load ratio and low cycle reversed loading and their influence on bearing capacity， deformation and energy dissipation were analyzed． The results indicate that skeleton curve of specimen declines slightly，ductility and ultimate deformation are small，and the bearing capacity and energy dissipation increase as axial load ratio increases． Strength degradation of specimen under low cycle reversed loading is rapid relative to the specimen under monotonic loading，and there is also less ultimate deformation．
Four 700mm × 700mm reinforced concrete columns were tested under monotonic horizontal loading and low cycle reversed loading with high axial load ratio． Their bearing capacity，failure characteristic and hysteretic behavior were discussed． The axial load ratio and low cycle reversed loading and their influence on bearing capacity， deformation and energy dissipation were analyzed． The results indicate that skeleton curve of specimen declines slightly，ductility and ultimate deformation are small，and the bearing capacity and energy dissipation increase as axial load ratio increases． Strength degradation of specimen under low cycle reversed loading is rapid relative to the specimen under monotonic loading，and there is also less ultimate deformation．
2014, 44(07): 37-41.
Abstract:
Based on the internal force and deformation analysis method of frame-shear wall structure，the equation of stiffness characteristic coefficient of wall frame-shear wall structure was derived to analyze the deformation characteristics of structures with different wall frames ratio and height of house． The results of theoretical analysis was verified by elastic response spectrum calculation． Through static elasto-plastic analysis，the seismic performance of structures were evaluated by interlayer displacement angle and plastic hinge development process． The research results show that the wall frames bring adverse effects on the structural seismic performance，so the different design regulations such as strengthening of member and control of structure height should be implemented according to the overturning moment proportion of wall frames．
Based on the internal force and deformation analysis method of frame-shear wall structure，the equation of stiffness characteristic coefficient of wall frame-shear wall structure was derived to analyze the deformation characteristics of structures with different wall frames ratio and height of house． The results of theoretical analysis was verified by elastic response spectrum calculation． Through static elasto-plastic analysis，the seismic performance of structures were evaluated by interlayer displacement angle and plastic hinge development process． The research results show that the wall frames bring adverse effects on the structural seismic performance，so the different design regulations such as strengthening of member and control of structure height should be implemented according to the overturning moment proportion of wall frames．
2014, 44(07): 42-45.
Abstract:
In high-rise frame-supported shear wall structure，the lateral stiffness of structure nearby transfer storey is usually changed sharply，which easily causes stress concentration and is harmful to seismic performance． In order to improve the seismic performance of structure，parts of shear wall are usually linked with ground． The ground wall thickness has an important influence on seismic performance of structure． This paper is based on the engineering example about a commercial and residential building，calculates and analyses respectively the seismic response of different structure with different thickness，and focuses on the influence of different parameters on shear mutation between frame-supported wall and ground wall near conversion layers． The analysis results show that the change of shear wall thickness have an important influence on equivalent lateral stiffness of structure under transfer storey and a limited influence on the whole lateral stiffness，shear mutation to some extent can be abated．
In high-rise frame-supported shear wall structure，the lateral stiffness of structure nearby transfer storey is usually changed sharply，which easily causes stress concentration and is harmful to seismic performance． In order to improve the seismic performance of structure，parts of shear wall are usually linked with ground． The ground wall thickness has an important influence on seismic performance of structure． This paper is based on the engineering example about a commercial and residential building，calculates and analyses respectively the seismic response of different structure with different thickness，and focuses on the influence of different parameters on shear mutation between frame-supported wall and ground wall near conversion layers． The analysis results show that the change of shear wall thickness have an important influence on equivalent lateral stiffness of structure under transfer storey and a limited influence on the whole lateral stiffness，shear mutation to some extent can be abated．
2014, 44(07): 46-50.
Abstract:
Based on elastic-plastic time-history analysis of the MSCSS without additional dampers under seismic action，it was given that different arranging schemes of the additional dampers from different angles． The Hilbert- Huang transform method ( HHT) was used to obtain the progressive power spectrum of measured seismic wave，the non-stationary trigonometric series method was used to obtain a plurality of artificial waves，and multiple artificial waves with similar response spectrum were selected as the sample library of a random process，the reliability analysis method based on the probability density evolution equation was used to MSCSS under different arranging schemes of additional dampers，which was compared with the mega frame structure． Ｒesearch shows that reliability of MSCSS is much better than mega frame structure，arranging schemes of the additional dampers have great impact on reliability of the MSCSS，the performance of MSCSS is the best when additional dampers are arranged in the maximum story drift layer and the maximum displacement layer of sub-structure respectively．
Based on elastic-plastic time-history analysis of the MSCSS without additional dampers under seismic action，it was given that different arranging schemes of the additional dampers from different angles． The Hilbert- Huang transform method ( HHT) was used to obtain the progressive power spectrum of measured seismic wave，the non-stationary trigonometric series method was used to obtain a plurality of artificial waves，and multiple artificial waves with similar response spectrum were selected as the sample library of a random process，the reliability analysis method based on the probability density evolution equation was used to MSCSS under different arranging schemes of additional dampers，which was compared with the mega frame structure． Ｒesearch shows that reliability of MSCSS is much better than mega frame structure，arranging schemes of the additional dampers have great impact on reliability of the MSCSS，the performance of MSCSS is the best when additional dampers are arranged in the maximum story drift layer and the maximum displacement layer of sub-structure respectively．
2014, 44(07): 51-55.
Abstract:
In order to simplify the performance-based earthquake loss evaluation process，the paper puts forward the method of earthquake loss evaluation of buildings based on story engineering demand parameter- decision variable ( EDP-DV) functions． Firstly，when considering the randomness of seismic response parameters，it can be achieved the distribution functions of story response parameters with the intensity measure given through incremental dynamic analysis． Meanwhile，the fragility functions are combined with loss functions to establish story EDP-DV functions． On this occasion，the damage measures are omitted and the storey not component is made to be a unit of account to simplify the earthquake loss evaluation process． Lastly，the relational function is established which is between seismic intensity and the buildings’economic loss by combing the distribution functions of story response with story EDP-DV functions． It is no need for dividing performance levels． The numerical example shows that the proposed method is feasible and reasonable to quantify the building’s seismic performance．
In order to simplify the performance-based earthquake loss evaluation process，the paper puts forward the method of earthquake loss evaluation of buildings based on story engineering demand parameter- decision variable ( EDP-DV) functions． Firstly，when considering the randomness of seismic response parameters，it can be achieved the distribution functions of story response parameters with the intensity measure given through incremental dynamic analysis． Meanwhile，the fragility functions are combined with loss functions to establish story EDP-DV functions． On this occasion，the damage measures are omitted and the storey not component is made to be a unit of account to simplify the earthquake loss evaluation process． Lastly，the relational function is established which is between seismic intensity and the buildings’economic loss by combing the distribution functions of story response with story EDP-DV functions． It is no need for dividing performance levels． The numerical example shows that the proposed method is feasible and reasonable to quantify the building’s seismic performance．
2014, 44(07): 56-59.
Abstract:
In order to improve the effect of old industrial building’s regeneration，improve the comfort of using， reduce energy consumption of buildings，an assessment index system of the green regeneration of old industrial buildings needs to be established． Based on summarizing the existing mature evaluation systems at home and overseas，combining with engineering examples，papers，theoretical research，and the field survey of 22 typical cities in China，this article summarized the problems existing in the green regeneration of the old industrial buildings and their characteristics，and made a comprehensive analysis to extract the representative and comprehensive，scientific， feasibility assessment indexes as well． This paper also introduced the screening of index and the basic methods for the determining of index weights，which provided a necessary theoretical basis for the establishment of assessment index system for old industrial building’s green regeneration．
In order to improve the effect of old industrial building’s regeneration，improve the comfort of using， reduce energy consumption of buildings，an assessment index system of the green regeneration of old industrial buildings needs to be established． Based on summarizing the existing mature evaluation systems at home and overseas，combining with engineering examples，papers，theoretical research，and the field survey of 22 typical cities in China，this article summarized the problems existing in the green regeneration of the old industrial buildings and their characteristics，and made a comprehensive analysis to extract the representative and comprehensive，scientific， feasibility assessment indexes as well． This paper also introduced the screening of index and the basic methods for the determining of index weights，which provided a necessary theoretical basis for the establishment of assessment index system for old industrial building’s green regeneration．
2014, 44(07): 60-63.
Abstract:
Based on consulting a large number of theoretical data on the construction and development of Taiwan National Parks，combined with the theory of recreation opportunity spectrum ( ＲOS) and green architecture，as well as sustainable design，it was summarized and compiled the basic concepts and principles of national park building facilities design in Taiwan，as well as the regulations and systems formulated by Taiwan's Construction Sector，thus embodying completely the system of national park building facilities in Taiwan，which is a good demonstration and reference for the design of scenic area building facilities in PRC．
Based on consulting a large number of theoretical data on the construction and development of Taiwan National Parks，combined with the theory of recreation opportunity spectrum ( ＲOS) and green architecture，as well as sustainable design，it was summarized and compiled the basic concepts and principles of national park building facilities design in Taiwan，as well as the regulations and systems formulated by Taiwan's Construction Sector，thus embodying completely the system of national park building facilities in Taiwan，which is a good demonstration and reference for the design of scenic area building facilities in PRC．
2014, 44(07): 64-67.
Abstract:
Choosing the appropriate wall material can reduce the energy consumption effectively，this paper selects a constructing house as the research object which uses straw-bale as the filling material for external wall． Through testing indoor and outdoor temperature and relative humidity and the wall surface temperature， and simulating annual heating energy consumption，then it is contrasted the energy consumption of using straw-bale and clay brick． The result shows that the straw-bale has good thermal insulation and heat preservation，and it could adjust the indoor relative humidity to some extent，the house using the straw-bale can reduce 61. 69% energy consumption comparing with the clay brick houses in Datong，Shanxi Province． The paper also compares the energy conservation of straw-bale house and clay brick house in different climate zone，and the result indicates that as compared with the clay brick house， the straw-bale house can reduce 56. 59%，61. 96% and 65. 55% energy consumption in Harbin，Xi’an and Datong． So it can be concluded that straw-bale has good energy-saving effects and universal adaptability for rural houses in cold and severe cold zones．
Choosing the appropriate wall material can reduce the energy consumption effectively，this paper selects a constructing house as the research object which uses straw-bale as the filling material for external wall． Through testing indoor and outdoor temperature and relative humidity and the wall surface temperature， and simulating annual heating energy consumption，then it is contrasted the energy consumption of using straw-bale and clay brick． The result shows that the straw-bale has good thermal insulation and heat preservation，and it could adjust the indoor relative humidity to some extent，the house using the straw-bale can reduce 61. 69% energy consumption comparing with the clay brick houses in Datong，Shanxi Province． The paper also compares the energy conservation of straw-bale house and clay brick house in different climate zone，and the result indicates that as compared with the clay brick house， the straw-bale house can reduce 56. 59%，61. 96% and 65. 55% energy consumption in Harbin，Xi’an and Datong． So it can be concluded that straw-bale has good energy-saving effects and universal adaptability for rural houses in cold and severe cold zones．
2014, 44(07): 68-72.
Abstract:
Exterior window is an important room transformation medium for residential building between indoor and outdoor environment，and it is also the key link for building energy-efficiency． Based on the field investigation and statistics data of building exterior windows in local market and existing residential buildings，window’s problems and basic physical and thermal properties were analyzed． Then，key design techniques for new kind energy-saving exterior window were summarized． The paper pointed out it would achieved the purpose of lowing building energy-consumption and reducing green house gas emission，only in popularizing the energy-saving window optimally designed based on local architecture culture and climate characteristics．
Exterior window is an important room transformation medium for residential building between indoor and outdoor environment，and it is also the key link for building energy-efficiency． Based on the field investigation and statistics data of building exterior windows in local market and existing residential buildings，window’s problems and basic physical and thermal properties were analyzed． Then，key design techniques for new kind energy-saving exterior window were summarized． The paper pointed out it would achieved the purpose of lowing building energy-consumption and reducing green house gas emission，only in popularizing the energy-saving window optimally designed based on local architecture culture and climate characteristics．
2014, 44(07): 73-78.
Abstract:
Taking a three-span prestressed concrete continuous box girder bridge as a research object， the vehicle and bridge differential equations of motion of single beam were established using vehicle-bridge coupling vibration relationship which was built through compatible relationship of deformation and force between vehicle and bridge． Using the WIM system installed on bridge， the actual traffic load moving on bridge was efficiently identified，which was taken as vehicle load information inputting into updated self-developed bridge dynamic response calculation program． The bridge dynamic response under actual vehicle load can be calculated by the program quickly， and the calculation result has been verified statically and dynamic verification has been done using ANSYS software and bridge dynamic strain response under actual traffic flow， respectively．
Taking a three-span prestressed concrete continuous box girder bridge as a research object， the vehicle and bridge differential equations of motion of single beam were established using vehicle-bridge coupling vibration relationship which was built through compatible relationship of deformation and force between vehicle and bridge． Using the WIM system installed on bridge， the actual traffic load moving on bridge was efficiently identified，which was taken as vehicle load information inputting into updated self-developed bridge dynamic response calculation program． The bridge dynamic response under actual vehicle load can be calculated by the program quickly， and the calculation result has been verified statically and dynamic verification has been done using ANSYS software and bridge dynamic strain response under actual traffic flow， respectively．
2014, 44(07): 79-83.
Abstract:
The p-y curve method is widely used in the design of pile foundation at home and abroad，but few researches have been concerned about the newly deposited silt in the Yellow Ｒiver delta． In order to study the mechanical features，tests of a model pile embedded in deposit of saturated silt were carried out under lateral loadings． The p-y curves at different depths were obtained on the basis of relationships among the moment of the pile shaft，the lateral displacement and the soil reaction force． The experimental p-y curves were compared with the p-y curves recommended by API and two existing silt p-y curves，respectively． The results indicated that the API recommended p-y curves was of relatively larger initial stiffness but smaller ultimate soil-pile interaction，while the two existing silt p-y curves was of relatively larger ultimate soil-pile interaction． Suggestions on the design of pile foundations in the Yellow River delta were proposed．
The p-y curve method is widely used in the design of pile foundation at home and abroad，but few researches have been concerned about the newly deposited silt in the Yellow Ｒiver delta． In order to study the mechanical features，tests of a model pile embedded in deposit of saturated silt were carried out under lateral loadings． The p-y curves at different depths were obtained on the basis of relationships among the moment of the pile shaft，the lateral displacement and the soil reaction force． The experimental p-y curves were compared with the p-y curves recommended by API and two existing silt p-y curves，respectively． The results indicated that the API recommended p-y curves was of relatively larger initial stiffness but smaller ultimate soil-pile interaction，while the two existing silt p-y curves was of relatively larger ultimate soil-pile interaction． Suggestions on the design of pile foundations in the Yellow River delta were proposed．
2014, 44(07): 84-89.
Abstract:
The flexural bearing capacity of prestressed concrete pipe pile was enhanced by filling，steel fiber and nonprestressed steel bar in engineering，but the mechanical property of improved prestressed concrete pipe pile under earthquake was not clear． Based on the test results of three groups of specimens under low-cyclic loading，the hysteretic energy dissipation，ductility and bearing capacity of prestressed high strength concrete pipe pile ( PHC pile) ，prestressed high strength concrete pile reinforced with steel fiber ( SFPHC pile) and prestressed high strength concrete pipe pile reinforced with nonprestressed steel bar ( PRC pile) were studied respectively and the impact on the seismic performance of such pile was studied． It was shown that the seismic performance of PHC pipe pile could be improved with configuring of nonprestressed steel bar and the bearing capacity of PHC and SFPHC pipe piles under low-cyclic loading could be improved and the energy dissipation of PRC piles could be enhanced with filled in the core from the test results． The ductility of filled pipe pile had a significant improvement compared with unfilled pipe pile．
The flexural bearing capacity of prestressed concrete pipe pile was enhanced by filling，steel fiber and nonprestressed steel bar in engineering，but the mechanical property of improved prestressed concrete pipe pile under earthquake was not clear． Based on the test results of three groups of specimens under low-cyclic loading，the hysteretic energy dissipation，ductility and bearing capacity of prestressed high strength concrete pipe pile ( PHC pile) ，prestressed high strength concrete pile reinforced with steel fiber ( SFPHC pile) and prestressed high strength concrete pipe pile reinforced with nonprestressed steel bar ( PRC pile) were studied respectively and the impact on the seismic performance of such pile was studied． It was shown that the seismic performance of PHC pipe pile could be improved with configuring of nonprestressed steel bar and the bearing capacity of PHC and SFPHC pipe piles under low-cyclic loading could be improved and the energy dissipation of PRC piles could be enhanced with filled in the core from the test results． The ductility of filled pipe pile had a significant improvement compared with unfilled pipe pile．
2014, 44(07): 90-94.
Abstract:
Because of effect of well resistance and smear，deep soil can not achieve adquate vacuum when adopting the common vacuum preloading to reinforce soft soil． So deep soil can not be reinforced effectively． A method of deep air-boosted vacuum preloading to overcome the shortage of common vacuum preloading was proposed，which could improve the rate of drainage through enlarge the pressure difference between soil and the vertical drain． In addition， convection was produced between deep soil and upper soil with deep air-boosted，the rate of drainage would be improved due to that reason． Compared with the physical indicators of common preloading model test and found that the indicators of the moisture content，cross shear strength，cumulation settlement were better than those of the common vacuum preloading． It concluded that the soft soil could achieved better reinforcement through deep airboosted vacuum preloading．
Because of effect of well resistance and smear，deep soil can not achieve adquate vacuum when adopting the common vacuum preloading to reinforce soft soil． So deep soil can not be reinforced effectively． A method of deep air-boosted vacuum preloading to overcome the shortage of common vacuum preloading was proposed，which could improve the rate of drainage through enlarge the pressure difference between soil and the vertical drain． In addition， convection was produced between deep soil and upper soil with deep air-boosted，the rate of drainage would be improved due to that reason． Compared with the physical indicators of common preloading model test and found that the indicators of the moisture content，cross shear strength，cumulation settlement were better than those of the common vacuum preloading． It concluded that the soft soil could achieved better reinforcement through deep airboosted vacuum preloading．
2014, 44(07): 95-101.
Abstract:
Based on two assumptions that elemental vertical stress remained unchanged in the process of computation and that the principal stresses directions remaind unchanged before and after reduction，the calculation formulas and operation steps of the stress migration method was presented and then be applied to do numerical simulation analysis by ABAQUS． Then，the stress migration law was applied in the slope stability analysis of resettlement project． Preliminarily，the practical application of the research results in enigeering was discussed． Through the analysis of that project example，it concluded that it had good consistency to judge instability taking the displacement mutations， the plastic zone breakthrough and equivalent plastic strain breakthrough as the criterion，while it was slightly larger than the above criterions to taking calculation misconvergence．
Based on two assumptions that elemental vertical stress remained unchanged in the process of computation and that the principal stresses directions remaind unchanged before and after reduction，the calculation formulas and operation steps of the stress migration method was presented and then be applied to do numerical simulation analysis by ABAQUS． Then，the stress migration law was applied in the slope stability analysis of resettlement project． Preliminarily，the practical application of the research results in enigeering was discussed． Through the analysis of that project example，it concluded that it had good consistency to judge instability taking the displacement mutations， the plastic zone breakthrough and equivalent plastic strain breakthrough as the criterion，while it was slightly larger than the above criterions to taking calculation misconvergence．
2014, 44(07): 102-105.
Abstract:
Cement was replaced by the same amount of nano-SiO2 to prepare high performance concrete，it was tested the performance changes of concrete specimens in different admixture amounts of nano-SiO2 ． The results show that nano-SiO2 would reduce the workability of concrete． Cube compressive strength of concrete in 7 d was markedly increased with the increase of the admixture amounts of nano-SiO2 ． Compressive strength and elastic modulus in 28 d were first increased with the increase of the admixture amounts of nano-SiO2 then decreased，the maximum value was got when the admixture amounts nano-SiO2 was in the range of 2% to 3%，with the increasing range being 10% and 11% respectively． The impervious performance of concrete was improved with the increasing of the admixture amounts of nano-SiO2 ，and the increment of the impervious performance was also obvious in late period．
Cement was replaced by the same amount of nano-SiO2 to prepare high performance concrete，it was tested the performance changes of concrete specimens in different admixture amounts of nano-SiO2 ． The results show that nano-SiO2 would reduce the workability of concrete． Cube compressive strength of concrete in 7 d was markedly increased with the increase of the admixture amounts of nano-SiO2 ． Compressive strength and elastic modulus in 28 d were first increased with the increase of the admixture amounts of nano-SiO2 then decreased，the maximum value was got when the admixture amounts nano-SiO2 was in the range of 2% to 3%，with the increasing range being 10% and 11% respectively． The impervious performance of concrete was improved with the increasing of the admixture amounts of nano-SiO2 ，and the increment of the impervious performance was also obvious in late period．
2014, 44(07): 106-111.
Abstract:
It was studied the mechanical behaviors of C80 high-strength commercial concrete at different ages，based on the test of C80 high-strength commercial concrete specimens． It was also studied a variety of performance indicators such as the cube compressive strength，axial compressive strength，splitting tensile strength，static elastic modulus and the whole process of uniaxial stress-strain of concrete and so on at the age of 12 h，1 ，3，7， 14， 28 and 90 d． It was analyzed the variation of performance index with age growth and explored the variation of early strength 7 d ago) and ultra-early strength 3 d ago of C80 high-strength concrete． At last，the paper obtained formulas of cube compressive strength and elastic modulus of C80 high-strength concrete at any age．
It was studied the mechanical behaviors of C80 high-strength commercial concrete at different ages，based on the test of C80 high-strength commercial concrete specimens． It was also studied a variety of performance indicators such as the cube compressive strength，axial compressive strength，splitting tensile strength，static elastic modulus and the whole process of uniaxial stress-strain of concrete and so on at the age of 12 h，1 ，3，7， 14， 28 and 90 d． It was analyzed the variation of performance index with age growth and explored the variation of early strength 7 d ago) and ultra-early strength 3 d ago of C80 high-strength concrete． At last，the paper obtained formulas of cube compressive strength and elastic modulus of C80 high-strength concrete at any age．
2014, 44(07): 112-119.
Abstract:
The thickness，resistivity and degree of pore saturation of concrete cover have significant influences on the corrosion mechanism and corrosion rate of steel bar embedded in concrete． The influences of the thickness，resistivity and degree of pore saturation of concrete cover on the corrosion mechanism and corrosion rate of steel bar were investigated quantitatively，based on the macro-cell corrosion model of steel bar． The results show that the thickness and degree of pore saturation of concrete cover significantly affect the corrosion mechanism and corrosion rate of steel bar corrosion． If the corrosion of steel bar is under the control of resistivity，the corrosion rate diminishes with the increase of resistivity and accelerates with the increase of cover thickness，while the degree of pore saturation of concrete cover has negligible effect． When the cathodic reaction prevails，however，the corrosion rate decelerates with the increase of the degree of pore saturation and thickness of concrete cover while the effect of resistivity can be neglected．
The thickness，resistivity and degree of pore saturation of concrete cover have significant influences on the corrosion mechanism and corrosion rate of steel bar embedded in concrete． The influences of the thickness，resistivity and degree of pore saturation of concrete cover on the corrosion mechanism and corrosion rate of steel bar were investigated quantitatively，based on the macro-cell corrosion model of steel bar． The results show that the thickness and degree of pore saturation of concrete cover significantly affect the corrosion mechanism and corrosion rate of steel bar corrosion． If the corrosion of steel bar is under the control of resistivity，the corrosion rate diminishes with the increase of resistivity and accelerates with the increase of cover thickness，while the degree of pore saturation of concrete cover has negligible effect． When the cathodic reaction prevails，however，the corrosion rate decelerates with the increase of the degree of pore saturation and thickness of concrete cover while the effect of resistivity can be neglected．
2014, 44(07): 120-123.
Abstract:
Smart material structure is one of the hotspots in civil engineering field． The carbon black cement mortar was used as sensing element of concrete and nano-composite resin was used as sensing element of steel． With the study of two sets of smart beam experiments， the piezoresistive effect was researched． The results proved that the piezoresistive effect of sensing element was obvious in the beam under pure bending regions． It also proved that there existed the piezoresistive effect in shear moment regions of beams．
Smart material structure is one of the hotspots in civil engineering field． The carbon black cement mortar was used as sensing element of concrete and nano-composite resin was used as sensing element of steel． With the study of two sets of smart beam experiments， the piezoresistive effect was researched． The results proved that the piezoresistive effect of sensing element was obvious in the beam under pure bending regions． It also proved that there existed the piezoresistive effect in shear moment regions of beams．
2014, 44(07): 124-127.
Abstract:
Tibet Convention and Exhibition Center project is located in high altitude，low oxygen levels in Lhasa area，with the complexity of roof shape，height，large span and lots of pipes，a construction plan of the outer part of the roof lifting by combining unit，the internal part of roof by integral lifting technology is established． Nonlinear finite element analysis of the construction process verified the feasibility of this technique． Analyses were performed for synchronized hoisting and unsynchronized hoisting，the forces of the lifting frame were then analyzed to provide theoretical support for the safety of the construction．
Tibet Convention and Exhibition Center project is located in high altitude，low oxygen levels in Lhasa area，with the complexity of roof shape，height，large span and lots of pipes，a construction plan of the outer part of the roof lifting by combining unit，the internal part of roof by integral lifting technology is established． Nonlinear finite element analysis of the construction process verified the feasibility of this technique． Analyses were performed for synchronized hoisting and unsynchronized hoisting，the forces of the lifting frame were then analyzed to provide theoretical support for the safety of the construction．
2014, 44(07): 128-131.
Abstract:
Low-position lifting refers to that the design height of the lifting platform is low，and structure installation height is above the lifting platform，in the process of lifting，structure needs to be out of the lifting platform． Notable features of the low lifting is the lifting platform lower than the structure position，the first lifting，truss structure only installed the part above the middle chord，hence the stiffness of the structure can not meet the design requirements． Therefore，two hoisting points should be set in the truss structure region to ensure truss structure stability in the whole lifting process． After the lower chord installation completed，the temporary hoisting points should be removed，and replacing the lifting equipment to the second other lifting point，at the same time，low hoisting points within the truss area would be set from the original string position to the bottom，hanging point displacement has become the focus of the second lifting． With the actual situation of the lifting，MIDAS software was used to conduct two lifting digital analysis，the structure offset in the whole lifting process was got，and through pre adjusting the steel net set up value， with which two low-position liftings of steel truss structure were realized smoothly．
Low-position lifting refers to that the design height of the lifting platform is low，and structure installation height is above the lifting platform，in the process of lifting，structure needs to be out of the lifting platform． Notable features of the low lifting is the lifting platform lower than the structure position，the first lifting，truss structure only installed the part above the middle chord，hence the stiffness of the structure can not meet the design requirements． Therefore，two hoisting points should be set in the truss structure region to ensure truss structure stability in the whole lifting process． After the lower chord installation completed，the temporary hoisting points should be removed，and replacing the lifting equipment to the second other lifting point，at the same time，low hoisting points within the truss area would be set from the original string position to the bottom，hanging point displacement has become the focus of the second lifting． With the actual situation of the lifting，MIDAS software was used to conduct two lifting digital analysis，the structure offset in the whole lifting process was got，and through pre adjusting the steel net set up value， with which two low-position liftings of steel truss structure were realized smoothly．
2014, 44(07): 132-136.
Abstract:
Formwork accounts for a large proportion of concrete construction，in recent years accidents occur frequently on concrete formwork，resulting in greater casualties and property losses． This is not entirely due to improper construction operations，but also related to the unreasonable values in current standards on lateral pressure of concrete formwork． With an engineering project as the background，comparative studying of different formulas at home and abroad is done mainly from the effects of ambient temperature，concrete slump，initial setting time and pouring speed on the lateral pressure of concrete formwork ，which reveals the problems involving calculation of lateral pressure of concrete formwork，in order to arouse attention of the engineering circles．
Formwork accounts for a large proportion of concrete construction，in recent years accidents occur frequently on concrete formwork，resulting in greater casualties and property losses． This is not entirely due to improper construction operations，but also related to the unreasonable values in current standards on lateral pressure of concrete formwork． With an engineering project as the background，comparative studying of different formulas at home and abroad is done mainly from the effects of ambient temperature，concrete slump，initial setting time and pouring speed on the lateral pressure of concrete formwork ，which reveals the problems involving calculation of lateral pressure of concrete formwork，in order to arouse attention of the engineering circles．
2014, 44(07): 137-140.
Abstract:
The importance of study on seismic behavior of precast concrete frame structures was described． Progress of investigation on seismic behavior of precast reinforced concrete frame structures was introduced，including prestressed precast reinforced concrete structures，postcast assembled monolithic reinforced concrete structures，and precast assembled reinforced concrete structures． The progress in design codes and design methods of precast reinforced concrete structures at home and abroad were introduced． It was pointed out that the precast reinforced concrete structures with energy dissipation members and precast reinforced concrete isolation structures should be paid more attention to in future research work．
The importance of study on seismic behavior of precast concrete frame structures was described． Progress of investigation on seismic behavior of precast reinforced concrete frame structures was introduced，including prestressed precast reinforced concrete structures，postcast assembled monolithic reinforced concrete structures，and precast assembled reinforced concrete structures． The progress in design codes and design methods of precast reinforced concrete structures at home and abroad were introduced． It was pointed out that the precast reinforced concrete structures with energy dissipation members and precast reinforced concrete isolation structures should be paid more attention to in future research work．
2014, 44(07): 141-145.
Abstract:
Taking slenderness ratio and eccentricity ratio as the principal factors，static behavior of 24 pieces of concrete filled square steel tubular beam-columns strengthened by CFＲP externally ( S-CF-CFＲP-ST ) were experimentally investigated． The test results showed that the axial load-deflection curves on the cross-section at midheight of the composite members could be divided into elastic stage，elasto-plastic stage and softening stage． Analysis on the experimental results showed that the steel tube and its outer CFＲP material could cooperate both longitudinally and transversely，in addition，deflection curves of the tested members behaved much similarly as half sinusoidal curve． The failure modes and the axial load-deflection curves on the cross-section at mid-height of the specimens were simulated by using ABAQUS software． The simulated results agreed well with experimental values．
Taking slenderness ratio and eccentricity ratio as the principal factors，static behavior of 24 pieces of concrete filled square steel tubular beam-columns strengthened by CFＲP externally ( S-CF-CFＲP-ST ) were experimentally investigated． The test results showed that the axial load-deflection curves on the cross-section at midheight of the composite members could be divided into elastic stage，elasto-plastic stage and softening stage． Analysis on the experimental results showed that the steel tube and its outer CFＲP material could cooperate both longitudinally and transversely，in addition，deflection curves of the tested members behaved much similarly as half sinusoidal curve． The failure modes and the axial load-deflection curves on the cross-section at mid-height of the specimens were simulated by using ABAQUS software． The simulated results agreed well with experimental values．
2014, 44(07): 146-150.
Abstract:
The mechanism of the concrete filled square steel tubular beam-columns strengthened by CFRP externally ( S-CF-CFRP-ST) were analyzed by using ABAQUS software，and the results showed that the compressive region on cross-section varied from compression on the whole cross-section to tension on partial cross-section with loading increase． The steel tube yielded firstly on the cross-section at mid-height，and then the yielding propagated toward the end plates． The transverse CFRP in tension provided effective confinement on the specimens． The interaction force between the steel tube and the concrete reached its maximum value on the cross-section at mid-height，and it decreases when the distance to the end plates became smaller． On the cross-section，the interaction force had its maximum value at the corner while it decreased when the position moved to the mid-point of the tube side． The adhesive strength between the steel tube and the concrete had little effect on the load carrying capacity，and on the elastic stiffness of the specimens as well as on the interaction force between the steel tube and the concrete． The static behavior of the members was not sensitive to the different loading routes． Equation for calculating the loading carrying capacity of the composite columns was presented，and the estimated results agreed well with the experimental results．
The mechanism of the concrete filled square steel tubular beam-columns strengthened by CFRP externally ( S-CF-CFRP-ST) were analyzed by using ABAQUS software，and the results showed that the compressive region on cross-section varied from compression on the whole cross-section to tension on partial cross-section with loading increase． The steel tube yielded firstly on the cross-section at mid-height，and then the yielding propagated toward the end plates． The transverse CFRP in tension provided effective confinement on the specimens． The interaction force between the steel tube and the concrete reached its maximum value on the cross-section at mid-height，and it decreases when the distance to the end plates became smaller． On the cross-section，the interaction force had its maximum value at the corner while it decreased when the position moved to the mid-point of the tube side． The adhesive strength between the steel tube and the concrete had little effect on the load carrying capacity，and on the elastic stiffness of the specimens as well as on the interaction force between the steel tube and the concrete． The static behavior of the members was not sensitive to the different loading routes． Equation for calculating the loading carrying capacity of the composite columns was presented，and the estimated results agreed well with the experimental results．
2014, 44(07): 151-154.
doi: 10.13204/j.gyjz2001407031
Abstract:
Based on the twin shear unified strength theory，it was analyzed the condition of load for the steel tube and the core-concrete under tri-axial compression，the formula of axial bearing capacity of steel reinforced concrete short column with double circular steel tubes was established whose influencing factors were analyzed． By the comparison between the results calculated by the formula and the test results，it shows good agreement． Meanwhile，applying the formula in this paper to an engineering example，higher accuracy can be found in this calculation than the results in relevant documents by the comparison between them and the finite element analysis results．
Based on the twin shear unified strength theory，it was analyzed the condition of load for the steel tube and the core-concrete under tri-axial compression，the formula of axial bearing capacity of steel reinforced concrete short column with double circular steel tubes was established whose influencing factors were analyzed． By the comparison between the results calculated by the formula and the test results，it shows good agreement． Meanwhile，applying the formula in this paper to an engineering example，higher accuracy can be found in this calculation than the results in relevant documents by the comparison between them and the finite element analysis results．
2014, 44(07): 155-158.
doi: 10.13204/j.gyjz2001407032
Abstract:
Based on the restraint characteristic of concrete-filled steel square tubular ( CFST) column，core concrete area is divided into the strong restraint area and the weak restraint area． A formula is derived for estimating the bearing capacity of square CFST column by analogy RC column with spiral stirrup． The proposed formula is compared with the experiment results， the computing results of square CFST column formula agree well with the experimental results．
Based on the restraint characteristic of concrete-filled steel square tubular ( CFST) column，core concrete area is divided into the strong restraint area and the weak restraint area． A formula is derived for estimating the bearing capacity of square CFST column by analogy RC column with spiral stirrup． The proposed formula is compared with the experiment results， the computing results of square CFST column formula agree well with the experimental results．
2014, 44(07): 159-163.
doi: 10.13204/j.gyjz2001407033
Abstract:
Composite floor slab，as one of major steel frame structural elements，could greatly influence the antiprogressive collapse performance of structures． But the influence of slabs was not taken into consideration in the existing researches． In this paper，based on the two-way tension model of composite floor slab ， the mechanical behavior of composite floor slabs in the process of progressive collapse was analyzed，and established a simple calculation method of ultimate bearing capacity at failure point considering the tie force of slabs． Progressive collapse analysis of frames based on the simplification model is simulated by the finite element method，in order to validate the simple calculation method，and investigate the slab’s influences on plastic hinges，ultimate bearing capacity，amplitudes and periods of dynamic response at failure point，the result shows that slabs can effectively enhance the performance of structure to prevent progressive collapse．
Composite floor slab，as one of major steel frame structural elements，could greatly influence the antiprogressive collapse performance of structures． But the influence of slabs was not taken into consideration in the existing researches． In this paper，based on the two-way tension model of composite floor slab ， the mechanical behavior of composite floor slabs in the process of progressive collapse was analyzed，and established a simple calculation method of ultimate bearing capacity at failure point considering the tie force of slabs． Progressive collapse analysis of frames based on the simplification model is simulated by the finite element method，in order to validate the simple calculation method，and investigate the slab’s influences on plastic hinges，ultimate bearing capacity，amplitudes and periods of dynamic response at failure point，the result shows that slabs can effectively enhance the performance of structure to prevent progressive collapse．
2014, 44(07): 164-169.
doi: 10.13204/j.gyjz2001407034
Abstract:
The current anti-seism design method of civil engineering structure possibly loses system optimal solution because it does not consider the mutual coupling effect between structure design and control design． The collaborative optimization strategy is used for the integrated optimization of steel structure and control systems． The equation of motion for steel structure including MＲD under coupling earthquake is built，where the instantaneous optimal control strategy is applied for the control design． The integrated optimization model for the controlled structures is established． The multi-objective AFSA is chosen as the optimization method for the integrated optimization． The results of a numerical example show that structure and control system have better properties after the integrated optimization than those after the serial design，and the optimal structural weight under coupling earthquake is larger than that under horizontal earthquake only．
The current anti-seism design method of civil engineering structure possibly loses system optimal solution because it does not consider the mutual coupling effect between structure design and control design． The collaborative optimization strategy is used for the integrated optimization of steel structure and control systems． The equation of motion for steel structure including MＲD under coupling earthquake is built，where the instantaneous optimal control strategy is applied for the control design． The integrated optimization model for the controlled structures is established． The multi-objective AFSA is chosen as the optimization method for the integrated optimization． The results of a numerical example show that structure and control system have better properties after the integrated optimization than those after the serial design，and the optimal structural weight under coupling earthquake is larger than that under horizontal earthquake only．
2014, 44(07): 170-174.
doi: 10.13204/j.gyjz2001407035
Abstract:
Adopting the common and base isolation and non-islotion systems，comparative analysis of structure’s seismic performance was conducted on a multi-storey custom steel structure residence． El centro wave，Tianjin wave and an artificial earthquake wave are the seismic input． A two-degree of freedom Bouc-Wen hysteretic model was used to simplify the vibration isolation structure when analyzing the ductility demands． A brief analysis of the life cycle cost of this residence was also worked out． The results demonstrate that the gradually matured seismic isolated technology can be applied to steel structures as well． With the satisfaction of required bearing capacity，the seismic isolation layer has effectively controlled the vibration of superstructure，the structural response to earthquake has been effectively reduced and the interstorey acceleration response has also been greatly reduced，the safety of this structure has been guaranteed． Which meets the higher requirements towards the comforts of residence structures．
Adopting the common and base isolation and non-islotion systems，comparative analysis of structure’s seismic performance was conducted on a multi-storey custom steel structure residence． El centro wave，Tianjin wave and an artificial earthquake wave are the seismic input． A two-degree of freedom Bouc-Wen hysteretic model was used to simplify the vibration isolation structure when analyzing the ductility demands． A brief analysis of the life cycle cost of this residence was also worked out． The results demonstrate that the gradually matured seismic isolated technology can be applied to steel structures as well． With the satisfaction of required bearing capacity，the seismic isolation layer has effectively controlled the vibration of superstructure，the structural response to earthquake has been effectively reduced and the interstorey acceleration response has also been greatly reduced，the safety of this structure has been guaranteed． Which meets the higher requirements towards the comforts of residence structures．
2014, 44(07): 175-177.
doi: 10.13204/j.gyjz2001407036
Abstract:
By the comparison of the connection and reinforced connections’loading tests，this paper aims to analyse the different distance from the side of the beam to CFＲP and the changing influence on the reinforcement effect of connection owning to different layers of CFＲP sheets． The experimental results show that the closer distance from sticking CFＲP to beam edge，the better the consolidation． Conversely，the effect is worse． The more layers of CFＲP sheets，the more effect． But when the layer of the CFＲP sheets is more than 3，the ultimate flexural resistance of the beam-to-column connection will not be obvious．
By the comparison of the connection and reinforced connections’loading tests，this paper aims to analyse the different distance from the side of the beam to CFＲP and the changing influence on the reinforcement effect of connection owning to different layers of CFＲP sheets． The experimental results show that the closer distance from sticking CFＲP to beam edge，the better the consolidation． Conversely，the effect is worse． The more layers of CFＲP sheets，the more effect． But when the layer of the CFＲP sheets is more than 3，the ultimate flexural resistance of the beam-to-column connection will not be obvious．
2014, 44(07): 178-182.
doi: 10.13204/j.gyjz2001407037
Abstract:
Modular construction is used for AP1000 nuclear island of the third generation of nuclear power station， which provides great economic benefit． The important load lifting becomes one of the key techniques． The necessity of the important load lifting simulation based on BIM technique is pointed out，which is for the problems exist during the AP1000 nuclear island lifting，such as lifting planning，lifting animation and simulation and collision detection． The BIM-based lifting animation and simulation platform is put forward after the brief introduction of BIM． The definition method of the crane BIM model is shown． And the way to simulate with the BIM model based on 3DS Max software and do structural analysis based on ANSYS software is introduced.
Modular construction is used for AP1000 nuclear island of the third generation of nuclear power station， which provides great economic benefit． The important load lifting becomes one of the key techniques． The necessity of the important load lifting simulation based on BIM technique is pointed out，which is for the problems exist during the AP1000 nuclear island lifting，such as lifting planning，lifting animation and simulation and collision detection． The BIM-based lifting animation and simulation platform is put forward after the brief introduction of BIM． The definition method of the crane BIM model is shown． And the way to simulate with the BIM model based on 3DS Max software and do structural analysis based on ANSYS software is introduced.
2014, 44(07): 183-186.
doi: 10.13204/j.gyjz2001407038
Abstract:
The present study of roof greening is more concentrated in the flat roof，and less in the sloping roof． With respect to flat roof，loss of soil and water is the main problem of greening of sloping roofs． The paper studied anti-skid measures，irrigation and drainage system and combining with rainwater collection to popularize the design of greening of sloping roofs．
The present study of roof greening is more concentrated in the flat roof，and less in the sloping roof． With respect to flat roof，loss of soil and water is the main problem of greening of sloping roofs． The paper studied anti-skid measures，irrigation and drainage system and combining with rainwater collection to popularize the design of greening of sloping roofs．
