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2020 Vol. 50, No. 5
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2020, 50(5): 1-7.
doi: 10.13204/j.gyjz202005001
Abstract:
Shenhou is a typical representative of the ancient town of central plains,and riching in Jun porcelain. The paper analyzed the spatial characteristics of the ancient town of Shenhou, and the continuous evolution of the ancient town along with the development of the Jun porcelain industry on the spatial level, clarifying the main research content of the ancient town of Shenhou. The industry-dependent ancient towns have traditional local characteristics and connotations that are different from those of ordinary ancient towns. For the production space that carries the development and changes of the traditional Jun porcelain industry, the historical value should be studied in depth, so as to provide a reference to the research method and technical route.
Shenhou is a typical representative of the ancient town of central plains,and riching in Jun porcelain. The paper analyzed the spatial characteristics of the ancient town of Shenhou, and the continuous evolution of the ancient town along with the development of the Jun porcelain industry on the spatial level, clarifying the main research content of the ancient town of Shenhou. The industry-dependent ancient towns have traditional local characteristics and connotations that are different from those of ordinary ancient towns. For the production space that carries the development and changes of the traditional Jun porcelain industry, the historical value should be studied in depth, so as to provide a reference to the research method and technical route.
2020, 50(5): 8-12.
doi: 10.13204/j.gyjz202005002
Abstract:
This paper focused on the deep research of the spatial form features and cultural connotations of the silo-cave village in Shanzhou District, Sanmenxia City. Taking Liusi Village as an example, the formation and development, spatial pattern and formation factors, public space and architectural space were analyzed. The results showed that the change of site selection in Liusi Village was closely related to the idea of construction, population growth, and construction technology. Village form shows a pattern of large dispersion, small concentration. It was significantly influenced by the terrain, surname and bold relationship, street pattern, and landscape pattern. The characteristic public spaces of Liusi Village were made of temples, cave surface space and the ponds, etc. Furthermore, the layout of their buildings groups gives two features, intersection and side-by-side, in term of architectural forms. Its formation is attributed to different times and cultural backgrounds.
This paper focused on the deep research of the spatial form features and cultural connotations of the silo-cave village in Shanzhou District, Sanmenxia City. Taking Liusi Village as an example, the formation and development, spatial pattern and formation factors, public space and architectural space were analyzed. The results showed that the change of site selection in Liusi Village was closely related to the idea of construction, population growth, and construction technology. Village form shows a pattern of large dispersion, small concentration. It was significantly influenced by the terrain, surname and bold relationship, street pattern, and landscape pattern. The characteristic public spaces of Liusi Village were made of temples, cave surface space and the ponds, etc. Furthermore, the layout of their buildings groups gives two features, intersection and side-by-side, in term of architectural forms. Its formation is attributed to different times and cultural backgrounds.
2020, 50(5): 13-17,93.
doi: 10.13204/j.gyjz202005003
Abstract:
Fushun Electric Railway, as an unexcavated and idle linear railway industrial heritage, is the first light rail transit built in modern China. Based on the analysis of the important value of Fushun Electric Railway industry heritage, different transformation strategies were put forward for each section of the electric railway line, that is, the main line of the electric railway should be transformed into a tram to continue its original functions; making rational use of the well-preserved electric railway locomotives and many surrounding industrial heritage, and transforming the electric railway branch line into a small train tourism and sightseeing line, so as to activate the cultural value; the specific transformation and reuse strategies for the heritage transformation of the core area along the electric railway line were also put forward.
Fushun Electric Railway, as an unexcavated and idle linear railway industrial heritage, is the first light rail transit built in modern China. Based on the analysis of the important value of Fushun Electric Railway industry heritage, different transformation strategies were put forward for each section of the electric railway line, that is, the main line of the electric railway should be transformed into a tram to continue its original functions; making rational use of the well-preserved electric railway locomotives and many surrounding industrial heritage, and transforming the electric railway branch line into a small train tourism and sightseeing line, so as to activate the cultural value; the specific transformation and reuse strategies for the heritage transformation of the core area along the electric railway line were also put forward.
2020, 50(5): 18-23.
doi: 10.13204/j.gyjz202005004
Abstract:
In order to study the shear bearing mechanism of the beam-column interface of the pre-stressed prefabricated monolithic concrete frame, the provisions of the friction coefficient in the domestic and foreign codes were summarized and analyzed. Through the study of five groups of 19 direct shear specimens of beam-column joints, the effects of joint area, pre-stressed, eccentricity of pre-stressed screw position and grouting material on friction performance were analyzed, and the shear bearing capacity and equivalent friction system of specimens under pure shear state were obtained. The test results showed that the shear bearing capacity of beam-column joints was discrete when there was no prestressing force, which was mainly related to the construction quality of post-poured joints; the shear area of the specimen and the eccentricity of the prestressing screw position had little effect on the shear capacity; the relationship between shear capacity and prestressing force was basically linear, increasing prestressing force could effectively improve the shear bearing capacity of joints; equivalent friction coefficient of shear joint could be effectively improved by using steel fiber mortar in grouting joint; the equivalent friction coefficient decreased with the increase of prestressing stress; for joints without rough treatment, using the friction coefficient in Technical Specification for Integral Prefabricated Prestressed Concrete Slab-Column Structure(CECS 52:2010) or Technical Specification for Concrete Structures with Precast Components(SJG 18-2009) would result in insufficient shear bearing capacity or insufficient safety reserve. The friction coefficient in the formula of shear bearing capacity should be determined according to the magnitude of prestressing force.
In order to study the shear bearing mechanism of the beam-column interface of the pre-stressed prefabricated monolithic concrete frame, the provisions of the friction coefficient in the domestic and foreign codes were summarized and analyzed. Through the study of five groups of 19 direct shear specimens of beam-column joints, the effects of joint area, pre-stressed, eccentricity of pre-stressed screw position and grouting material on friction performance were analyzed, and the shear bearing capacity and equivalent friction system of specimens under pure shear state were obtained. The test results showed that the shear bearing capacity of beam-column joints was discrete when there was no prestressing force, which was mainly related to the construction quality of post-poured joints; the shear area of the specimen and the eccentricity of the prestressing screw position had little effect on the shear capacity; the relationship between shear capacity and prestressing force was basically linear, increasing prestressing force could effectively improve the shear bearing capacity of joints; equivalent friction coefficient of shear joint could be effectively improved by using steel fiber mortar in grouting joint; the equivalent friction coefficient decreased with the increase of prestressing stress; for joints without rough treatment, using the friction coefficient in Technical Specification for Integral Prefabricated Prestressed Concrete Slab-Column Structure(CECS 52:2010) or Technical Specification for Concrete Structures with Precast Components(SJG 18-2009) would result in insufficient shear bearing capacity or insufficient safety reserve. The friction coefficient in the formula of shear bearing capacity should be determined according to the magnitude of prestressing force.
2020, 50(5): 24-30.
doi: 10.13204/j.gyjz202005005
Abstract:
The connection of embedded steel plate and bolt is a new type of vertical connection for prefabricated concrete shear wall. In order to study the seismic behavior, quasi-static test was conducted on two shear walls with vertical connection and stirrup bolted connection respectively, and the test was simulated by using the ABAQUS software. The indexes for the two types of shear walls, including the bearing capacity, stiffness, ductility and energy consumption, were analyzed and compared. The results showed that the two types of shear walls both had good mechanical properties. The shear wall with vertical connections of embedded steel plate and bolt had a slightly smaller bearing capacity, stiffness and energy consumption capacity, and a slightly larger ductility compared with the shear wall with stirrup bolted connection. In general, the numerical simulation results could agree well with the test results.
The connection of embedded steel plate and bolt is a new type of vertical connection for prefabricated concrete shear wall. In order to study the seismic behavior, quasi-static test was conducted on two shear walls with vertical connection and stirrup bolted connection respectively, and the test was simulated by using the ABAQUS software. The indexes for the two types of shear walls, including the bearing capacity, stiffness, ductility and energy consumption, were analyzed and compared. The results showed that the two types of shear walls both had good mechanical properties. The shear wall with vertical connections of embedded steel plate and bolt had a slightly smaller bearing capacity, stiffness and energy consumption capacity, and a slightly larger ductility compared with the shear wall with stirrup bolted connection. In general, the numerical simulation results could agree well with the test results.
2020, 50(5): 31-35.
doi: 10.13204/j.gyjz202005006
Abstract:
A new type of connection technique for bidirectional composite floor slabs without gap was proposed. Full-scale tests on the construction of slabs' joints were carried out, and compared with cast-in-place slab. The mechanical properties of the new type of joint structure were studied, including the failure mode, bearing capacity, stiffness and crack distribution of floor slab. On the basis of the tests, a refined finite element analysis was performed, then the mechanism of force transfer between steel bar and concrete at the joint was deeply studied. The results showed that the mechanical properties of the new joint connected without gap was basically the same as that of the cast-in-place structure. The numerical calculation agreed well with the experimental results. The reinforcement at joint could effectively transfer structural internal force.
A new type of connection technique for bidirectional composite floor slabs without gap was proposed. Full-scale tests on the construction of slabs' joints were carried out, and compared with cast-in-place slab. The mechanical properties of the new type of joint structure were studied, including the failure mode, bearing capacity, stiffness and crack distribution of floor slab. On the basis of the tests, a refined finite element analysis was performed, then the mechanism of force transfer between steel bar and concrete at the joint was deeply studied. The results showed that the mechanical properties of the new joint connected without gap was basically the same as that of the cast-in-place structure. The numerical calculation agreed well with the experimental results. The reinforcement at joint could effectively transfer structural internal force.
2020, 50(5): 36-43.
doi: 10.13204/j.gyjz202005007
Abstract:
A new type of floor slab applied to prefabricated steel structures was proposed in the paper. The lower floor is the structural floor and the upper floor is the building floor. The building floor is poured at the decoration stage, and the structural floor and beam are integrally manufactured in the factory. The beams are all hidden in the floor. The position of the partition wall does not have to correspond to the beam, which makes the layout of the partition wall flexible and meets the individual requirements of owner for functional layout. Web openings allows the pipeline in the floor to easily pass through the beam, which is conducive to the personalized layout and installation of the pipeline during the decoration stage, and at the same time facilitates later maintenance and renovation. In order to study the mechanical properties of this floor during construction, static performance tests were performed on two beams and floors during construction. The cracking load, crack development distribution, design load and failure mode of two floors were analyzed. The design bearing capacity of the beam was analyzed, and the results obtained from the finite element analysis were compared with the test results. The results showed that the invisible beams and floors had reasonable bearing capacity during the construction stage and could meet the requirements of construction bearing capacity. Based on the test results, a calculation method for the bending bearing capacity of the invisible beams and floors was proposed.
A new type of floor slab applied to prefabricated steel structures was proposed in the paper. The lower floor is the structural floor and the upper floor is the building floor. The building floor is poured at the decoration stage, and the structural floor and beam are integrally manufactured in the factory. The beams are all hidden in the floor. The position of the partition wall does not have to correspond to the beam, which makes the layout of the partition wall flexible and meets the individual requirements of owner for functional layout. Web openings allows the pipeline in the floor to easily pass through the beam, which is conducive to the personalized layout and installation of the pipeline during the decoration stage, and at the same time facilitates later maintenance and renovation. In order to study the mechanical properties of this floor during construction, static performance tests were performed on two beams and floors during construction. The cracking load, crack development distribution, design load and failure mode of two floors were analyzed. The design bearing capacity of the beam was analyzed, and the results obtained from the finite element analysis were compared with the test results. The results showed that the invisible beams and floors had reasonable bearing capacity during the construction stage and could meet the requirements of construction bearing capacity. Based on the test results, a calculation method for the bending bearing capacity of the invisible beams and floors was proposed.
2020, 50(5): 44-51,176.
doi: 10.13204/j.gyjz202005008
Abstract:
In order to study the influence of different reinforcement ratios on the bearing capacity of reinforced concrete bridge deck, eight reinforced concrete bridge deck models with different reinforcement ratios were established by numerical simulation on the basis of experiments, and their bearing capacity, change trend and failure mode were studied. It was found that for the failure mode, bending failure occurred when the reinforcement ratio was lower than 0.72%, and punching failure occurred when the reinforcement ratio was greater than 0.95%. For the bearing capacity, the effect of reinforcement ratio on the elastic section was not obvious, and the effect of reinforcement ratio on the bearing capacity was greater when it was 0.2%~0.72%. Based on the calculation formula of punching capacity in GB 50010-2010 Code for Design of Concrete Structures, the calculation model of punching capacity calculation formula considering the influence of reinforcement ratio was established, and the correlation coefficient of the model was calculated by linear regression method.Compared to European standards and national standards and test data of the researchers at home and abroad, the proposed formula was safe and reliable.
In order to study the influence of different reinforcement ratios on the bearing capacity of reinforced concrete bridge deck, eight reinforced concrete bridge deck models with different reinforcement ratios were established by numerical simulation on the basis of experiments, and their bearing capacity, change trend and failure mode were studied. It was found that for the failure mode, bending failure occurred when the reinforcement ratio was lower than 0.72%, and punching failure occurred when the reinforcement ratio was greater than 0.95%. For the bearing capacity, the effect of reinforcement ratio on the elastic section was not obvious, and the effect of reinforcement ratio on the bearing capacity was greater when it was 0.2%~0.72%. Based on the calculation formula of punching capacity in GB 50010-2010 Code for Design of Concrete Structures, the calculation model of punching capacity calculation formula considering the influence of reinforcement ratio was established, and the correlation coefficient of the model was calculated by linear regression method.Compared to European standards and national standards and test data of the researchers at home and abroad, the proposed formula was safe and reliable.
2020, 50(5): 52-57.
doi: 10.13204/j.gyjz202005009
Abstract:
Based on ANSYS Fluent software platform,the SST k-w turbulence model was used to calculate and analyze the wind-load shape coefficient of the crescent-shaped cantilevered roof. In order to verify the reliability of numerical simulation, the simulation results were compared with the results of similar wind tunnel tests. The results showed that the numerical simulation had high reliability. Many models were established to research the influences of the ventilation rate, the roof inclination, the maximum cantilever length and the wind angle on the wind-load shape coefficient of the roof. The regularities of wind load distribution on the crescent-shaped cantilevered roof were obtained. The wind load shape coefficient of the crescent-shaped cantilevered roof was proposed.
Based on ANSYS Fluent software platform,the SST k-w turbulence model was used to calculate and analyze the wind-load shape coefficient of the crescent-shaped cantilevered roof. In order to verify the reliability of numerical simulation, the simulation results were compared with the results of similar wind tunnel tests. The results showed that the numerical simulation had high reliability. Many models were established to research the influences of the ventilation rate, the roof inclination, the maximum cantilever length and the wind angle on the wind-load shape coefficient of the roof. The regularities of wind load distribution on the crescent-shaped cantilevered roof were obtained. The wind load shape coefficient of the crescent-shaped cantilevered roof was proposed.
2020, 50(5): 58-65,30.
doi: 10.13204/j.gyjz202005010
Abstract:
The dynamic characteristics of saturated sand with fine grains were studied by hollow cylinder apparatus torsional shear test. The test results showed that the liquefaction cycles for sands under wave load by hollow cylinder torsional shear test were obviously smaller than that one by dynamic triaxial or dynamic torsional shear test; with the increase of fine grained content, the liquefaction cycles for sand with fine grained content first decreased and then increased, when the content of fine grains was about at 10%, the cycles were lowest; when the fine grained content was smaller, the development rule of excess pore water pressure of sand with fine graines was similar to that of pure sand, when the fine grained content reached more than 15%, the rule of clay gradually appeared. The results showed that the content of fine grains and the effective confining pressure had no effect on the modulus normalization curve; the damping ratio normalization curve of sand mixed with fine particles was obviously affected by the confining pressure, and the larger the initial effective confining pressure, the smaller the damping ratio.
The dynamic characteristics of saturated sand with fine grains were studied by hollow cylinder apparatus torsional shear test. The test results showed that the liquefaction cycles for sands under wave load by hollow cylinder torsional shear test were obviously smaller than that one by dynamic triaxial or dynamic torsional shear test; with the increase of fine grained content, the liquefaction cycles for sand with fine grained content first decreased and then increased, when the content of fine grains was about at 10%, the cycles were lowest; when the fine grained content was smaller, the development rule of excess pore water pressure of sand with fine graines was similar to that of pure sand, when the fine grained content reached more than 15%, the rule of clay gradually appeared. The results showed that the content of fine grains and the effective confining pressure had no effect on the modulus normalization curve; the damping ratio normalization curve of sand mixed with fine particles was obviously affected by the confining pressure, and the larger the initial effective confining pressure, the smaller the damping ratio.
2020, 50(5): 66-70,43.
doi: 10.13204/j.gyjz202005011
Abstract:
In order to quantitatively recognize the operation state of a slope and predict its risk of instability, based on the theory of Prognostic and Health Management (PHM), the framework of slope PHM system was studied considering the monitoring situation. Based on the performance degradation fault forecast method, the Failure Rate (FR) and Residual Safety Degree (RSD) were defined based on the actual displacement of slope. According to the characteristics of slope sliding, combining Saito Michitakanori method and neural networks, the slope slip time and the critical displacement were predicted from the monitoring displacements. The FR and RSD formulas were established, and the performance degradation time curve was drawn to realize the quantitative identification and forecast FR and RSD. They could be used to provide direct guidance for appropriate governance and maintenance. According to the monitoring information of a slope, the FR forecast process of displacement for slope PHM system was explained in detail. Its analytical model and forecasted results were in good agreement with the slope actual situation.
In order to quantitatively recognize the operation state of a slope and predict its risk of instability, based on the theory of Prognostic and Health Management (PHM), the framework of slope PHM system was studied considering the monitoring situation. Based on the performance degradation fault forecast method, the Failure Rate (FR) and Residual Safety Degree (RSD) were defined based on the actual displacement of slope. According to the characteristics of slope sliding, combining Saito Michitakanori method and neural networks, the slope slip time and the critical displacement were predicted from the monitoring displacements. The FR and RSD formulas were established, and the performance degradation time curve was drawn to realize the quantitative identification and forecast FR and RSD. They could be used to provide direct guidance for appropriate governance and maintenance. According to the monitoring information of a slope, the FR forecast process of displacement for slope PHM system was explained in detail. Its analytical model and forecasted results were in good agreement with the slope actual situation.
2020, 50(5): 71-74,132.
doi: 10.13204/j.gyjz202005012
Abstract:
Soft ground is one of common applicable conditions of transmission tower screw anchor foundation. In order to understand the uplift bearing capacity of screw anchor in soft soil, in-situ uplift loading tests of screw anchors with different diameters, depths and spacings of anchor plates were carried out. The load-displacement relationship curve and ultimate uplift bearing capacity of single anchor foundation were obtained, and the uplift resistance of screw anchor in mud soft soil was analyzed,as well as the effects of diameter, number, depth, and bearing layer properties of anchor plate on the uplift bearing capacity of screw anchor. The results showed that the relationship between load and displacement of screw anchors in soft ground had smaller plastic load and longer plastic deformation stage; the larger the diameter of anchor plate and the more anchor plates, the higher the bearing capacity; when the ratio of the distance between adjacent anchor plates to the diameter of anchor plate was larger than 2.0, the interaction of a screw anchor between the anchor plates could be neglected, and the effect of the anchor plate bearing layer on the uplift bearing capacity of the screw anchor was more obvious than that of the buried depth.
Soft ground is one of common applicable conditions of transmission tower screw anchor foundation. In order to understand the uplift bearing capacity of screw anchor in soft soil, in-situ uplift loading tests of screw anchors with different diameters, depths and spacings of anchor plates were carried out. The load-displacement relationship curve and ultimate uplift bearing capacity of single anchor foundation were obtained, and the uplift resistance of screw anchor in mud soft soil was analyzed,as well as the effects of diameter, number, depth, and bearing layer properties of anchor plate on the uplift bearing capacity of screw anchor. The results showed that the relationship between load and displacement of screw anchors in soft ground had smaller plastic load and longer plastic deformation stage; the larger the diameter of anchor plate and the more anchor plates, the higher the bearing capacity; when the ratio of the distance between adjacent anchor plates to the diameter of anchor plate was larger than 2.0, the interaction of a screw anchor between the anchor plates could be neglected, and the effect of the anchor plate bearing layer on the uplift bearing capacity of the screw anchor was more obvious than that of the buried depth.
2020, 50(5): 75-80.
doi: 10.13204/j.gyjz202005013
Abstract:
Coal gangue sintered composite insulation block is a kind of energy-saving wall material, which has the advantages of light weight, high strength and good insulation performance. In order to study the compression performance of coal gangue sintered composite insulation block, two groups of 12 specimens of coal gangue sintered composite insulation block masonry were studied, and the failure characteristics and mechanical properties of sintered gangue composite insulation block and ordinary mortar and gypsum mortar masonry specimens were analyzed. The results showed that the local failure of sintered gangue composite insulation block caused the overall instability and failure of the masonry specimen, the compressive strength of the masonry was less than that of the block, and the test value was less than the calculation value in GB 50003-2011. Based on the test data, the stress-strain relation curve was obtained, and the proposed expression of stress-strain relation and the recommended value of elastic modulus of masonry were proposed through the method of analysis and comparison.
Coal gangue sintered composite insulation block is a kind of energy-saving wall material, which has the advantages of light weight, high strength and good insulation performance. In order to study the compression performance of coal gangue sintered composite insulation block, two groups of 12 specimens of coal gangue sintered composite insulation block masonry were studied, and the failure characteristics and mechanical properties of sintered gangue composite insulation block and ordinary mortar and gypsum mortar masonry specimens were analyzed. The results showed that the local failure of sintered gangue composite insulation block caused the overall instability and failure of the masonry specimen, the compressive strength of the masonry was less than that of the block, and the test value was less than the calculation value in GB 50003-2011. Based on the test data, the stress-strain relation curve was obtained, and the proposed expression of stress-strain relation and the recommended value of elastic modulus of masonry were proposed through the method of analysis and comparison.
2020, 50(5): 81-87,80.
doi: 10.13204/j.gyjz202005014
Abstract:
In order to study the effects of desert sand replacement rate and fly ash content on the compressive strength of concrete under low temperature, the compressive strength tests of concrete with desert sand, fly ash, the mixture of desert sand and fly ash under room temperature, -10℃, -20℃, -30℃ were carried out. The influences of temperature, desert sand replacement rate and fly ash content on the compressive strength of concrete were analyzed. The regression model between the compressive strength of concrete with temperature, desert sand replacement rate and fly ash content was established. The test results showed that the compressive strength of concrete increased under low temperature with the decrease of temperature. Whereas, after being subjected to low temperature, the compressive strength of concrete decreased with the decrease of temperature. For the concrete with desert sand, the compressive strength of concrete increased firstly, and then decreased with the increase of desert sand replacement rate. The compressive strength of concrete with desert sand replacement rate 50% was the maximum value. For the concrete with fly ash, the compressive strength of concrete tended to decrease with the increase of fly ash content. For the concrete with the mixture of desert sand and fly ash, the compressive strength of concrete reached the maximum value when desert sand replacement rate and fly ash content were 50% and 10%, respectively.
In order to study the effects of desert sand replacement rate and fly ash content on the compressive strength of concrete under low temperature, the compressive strength tests of concrete with desert sand, fly ash, the mixture of desert sand and fly ash under room temperature, -10℃, -20℃, -30℃ were carried out. The influences of temperature, desert sand replacement rate and fly ash content on the compressive strength of concrete were analyzed. The regression model between the compressive strength of concrete with temperature, desert sand replacement rate and fly ash content was established. The test results showed that the compressive strength of concrete increased under low temperature with the decrease of temperature. Whereas, after being subjected to low temperature, the compressive strength of concrete decreased with the decrease of temperature. For the concrete with desert sand, the compressive strength of concrete increased firstly, and then decreased with the increase of desert sand replacement rate. The compressive strength of concrete with desert sand replacement rate 50% was the maximum value. For the concrete with fly ash, the compressive strength of concrete tended to decrease with the increase of fly ash content. For the concrete with the mixture of desert sand and fly ash, the compressive strength of concrete reached the maximum value when desert sand replacement rate and fly ash content were 50% and 10%, respectively.
2020, 50(5): 88-93.
doi: 10.13204/j.gyjz202005015
Abstract:
In view of the fluctuation of the quality of tuff manufactured sand in Taizhou area, Zhejiang,the influence of tuff manufactured sand on the performance of concrete was explored. The effects of different batches of manufactured tuff sand, manufactured limestone sand and river sand on mechanical properties and durability of concrete were studied. The results showed that the performance of the concrete with 20% mineral admixture was better than that of pure cement concrete. The grey correlation analysis was used to analyze the correlation between the content of stone powder, content of mud block, roughness and the 7 d compressive strength,28 d compressive strength, electric flux and cracking area of concrete. And two relational degree matrices were obtained. It was concluded that the content of manufactured stone powder was the main factor affecting chloride ion penetration resistance of concrete. While the main factor affecting the crack resistance of manufactured sand concrete was the content of mud. The correlation between compressive strength and roughness was the greatest, and when the content of stone powder was not more than a certain range, the influence of stone powder content on the compressive strength of concrete was very small. The permeability and crack resistance of concrete with manufactured tuff sand were more sensitive to the content of limestone powder and mud than that of concrete with manufactured limestone sand, and were more affected by the quality fluctuation of manufactured sand.
In view of the fluctuation of the quality of tuff manufactured sand in Taizhou area, Zhejiang,the influence of tuff manufactured sand on the performance of concrete was explored. The effects of different batches of manufactured tuff sand, manufactured limestone sand and river sand on mechanical properties and durability of concrete were studied. The results showed that the performance of the concrete with 20% mineral admixture was better than that of pure cement concrete. The grey correlation analysis was used to analyze the correlation between the content of stone powder, content of mud block, roughness and the 7 d compressive strength,28 d compressive strength, electric flux and cracking area of concrete. And two relational degree matrices were obtained. It was concluded that the content of manufactured stone powder was the main factor affecting chloride ion penetration resistance of concrete. While the main factor affecting the crack resistance of manufactured sand concrete was the content of mud. The correlation between compressive strength and roughness was the greatest, and when the content of stone powder was not more than a certain range, the influence of stone powder content on the compressive strength of concrete was very small. The permeability and crack resistance of concrete with manufactured tuff sand were more sensitive to the content of limestone powder and mud than that of concrete with manufactured limestone sand, and were more affected by the quality fluctuation of manufactured sand.
2020, 50(5): 102-108.
doi: 10.13204/j.gyjz202005017
Abstract:
Mechanical anchors have been widely used in existing building retrofitting and new steel-concrete composite structure construction. The safety of structure is directly influenced by the performance of anchors. JG/T 160-2017 Mechanical Anchors for Use in Concrete structure was issued, which was the basis for anchor design and construction. The quality control of anchor product was very important for concrete structure anchorage. On the basis of introducing the revision background and significance of the standard, the test content recently added and revised, the product evaluation criteria and its relationship with current domestic and foreign related standards, the key contents and the new characteristic of the new standard were introduced.
Mechanical anchors have been widely used in existing building retrofitting and new steel-concrete composite structure construction. The safety of structure is directly influenced by the performance of anchors. JG/T 160-2017 Mechanical Anchors for Use in Concrete structure was issued, which was the basis for anchor design and construction. The quality control of anchor product was very important for concrete structure anchorage. On the basis of introducing the revision background and significance of the standard, the test content recently added and revised, the product evaluation criteria and its relationship with current domestic and foreign related standards, the key contents and the new characteristic of the new standard were introduced.
2020, 50(5): 109-113,202.
doi: 10.13204/j.gyjz202005018
Abstract:
Diagrid tube has significant advantages in vertical and lateral horizontal load-bearing capacities. It is characterized by large lateral stiffness and high overall stability, and has been currently widely used in practical engineering. Several hyperboloid diagrid tubes are adopted as bottom support structures in the China Comic and Animation Museum in Hangzhou, of which the Y2 grid tube structure has both the largest scale and vertical loads on its top. Owing to a lack of both circumferential members (except the top ring beam) and radial lateral braces along the height direction, the Y2 tube structure would be prone to out-of-plane multi-column instability fail when subjected to vertical loads. Current design method in predicting the vertical bearing capacity of the grid tube are not available, thus experimental studies are recommended. This paper designed a new scheme of vertical loading experiments on grid tubes to realize the conversion from a single point vertical load applied at the top point of a load distribution structure to multi-point vertical loads applied on the top of the Y2 diagrid tube structure. This scheme not only saved the experimental space and cost, but also accurately realized the real load distribution ratio on the top of the Y2 tube structure. The experiment results revealed that the failure mode of the Y2 diagrid tube structure was regional multi-column instability at both sides of the opening 1. The ultimate bearing capacity of the Y2 diagrid tube structure specimen was found to be 3.37 times its design load, indicating that the Y2 diagrid tube structure had sufficient bearing capacity within a rational safety margin.
Diagrid tube has significant advantages in vertical and lateral horizontal load-bearing capacities. It is characterized by large lateral stiffness and high overall stability, and has been currently widely used in practical engineering. Several hyperboloid diagrid tubes are adopted as bottom support structures in the China Comic and Animation Museum in Hangzhou, of which the Y2 grid tube structure has both the largest scale and vertical loads on its top. Owing to a lack of both circumferential members (except the top ring beam) and radial lateral braces along the height direction, the Y2 tube structure would be prone to out-of-plane multi-column instability fail when subjected to vertical loads. Current design method in predicting the vertical bearing capacity of the grid tube are not available, thus experimental studies are recommended. This paper designed a new scheme of vertical loading experiments on grid tubes to realize the conversion from a single point vertical load applied at the top point of a load distribution structure to multi-point vertical loads applied on the top of the Y2 diagrid tube structure. This scheme not only saved the experimental space and cost, but also accurately realized the real load distribution ratio on the top of the Y2 tube structure. The experiment results revealed that the failure mode of the Y2 diagrid tube structure was regional multi-column instability at both sides of the opening 1. The ultimate bearing capacity of the Y2 diagrid tube structure specimen was found to be 3.37 times its design load, indicating that the Y2 diagrid tube structure had sufficient bearing capacity within a rational safety margin.
2020, 50(5): 114-120.
doi: 10.13204/j.gyjz202005019
Abstract:
A rigid structure model of long-span flat roof with overhanging eaves was designed and tested in wind tunnel. The average wind pressure and fluctuating wind pressure coefficients of the measured points on the surface of the model roof were obtained. Then the wind pressure coefficients at the joints were calculated by proper orthogonal decomposition (POD) method. The finite element analysis software ANSYS was used to analyze the wind-induced vibration response and the performance of vibration reduction. The results showed that negative wind pressure of overhanging eaves was large due to the superposition of upper and lower surface wind pressure. The effect of adding viscoelastic dampers on the corners of the eaves was remarkable for controlling the wind-induced vibration response of overhanging eaves. For the existing grid structures with certain degree of corrosion, the wind-induced response increased with the increase of corrosion depth, and the viscoelastic damper had an obvious effect on wind-induced vibration reduction.When the corrosion depth was less than 1 mm, the damping coefficient of root mean square of displacement response reached 10.3%~21.0%, and the damping coefficient of peak acceleration response reached 26.3%~39.6%.
A rigid structure model of long-span flat roof with overhanging eaves was designed and tested in wind tunnel. The average wind pressure and fluctuating wind pressure coefficients of the measured points on the surface of the model roof were obtained. Then the wind pressure coefficients at the joints were calculated by proper orthogonal decomposition (POD) method. The finite element analysis software ANSYS was used to analyze the wind-induced vibration response and the performance of vibration reduction. The results showed that negative wind pressure of overhanging eaves was large due to the superposition of upper and lower surface wind pressure. The effect of adding viscoelastic dampers on the corners of the eaves was remarkable for controlling the wind-induced vibration response of overhanging eaves. For the existing grid structures with certain degree of corrosion, the wind-induced response increased with the increase of corrosion depth, and the viscoelastic damper had an obvious effect on wind-induced vibration reduction.When the corrosion depth was less than 1 mm, the damping coefficient of root mean square of displacement response reached 10.3%~21.0%, and the damping coefficient of peak acceleration response reached 26.3%~39.6%.
2020, 50(5): 121-125,170.
doi: 10.13204/j.gyjz202005020
Abstract:
In order to realize the corrosion resistance of composite-aluminum space truss structure, the aluminum-alloy bolt-ball joint system is used. Considering that the high-strength bolts are the key points of joints, this paper adopt high-strength stainless steel-aluminum alloy as the materials of high-strength bolts, and study the flexural behavior of FRP-aluminum-alloy bolt-ball joint. According to the material of bolts and bearing area of sleeves, the joints are divided into four sections. Through the experimental, it studied the flexural bearing characteristics and failure mode under different parameters, got the moment-rotation curves, initial bending stiffness and ultimate tensile strength and so on. In the end, based on the existing classification system for the joints, it predicated that the aluminum-alloy bolt-ball joint can be used in the composite-aluminum space truss structure.
In order to realize the corrosion resistance of composite-aluminum space truss structure, the aluminum-alloy bolt-ball joint system is used. Considering that the high-strength bolts are the key points of joints, this paper adopt high-strength stainless steel-aluminum alloy as the materials of high-strength bolts, and study the flexural behavior of FRP-aluminum-alloy bolt-ball joint. According to the material of bolts and bearing area of sleeves, the joints are divided into four sections. Through the experimental, it studied the flexural bearing characteristics and failure mode under different parameters, got the moment-rotation curves, initial bending stiffness and ultimate tensile strength and so on. In the end, based on the existing classification system for the joints, it predicated that the aluminum-alloy bolt-ball joint can be used in the composite-aluminum space truss structure.
2020, 50(5): 126-132.
doi: 10.13204/j.gyjz202005021
Abstract:
In order to study the fire resistance of castellated composite beams, the fire resistance tests of castellated composite beams and composite beams were carried out. The performance of castellated composite beams at high temperature was studied. The effects of web opening and opening shape on the performance of composite beams under high temperature action were compared and analyzed. The results showed that the castellated composite beam was destroyed due to the flexural-torsional buckling of web under high temperature. Openings had a great influence on the temperature distribution of beams under fire, which significantly reduced the fire resistance limit of beams. The shape of openings had little effect on the fire resistance of castellated composite beams. The stability of circular castellated composite beams with openings was better than that of regular hexagonal castellated composite beams at high temperature.
In order to study the fire resistance of castellated composite beams, the fire resistance tests of castellated composite beams and composite beams were carried out. The performance of castellated composite beams at high temperature was studied. The effects of web opening and opening shape on the performance of composite beams under high temperature action were compared and analyzed. The results showed that the castellated composite beam was destroyed due to the flexural-torsional buckling of web under high temperature. Openings had a great influence on the temperature distribution of beams under fire, which significantly reduced the fire resistance limit of beams. The shape of openings had little effect on the fire resistance of castellated composite beams. The stability of circular castellated composite beams with openings was better than that of regular hexagonal castellated composite beams at high temperature.
2020, 50(5): 133-138.
doi: 10.13204/j.gyjz202005022
Abstract:
To study the properties of fracturing at the weld of cover plate reinforced joint, 3 local specimens of cover plate reinforce connection were tested under uniaxial tensile loading and analyzed by finite element model. The influence of thickness of cover plate and the material strength on fracture properties were studied. The results showed that the failure modes of the specimens could mainly be divided into two types; namely fracture of beam flange and fillet weld fracture at end of cover plate; when the cover-plate was thicker, the risk of cracking at weld increased; when the thickness of plate reached a certain value, the change of thickness had little effect on the bearing capacity of the specimen and the fracture performance of the weld; increasing the strength of the material could improve the bearing capacity of the specimen and reduce the plastic deformation capacity of the specimen, but had no obvious effect on the fracture properties of the weld; the fillet weld at the end of the cover plate had a higher risk of cracking than butt weld.
To study the properties of fracturing at the weld of cover plate reinforced joint, 3 local specimens of cover plate reinforce connection were tested under uniaxial tensile loading and analyzed by finite element model. The influence of thickness of cover plate and the material strength on fracture properties were studied. The results showed that the failure modes of the specimens could mainly be divided into two types; namely fracture of beam flange and fillet weld fracture at end of cover plate; when the cover-plate was thicker, the risk of cracking at weld increased; when the thickness of plate reached a certain value, the change of thickness had little effect on the bearing capacity of the specimen and the fracture performance of the weld; increasing the strength of the material could improve the bearing capacity of the specimen and reduce the plastic deformation capacity of the specimen, but had no obvious effect on the fracture properties of the weld; the fillet weld at the end of the cover plate had a higher risk of cracking than butt weld.
2020, 50(5): 139-144,120.
doi: 10.13204/j.gyjz202005023
Abstract:
The connection of square tube shear connector and H-shaped steel rib has been used in steel-concrete composite open-web sandwich plate recently. In order to study the mechanical properties of connection area, two full-scale specimens were manufactured to conduct contrast test and FEM analysis.The results showed that stiffening plate could make an obvious elastic-plastic behavior by seeting stiffening plate on the side wall of square tube shear connector. The stiffening plate could make a greater contribution to the tube's lateral stiffness and local stress concentration. Further finite element analysis showed that the width and thickness of stiffening plate, especially the plate width, had a significant effect on the stress distribution and lateral stiffness of shear connector.
The connection of square tube shear connector and H-shaped steel rib has been used in steel-concrete composite open-web sandwich plate recently. In order to study the mechanical properties of connection area, two full-scale specimens were manufactured to conduct contrast test and FEM analysis.The results showed that stiffening plate could make an obvious elastic-plastic behavior by seeting stiffening plate on the side wall of square tube shear connector. The stiffening plate could make a greater contribution to the tube's lateral stiffness and local stress concentration. Further finite element analysis showed that the width and thickness of stiffening plate, especially the plate width, had a significant effect on the stress distribution and lateral stiffness of shear connector.
2020, 50(5): 145-150,192.
doi: 10.13204/j.gyjz202005024
Abstract:
The finite element analysis model of concrete-filled square steel tubular (CFST) composite columns was established by using the sequential thermo-mechanical coupling analysis method and ABAQUS finite element software, and its reliability was verified by tests. On this basis, the factors affecting the fire resistance of concrete-filled square steel tubular columns were deeply analyzed. The results showed that the section area, load ratio, slenderness ratio and the thickness of fire protection layer of concrete were important factors affecting the mechanical properties of composite columns at high temperature. Under the effective fire protection, the composite column could bear greater axial force than the circular section and square section columns, the greater the load ratio, the lower the fire resistance limit of the composite column, the more significant the effect was when axial compression ratio n<0.5.
The finite element analysis model of concrete-filled square steel tubular (CFST) composite columns was established by using the sequential thermo-mechanical coupling analysis method and ABAQUS finite element software, and its reliability was verified by tests. On this basis, the factors affecting the fire resistance of concrete-filled square steel tubular columns were deeply analyzed. The results showed that the section area, load ratio, slenderness ratio and the thickness of fire protection layer of concrete were important factors affecting the mechanical properties of composite columns at high temperature. Under the effective fire protection, the composite column could bear greater axial force than the circular section and square section columns, the greater the load ratio, the lower the fire resistance limit of the composite column, the more significant the effect was when axial compression ratio n<0.5.
2020, 50(5): 151-157,108.
doi: 10.13204/j.gyjz202005025
Abstract:
In order to study the hysteretic behavior of the rotational friction damper under static cyclic loading, the quasi-static test of six rotational friction dampers was carried out. The working mechanism, hysteresis performance, energy dissipation capacity and friction coefficient were analyzed. The numerical simulation was carried out by using ABAQUS finite element software. The results were compared with the experimental results. The results showed that:1)rotational friction damper had full hysteretic curve and good energy dissipation capacity; 2)the friction of asbestos-free organic matter was relatively stable, and the friction dispersion of Al-Mg alloy and Cu-Zn alloy dampers was relatively large; 3)increasing the pre-tightening force of high-strength bolts and the number of elements of the damper could increase the friction force of the damper and effectively improve the energy dissipation capacity of the friction damper; 4)the energy dissipation capacity of Al-Mg alloy was better than that of Cu-Zn alloy and asbestos-free organic matter, the energy dissipation stability of asbestos-free organic matter was better than that of Cu-Zn alloy and Al-Mg alloy; 5)the friction coefficient of Cu-Zn alloy and Al-Mg alloy was greater than 0.3, the friction coefficient of asbestos-free organic matter was about 0.16; 6)the error between the finite element analysis results and the test values was small, the finite element model could simulate the test well.
In order to study the hysteretic behavior of the rotational friction damper under static cyclic loading, the quasi-static test of six rotational friction dampers was carried out. The working mechanism, hysteresis performance, energy dissipation capacity and friction coefficient were analyzed. The numerical simulation was carried out by using ABAQUS finite element software. The results were compared with the experimental results. The results showed that:1)rotational friction damper had full hysteretic curve and good energy dissipation capacity; 2)the friction of asbestos-free organic matter was relatively stable, and the friction dispersion of Al-Mg alloy and Cu-Zn alloy dampers was relatively large; 3)increasing the pre-tightening force of high-strength bolts and the number of elements of the damper could increase the friction force of the damper and effectively improve the energy dissipation capacity of the friction damper; 4)the energy dissipation capacity of Al-Mg alloy was better than that of Cu-Zn alloy and asbestos-free organic matter, the energy dissipation stability of asbestos-free organic matter was better than that of Cu-Zn alloy and Al-Mg alloy; 5)the friction coefficient of Cu-Zn alloy and Al-Mg alloy was greater than 0.3, the friction coefficient of asbestos-free organic matter was about 0.16; 6)the error between the finite element analysis results and the test values was small, the finite element model could simulate the test well.
2020, 50(5): 158-164,138.
doi: 10.13204/j.gyjz202005026
Abstract:
There are two modelling analysis methods for hybrid structure composed of space truss and concrete, one method is that the space truss and concrete supporting structure are considered separately, another method is collaborative modelling of the space truss and concrete supporting structure. The problems of the modelling analysis of the hybrid structure were introduced firstly. Based on the conception that complete design index met the specification requirements of GB 50011-2010, two modelling analysis methods of the hybrid structure were discussed for judging design index and designing reinforcing bar of the concrete members.
There are two modelling analysis methods for hybrid structure composed of space truss and concrete, one method is that the space truss and concrete supporting structure are considered separately, another method is collaborative modelling of the space truss and concrete supporting structure. The problems of the modelling analysis of the hybrid structure were introduced firstly. Based on the conception that complete design index met the specification requirements of GB 50011-2010, two modelling analysis methods of the hybrid structure were discussed for judging design index and designing reinforcing bar of the concrete members.
2020, 50(5): 165-170.
doi: 10.13204/j.gyjz202005027
Abstract:
In order to study the dynamic compression mechanical properties of basalt fiber reinforced cementitious composites (BFRCC), different strain rates were applied to three different fiber content BFRCC specimens by using ϕ 50 mm Split Hopkinson Pressure Bar (SHPB) device. Under the dynamic impact compression test, the energy absorption capacity and toughness index of each group of specimens were calculated by the principle of energy conservation. The results showed that the dynamic compressive strength, fracture state and toughness coefficient of cement-based composites with different fiber contents had obvious strain rate effects; with the increase of fiber content,under similar strain rate conditions, the absorbed energy of the specimen showed an upward trend; the toughness coefficient increased with the increase of fiber content.
In order to study the dynamic compression mechanical properties of basalt fiber reinforced cementitious composites (BFRCC), different strain rates were applied to three different fiber content BFRCC specimens by using ϕ 50 mm Split Hopkinson Pressure Bar (SHPB) device. Under the dynamic impact compression test, the energy absorption capacity and toughness index of each group of specimens were calculated by the principle of energy conservation. The results showed that the dynamic compressive strength, fracture state and toughness coefficient of cement-based composites with different fiber contents had obvious strain rate effects; with the increase of fiber content,under similar strain rate conditions, the absorbed energy of the specimen showed an upward trend; the toughness coefficient increased with the increase of fiber content.
2020, 50(5): 171-176.
doi: 10.13204/j.gyjz202005028
Abstract:
Aiming at the problem that the ductility of the prestressed CFRP strengthened members is obviously reduced, the safety reserve is insufficient, and there is no obvious omen before the damage, a prestressed CFRP bending reinforcement design method based on early warning theory was proposed. In this method, a clear early warning signal can be given by the break of the self-warning fuse when the actual safety reserve of the reinforcing member is lower than the designed target value. In order to study whether the component after reinforcement by using the design method can emit a clear early warning signal and whether the safety reserve can meet design requirements by defining reasonable yield point of components, four reinforced concrete beams were produced and tested for bending resistance. The test results showed that, when the safety reserve was lower than the design value, the fuse was detached from the beam after the fuse fractured, and an early warning signal was issued; the yield point of the component determined by the farthest method and the mapping method was consistent with the warning point. After evaluation by K0 and Keq, the yield point of the pre-warning point as the reinforcing member was more reasonable than the traditional method, and the safety reserve of the components could meet the requirements.
Aiming at the problem that the ductility of the prestressed CFRP strengthened members is obviously reduced, the safety reserve is insufficient, and there is no obvious omen before the damage, a prestressed CFRP bending reinforcement design method based on early warning theory was proposed. In this method, a clear early warning signal can be given by the break of the self-warning fuse when the actual safety reserve of the reinforcing member is lower than the designed target value. In order to study whether the component after reinforcement by using the design method can emit a clear early warning signal and whether the safety reserve can meet design requirements by defining reasonable yield point of components, four reinforced concrete beams were produced and tested for bending resistance. The test results showed that, when the safety reserve was lower than the design value, the fuse was detached from the beam after the fuse fractured, and an early warning signal was issued; the yield point of the component determined by the farthest method and the mapping method was consistent with the warning point. After evaluation by K0 and Keq, the yield point of the pre-warning point as the reinforcing member was more reasonable than the traditional method, and the safety reserve of the components could meet the requirements.
2020, 50(5): 177-185.
doi: 10.13204/j.gyjz202005029
Abstract:
The design of long-span curved surface structure is the difficulty of spatial structure. Especially in the curtain wall design, the connection with the main structure needs to be considered, and there are few cases. The paper described the steel structure design process for long-span curved surface curtain walls of Shanghai International Aviation Service Center. The upper part of the curtain wall connected the main structure of the tower, and the lower part diverged horizontally to the podium, which connected the two with a natural curved surface, formed a skirt effect, and realized the unity of architectural aesthetics and structural design concepts. In the long-span curved surface part, the grid was formed by parameterization, and the longitudinal open web quilting frame and the secondary beam were determined. In the middle part, the cross cable system was designed to form the overall stiffness in the plane. The steel structure of curtain wall was connected with the main body through tree column and tower extension rod, forming a complete structural system. Finally, finite element analysis software was used to perform elastic static analysis, static geometric non-linear analysis, elastic time-history analysis, and checking verification of key members, all indicators could meet the construction requirements.
The design of long-span curved surface structure is the difficulty of spatial structure. Especially in the curtain wall design, the connection with the main structure needs to be considered, and there are few cases. The paper described the steel structure design process for long-span curved surface curtain walls of Shanghai International Aviation Service Center. The upper part of the curtain wall connected the main structure of the tower, and the lower part diverged horizontally to the podium, which connected the two with a natural curved surface, formed a skirt effect, and realized the unity of architectural aesthetics and structural design concepts. In the long-span curved surface part, the grid was formed by parameterization, and the longitudinal open web quilting frame and the secondary beam were determined. In the middle part, the cross cable system was designed to form the overall stiffness in the plane. The steel structure of curtain wall was connected with the main body through tree column and tower extension rod, forming a complete structural system. Finally, finite element analysis software was used to perform elastic static analysis, static geometric non-linear analysis, elastic time-history analysis, and checking verification of key members, all indicators could meet the construction requirements.
2020, 50(5): 186-192.
doi: 10.13204/j.gyjz202005030
Abstract:
The roof system of the four pavilions and one center project in Nanchong needs to create a cultural impression of the silk capital and show the curved shape of "butterfly flying", it brings many challenges to the construction of the roof which is different from the conventional roof. In this project, the principle of differential approximation was used to transform free-form surface into a combination of surface and bevel. Through BIM technology, the design and installation of free-form surface metal roof panel was effectively solved. The problem of coordinated displacement of metal roof and main structure was solved by setting plug-in movable joints at adjacent sections of main keel. Through the comprehensive application of measurement data and BIM model, the size of connector was automatically generated. A kind of fast and convenient measuring scale was designed and manufactured, which solves the problem of free-form surface space measurement. The project used the cruciform guiding rule and rubber gasket to install the aluminum plate,which could ensure the slot width and smoothness between plates. Through the innovation and comprehensive application of techniques, the construction accuracy was improved, the construction period was shortened, and the installation cost was saved.
The roof system of the four pavilions and one center project in Nanchong needs to create a cultural impression of the silk capital and show the curved shape of "butterfly flying", it brings many challenges to the construction of the roof which is different from the conventional roof. In this project, the principle of differential approximation was used to transform free-form surface into a combination of surface and bevel. Through BIM technology, the design and installation of free-form surface metal roof panel was effectively solved. The problem of coordinated displacement of metal roof and main structure was solved by setting plug-in movable joints at adjacent sections of main keel. Through the comprehensive application of measurement data and BIM model, the size of connector was automatically generated. A kind of fast and convenient measuring scale was designed and manufactured, which solves the problem of free-form surface space measurement. The project used the cruciform guiding rule and rubber gasket to install the aluminum plate,which could ensure the slot width and smoothness between plates. Through the innovation and comprehensive application of techniques, the construction accuracy was improved, the construction period was shortened, and the installation cost was saved.
2020, 50(5): 193-197,57.
doi: 10.13204/j.gyjz202005031
Abstract:
As a special radioactive waste, there is no corresponding standards or technical specifications on the safe disposal of waste sealed sources in China up to now. According to the present situation of waste sealed sources in China, most of them are low and middle level radioactive waste. In order to solve the problem about the disposal of the waste sealed sources in China, the reception standard and disposal measures of waste sealed sources for the disposal site should be determined. In order to provide a reliable scientific basis for the safe disposal of waste sealed sources in China, the management regulations and practice experiences about waste sealed sources issuesed by the International Atomic Energy Agency, the United States and France were summarized.
As a special radioactive waste, there is no corresponding standards or technical specifications on the safe disposal of waste sealed sources in China up to now. According to the present situation of waste sealed sources in China, most of them are low and middle level radioactive waste. In order to solve the problem about the disposal of the waste sealed sources in China, the reception standard and disposal measures of waste sealed sources for the disposal site should be determined. In order to provide a reliable scientific basis for the safe disposal of waste sealed sources in China, the management regulations and practice experiences about waste sealed sources issuesed by the International Atomic Energy Agency, the United States and France were summarized.
2020, 50(5): 198-202.
doi: 10.13204/j.gyjz202005032
Abstract:
Railway heritage is a complex industrial heritage with many important values. The activation and utilization of railway heritage in Western countries began in the United Kingdom in the 1970s, and has since been widespread in Europe and the United States. They have accumulated a lot of experience and many successful cases. The activation and utilization of railway heritage is mainly reflected in the functional replacement of railway station buildings, the transformation and utilization of railway facilities and the regional renewal of the heritage network. Compared with western countries, China started late in this field and has many problems. It should learn from foreign experience to achieve scientific and rational conservation and utilization.
Railway heritage is a complex industrial heritage with many important values. The activation and utilization of railway heritage in Western countries began in the United Kingdom in the 1970s, and has since been widespread in Europe and the United States. They have accumulated a lot of experience and many successful cases. The activation and utilization of railway heritage is mainly reflected in the functional replacement of railway station buildings, the transformation and utilization of railway facilities and the regional renewal of the heritage network. Compared with western countries, China started late in this field and has many problems. It should learn from foreign experience to achieve scientific and rational conservation and utilization.
