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2021 Vol. 51, No. 12
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2021, 51(12): 1-6.
doi: 10.13204/j.gyjzG21120605
Abstract:
This paper took the world's first HPR1000 nuclear power plant(NPP) of Fuqing 5 unit and Pakistan K2 unit in Karachi as the research object. Firstly, based on the ABAQUS finite element model, the overall test and theoretical analysis of containment structure of the HPR1000 NPP were carried out, the damage process of the containment structure under the LOCA accident was studied, and the weak links of the containment were clarified. According to NB/T 20017-2010 "Structural Integrity Test of Containments of Pressurized Water Reactor Nuclear Power Plants", the displacement test data of SIT test was analyzed, and the rationalization suggestions for the above standards were proposed according to the test process and results. The results showed that the test parameters of Fuqing 5 unit and Karachi K2 unit of NPP had the same trend with the test pressure; the test results were consistent with the theoretical analysis, and the displacement test results of the two units both met the standard design requirements of NB/T 20017-2010. It was suggested to increase the number of measuring points at the expected maximum horizontal diameter deformation and vertical deformation of the cylinder in the supplementary radial deformation measurement in NB/T 20017-2010, and increase the frequency of measuring points and data collection near the gate of the equipment.
This paper took the world's first HPR1000 nuclear power plant(NPP) of Fuqing 5 unit and Pakistan K2 unit in Karachi as the research object. Firstly, based on the ABAQUS finite element model, the overall test and theoretical analysis of containment structure of the HPR1000 NPP were carried out, the damage process of the containment structure under the LOCA accident was studied, and the weak links of the containment were clarified. According to NB/T 20017-2010 "Structural Integrity Test of Containments of Pressurized Water Reactor Nuclear Power Plants", the displacement test data of SIT test was analyzed, and the rationalization suggestions for the above standards were proposed according to the test process and results. The results showed that the test parameters of Fuqing 5 unit and Karachi K2 unit of NPP had the same trend with the test pressure; the test results were consistent with the theoretical analysis, and the displacement test results of the two units both met the standard design requirements of NB/T 20017-2010. It was suggested to increase the number of measuring points at the expected maximum horizontal diameter deformation and vertical deformation of the cylinder in the supplementary radial deformation measurement in NB/T 20017-2010, and increase the frequency of measuring points and data collection near the gate of the equipment.
2021, 51(12): 7-12,73.
doi: 10.13204/j.gyjzG21101116
Abstract:
The overall strategy and the design scheme of the outer containment and shield building for the HPR1000 nuclear island of the independent third generation PWR against large commercial aircraft impact were introduced. The 3D finite element anlysis models of large commercial aircraft and nuclear island building were established and the numerical analysis method of explicit dynamics was used to simulate the aircraft impact on the outer containment of nuclear island. The numerical analysis results showed that the outer containment of HPR1000 could maintain the bearing capacity of the shell structure under typical adverse impact location of large-scale commercial aircraft, play the role of shielding external events, and ensure the integrity of the inner containment.
The overall strategy and the design scheme of the outer containment and shield building for the HPR1000 nuclear island of the independent third generation PWR against large commercial aircraft impact were introduced. The 3D finite element anlysis models of large commercial aircraft and nuclear island building were established and the numerical analysis method of explicit dynamics was used to simulate the aircraft impact on the outer containment of nuclear island. The numerical analysis results showed that the outer containment of HPR1000 could maintain the bearing capacity of the shell structure under typical adverse impact location of large-scale commercial aircraft, play the role of shielding external events, and ensure the integrity of the inner containment.
2021, 51(12): 13-18.
doi: 10.13204/j.gyjzG21102014
Abstract:
Based on the engineering practice of nuclear island building structural design, the paper studied the failure modes of concrete barrier as well as the structural design method under impact load. Various failure modes for reinforced concrete were introduced under the impact load. In addition, the empirical formulation and typical calculation example recommended by the civil engineering design codes for nuclear power plants at home and abroad were presented to evaluate the local effect for the concrete. Aiming at the analysis of the overall effect of reinforced concrete walls and slabs under impact load, the paper introduced the concentrated mass model for single degree freedom system commonly used in engineering practice, which is simple and mature. For the concrete barrier structure with large load and complex support relation, the elasto-plastic time-history analysis could be used to study the bearing capacity and failure mode of the concrete barrier structure more accurately. Finally, the process and method of numerical simulation analysis were introduced with the example of drop analysis for the head assembly of the pressure vessel in the reactor building.
Based on the engineering practice of nuclear island building structural design, the paper studied the failure modes of concrete barrier as well as the structural design method under impact load. Various failure modes for reinforced concrete were introduced under the impact load. In addition, the empirical formulation and typical calculation example recommended by the civil engineering design codes for nuclear power plants at home and abroad were presented to evaluate the local effect for the concrete. Aiming at the analysis of the overall effect of reinforced concrete walls and slabs under impact load, the paper introduced the concentrated mass model for single degree freedom system commonly used in engineering practice, which is simple and mature. For the concrete barrier structure with large load and complex support relation, the elasto-plastic time-history analysis could be used to study the bearing capacity and failure mode of the concrete barrier structure more accurately. Finally, the process and method of numerical simulation analysis were introduced with the example of drop analysis for the head assembly of the pressure vessel in the reactor building.
2021, 51(12): 19-23.
doi: 10.13204/j.gyjzG21102025
Abstract:
Due to the uncertainty of earthquake, the possibility of earthquake exceeding the design level may occure, so it is necessary to master the capacity of nuclear power plants to resist earthquake exceeding the design level. The aseismic margin analysis method was used internationally to evaluate the bearing margin of nuclear power plants subjected to earthquakes beyond the design level. The SFA method was an effective calculation method with the high degree of confidence and low probability of the failure value (HCLPF value) for nuclear power plants, in which the median aseismic capacity and uncertainty coefficient of the structure, system and members were calculated by the SFA according to obtained data, and then the HCLPF value was also calculated. A calculation method of HCLPF based on non-central distribution t was proposed, which did not need to assume the distribution of cognitive uncertainty, to avoid the problem that the value of relevant parameters of cognitive uncertainty had a great impact on the calculation results of HCLPF.
Due to the uncertainty of earthquake, the possibility of earthquake exceeding the design level may occure, so it is necessary to master the capacity of nuclear power plants to resist earthquake exceeding the design level. The aseismic margin analysis method was used internationally to evaluate the bearing margin of nuclear power plants subjected to earthquakes beyond the design level. The SFA method was an effective calculation method with the high degree of confidence and low probability of the failure value (HCLPF value) for nuclear power plants, in which the median aseismic capacity and uncertainty coefficient of the structure, system and members were calculated by the SFA according to obtained data, and then the HCLPF value was also calculated. A calculation method of HCLPF based on non-central distribution t was proposed, which did not need to assume the distribution of cognitive uncertainty, to avoid the problem that the value of relevant parameters of cognitive uncertainty had a great impact on the calculation results of HCLPF.
2021, 51(12): 24-30,6.
doi: 10.13204/j.gyjzG21102012
Abstract:
The nuclear island buildings of HTR-PM adopts reinforced concrete slab and shell structure. It is nuclear safety related, and the seismic classification is class I. When the nuclear power plant is subjected to the ultimate safe earthquake (SL-2) (once every 10 000 years), the structure is in the state of basic elasticity, and when it is subjected to the safe earthquake (SL-1) (once every 500 years) or below, the structure is in the state of complete elasticlity. Through the quasi-static tests of shear walls, the limit value of displacement angle was obtained and had been used as the control index of structural performance; at the same time, the calculation method of seismic response of the nuclear island buildings and the calculation formulas of in-plane bearing capacity of reinforced concrete slab shell structure were proposed. The above seismic performance objectives and design methods were adopted in the seismic design of the nuclear island buildings. Finally, through shaking table tests, it was proved that the nuclear island buildings with seismic design method proposed in this paper had good seismic performance and could meet the requirements of nuclear safety function. The calculation formulas of in-plane bearing capacity of reinforced concrete slab and shell structure proposed in this paper had been adopted by relevant standards.
The nuclear island buildings of HTR-PM adopts reinforced concrete slab and shell structure. It is nuclear safety related, and the seismic classification is class I. When the nuclear power plant is subjected to the ultimate safe earthquake (SL-2) (once every 10 000 years), the structure is in the state of basic elasticity, and when it is subjected to the safe earthquake (SL-1) (once every 500 years) or below, the structure is in the state of complete elasticlity. Through the quasi-static tests of shear walls, the limit value of displacement angle was obtained and had been used as the control index of structural performance; at the same time, the calculation method of seismic response of the nuclear island buildings and the calculation formulas of in-plane bearing capacity of reinforced concrete slab shell structure were proposed. The above seismic performance objectives and design methods were adopted in the seismic design of the nuclear island buildings. Finally, through shaking table tests, it was proved that the nuclear island buildings with seismic design method proposed in this paper had good seismic performance and could meet the requirements of nuclear safety function. The calculation formulas of in-plane bearing capacity of reinforced concrete slab and shell structure proposed in this paper had been adopted by relevant standards.
2021, 51(12): 31-36.
doi: 10.13204/j.gyjzG21102017
Abstract:
The foundation soil profile and corresponding consistent input motion, simulation of pile foundation, design seismic motion and the input level are the most important influence factors on the seismic response analysis of NI buildings with pile foundation. Base on the site soil properties of a typical non-bedrock nuclear power plant, the seismic response analysis model were developed with piles, soil and NI buildings. The equivalent linearization method was introduced to consider the nonlinear dynamic properties, and the development of soil profile and corresponding consistent input motion were proposed. The influences of simulation method of pile foundation, design seismic motion and input level on the seismic response of NI buildings with pile foundation were studied. The research showed that, the input motion should be consistent with the soil profiles used in seismic analysis of non-bedrock NI building; piles might be modeled by solid element which could simulate the seismic response more accurately; and there was small influence of equivalent seismic motion at different input level on the seismic response of NI building, but influence are significant due to the different design seismic motion at different level. The research works are of great importance to the design of nuclear island with pile foundation, and also the site selection of non-bedrock nuclear power plant.
The foundation soil profile and corresponding consistent input motion, simulation of pile foundation, design seismic motion and the input level are the most important influence factors on the seismic response analysis of NI buildings with pile foundation. Base on the site soil properties of a typical non-bedrock nuclear power plant, the seismic response analysis model were developed with piles, soil and NI buildings. The equivalent linearization method was introduced to consider the nonlinear dynamic properties, and the development of soil profile and corresponding consistent input motion were proposed. The influences of simulation method of pile foundation, design seismic motion and input level on the seismic response of NI buildings with pile foundation were studied. The research showed that, the input motion should be consistent with the soil profiles used in seismic analysis of non-bedrock NI building; piles might be modeled by solid element which could simulate the seismic response more accurately; and there was small influence of equivalent seismic motion at different input level on the seismic response of NI building, but influence are significant due to the different design seismic motion at different level. The research works are of great importance to the design of nuclear island with pile foundation, and also the site selection of non-bedrock nuclear power plant.
2021, 51(12): 37-40,63.
doi: 10.13204/j.gyjzG21102015
Abstract:
In the structural design of a nuclear safety related plant, it is necessary to consider the impact of heavy container falling. Laying vibration reduction materials (such as autoclaved aerated concrete) at the falling position to form a buffer-layer can effectively reduce the impact caused by falling. Based on the vibration reduction material test and structural scale test, the nonlinear dynamic finite element analysis of the buffer-layer of the plant under impact load was carried out by using ANSYS/LS-DYNA, the constitutive model and its parameters suitable for autoclaved aerated concrete were determined, the key factors affecting the finite element analysis results were explored, and the reduction coefficient considering the influence of stacking was analyzed and defined. The finite element analysis results were in good agreement with the experimental results. Finally, according to the determined constitutive model, parameters and methods, the finite element model of the whole plant was established for impact calculation and analysis, and the vibration reduction design and vibration reduction effect were determined.
In the structural design of a nuclear safety related plant, it is necessary to consider the impact of heavy container falling. Laying vibration reduction materials (such as autoclaved aerated concrete) at the falling position to form a buffer-layer can effectively reduce the impact caused by falling. Based on the vibration reduction material test and structural scale test, the nonlinear dynamic finite element analysis of the buffer-layer of the plant under impact load was carried out by using ANSYS/LS-DYNA, the constitutive model and its parameters suitable for autoclaved aerated concrete were determined, the key factors affecting the finite element analysis results were explored, and the reduction coefficient considering the influence of stacking was analyzed and defined. The finite element analysis results were in good agreement with the experimental results. Finally, according to the determined constitutive model, parameters and methods, the finite element model of the whole plant was established for impact calculation and analysis, and the vibration reduction design and vibration reduction effect were determined.
2021, 51(12): 41-48.
doi: 10.13204/j.gyjzG21101113
Abstract:
Taking the nuclear island plant of a million kilowatt PWR nuclear power plant as the research object, using the overall isolation technical scheme of nuclear island raft foundation, the seismic response of nuclear island plant with three common types of base isolation bearings, including multi lead-core rubber bearing(MLRB), eradi quake system bearing(EQS), triple friction pendulum bearing(TFPB), was compared and analyzed under different periods of ground motions. The floor acceleration response spectrum of the above structure considering the effect of soil-structure interaction (SSI) was discussed. The analysis results showed that the isolation performance of TFPB under short period ground motion was better than that of the other two types of isolation bearings. The MLRB could meet the requirements of isolation performance under different periodic ground motions. Based on the influence analysis of homogeneous foundation soil, the SSI effect of non-isolated structure was significantly greater than that of isolated structure, and the SSI effect of isolated structure was less than 5%. The floor response spectrum of isolated structure with EQS or TFPB considering SSI effect could not be completely enveloped by the floor response spectrum without considering SSI effect in low frequency stage.
Taking the nuclear island plant of a million kilowatt PWR nuclear power plant as the research object, using the overall isolation technical scheme of nuclear island raft foundation, the seismic response of nuclear island plant with three common types of base isolation bearings, including multi lead-core rubber bearing(MLRB), eradi quake system bearing(EQS), triple friction pendulum bearing(TFPB), was compared and analyzed under different periods of ground motions. The floor acceleration response spectrum of the above structure considering the effect of soil-structure interaction (SSI) was discussed. The analysis results showed that the isolation performance of TFPB under short period ground motion was better than that of the other two types of isolation bearings. The MLRB could meet the requirements of isolation performance under different periodic ground motions. Based on the influence analysis of homogeneous foundation soil, the SSI effect of non-isolated structure was significantly greater than that of isolated structure, and the SSI effect of isolated structure was less than 5%. The floor response spectrum of isolated structure with EQS or TFPB considering SSI effect could not be completely enveloped by the floor response spectrum without considering SSI effect in low frequency stage.
2021, 51(12): 49-55.
doi: 10.13204/j.gyjzG21102016
Abstract:
The support of reactor pressure vessel is the key part in the structural design of nuclear power plant. The wall at support position of reactor pressure vessel of Huaneng Shandong Shidaowan high temperature reactor demonstration project was taken as the research object. According to the theory of local pressure, combined with the concrete stress characteristics of the wall at support position of reactor pressure vessel, the multiaxial strength criterion of concrete was used to analyze the local concrete stress of the side frame,the lower frame and the bolt group in the composite stress state. According to the finite element elastic and elastic-plastic calculation results and the structural analysis, the shortcomings of the original design scheme were found and the optimization suggestions were put forward. According to the optimized design scheme, the bearing capacity and construction feasibility of the wall were analyzed and demonstrated again to ensure that the area met the requirements of the current national standards. Most of the research results in the paper were adopted by the demonstration project.
The support of reactor pressure vessel is the key part in the structural design of nuclear power plant. The wall at support position of reactor pressure vessel of Huaneng Shandong Shidaowan high temperature reactor demonstration project was taken as the research object. According to the theory of local pressure, combined with the concrete stress characteristics of the wall at support position of reactor pressure vessel, the multiaxial strength criterion of concrete was used to analyze the local concrete stress of the side frame,the lower frame and the bolt group in the composite stress state. According to the finite element elastic and elastic-plastic calculation results and the structural analysis, the shortcomings of the original design scheme were found and the optimization suggestions were put forward. According to the optimized design scheme, the bearing capacity and construction feasibility of the wall were analyzed and demonstrated again to ensure that the area met the requirements of the current national standards. Most of the research results in the paper were adopted by the demonstration project.
2021, 51(12): 56-63.
doi: 10.13204/j.gyjzG21101111
Abstract:
According to the project requirements of HTR-PM600, the single-sided fire resistance test of double-steel-plate concrete shear wall (SC shear wall) structure in nuclear power plant was carried out. Based on the single-sided ISO834 standard fire test of 4 typical specimens under the same axial compression ratio, the effects of wall thickness of SC shear wall, the thickness of steel plates on otherside, tie rod structure, etc. on the thermal insulation property of specimens were analyzed and compared. The temperature field distribution across the cross section, vertical deformation, damage mode, fire resistance, etc. of the SC shear walls subjected to sigle-sided fire exposure were ascertained. The test results showed that the steel plates on the fire surface of the four SC shear wall specimens were slightly damaged, but the steel plates on the back fire surface were basically intact. The total thickness of shear wall section had a significant effect on the fire resistance of one side under fire condition, and the thickness of outer steel plate on fire side also had a certain effect on the temperature difference between the furnace temperature and the concrete on fire surface. SC shear wall structure had good vertical bearing capacity and fire resistance under large temperature difference on both sides.
According to the project requirements of HTR-PM600, the single-sided fire resistance test of double-steel-plate concrete shear wall (SC shear wall) structure in nuclear power plant was carried out. Based on the single-sided ISO834 standard fire test of 4 typical specimens under the same axial compression ratio, the effects of wall thickness of SC shear wall, the thickness of steel plates on otherside, tie rod structure, etc. on the thermal insulation property of specimens were analyzed and compared. The temperature field distribution across the cross section, vertical deformation, damage mode, fire resistance, etc. of the SC shear walls subjected to sigle-sided fire exposure were ascertained. The test results showed that the steel plates on the fire surface of the four SC shear wall specimens were slightly damaged, but the steel plates on the back fire surface were basically intact. The total thickness of shear wall section had a significant effect on the fire resistance of one side under fire condition, and the thickness of outer steel plate on fire side also had a certain effect on the temperature difference between the furnace temperature and the concrete on fire surface. SC shear wall structure had good vertical bearing capacity and fire resistance under large temperature difference on both sides.
2021, 51(12): 64-67,78.
doi: 10.13204/j.gyjzg21102026
Abstract:
Combined with the technical requirement of standards at home and aborad on structural strength tests for prestressed concrete containments, the test cycle, the process and the acceptance criteria were compared, the differences of standards were pointed out. Combined with a structural strength test of raising pressure and descending pressure in a practical project, some suggestions on the strength test in the structural integrity test of containments were proposed, which would provide reference to the successful implementation of the subsequent of structure strength test for containments in China.
Combined with the technical requirement of standards at home and aborad on structural strength tests for prestressed concrete containments, the test cycle, the process and the acceptance criteria were compared, the differences of standards were pointed out. Combined with a structural strength test of raising pressure and descending pressure in a practical project, some suggestions on the strength test in the structural integrity test of containments were proposed, which would provide reference to the successful implementation of the subsequent of structure strength test for containments in China.
2021, 51(12): 68-73.
doi: 10.13204/j.gyjzG21102020
Abstract:
The pressurization test of containment, which has the characteristics of high risk, complex process and long holding time, is one of the most important special projects during construction and operation period. For the sake of increasing the economy capacity units and saving the maintenance time, an effective approach is to increase the pressurization rate. However, the approach is likely to cause the increase of the stability time of air in containment and the decrease of the accuracy and reliability of the containment leakage test. Therefore, it is necessary to study the influence of the increase of pressurization rate on the stability of air. Taking the M310 reactor as an example, the theory of computational fluid dynamics was adopted to simulate the whole process of the pressurization test. When the rate of pressurization was 15 kPa/h and 40 kPa/h, the variation of the internal pressure, velocity and temperature of the containment was analyzed, and the influence of the pressurization rate on the stability of air in containment was investigated. It was shown by the results that if the rate of pressurization was raised to 40 kPa/h, the internal air of the containment was stable after reaching the test pressure for 4 h.
The pressurization test of containment, which has the characteristics of high risk, complex process and long holding time, is one of the most important special projects during construction and operation period. For the sake of increasing the economy capacity units and saving the maintenance time, an effective approach is to increase the pressurization rate. However, the approach is likely to cause the increase of the stability time of air in containment and the decrease of the accuracy and reliability of the containment leakage test. Therefore, it is necessary to study the influence of the increase of pressurization rate on the stability of air. Taking the M310 reactor as an example, the theory of computational fluid dynamics was adopted to simulate the whole process of the pressurization test. When the rate of pressurization was 15 kPa/h and 40 kPa/h, the variation of the internal pressure, velocity and temperature of the containment was analyzed, and the influence of the pressurization rate on the stability of air in containment was investigated. It was shown by the results that if the rate of pressurization was raised to 40 kPa/h, the internal air of the containment was stable after reaching the test pressure for 4 h.
2021, 51(12): 74-78.
doi: 10.13204/j.gyjzG21102021
Abstract:
The failure mechanics of containment subjected to internal pressure were studied, and the functional and structural failure criteria were determined. Then, based on the concrete damage model, the nonlinear finite element analysis of the HPR1000 containment was carried out in order to research the failure process and determine the ultimate bearing capability of the containment subjected to internal pressure. The results showed that the damage and cracking first occurred near the equipment hatch when the inner pressure was increased to 2.5 times of the design pressure, indicating that the containment entered the plastic state. When the inner pressure was increased to 2.713 times of the design pressure, the steel lining began to be teared,which indicated that the containment reached the functional failure limit state. When the inner pressure was increased to 2.857 times of the design pressure, the concrete near the equipment hatch was damaged severely, and the failure occurred because of the considerable local displacement. It was illustrated that the containment reached the structural failure limit state.
The failure mechanics of containment subjected to internal pressure were studied, and the functional and structural failure criteria were determined. Then, based on the concrete damage model, the nonlinear finite element analysis of the HPR1000 containment was carried out in order to research the failure process and determine the ultimate bearing capability of the containment subjected to internal pressure. The results showed that the damage and cracking first occurred near the equipment hatch when the inner pressure was increased to 2.5 times of the design pressure, indicating that the containment entered the plastic state. When the inner pressure was increased to 2.713 times of the design pressure, the steel lining began to be teared,which indicated that the containment reached the functional failure limit state. When the inner pressure was increased to 2.857 times of the design pressure, the concrete near the equipment hatch was damaged severely, and the failure occurred because of the considerable local displacement. It was illustrated that the containment reached the structural failure limit state.
2021, 51(12): 79-83.
doi: 10.13204/j.gyjzG21120604
Abstract:
The profiled steel sheet roof system with standing seam 360 panels has been widely applied in China in recent years. Due to strong locking modes between ribs and supports, the panels are of stronger wind resistance compared with concealed gusset panels, 180-degree seams and aluminum-magnesium-manganese panels. Because of the limit of rib height, the conventional panels cannot meet the requirements of wind-uplift resistance and deformation for super typhoons. Analyzing the structure of the panels and the statistics of wind-uplift resistance for conventional panels, improved methods for the panels was presented. The capacity of the roof system with standing seam 360 panels of being improved by different measures was verified by tests of wind-uplift resistance. The test results showed the wind resistance of the roof system with high rib panels were greatly improved when other conditions remained the same.
The profiled steel sheet roof system with standing seam 360 panels has been widely applied in China in recent years. Due to strong locking modes between ribs and supports, the panels are of stronger wind resistance compared with concealed gusset panels, 180-degree seams and aluminum-magnesium-manganese panels. Because of the limit of rib height, the conventional panels cannot meet the requirements of wind-uplift resistance and deformation for super typhoons. Analyzing the structure of the panels and the statistics of wind-uplift resistance for conventional panels, improved methods for the panels was presented. The capacity of the roof system with standing seam 360 panels of being improved by different measures was verified by tests of wind-uplift resistance. The test results showed the wind resistance of the roof system with high rib panels were greatly improved when other conditions remained the same.
2021, 51(12): 84-89.
doi: 10.13204/j.gyjzG21102018
Abstract:
For the YX51-380-760 corrugated roof plate which has been widely applied in the metal roof, in order to confirm its theoretical and actual wind-uplift resistance and the improvement degree of wind resistance after reinforcement,the paper analyzed the structural feature and wind-uplift resistance capacity of this type of plate. then the work of checking the theoretical wind-uplift resistance capacity was conducted on an actual project, and the reasons for the low bearing capacity of the prototype system in the wind resistance test were amalysed. The targeted reinforcement measures were put forward, and the wind resistance test was carried out to verify the system after the reinforcement measures were taken. The test results showed that the wind-uplift resistance of the reinforced system was greatly improved compared with the prototype plate system.
For the YX51-380-760 corrugated roof plate which has been widely applied in the metal roof, in order to confirm its theoretical and actual wind-uplift resistance and the improvement degree of wind resistance after reinforcement,the paper analyzed the structural feature and wind-uplift resistance capacity of this type of plate. then the work of checking the theoretical wind-uplift resistance capacity was conducted on an actual project, and the reasons for the low bearing capacity of the prototype system in the wind resistance test were amalysed. The targeted reinforcement measures were put forward, and the wind resistance test was carried out to verify the system after the reinforcement measures were taken. The test results showed that the wind-uplift resistance of the reinforced system was greatly improved compared with the prototype plate system.
2021, 51(12): 90-95,122.
doi: 10.13204/j.gyjzG21120602
Abstract:
Based on the analysis of the basic characteristics of the buckled metal roof panel, the weak points of its wind-uplift resistance were theoretically analyzed. It was pointed out that the weak link was that the stiffness of metal plate was insufficient and the redundancy of fastening method was insufficient. Wind-uplift test on its prototype plate system showed that mid-span deformations of the plate were too large when the system was damaged and the initial damage occured at the fastening position. According to the analysis of the weak points of wind-uplift resistance and the failure characteristics of the prototype plate system, the wind-uplift resistance of the strengthened plate system was tested. Comparing with the wind-uplift resistance capacity of the prototype system before reinforcement, the results of series tests showed that the static wind-uplift resistance capacity could be increased by 139% and 121% by using the long and short trough-pass beads respectively. Based on the theoretical analysis and test results, suggestions on application scope and reinforcement optimization measures of this type of plate were put forward.
Based on the analysis of the basic characteristics of the buckled metal roof panel, the weak points of its wind-uplift resistance were theoretically analyzed. It was pointed out that the weak link was that the stiffness of metal plate was insufficient and the redundancy of fastening method was insufficient. Wind-uplift test on its prototype plate system showed that mid-span deformations of the plate were too large when the system was damaged and the initial damage occured at the fastening position. According to the analysis of the weak points of wind-uplift resistance and the failure characteristics of the prototype plate system, the wind-uplift resistance of the strengthened plate system was tested. Comparing with the wind-uplift resistance capacity of the prototype system before reinforcement, the results of series tests showed that the static wind-uplift resistance capacity could be increased by 139% and 121% by using the long and short trough-pass beads respectively. Based on the theoretical analysis and test results, suggestions on application scope and reinforcement optimization measures of this type of plate were put forward.
2021, 51(12): 96-101.
doi: 10.13204/j.gyjzG21101112
Abstract:
The concealed fastener metal roofing panel has been widely used because of its simple structure, convenient installation and ensuring waterproof effect. However, its connection mode mainly depends on the snap connection at the wave crest. When the wind uplift is large, the arching deformation of the wave trough is easy to lead to the excessive deformation of the wave crest, which is separated from the support. In coastal areas, this type of roofing panel is lifted from time to time. Because the stress between the plate and the support is complex and difficult to simulate, Technical Code for Application of Profiled Metal Sheets(GB 50896-2013) clearly requires that the profiled metal roofing system should be tested to verify the overall wind-uplift resistance capacity. Through the analysis and research on the use, structural principle and damage of the concealed fastener roofing panel, targeted reinforcement measures were put forward. The damage wind pressures of CC750 concealed fastener roofing panel before and after reinforcement were obtained according to the wind-uplift resistance test, which the best reinforcement combination scheme could be selected. Finally, according to the test results and the actual situation, practical reinforcement measures and suggestions were put forward.
The concealed fastener metal roofing panel has been widely used because of its simple structure, convenient installation and ensuring waterproof effect. However, its connection mode mainly depends on the snap connection at the wave crest. When the wind uplift is large, the arching deformation of the wave trough is easy to lead to the excessive deformation of the wave crest, which is separated from the support. In coastal areas, this type of roofing panel is lifted from time to time. Because the stress between the plate and the support is complex and difficult to simulate, Technical Code for Application of Profiled Metal Sheets(GB 50896-2013) clearly requires that the profiled metal roofing system should be tested to verify the overall wind-uplift resistance capacity. Through the analysis and research on the use, structural principle and damage of the concealed fastener roofing panel, targeted reinforcement measures were put forward. The damage wind pressures of CC750 concealed fastener roofing panel before and after reinforcement were obtained according to the wind-uplift resistance test, which the best reinforcement combination scheme could be selected. Finally, according to the test results and the actual situation, practical reinforcement measures and suggestions were put forward.
2021, 51(12): 102-106.
doi: 10.13204/j.gyjzG21102024
Abstract:
It is a complex project to realize intelligent monitoring and evaluation in civil engineering involving the intersection of multiple theories and technologies. An intelligent monitoring and evaluation system in civil engineering structures (MDCRS) was put forward, which could provide technical support for the safe operation and scientific management of large civil engineering and basic public facilities such as nuclear power generating stations, long-span bridges and industrial buildings. The system was mainly comprised of a monitoring system, a calculation and evaluation system, and a visualization system. Its main functions were as follows:implementing real-time and effective monitoring in engineering structure, processing and analyzing monitoring data, getting the inner physical nature of the structure by a fast algorithm and digital mapping tenchnique according to the specific characteristics of the structure, conducting simulations, analysis and research of various working conditions of the structure to assess structural safety, and displaying the structure state objectively and truthfully through the computer graphics display tenchnique. Two application instances were taken in the paper to illustrate the fact that the civil engineering intelligent monitoring and evaluation system could not only realize real-time and effective collection, transmission and storage of monitoring information, but also obtain the actual performance of the structure by a fast and scientific algorithm, further, could conduct a three-dimensional visual display and provide technical support for safe construction, operation, scientific management and decision-making in civil engineering.
It is a complex project to realize intelligent monitoring and evaluation in civil engineering involving the intersection of multiple theories and technologies. An intelligent monitoring and evaluation system in civil engineering structures (MDCRS) was put forward, which could provide technical support for the safe operation and scientific management of large civil engineering and basic public facilities such as nuclear power generating stations, long-span bridges and industrial buildings. The system was mainly comprised of a monitoring system, a calculation and evaluation system, and a visualization system. Its main functions were as follows:implementing real-time and effective monitoring in engineering structure, processing and analyzing monitoring data, getting the inner physical nature of the structure by a fast algorithm and digital mapping tenchnique according to the specific characteristics of the structure, conducting simulations, analysis and research of various working conditions of the structure to assess structural safety, and displaying the structure state objectively and truthfully through the computer graphics display tenchnique. Two application instances were taken in the paper to illustrate the fact that the civil engineering intelligent monitoring and evaluation system could not only realize real-time and effective collection, transmission and storage of monitoring information, but also obtain the actual performance of the structure by a fast and scientific algorithm, further, could conduct a three-dimensional visual display and provide technical support for safe construction, operation, scientific management and decision-making in civil engineering.
2021, 51(12): 107-112.
doi: 10.13204/j.gyjzG21121503
Abstract:
Steel truss trestle is an important material transportation structure in coal mines and other enterprises, which has the characteristics of good force performance, rapid construction and convenient demolition. Sprinklering and poor maintenance within the trestle may cause the bridge rod to corrode or weaken its bearing capacity, or even collapse. The study of such typical accidents can reduce the associated losses. In this paper, a trestle collapse accident was investigated and analyzed in detail.First of all, the collapse of the trestle and the existence of damage or defects were investigateed, and component size, material strength, tilt, corrosion and surface thickness of the corresponding were tested as well. The actual load of the structure was considered and the rod damage was taken into account to obtain the safety margin of the structure. Considering the results of investigation, detection and calculation analysis, the detailed process of trestle collapse and the main cause of bridge collapse were obtained, and the safety of the affected bridge structure were analyzed. On this basis, it was proposed to strengthen the abdominal rod, add stent and other targeted reinforcement treatment methods to ensure structural safety.
Steel truss trestle is an important material transportation structure in coal mines and other enterprises, which has the characteristics of good force performance, rapid construction and convenient demolition. Sprinklering and poor maintenance within the trestle may cause the bridge rod to corrode or weaken its bearing capacity, or even collapse. The study of such typical accidents can reduce the associated losses. In this paper, a trestle collapse accident was investigated and analyzed in detail.First of all, the collapse of the trestle and the existence of damage or defects were investigateed, and component size, material strength, tilt, corrosion and surface thickness of the corresponding were tested as well. The actual load of the structure was considered and the rod damage was taken into account to obtain the safety margin of the structure. Considering the results of investigation, detection and calculation analysis, the detailed process of trestle collapse and the main cause of bridge collapse were obtained, and the safety of the affected bridge structure were analyzed. On this basis, it was proposed to strengthen the abdominal rod, add stent and other targeted reinforcement treatment methods to ensure structural safety.
2021, 51(12): 113-116.
doi: 10.13204/j.gyjzG21120610
Abstract:
Truss is a structure composed of members connected by hinges at both ends. It mainly bears axial tension or compression, so it can make full use of the strength of materials. When the span is large, it can save materials compared with solid web beams, reduce self weight and increase stiffness. However, structural collapse oftens occurs due to non-standard construction and poor construction quality. The collapsed truss of a stockyard was taken as the research object. In order to find out the causes of the collapse of the truss, by detecting the material strength, weld size and weld strength of truss members, the actual load of the structure was investigated, the mechanical properties test and numerical simulation analysis of welds were also conducted, it was finally concluded that the root cause of the collapse of the truss was that the weld of the main truss did not meet the requirements of specification and design.
Truss is a structure composed of members connected by hinges at both ends. It mainly bears axial tension or compression, so it can make full use of the strength of materials. When the span is large, it can save materials compared with solid web beams, reduce self weight and increase stiffness. However, structural collapse oftens occurs due to non-standard construction and poor construction quality. The collapsed truss of a stockyard was taken as the research object. In order to find out the causes of the collapse of the truss, by detecting the material strength, weld size and weld strength of truss members, the actual load of the structure was investigated, the mechanical properties test and numerical simulation analysis of welds were also conducted, it was finally concluded that the root cause of the collapse of the truss was that the weld of the main truss did not meet the requirements of specification and design.
2021, 51(12): 117-122.
doi: 10.13204/j.gyjzG21102011
Abstract:
With the development of industry, industrial buildings are developing towards the direction of large span, large column spacing, large tonnage and ultra high-rise. However, the structural system of tall and heavy steel structure plants has not been systematically studied in domestic specifications, and its structural system has not yet formed a complete conclusion. Based on the design of a heavy-duty steel structure plant, the application of the roofing system composed of concrete-filled steel tubular lattice column and spatial pipe truss was studied. The selection idea from foundation to superstructure was described in detail, and the span of the enclosure structure was reduced by optimizing the form of spatial structure. The finite element software SAP 2000 was used for the overall analysis, and the calculation of key components and joints was studied. By consulting relevant information, the overall stability, strength, deformation, settlement and other indicators of the structure were determined, which were controlled from the overall structure to local components to ensure the accuracy and reliability of the analysis results. According to the complex geological conditions, the control standards of pipe piles were adjusted in time and applied to subsequent related projects, which had achieved good application effect and economic benefits.
With the development of industry, industrial buildings are developing towards the direction of large span, large column spacing, large tonnage and ultra high-rise. However, the structural system of tall and heavy steel structure plants has not been systematically studied in domestic specifications, and its structural system has not yet formed a complete conclusion. Based on the design of a heavy-duty steel structure plant, the application of the roofing system composed of concrete-filled steel tubular lattice column and spatial pipe truss was studied. The selection idea from foundation to superstructure was described in detail, and the span of the enclosure structure was reduced by optimizing the form of spatial structure. The finite element software SAP 2000 was used for the overall analysis, and the calculation of key components and joints was studied. By consulting relevant information, the overall stability, strength, deformation, settlement and other indicators of the structure were determined, which were controlled from the overall structure to local components to ensure the accuracy and reliability of the analysis results. According to the complex geological conditions, the control standards of pipe piles were adjusted in time and applied to subsequent related projects, which had achieved good application effect and economic benefits.
2021, 51(12): 123-128.
doi: 10.13204/j.gyjzG21121504
Abstract:
Based on the typical island roof reinforcement project of a nuclear power lant, this paper expounded the application of R130 strong wind resistant roof system in coastal nuclear power plant reinforcement project. Through the test of wind resistance and uncovering performance, the results showed that R130 strong wind resistant roof system had advantages of super wind uplift resistance and uncovering performance, perfect system, good waterproof performance, good durability and so on. Based on the test results, this paper focused on the key points and difficulties in the construction and application of R130 strong wind resistant roof system and matters for attention, so as to provide reliable experience for the construction of similar projects in coastal areas and strong typhoon areas.
Based on the typical island roof reinforcement project of a nuclear power lant, this paper expounded the application of R130 strong wind resistant roof system in coastal nuclear power plant reinforcement project. Through the test of wind resistance and uncovering performance, the results showed that R130 strong wind resistant roof system had advantages of super wind uplift resistance and uncovering performance, perfect system, good waterproof performance, good durability and so on. Based on the test results, this paper focused on the key points and difficulties in the construction and application of R130 strong wind resistant roof system and matters for attention, so as to provide reliable experience for the construction of similar projects in coastal areas and strong typhoon areas.
