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2024 Vol. 54, No. 2
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2024, 54(2): 1-7.
doi: 10.3724/j.gyjzG23120204
Abstract:
In view of the existing various seismic hazard analysis methods, the seismic hazard analysis method based on historical seismic intensity data and the probabilistic seismic hazard analysis method to analyze the seismic hazards of the main urban area in Beijing was taken, and the peak ground acceleration with a probability of exceeding 10% in 50 years was obtained. The results showed that the peak ground acceleration of the main urban area in Beijing was of obvious spatial variability, which was gradually increasing from the west of the city to the east; the results obtained from those two methods were reliable and the differences were slight. The methods had their own characteristics, the former had fewer assumptions including site effects and was moderately difficult to calculate, but the application range was limited; the latter was integrated influences of various factors, with multiple assumptions and high computational complexity, but be widely used. Those two methods could provide reference to seismic hazard assessment.
In view of the existing various seismic hazard analysis methods, the seismic hazard analysis method based on historical seismic intensity data and the probabilistic seismic hazard analysis method to analyze the seismic hazards of the main urban area in Beijing was taken, and the peak ground acceleration with a probability of exceeding 10% in 50 years was obtained. The results showed that the peak ground acceleration of the main urban area in Beijing was of obvious spatial variability, which was gradually increasing from the west of the city to the east; the results obtained from those two methods were reliable and the differences were slight. The methods had their own characteristics, the former had fewer assumptions including site effects and was moderately difficult to calculate, but the application range was limited; the latter was integrated influences of various factors, with multiple assumptions and high computational complexity, but be widely used. Those two methods could provide reference to seismic hazard assessment.
2024, 54(2): 8-17.
doi: 10.3724/j.gyjzG23120803
Abstract:
The complexity of major transportation infrastructure projects makes them prone to various conflicts of interest during the construction process, and various risk factors interact with each other, which can easily lead to social stability problems.In the paper, social stability risks were divided into internal risks and external risks, social stability risk indicators were selected based on the five dimensions of government, public, ecology, economy and society, the risk coupling relations of each dimension was analyzed, a coupling model of social stability risks of major transportation infrastructure construction projects based on system dynamics was established, and the social stability risk simulation analysis of a tunnel engineering project in Qingdao was carried out by using Vensim software.The results showed that government risks and ecological risks had greater influence on the tunnel projects. The coupling effect of homogeneous internal risks was stronger than that of homogeneous external risks. The coupling effect of heterogeneous internal risks and the coupling effect of heterogeneous internal-external risks were stronger than the coupling effect of heterogeneous external risks.
The complexity of major transportation infrastructure projects makes them prone to various conflicts of interest during the construction process, and various risk factors interact with each other, which can easily lead to social stability problems.In the paper, social stability risks were divided into internal risks and external risks, social stability risk indicators were selected based on the five dimensions of government, public, ecology, economy and society, the risk coupling relations of each dimension was analyzed, a coupling model of social stability risks of major transportation infrastructure construction projects based on system dynamics was established, and the social stability risk simulation analysis of a tunnel engineering project in Qingdao was carried out by using Vensim software.The results showed that government risks and ecological risks had greater influence on the tunnel projects. The coupling effect of homogeneous internal risks was stronger than that of homogeneous external risks. The coupling effect of heterogeneous internal risks and the coupling effect of heterogeneous internal-external risks were stronger than the coupling effect of heterogeneous external risks.
2024, 54(2): 18-24.
doi: 10.3724/j.gyjzG23121004
Abstract:
Industrial superstructures are a new type of industrial space model, which realizes the efficient use of urban industrial space and also brings new safety risk factors to industrial parks. In order to scientifically and accurately assess the safety risks of industrial buildings, the paper proposed a safety risk assessment index system for industrial buildings based on the theoretical framework of "risk source-risk exposure-mitigation force", which consists of three guideline layers of risk source control, carrier toughness, and mitigation force, as well as 20 secondary indicators. At the same time, combining the network analysis method (ANP) and the object-element topology model to determine the indicator weighting system and evaluation method, the establishment of industrial superstructure safety risk assessment model, the industrial superstructure safety risk assessment data to realize topology quantification, and then enhance the objectivity of the assessment results. The paper took an industrial superstructure park in Shenzhen as an example, and the analysis results showed that the safety risk level of the industrial superstructure park was light risk, and the assessment results were better, which was in line with the actual situation; through a comparison, it was found that the assessment method proposed in the paper was practical and scientific; the park should focus on the construction of the resilience level of the disaster-bearing body, strengthen a small amount of hazardous chemicals management, reasonably control the risks of productive vibration, etc., and strengthen the capacity of risk monitoring and early-warning, in order to better guarantee the safety of industrial superstructures.
Industrial superstructures are a new type of industrial space model, which realizes the efficient use of urban industrial space and also brings new safety risk factors to industrial parks. In order to scientifically and accurately assess the safety risks of industrial buildings, the paper proposed a safety risk assessment index system for industrial buildings based on the theoretical framework of "risk source-risk exposure-mitigation force", which consists of three guideline layers of risk source control, carrier toughness, and mitigation force, as well as 20 secondary indicators. At the same time, combining the network analysis method (ANP) and the object-element topology model to determine the indicator weighting system and evaluation method, the establishment of industrial superstructure safety risk assessment model, the industrial superstructure safety risk assessment data to realize topology quantification, and then enhance the objectivity of the assessment results. The paper took an industrial superstructure park in Shenzhen as an example, and the analysis results showed that the safety risk level of the industrial superstructure park was light risk, and the assessment results were better, which was in line with the actual situation; through a comparison, it was found that the assessment method proposed in the paper was practical and scientific; the park should focus on the construction of the resilience level of the disaster-bearing body, strengthen a small amount of hazardous chemicals management, reasonably control the risks of productive vibration, etc., and strengthen the capacity of risk monitoring and early-warning, in order to better guarantee the safety of industrial superstructures.
2024, 54(2): 25-34.
doi: 10.3724/j.gyjzG23121501
Abstract:
High-density building clusters, with a large population, a number of high-rise buildings, and significant assets, have been noticeable in the context of economic and urbanization progress. These provide focal points as well as new challenges for urban seismic mitigation and disaster prevention. Concurrently, with the progress in seismic engineering research and its practical applications, traditional seismic risks, such as structural collapses, have seen a gradual decline. Nonetheless, novel seismic disasters, such as post-earthquake falling debris and fires, have gained prominence. These are extremely destructive and lack effective mitigation measures. Therefore, the paper focused on four typical novel seismic secondary disasters: post-earthquake falling debris, post-earthquake fires, people trapped in elevators under earthquakes, and site-city interaction effects. The current preliminary research findings on novel seismic secondary disasters were summarized, and an outlook on future research directions was proposed, so as to provide a scholarly reference for the exploration of novel seismic disasters.
High-density building clusters, with a large population, a number of high-rise buildings, and significant assets, have been noticeable in the context of economic and urbanization progress. These provide focal points as well as new challenges for urban seismic mitigation and disaster prevention. Concurrently, with the progress in seismic engineering research and its practical applications, traditional seismic risks, such as structural collapses, have seen a gradual decline. Nonetheless, novel seismic disasters, such as post-earthquake falling debris and fires, have gained prominence. These are extremely destructive and lack effective mitigation measures. Therefore, the paper focused on four typical novel seismic secondary disasters: post-earthquake falling debris, post-earthquake fires, people trapped in elevators under earthquakes, and site-city interaction effects. The current preliminary research findings on novel seismic secondary disasters were summarized, and an outlook on future research directions was proposed, so as to provide a scholarly reference for the exploration of novel seismic disasters.
2024, 54(2): 35-42.
doi: 10.3724/j.gyjzG22122605
Abstract:
In recent years, the new concepts and technologies of digital twin have provided important technical means for the study of urban safety governance modernization, which has produced positive effects. With the increase of urban safety accidents and risks, the world’s important economies, including China, have actively promoted the construction of digital twins at the national strategic policy level, which has important applications in urban safety planning, urban safety smart governance, urban safety risk monitoring and early warning, etc. The research trends of digital twin applications in urban safety at home and abroad were analyzed, and the problems that applications of digital twins in urban safety may face, such as lack of scientific cognition, data security, and lack of resources, were discussed. Based on this, the possible improvement and development directions of the applications of digital twin technology in urban safety with respect to theoretical research, unified standard, data governance and other aspects were proposed.
In recent years, the new concepts and technologies of digital twin have provided important technical means for the study of urban safety governance modernization, which has produced positive effects. With the increase of urban safety accidents and risks, the world’s important economies, including China, have actively promoted the construction of digital twins at the national strategic policy level, which has important applications in urban safety planning, urban safety smart governance, urban safety risk monitoring and early warning, etc. The research trends of digital twin applications in urban safety at home and abroad were analyzed, and the problems that applications of digital twins in urban safety may face, such as lack of scientific cognition, data security, and lack of resources, were discussed. Based on this, the possible improvement and development directions of the applications of digital twin technology in urban safety with respect to theoretical research, unified standard, data governance and other aspects were proposed.
2024, 54(2): 43-50.
doi: 10.3724/j.gyjzG24010401
Abstract:
With the rapid development of metro networks in major cities in China, the challenges and bottlenecks faced by the operation and maintenance management of metro bridge and tunnel structures have become increasingly significant. In order to improve the structural safety of metro bridges and tunnels in operation, a digital twin-based platform framework for metro bridge and tunnel structure service was proposed. First, the application requirements of digital twins in the operation and maintenance of metro bridge and tunnel structures were analyzed. Then, the digital twin model structure, operation mechanism and platform architecture design were proposed based on those requirements. Finally, the functional application of digital twins for operations and maintenances of metro bridges and tunnels were elaborated, which would provide a new technical support program for operation and maintenance management of urban rail transportation facilities and structures.
With the rapid development of metro networks in major cities in China, the challenges and bottlenecks faced by the operation and maintenance management of metro bridge and tunnel structures have become increasingly significant. In order to improve the structural safety of metro bridges and tunnels in operation, a digital twin-based platform framework for metro bridge and tunnel structure service was proposed. First, the application requirements of digital twins in the operation and maintenance of metro bridge and tunnel structures were analyzed. Then, the digital twin model structure, operation mechanism and platform architecture design were proposed based on those requirements. Finally, the functional application of digital twins for operations and maintenances of metro bridges and tunnels were elaborated, which would provide a new technical support program for operation and maintenance management of urban rail transportation facilities and structures.
2024, 54(2): 51-57.
doi: 10.3724/j.gyjzG23120809
Abstract:
The safety of urban buildings involves people’s lives and property. In recent years, there have been many local collapses of buildings causing serious damage. In order to realize the "pre-disaster prevention" safety supervision of modern urban building facilities, a large-scale safety risk assessment method for urban buildings and infrastructure was proposed based on PS-InSAR technology. By combining InSAR principle, the building PS point clustering was extracted, the deformation information of cluster points was analyzed, the effective deformation was extracted according to building risk related indicators, and risk grade standards were divided according to building types and regional conditions, so as to evaluate the safety risk situation of building facilities in the region. Taking Changchun City as an example, using the COSMO-SkyMed satellite time series data, a large-scale safety risk monitoring experiment was conducted on buildings in the main urban area, and a field survey was conducted on buildings that were evaluated as grade D and needed to be paid attention to, and it was found that there were obvious hidden dangers. The feasibility and accuracy of the method were confirmed, and it could provide technical supports for regular "physical examination" of large-scale urban building facilities and ensure the safety of urban buildings.
The safety of urban buildings involves people’s lives and property. In recent years, there have been many local collapses of buildings causing serious damage. In order to realize the "pre-disaster prevention" safety supervision of modern urban building facilities, a large-scale safety risk assessment method for urban buildings and infrastructure was proposed based on PS-InSAR technology. By combining InSAR principle, the building PS point clustering was extracted, the deformation information of cluster points was analyzed, the effective deformation was extracted according to building risk related indicators, and risk grade standards were divided according to building types and regional conditions, so as to evaluate the safety risk situation of building facilities in the region. Taking Changchun City as an example, using the COSMO-SkyMed satellite time series data, a large-scale safety risk monitoring experiment was conducted on buildings in the main urban area, and a field survey was conducted on buildings that were evaluated as grade D and needed to be paid attention to, and it was found that there were obvious hidden dangers. The feasibility and accuracy of the method were confirmed, and it could provide technical supports for regular "physical examination" of large-scale urban building facilities and ensure the safety of urban buildings.
2024, 54(2): 58-64.
doi: 10.3724/j.gyjzG23120810
Abstract:
The detection and location of illegal buildings has always been a challenge for urban management, Color steel tile buildings are one of the key objects of attention in determining whether they are illegal buildings. Existing research focuses on how to detect colored steel and tile buildings, but lacks the specific street positioning of such buildings. This study aims to address this issue by proposing a framework that integrates illegal building detection with location. An empirical study in a particular street area in Shenzhen was conducted, aerial visible light images taken by drones were used as the dataset. Firstly, drones were used to collect image data from the detection area, and then DINO was applied to detect color steel tile buildings and obtain the center points of their bounding box. After coordinate system transformation, the coordinates of the color steel tile buildings were obtained, and Aruco codes were used to verify the accuracy of the location. Finally, the coordinates were correlated with street information through the interface of a map engine. The detection results indicated that DINO performed well in detecting color steel tile buildings, achieving a detection accuracy of 90%. The positioning test results indicated that when the drone was within 30 m of the measured object, the positioning accuracy could be controlled within 1 m, but the increase in the height of the drone from the measured object wouldcause the positioning accuracy to decrease. An effective framework for the detection and location of illegal buildings was proposed and validated. This method not only has high accuracy in detecting color steel tile buildings, but can also determine the specific street location of color steel tile buildings, which contributes to more accurate and efficient urban management.
The detection and location of illegal buildings has always been a challenge for urban management, Color steel tile buildings are one of the key objects of attention in determining whether they are illegal buildings. Existing research focuses on how to detect colored steel and tile buildings, but lacks the specific street positioning of such buildings. This study aims to address this issue by proposing a framework that integrates illegal building detection with location. An empirical study in a particular street area in Shenzhen was conducted, aerial visible light images taken by drones were used as the dataset. Firstly, drones were used to collect image data from the detection area, and then DINO was applied to detect color steel tile buildings and obtain the center points of their bounding box. After coordinate system transformation, the coordinates of the color steel tile buildings were obtained, and Aruco codes were used to verify the accuracy of the location. Finally, the coordinates were correlated with street information through the interface of a map engine. The detection results indicated that DINO performed well in detecting color steel tile buildings, achieving a detection accuracy of 90%. The positioning test results indicated that when the drone was within 30 m of the measured object, the positioning accuracy could be controlled within 1 m, but the increase in the height of the drone from the measured object wouldcause the positioning accuracy to decrease. An effective framework for the detection and location of illegal buildings was proposed and validated. This method not only has high accuracy in detecting color steel tile buildings, but can also determine the specific street location of color steel tile buildings, which contributes to more accurate and efficient urban management.
A Safety Monitoring Method for High-Formwork Support Structures Based on Computer Vision Recognition
2024, 54(2): 65-72.
doi: 10.3724/j.gyjzG23121903
Abstract:
To ensure the construction safety of high-formwork support structures, a set of construction intelligent real-time monitoring method based on computer vision and finite element technology was proposed. A refined finite element model was established according to the real situation of the rods arrangement of the high-formwork support structure, and the buckling analysis was carried out under a variety of working conditions, so as to obtain the vertical displacement of the key joints during the buckling damage of the high-formwork support structure, and to obtain the alarm threshold value of the intelligent real-time monitoring of the construction. The intelligent real-time monitoring algorithm based on computer vision was developed to monitor the displacement changes of the high-formwork support structure in the construction process in real time, and the algorithm will automatically alarm and guide the elimination of dangers and the protection of construction safety when unsafe displacement occurs. After the construction, according to the theoretical calculation results and the actual measurement results, the finite element model was corrected parametrically, and the corrected finite element model was subjected to buckling damage analysis, and the sizes of the corrected buckling vertical displacement and the alarm threshold were compared to illustrate the reasonableness of the alarm threshold. The successful completion of a high-formwork support structure project for a multi-use building verified the effectiveness of the new construction monitoring method proposed in the paper.
To ensure the construction safety of high-formwork support structures, a set of construction intelligent real-time monitoring method based on computer vision and finite element technology was proposed. A refined finite element model was established according to the real situation of the rods arrangement of the high-formwork support structure, and the buckling analysis was carried out under a variety of working conditions, so as to obtain the vertical displacement of the key joints during the buckling damage of the high-formwork support structure, and to obtain the alarm threshold value of the intelligent real-time monitoring of the construction. The intelligent real-time monitoring algorithm based on computer vision was developed to monitor the displacement changes of the high-formwork support structure in the construction process in real time, and the algorithm will automatically alarm and guide the elimination of dangers and the protection of construction safety when unsafe displacement occurs. After the construction, according to the theoretical calculation results and the actual measurement results, the finite element model was corrected parametrically, and the corrected finite element model was subjected to buckling damage analysis, and the sizes of the corrected buckling vertical displacement and the alarm threshold were compared to illustrate the reasonableness of the alarm threshold. The successful completion of a high-formwork support structure project for a multi-use building verified the effectiveness of the new construction monitoring method proposed in the paper.
2024, 54(2): 73-79.
doi: 10.3724/j.gyjzG23021204
Abstract:
Construction accidents are primarily and directly caused by unsafe behavior. Traditional safety intervention techniques based on behavioral safety are restricted to rewards and punishments, which have a limited capacity for sustainability, and the intervention effect declines noticeably as intervention time increases. Based on the (Leadership-Culture-Behavior) LCB theory of construction safety, the aim of this study is to develop a targeted LCB intervention approach, and through comprehensive LCB intervention, to enhance the safety management of construction projects. In order to establish the goals of the intervention, the case project’s performance in terms of safety leadership, safety culture, and safety management behavior was first assessed by using the LCB measuring scale. Following the identification of five interventions using LCB theory, an intervention program was developed based on on-site research and interviews. Finally, LCB measurement during the observation period and another LCB measurement during the follow-up period were undertaken to validate the sustainability of the intervention effects. The results indicated that the developed intervention program achieved significant and sustained improvements in the three LCB dimensions of attention to respect, education and training, and safety education. The methods described in this paper can be used as a reference for similar programs to conduct safety interventions, enriching LCB intervention practices and further deepening LCB theory.
Construction accidents are primarily and directly caused by unsafe behavior. Traditional safety intervention techniques based on behavioral safety are restricted to rewards and punishments, which have a limited capacity for sustainability, and the intervention effect declines noticeably as intervention time increases. Based on the (Leadership-Culture-Behavior) LCB theory of construction safety, the aim of this study is to develop a targeted LCB intervention approach, and through comprehensive LCB intervention, to enhance the safety management of construction projects. In order to establish the goals of the intervention, the case project’s performance in terms of safety leadership, safety culture, and safety management behavior was first assessed by using the LCB measuring scale. Following the identification of five interventions using LCB theory, an intervention program was developed based on on-site research and interviews. Finally, LCB measurement during the observation period and another LCB measurement during the follow-up period were undertaken to validate the sustainability of the intervention effects. The results indicated that the developed intervention program achieved significant and sustained improvements in the three LCB dimensions of attention to respect, education and training, and safety education. The methods described in this paper can be used as a reference for similar programs to conduct safety interventions, enriching LCB intervention practices and further deepening LCB theory.
2024, 54(2): 80-89.
doi: 10.3724/j.gyjzG23120805
Abstract:
Hospital, as a critical public facility in urban settings, faces the challenges of emergencies that can lead to chaotic evacuation processes, jeopardizing both personnel safety and overall evacuation efficiency. Hospital staff, including doctors, security personnel, and various social roles, play indispensable roles in emergency evacuations. This study conducted two expert questionnaire surveys to investigate the social role identification and performance of hospital staff during routine and emergency situations. The research identified five distinct emergency evacuation roles, offering a clear distinction between the daily behaviors of hospital staff and their evacuation behaviors, while also pinpointing potential influencing factors for these behaviors. Findings revealed that hospital staff would be assumed to play emergency evacuation roles during unforeseen events, with their behavior and performance shaped by a complex interplay of personal characteristics, organizational factors, and environmental considerations. An evacuation role evolution questionnaire was developed and validated, facilitating a comprehensive analysis of phenomena such as role ambiguity, conflicts, and tension that may arise during hospital emergency evacuations.
Hospital, as a critical public facility in urban settings, faces the challenges of emergencies that can lead to chaotic evacuation processes, jeopardizing both personnel safety and overall evacuation efficiency. Hospital staff, including doctors, security personnel, and various social roles, play indispensable roles in emergency evacuations. This study conducted two expert questionnaire surveys to investigate the social role identification and performance of hospital staff during routine and emergency situations. The research identified five distinct emergency evacuation roles, offering a clear distinction between the daily behaviors of hospital staff and their evacuation behaviors, while also pinpointing potential influencing factors for these behaviors. Findings revealed that hospital staff would be assumed to play emergency evacuation roles during unforeseen events, with their behavior and performance shaped by a complex interplay of personal characteristics, organizational factors, and environmental considerations. An evacuation role evolution questionnaire was developed and validated, facilitating a comprehensive analysis of phenomena such as role ambiguity, conflicts, and tension that may arise during hospital emergency evacuations.
2024, 54(2): 90-97.
doi: 10.3724/j.gyjzG23121007
Abstract:
Aiming at the characteristics of large fire load, cramped space, and complex interior decoration of escape rooms, and their safety hazards of rapid fire spread and difficult evacuation after fire, the study was based on the Pyrosim software to investigate the fire spread, smoke flow, visibility changes and temperature changes after fire in the escape room, and to analyze the problems and deficiencies of the existing decoration methods in the case of fire, and to propose improvement measures for the existing decoration methods. The simulation results showed that the design of long and narrow corridors should be avoided in the escape room, and the partition walls of the escape room should be designed with through-roofs in the process of renovation, and the escape room should be equipped with two evacuation paths in order to shorten the escape time to the greatest extent possible. The study of the fire spread characteristics is of great significance to safeguarding the lives of entertainers, and it can also provide a reference for the evacuation of escape room entertainment venues.
Aiming at the characteristics of large fire load, cramped space, and complex interior decoration of escape rooms, and their safety hazards of rapid fire spread and difficult evacuation after fire, the study was based on the Pyrosim software to investigate the fire spread, smoke flow, visibility changes and temperature changes after fire in the escape room, and to analyze the problems and deficiencies of the existing decoration methods in the case of fire, and to propose improvement measures for the existing decoration methods. The simulation results showed that the design of long and narrow corridors should be avoided in the escape room, and the partition walls of the escape room should be designed with through-roofs in the process of renovation, and the escape room should be equipped with two evacuation paths in order to shorten the escape time to the greatest extent possible. The study of the fire spread characteristics is of great significance to safeguarding the lives of entertainers, and it can also provide a reference for the evacuation of escape room entertainment venues.
2024, 54(2): 98-105.
doi: 10.3724/j.gyjzG23121101
Abstract:
The wind-resistant design of building structures in the typhoon affected area in the codes is carried out by analogy with the non-cyclonic wind field, however, many measured results show that there is a large difference between the typhoon wind profile and the profile of the non-cyclonic wind field, and the influencing factors and changing rules of the typhoon wind profile are still not clear at present. To clearly understand the profile characteristics of typhoons, many measured profile data of several typhoons were used for the analysis. The measured data were categorized by three factors, namely, the underlying surface categories, the typhoon structural partitions,and the wind speed, and the wind profile data of each category were comparatively analyzed, and the study showed that: the low-level jet phenomena in typhoon wind profiles was related to the underlying surface categories, the typhoon structural partitions, and the wind speed, the low-level jets were more likely to occur at exposure category A, B, larger wind speed, and in the back eyewall region in typhoon; there was a certain relationship between the gradient wind height of the typhoon wind profile and the type of underlying surface and average wind speed. The gradient wind height of exposure category A and B showed an increasing trend from the center of the typhoon outward, while the gradient wind height underground of exposure category C showed a decreasing and then increasing trend from the center of the typhoon outward.
The wind-resistant design of building structures in the typhoon affected area in the codes is carried out by analogy with the non-cyclonic wind field, however, many measured results show that there is a large difference between the typhoon wind profile and the profile of the non-cyclonic wind field, and the influencing factors and changing rules of the typhoon wind profile are still not clear at present. To clearly understand the profile characteristics of typhoons, many measured profile data of several typhoons were used for the analysis. The measured data were categorized by three factors, namely, the underlying surface categories, the typhoon structural partitions,and the wind speed, and the wind profile data of each category were comparatively analyzed, and the study showed that: the low-level jet phenomena in typhoon wind profiles was related to the underlying surface categories, the typhoon structural partitions, and the wind speed, the low-level jets were more likely to occur at exposure category A, B, larger wind speed, and in the back eyewall region in typhoon; there was a certain relationship between the gradient wind height of the typhoon wind profile and the type of underlying surface and average wind speed. The gradient wind height of exposure category A and B showed an increasing trend from the center of the typhoon outward, while the gradient wind height underground of exposure category C showed a decreasing and then increasing trend from the center of the typhoon outward.
2024, 54(2): 106-116.
doi: 10.3724/j.gyjzG23121431
Abstract:
After disasters, especially earthquakes, the vulnerability of hospitals becomes increasingly evident, and the resilience of hospitals plays a crucial role in disaster prevention, mitigation, adaptation, and recovery in seismic areas. The research on seismic resilience of hospitals is not limited to the structural safety of hospitals, but focus more on the seismic performance of non-structural componentsand medical equipment within hospitals, as well as quantification and rapidly recover of hospital functions after earthquakes. The paper explored the connotation, theoretical framework, and modeling methods of hospital resilience from engineering dimension. By reviewing the progress of hospital resilience research at home and abroadd, the connections and distinctions among relevant concepts of hospital resilience were analyzed, and qualitative and quantitative methods for assessing hospital resilience were summarized. Finally, the paper provided an outlook on future directions and research points in light of the limitations of existing research.
After disasters, especially earthquakes, the vulnerability of hospitals becomes increasingly evident, and the resilience of hospitals plays a crucial role in disaster prevention, mitigation, adaptation, and recovery in seismic areas. The research on seismic resilience of hospitals is not limited to the structural safety of hospitals, but focus more on the seismic performance of non-structural componentsand medical equipment within hospitals, as well as quantification and rapidly recover of hospital functions after earthquakes. The paper explored the connotation, theoretical framework, and modeling methods of hospital resilience from engineering dimension. By reviewing the progress of hospital resilience research at home and abroadd, the connections and distinctions among relevant concepts of hospital resilience were analyzed, and qualitative and quantitative methods for assessing hospital resilience were summarized. Finally, the paper provided an outlook on future directions and research points in light of the limitations of existing research.
2024, 54(2): 117-127.
doi: 10.3724/j.gyjzG23121430
Abstract:
Infill walls are commonly subjected to bidirectional seismic actions in actual seismic events. A robust interaction prevails between the in-plane and out-of-plane seismic performance of infill walls, where in-plane damage often diminishes the out-of-plane bearing capacity of infill walls. A finite element model for RC frames with infill walls was established and validated against experimental data, and extensively employed in numerical analysis. The objective was to delve into the seismic performance of masonry infill walls under bidirectional loading, considering the effects of loading modes, aspect ratio, slenderness ratio, and block compressive strength on the out-of-plane bearing capacity of infill walls with prior in-plane damage. Based on experimental data and parameter analysis, a formula for predicting out-of-plane bearing capacity reduction factors of masonry infill walls with prior in-plane damage was proposed. A new comprehensive geometric parameter was introduced considering the mechanism of out-of-plane load transfer for infill walls. The new formula exhibited a superior fit with experimental data compared to existing equations.
Infill walls are commonly subjected to bidirectional seismic actions in actual seismic events. A robust interaction prevails between the in-plane and out-of-plane seismic performance of infill walls, where in-plane damage often diminishes the out-of-plane bearing capacity of infill walls. A finite element model for RC frames with infill walls was established and validated against experimental data, and extensively employed in numerical analysis. The objective was to delve into the seismic performance of masonry infill walls under bidirectional loading, considering the effects of loading modes, aspect ratio, slenderness ratio, and block compressive strength on the out-of-plane bearing capacity of infill walls with prior in-plane damage. Based on experimental data and parameter analysis, a formula for predicting out-of-plane bearing capacity reduction factors of masonry infill walls with prior in-plane damage was proposed. A new comprehensive geometric parameter was introduced considering the mechanism of out-of-plane load transfer for infill walls. The new formula exhibited a superior fit with experimental data compared to existing equations.
2024, 54(2): 128-132.
doi: 10.3724/j.gyjzG23122230
Abstract:
The connotation, characteristics, and evaluation methods of the resilience of waterlogging prevention and control management systems were studied. A resilience enhancement strategy for waterlogging prevention and control management systems was proposed from three perspectives of spatial planning, engineering construction, and management mechanism. The overall planning takes urban drainage system as the core, emphasizes the relation with urban flood control, including provisions for emergency capacity and outlets for excessive rainfall. The urban flood drainage capacity is systematically improved throughout the entire process from source to end point by considering construction standards for system facilities, mutual adaptability, and waterlogging prevention design. Management systems and intelligent approaches for pre-disaster prevention, resistance during disasters, and recovery after disasters are integrated to enhance the adaptability, recoverability, and disaster intelligence.
The connotation, characteristics, and evaluation methods of the resilience of waterlogging prevention and control management systems were studied. A resilience enhancement strategy for waterlogging prevention and control management systems was proposed from three perspectives of spatial planning, engineering construction, and management mechanism. The overall planning takes urban drainage system as the core, emphasizes the relation with urban flood control, including provisions for emergency capacity and outlets for excessive rainfall. The urban flood drainage capacity is systematically improved throughout the entire process from source to end point by considering construction standards for system facilities, mutual adaptability, and waterlogging prevention design. Management systems and intelligent approaches for pre-disaster prevention, resistance during disasters, and recovery after disasters are integrated to enhance the adaptability, recoverability, and disaster intelligence.
2024, 54(2): 133-143.
doi: 10.3724/j.gyjzG23122904
Abstract:
In order to comprehensively understand the application and research status of helical piles in the field of seismic resistance, the software CiteSpace was used to analyze relevant literature in CNKI and WOS databases. The conclusions are as follows: 1) in terms of testing, early researchers studied the horizontal and lateral dynamic responses of helical piles through field experiments. After that, scholars studied the seismic response of helical piles through shaking table tests. 2) in terms of theory, most foreign scholars use a combination of numerical calculations and shaking table tests to study the dynamic performance; domestic scholars mainly focus on the horizontal vibration and vertical vibrations of helical piles. 3) in terms of numerical simulation, the research is mainly conducted through numerical simulation software such as OpenSees. In addition, the latest research progress, existing problems, opinions and suggestions for future research on the seismic performance of helical piles were discussed.
In order to comprehensively understand the application and research status of helical piles in the field of seismic resistance, the software CiteSpace was used to analyze relevant literature in CNKI and WOS databases. The conclusions are as follows: 1) in terms of testing, early researchers studied the horizontal and lateral dynamic responses of helical piles through field experiments. After that, scholars studied the seismic response of helical piles through shaking table tests. 2) in terms of theory, most foreign scholars use a combination of numerical calculations and shaking table tests to study the dynamic performance; domestic scholars mainly focus on the horizontal vibration and vertical vibrations of helical piles. 3) in terms of numerical simulation, the research is mainly conducted through numerical simulation software such as OpenSees. In addition, the latest research progress, existing problems, opinions and suggestions for future research on the seismic performance of helical piles were discussed.
2024, 54(2): 144-154.
doi: 10.3724/j.gyjzG23120902
Abstract:
Digital twin technology is being rapidly applied and developed in the field of urban water security. Firstly, the paper sorted out and analyzed the current situation of digital twin technology applications for urban water security, explained the framework of urban water security system based on digital twins, and introduced the key techniques and capability requirements in the digital twin system from the perception and collection layer, infrastructure layer, data layer, model layer, knowledge layer, and application layer. Secondly, the application progress of digital twins in urban water security was reviewed, including flood control and disaster reduction, water resource conservation and intensive safe utilization, water ecological protection, and intelligent water conservancy engineering. The construction progress and application effectiveness of digital twin platforms for water conservancy projects in typical cities were introduced. Finally, the paper summarized the challenges faced by the in-depth application of digital twins in the field of urban water security and proposed prospects, aiming to provide a reference and guidance for the construction of urban water security capabilities that integrate digital twin technology.
Digital twin technology is being rapidly applied and developed in the field of urban water security. Firstly, the paper sorted out and analyzed the current situation of digital twin technology applications for urban water security, explained the framework of urban water security system based on digital twins, and introduced the key techniques and capability requirements in the digital twin system from the perception and collection layer, infrastructure layer, data layer, model layer, knowledge layer, and application layer. Secondly, the application progress of digital twins in urban water security was reviewed, including flood control and disaster reduction, water resource conservation and intensive safe utilization, water ecological protection, and intelligent water conservancy engineering. The construction progress and application effectiveness of digital twin platforms for water conservancy projects in typical cities were introduced. Finally, the paper summarized the challenges faced by the in-depth application of digital twins in the field of urban water security and proposed prospects, aiming to provide a reference and guidance for the construction of urban water security capabilities that integrate digital twin technology.
2024, 54(2): 155-160.
doi: 10.3724/j.gyjzG23121201
Abstract:
With the rapid development of big data in China’s government affairs, it is of great significance to fully utilize a large amount of unlabeled text data in the field of public safety, effectively extract key information from the text, and enhance urban safety governance capabilities. Therefore, a public safety domain text keyword extraction model based on deep reinforcement learning was proposed to quickly label the text content in an unsupervised manner, in order to improve the user's retrieval ability for public safety domain files or events. The paper used the log-sum norm regularization term as the sparse constraint of the loss function of the model to guide the policy network to learn strategies that retain important vocabulary and discard unimportant vocabulary. At the same time, a model training method with variable mini-batch sizes was designed, which could control the difficulty of learning the policy network by setting different mini batch sizes, thereby improving the generalization capacity of the policy network. The performance comparison results showed that the model outperformed traditional unsupervised methods in the task of keyword extraction.
With the rapid development of big data in China’s government affairs, it is of great significance to fully utilize a large amount of unlabeled text data in the field of public safety, effectively extract key information from the text, and enhance urban safety governance capabilities. Therefore, a public safety domain text keyword extraction model based on deep reinforcement learning was proposed to quickly label the text content in an unsupervised manner, in order to improve the user's retrieval ability for public safety domain files or events. The paper used the log-sum norm regularization term as the sparse constraint of the loss function of the model to guide the policy network to learn strategies that retain important vocabulary and discard unimportant vocabulary. At the same time, a model training method with variable mini-batch sizes was designed, which could control the difficulty of learning the policy network by setting different mini batch sizes, thereby improving the generalization capacity of the policy network. The performance comparison results showed that the model outperformed traditional unsupervised methods in the task of keyword extraction.
2024, 54(2): 161-166.
doi: 10.3724/j.gyjzG24010402
Abstract:
The concrete of bridge pile foundations always bear excessive axial loads, and accompanying with its internal failure and crack process, elastic waves will be emitted. In order to quantify the characteristics of the entire instability evolution process of concrete, the temporal and spatial evolution characteristics of acoustic emission in the whole loading process of concrete specimens drilled in situ from bridge pile foundation structures were studied and synchronous monitoring tests of axial compression and acoustic emission were conducted. The relation between the whole process of compressive instability and the acoustic emission ringing counts, energy release, focal locations and other characterization parameters were analyzed. Then, a quantitative description of the correlation between the loading process and acoustic emission characteristics was obtained, and its instability evolution process was analyzed. The results indicated that the stress of concrete specimens under axial compression was consistent with the change law of the acoustic emission ringing counts and energy release with times, and the acoustic emission positioning points mainly located in a macro "positioning zone" in the shear stress concentration area, which was consistent with the development and failure of concrete cracks. The loading stage of concrete could be quantitatively judged according to activity of acoustic emission, which could reflected the critical characteristics of concrete instability, and was of great significance to service monitoring of pile foundation concrete.
The concrete of bridge pile foundations always bear excessive axial loads, and accompanying with its internal failure and crack process, elastic waves will be emitted. In order to quantify the characteristics of the entire instability evolution process of concrete, the temporal and spatial evolution characteristics of acoustic emission in the whole loading process of concrete specimens drilled in situ from bridge pile foundation structures were studied and synchronous monitoring tests of axial compression and acoustic emission were conducted. The relation between the whole process of compressive instability and the acoustic emission ringing counts, energy release, focal locations and other characterization parameters were analyzed. Then, a quantitative description of the correlation between the loading process and acoustic emission characteristics was obtained, and its instability evolution process was analyzed. The results indicated that the stress of concrete specimens under axial compression was consistent with the change law of the acoustic emission ringing counts and energy release with times, and the acoustic emission positioning points mainly located in a macro "positioning zone" in the shear stress concentration area, which was consistent with the development and failure of concrete cracks. The loading stage of concrete could be quantitatively judged according to activity of acoustic emission, which could reflected the critical characteristics of concrete instability, and was of great significance to service monitoring of pile foundation concrete.
