In recent years,the escalation in accidental explosions has emerged as a formidable threat to tunnel infrastructures.Therefore,it is of great significance to conduct a dynamic performance analysis of the tunnels,to im...In recent years,the escalation in accidental explosions has emerged as a formidable threat to tunnel infrastructures.Therefore,it is of great significance to conduct a dynamic performance analysis of the tunnels,to improve the safety and maintain the functionality of underground transport hubs.To this end,this study proposes a dynamic performance assessment framework to assess the extent of damage of shallow buried circular tunnels under explosion hazards.First,the nonlinear dynamic finite element numerical model of soil-tunnel interaction system under explosion hazard was established and validated.Then,based on the validated numerical model,an explosion intensity(EI)considering both explosion equivalent and relative distance was used to further analyze the dynamic response characteristics under typical explosion conditions.Finally,this study further explored the influence of the integrity and strength of the surrounding soil,concrete strength,lining thickness,rebar strength,and rebar rate on the tunnel dynamic performance.Our results show that the dynamic performance assessment framework proposed for shallow circular tunnels fully integrates the coupling effects of explosion equivalent and distance,and is able to accurately measure the degree of damage sustained by these structures under different EI.This work contributes to designing and managing tunnels and underground transport networks based on dynamic performance,thereby facilitating decision-making and efficient allocation of resources by consultants,operators,and stakeholders.展开更多
In view of the environmental and safety risks of hazardous chemical explosions in chemical enterprises,the fault tree analysis was used to establish a fault tree model of hazardous chemical explosions and comprehensiv...In view of the environmental and safety risks of hazardous chemical explosions in chemical enterprises,the fault tree analysis was used to establish a fault tree model of hazardous chemical explosions and comprehensively analyze the possibility of the explosions.The 34 basic events that caused hazardous chemical explosions were expounded,and the minimum cut and path sets were obtained.The structure importance of basic events were calculated.According to the minimum path sets,the basic events when the accident does not occur were determined,and combined with the sequence of structure importance,the preventive measures for hazardous chemical explosion accidents were proposed.The fault tree model intuitively clarified the correlation between the direct causes of hazardous chemical explosion accidents,and proposed directions for effectively reducing the probability of hazardous chemical explosion accidents in the chemical industry.展开更多
Driven by the goals of carbon neutrality,electrochemical storage technologies play a vital role in supporting the integration of renewable energy and reducing dependency on fossil fuels.The Mn-based rechargeable batte...Driven by the goals of carbon neutrality,electrochemical storage technologies play a vital role in supporting the integration of renewable energy and reducing dependency on fossil fuels.The Mn-based rechargeable battery(MnRB)is gaining significant attention in the battery industry due to its high voltage platform and high energy density,making it a potential alternative in the e-bike and energy storage system area.The safety performance of MnRB is crucial for its widespread application.However,there has been a scarcity of studies evaluating the safety of MnRB.In this study,the thermal safety behavior of a commercial Mn-based composite cathode battery from the perspectives of"heat generation-gas emission-explosion risks".Its safety performance was compared with that of existing batteries using Li(Ni_(x)Co_(y)Mn_(z))O_(2) and LiFePO_(4)(LFP)as cathode materials.The results indicate that MnRB exhibits a higher triggering temperature,0.8%lower than Li(Ni_(0.5)Co_(0.2)Mn_(0.3))O_(2)(NCM523)and approximately 12.7%lower than LFP.MnRB’s normalized gas emission during thermal runway(TR)is 1.3%lower than that of NCM523,with the primary gas components being CO,H_(2),and CO_(2).The lower explosion limit of MnRB is approximately 2.7%lower than NCM523 and 44.0%higher than LFP.MnRB exhibits intermediate thermal stability and combustion-explosion characteristics between NCM523 and LFP.This study provides valuable data on MnRB’s TR behavior,offering a comprehensive assessment of MnRB’s intrinsic safety performance through quantitative evaluation.The findings present clear directions for designing,optimizing,and implementing safety measures for MnRB against TR.展开更多
基金Project(22dz1201202)supported by the Shanghai Science and Technology Committee Program,ChinaProjects(52108381,52090082)supported by the National Natural Science Foundation of China+1 种基金Project(2023QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST,ChinaProject(TSY2022QT161)supported by the Damage Database for Urban Rail Transit Underground Structures and Resilience Evaluation Algorithm Research。
文摘In recent years,the escalation in accidental explosions has emerged as a formidable threat to tunnel infrastructures.Therefore,it is of great significance to conduct a dynamic performance analysis of the tunnels,to improve the safety and maintain the functionality of underground transport hubs.To this end,this study proposes a dynamic performance assessment framework to assess the extent of damage of shallow buried circular tunnels under explosion hazards.First,the nonlinear dynamic finite element numerical model of soil-tunnel interaction system under explosion hazard was established and validated.Then,based on the validated numerical model,an explosion intensity(EI)considering both explosion equivalent and relative distance was used to further analyze the dynamic response characteristics under typical explosion conditions.Finally,this study further explored the influence of the integrity and strength of the surrounding soil,concrete strength,lining thickness,rebar strength,and rebar rate on the tunnel dynamic performance.Our results show that the dynamic performance assessment framework proposed for shallow circular tunnels fully integrates the coupling effects of explosion equivalent and distance,and is able to accurately measure the degree of damage sustained by these structures under different EI.This work contributes to designing and managing tunnels and underground transport networks based on dynamic performance,thereby facilitating decision-making and efficient allocation of resources by consultants,operators,and stakeholders.
基金Supported by the Science and Technology Plan Project of Liaoning Province,China(2019JH8/10300102)。
文摘In view of the environmental and safety risks of hazardous chemical explosions in chemical enterprises,the fault tree analysis was used to establish a fault tree model of hazardous chemical explosions and comprehensively analyze the possibility of the explosions.The 34 basic events that caused hazardous chemical explosions were expounded,and the minimum cut and path sets were obtained.The structure importance of basic events were calculated.According to the minimum path sets,the basic events when the accident does not occur were determined,and combined with the sequence of structure importance,the preventive measures for hazardous chemical explosion accidents were proposed.The fault tree model intuitively clarified the correlation between the direct causes of hazardous chemical explosion accidents,and proposed directions for effectively reducing the probability of hazardous chemical explosion accidents in the chemical industry.
基金Funded by the National Key R&D Program-Strategic Scientific and Technological Innovation Cooperation 2022YFB2404400.
文摘Driven by the goals of carbon neutrality,electrochemical storage technologies play a vital role in supporting the integration of renewable energy and reducing dependency on fossil fuels.The Mn-based rechargeable battery(MnRB)is gaining significant attention in the battery industry due to its high voltage platform and high energy density,making it a potential alternative in the e-bike and energy storage system area.The safety performance of MnRB is crucial for its widespread application.However,there has been a scarcity of studies evaluating the safety of MnRB.In this study,the thermal safety behavior of a commercial Mn-based composite cathode battery from the perspectives of"heat generation-gas emission-explosion risks".Its safety performance was compared with that of existing batteries using Li(Ni_(x)Co_(y)Mn_(z))O_(2) and LiFePO_(4)(LFP)as cathode materials.The results indicate that MnRB exhibits a higher triggering temperature,0.8%lower than Li(Ni_(0.5)Co_(0.2)Mn_(0.3))O_(2)(NCM523)and approximately 12.7%lower than LFP.MnRB’s normalized gas emission during thermal runway(TR)is 1.3%lower than that of NCM523,with the primary gas components being CO,H_(2),and CO_(2).The lower explosion limit of MnRB is approximately 2.7%lower than NCM523 and 44.0%higher than LFP.MnRB exhibits intermediate thermal stability and combustion-explosion characteristics between NCM523 and LFP.This study provides valuable data on MnRB’s TR behavior,offering a comprehensive assessment of MnRB’s intrinsic safety performance through quantitative evaluation.The findings present clear directions for designing,optimizing,and implementing safety measures for MnRB against TR.
