To understand the characteristics of goaf air leakage and gas migration in different mining periods of Y-type ventilation working face without coal pillar mining，97312 working face in Sihe No.2 coal mine of Jinneng Holding Equipment Manufacturing Group Co.，Ltd. was selected. The sulfur hexafluoride (SF₆) tracer gas approach was used to determine the air leakage area distribution，air leakage type，and air leakage volume of 97312 working face and the roadways under different connectivity states with the adjacent 97311 working face goaf. The air leakage flow field distribution and gas migration characteristics in the goaf area were analyzed by numerical simulation. The results showed that 97312 working face had four air leakage areas of positive pressure-negative pressure-positive pressure-negative pressure along the wind direction. The main air intake roadway 97222 had positive pressure leakage. The air return roadway 97224 had mainly negative pressure air leakage along the gob-side entry retaining section，but positive pressure leakage was prone to occur near the extraction pipe and in the area where the roadway was severely deformed. After connectivity with the adjacent goaf area，an additional air leakage path was created. Moreover，the connection status with the adjacent goaf affected the internal air leakage flow field and gas migration of the goaf. Air leakage from the 97311 goaf area carried gas to the 97312 goaf，causing an increase in gas volume fraction in the 97312 goaf，working face，and the gob-side entry retaining section of the 97224 roadway. After the closure of the 97311 working face，the gas volume fraction near the connected goaf area decreased.

To effectively prevent and control the risk of subway waterlogging accidents，a quantitative analysis method integrating the AcciMap model，FAHP，and triangular fuzzy DEMATEL-ISM method was proposed to investigate the causes of urban subway waterlogging accidents and their coupling associations. Accident causation factors were selected from the system level through AcciMap model. FAHP was used to integrate expert opinions and determine expert weights. The DEMATEL method was used to calculate the importance of accident causes，ISM method was used to reveal the relationship between factors，and a multi-level ladder stepwise graph was constructed. The model was validated by waterlogging accidents on the Zhengzhou subway. The results showed that the core contributing factors leading to the incident were inadequate awareness and prevention measures of major disasters by the management department，the lack of diligence in supervision and inspection duties by regulatory authorities，and ineffective response and handling by operational departments. These factors can be paid special attention to prevent system failures.

In order to improve the theoretical guidance of safety training and promote the effective promotion of safety training in enterprises，a safety training curriculum system framework based on "principle，law，technique，instrument，power，and goal" was created by applying the related theories such as the ACT training method，safety-Ⅰ and safety-Ⅱ. Then，important training points and the level of mastery of knowledge for various types of employees were clarified，and the application study was conducted. The results show that the training covers six dimensions: safety management objective，safety ideology principles，safety laws and regulations，safety management requirements，safety management tools and safety production situation. The 77 sets of video courses made according to the framework of the developed safety training course system have achieved good feedback in application. It can offer enterprises some direction and a point of reference when creating training materials，making training schedules and setting up safety training.

In order to solve the heat damage issue brought by deep mining in coal mines，based on ANSYS simulation software，the roadway heat insulation model was constructed. The influence of basic parameters of different heat insulation layers and laying methods on the roadway wall structure was analyzed，and the cooling effect of the heat insulation roadway was further investigated. The results of the study show that the laying of the heat insulation layer could reduce the radius of the peripheral rock heat-regulating circle and slow down the heat dissipation of the peripheral rock，and the three ways of laying the heat insulation layer have little effect on the temperature field of the peripheral rock. Compared with the temperature of the non-insulated support layer，the average temperature of the support layer is reduced significantly by laying of the heat insulation layer in the rock-adhering type，whereas the opposite is true for wall-adhering type and the sandwich type. The increase in the thickness of the heat insulation layer and the decrease in the heat conduction coefficient of heat-insulating material could increase the heat-insulating effect，and 7cm is the optimal thickness of heat insulation layer. Excessive inlet wind speed or air temperature will affect the cooling effect of heat-insulated roadway. Heat-insulated roadway is suitable for high temperature roadway with low wind speed，low inlet air temperature and long ventilation distance.

In order to improve the safety of the shale oil gathering and transportation process，this paper took the shale oil gathering and transportation process under the in-situ transformation technology of superheated steam injection of oil shale as the evaluation object. In the process of shale oil gathering and transportation，the hazard were analyzed and the whole process was divided into three subsystems. The risk of each subsystem was analyzed qualitatively by using hazard and operability analysis(HAZOP) method. According to the results of the qualitative analysis，the probability of fire and explosion accidents and the risk grade of each subsystem were calculated by using layer of protection analysis(LOPA) and Dow fire and explosion index(F&EI) method. The nodes of shale oil gathering and transportation process were divided，and Bow-tie models for oil and gas leakage accidents containing hydrogen sulfide and oil and gas leakage accidents after purification were established respectively. Based on results of risk assessment，effective safety prevention and control measures were developed. The results show that the subsystems that may cause accidents in the oil and gas gathering and transportation process are: steam generation system，cooling separation system，ammonia desulfurization system and cooling separation system，in which the leakage of the steam generation system will not cause fire and explosion accidents，and the fire and explosion risk grades of the remaining subsystems are: ammonia desulfurization system，cooling separation system and gas extraction and desulfurization system in order from heavy to light.

To improve the efficiency of urban sewage pipeline defect detection，reduce resource wastage resulting from indiscriminate inspection methods，and mitigate environmental safety risks，the XGBoost model was used to predict the probability of urban sewage pipeline defects. Firstly，the causes of sewage pipe defects were statistically analyzed to determine key indicators that can characterize the pipeline defects as the inputs of the XGBoost model. Secondly，appropriate objective functions and base learner parameters were selected. Then the model training and optimization were performed by a grid search algorithm to determine the key parameters of the base learner. Finally，the XGBoost model prediction performance was validated against an area of the sewage pipeline network in Zhongshan，Guangdong province. Moreover，the main factors and paths affecting defect probability were investigated based on the model output，and the defect probability of the sewage pipe network in the area was divided into 4 different levels for visualization.The results indicated that the average area under curve (AUC) of the XGBoost model was 0.97 under 10-fold cross-validation with a prediction accuracy of 93%. Pipeline depth，slope，and length had the greatest impact on the probability of pipeline defect. As the pipe length increases，the sewage pipe defect probability will increase if the slope becomes greater and the buried depth becomes shallower.

To improve the efficiency of disaster reconnaissance，a prioritized multi-UAV cooperative scheduling optimization model was proposed for the UAV reconnaissance scheduling problem in disaster emergency responses. An improved tabu search algorithm was proposed by using a mixed integer nonlinear programming model. Moreover，specific neighborhood operators and repair operators were used to enhance the algorithm's search capability and solution quality. Two cases were designed to validate the model and algorithm performance. The first case was based on the actual scenario of the Zhengzhou flood in 2021，and the second case simulated examples of different scales. The results indicated that the model and algorithm were effectively validated. The effects of flight speed，UAV quantity，model，and endurance on reconnaissance capabilities were investigated through sensitivity analyses. The reconnaissance efficiency can be significantly improved by increasing the number of UAV models and optimizing them. UAVs with strong reconnaissance capabilities should be given priority when resources are limited. However，flight speed is more critical when resources are sufficient.

To improve the evacuation efficiency and ensure the safety of passengers on an open deck in the event of an accident，a heterogeneous evacuation model considering passenger heterogeneity and group effect was constructed using AnyLogic software. Four simulated evacuation scenarios，including individuals，two-person，three-person and mixed groups，were constructed，and the evacuation process of heterogeneous passengers under different group sizes was simulated. The results indicate that with the increase of the group size，the total evacuation time increases nonlinearly. Specifically，the evacuation time for passengers in two-person，three-person and mixed-group scenarios is 11.8%，19.6% and 15.5% longer than that in individual evacuations，respectively. Additionally，the peak of passengers' arrival at the terminal occurs in the early and middle stages of evacuation. In group evacuations，the higher expected passenger speed correlates with more dispersed arrival time distributions. These findings highlight the interaction effect between heterogeneous passengers and group effect in the evacuation process.

In order to quantify the psychological changes of crowds and the impact of competitive factors on the behaviors of evacuees in emergency evacuation situations，a dynamic model was constructed that closely links the state of personnel psychological state with competitive influencing factors. In this model，the crowd was divided into three categories based on individual behavioral characteristics: independent evacuees，cooperative evacuees，and competitive evacuees. Three major factors influencing individual decision-making during the evacuation process were analyzed in depth: personal characteristics，social guidance mechanisms，and environmental factors. Specific parameter values were set，and SD were employed to simulate and study the behavioral characteristics of pedestrians during emergency evacuation. The research results indicate that as environmental visibility decreases and panic spreads，the proportion of competitive evacuees significantly increases. Conversely，when there are positive guiding behaviors and acts of helping others in the environment，these positive factors can effectively alleviate the crowd's anxiety and reduce competitive behaviors. Particularly noteworthy is that when multiple factors are coupled，the greater the competitive intensity，the more significant the positive effect of helping behaviors becomes. This shows that in highly stressful evacuation environments，positive social guidance and mutual assistance behaviors play a non-negligible role in relieving competitive pressure and improving evacuation efficiency.

To investigate the evolution of overburden structure and the stability of district coal pillars during the mining of shallow-buried coal seam island faces，a study was conducted with the 50104 working face of Taihua coal mine as the engineering background. The research employed a combination of theoretical analysis，numerical simulation，and on-site measurement to analyze the load-bearing capacity of the district coal pillars and the characteristics of overburden structure evolution on both sides. The FLAC^3D numerical software was utilized to simulate the distribution of plastic zones and the evolution of mining-induced stress. The results indicate that during the advancement of the 50104 working face，the plastic destruction of the district coal pillars on both sides lagged behind the progress of the working face. The district coal pillars located in the goaf area behind the working face were in a state of plastic destruction，while those in front of the working face coal wall maintained a stable elastic zone，overall remaining stable. Throughout the working face advancement，the stress distribution of the district coal pillars on both sides exhibited the same characteristics，with two 11 m coal pillars showing symmetric high-stress concentration areas，both located behind the working face. The development speed of the high-stress destruction area of the district coal pillars lagged behind the advancement speed of the working face. The average stress value in the central area of the district coal pillars in front of the working face increased from 3.35 MPa to 3.54 MPa，but it never exceeded the coal pillar bearing capacity value calculated theoretically. Analysis of the mine pressure monitoring data from the 50104 working face revealed that the average initial support force was 3 932.4 kN，accounting for 55% of the rated initial support force of hydraulic support. The average maximum working resistance was 5 812.3 kN，representing 61.2% of the rated working resistance. The weighted average resistance was 4 836.6 kN per support，which is 50.9% of the rated working resistance. The maximum pressure was 6 013 kN，with a support stress of about 2.35 MPa，proving the stability of 11 m coal pillars and indicating that the overall stability of the district coal pillars in front of the working face coal wall is relatively good.