Simulation Of Fire And Evacuation In The Construction Of Underground Integrated Pipe Gallery

With the continuous improvement of the development and utilization of urban underground integrated pipe corridors,the number of dangerous sources with sudden,uncertain and difficult to control characteristics has also increased,which is likely to cause major safety accidents.Therefore,considering the particularity of the underground integrated pipe gallery and the severity of the fire in the construction,it is very important to study the characteristics of the fire smoke and temperature field,and can provide suggestions and construction optimization ideas for the safety management of underground integrated pipe gallery during construction.The main findings are as follows:(1)BIM technology was applied to the identification of hazard sources,combined with the design of construction organization,using the characteristics of BIM technology coordination and visualization,to identify typical hazards such as collapse,high ground fall and fire in the underground integrated pipe gallery construction site,and summarized the source of energy from the source of the hazard and possible accidents.Then fishbone diagram was used to find out the cause of the accident.The PHA method was used to scientifically evaluate the degree of danger of four typical hazards.Ten experts in construction management were invited to analyze and judge the conditions and possible consequences of the accident.The principle of majority referendum was used to determine the hazard level of the hazard source,and the hazard level of the fire accident was obtained as IV,which was the highest.(2)The PyroSim fire software was used to simulate the fire accidents during construction.Through the investigation of the construction site,the simulation parameters were set,and the fire situation was simulated realistically and objectively.By setting multiple sets of thermocouples,smoke and other measuring points and visibility slices,the temperature,smoke and visibility changes under different working conditions were studied.At the same time,smokeview was used to observe the spread of smoke,thus determining the available safe evacuation time of construction workers.Through the comparative analysis of three working conditions,it is found that the first working condition has the highest risk,and the available evacuation time is the shortest.The second condition is the second most dangerous.The third type of working condition has the least risk,and the construction workers have the longest available evacuation time.(3)To ensure that the construction workers were able to safely evacuate,Pathfinder software was used to determine the evacuation.On the basis of simplifying the evacuation model,the simulation of different working conditions were carried out by setting parameters such as construction personnel’s physical signs,evacuation mode,evacuation path and evacuation speed.Then combined with the warning time and response time to determine the required evacuation time for each working condition.Comparing the available safe evacuation time with the required safety evacuation time,the first most dangerous working condition couldn′t meet the safety evacuation requirements.The construction was optimized from the perspective of increasing the alternate escape port and adjusting the schedule and reducing the number of construction personnel until the safety evacuation requirements were met.The latter two conditions were relatively less dangerous and the construction personnel could evacuate safely.Based on the analysis of the simulation results,the construction suggestions and countermeasures were put forward and fed back to the project management office,which provided a new idea for the safety construction management optimization.