Mechanical Properties And Damage Analysis Of Urban Underground Pipe Gallery Structure Under Fire

With the development of Chinese economy,urban land resources are becoming increasingly tense.Because of the non-renewable performance of land resources,in order to increase social resources and economic benefits,more functions are realized in limited underground space,and road re-excavation rates are reduced.The project came into being.Due to the intensive laying of pipelines in the integrated pipe gallery,valuable underground space is reserved for the development of the city,and at the same time,the basic necessary conditions for the construction and management of urban underground pipelines are provided.With the development of China’s smart city,the integrated pipe gallery has gradually developed and built in China.With the development of integrated pipe corridor construction,the pipelines integrated into the integrated pipe gallery have become increasingly complex in recent years,especially the inclusion of natural gas,and the fy fire hazards in the pipe gallery.In the event of a fire,on the one hand,a large number of cable pipelines will lead to rapid expansion of the fire and rapid spread of smoke,resulting in a large loss of personnel and property.At present,the relevant construction standards and norms for integrated domestic corridors are still not perfect.Therefore,in order to improve the safety and security of the development of the corridor industry,and gradually improve the construction standards of the corridors,how to ensure the fire safety of urban underground integrated corridors is of paramount importance.In this paper,through the investigation of tunnel fire experiment and simulation data,the fire scene design suitable for fire in hiire problem of the integrated pipe gallery has gradually entered people’s sight.There are manghway tunnels is obtained.Select the temperature rise curve and the key parameters of the fire scene suitable for the fire scene of the urban underground road tunnel in this paper.Through the finite element software abaqus to establish a three-dimensional model of the integrated pipe gallery,the temperature field simulation analysis of the integrated pipe gallery model under the predefined temperature field is carried out,and the temperature field distribution cloud map of the pipe gallery piece is obtained,and then the temperature field distribution of the tunnel segment piece is obtained.Analyze with the law.The thermal stress temperature-displacement coupling analysis was carried out on the integrated pipe corridor model,and the stress cloud diagram,bending moment value,internal force value and displacement cloud diagram of the pipe corridor structure without fire were analyzed.The stress cloud diagram,moment value,internal force value and displacement cloud diagram of different time period after fire are also analyzed.By comparing and analyzing the data of the composite pipe corridor structure in the absence of fire and the fire,the change of each data is obtained,the regular form of data change is summarized,and the cause of data change is analyzed.Based on the structural fire damage analysis of the composite pipe corridor,the calculated temperature field,combined with the calculation formula of the material strength and elastic modulus after high temperature,can get the cumulative damage depth of the structure,the residual strength and the elastic modulus of the material.Furthermore,the ultimate bearing capacity of the pipe corridor structure is obtained by the equivalent section method,which provides a reference for the design and construction of the comprehensive pipe corridor.