Study On Structural Dynamic Response And Damage Laws Of Under Gas Explosion In Underground Utility Tunnel

Underground Utility tunnel means that two or more municipal pipelines such as communication,electricity,network,water supply,gas,drainage,and heat are laid in the tunnel to implement unified planning,design,construction,operation and maintenance.The underground utility tunnel plays a vital role in the normal operation of the city.At present,China’s urban modernization process is very rapid.In order to ensure the safe operation of municipal pipelines,it is urgent to adopt a new pipeline laying method-underground utility tunnel.However,due to concerns about fires and explosions caused by gas pipelines being incorporated into the Utility tunnel,several scholars have proposed some anti-explosion measures to reduce the damage to the structure of the utility tunnel.However,most of the research only focuses on adding antiknock materials to the gas tank,and does not consider the existence of pipeline brackets in the gas tank.If the brackets are properly arranged,they can support the pipeline while hindering the propagation of shock waves and reduce the damage to the tunnel structure.Aiming at the above problems,this paper makes ideal assumptions on the design requirements of gas tanks based on the specifications,and the stress and boundary con ditions of the gas tank and its auxiliary structures.Using ANSYS/LS-DYNA software and the ALE fluid-solid coupling algorithm,the simulation and analysis of different working conditions under the circumstances,the dynamic response of the gas explosion to the gas tank and other compartments,the main research contents and conclusions are as follows:(1)The ANSYS/LS-DYNA large-scale finite element software is used to establish a three-dimensional finite element model of the main structure,explosive gas and air of a typical three-cabin pipe gallery and a fluid-structure coupling numerical model with the same cross-sectional dimensions of utility tunnel.Different board heights indicate different congestion conditions,and the dynamic response and law of the tunnel structure under different congestion conditions are simulated and analyzed.The results show that the concrete partition has a significant effect on preventing explosion impact.The inner side wall of the integrated warehouse generates a large negative pressure.The overpressure stress on the side wall of the integrated warehouse is greater than the roof,and the overpressure stress on the roof of the power warehouse is greater than the side wall.Design and construction Should be considered.(2)Modeling and calculation of the explosion response of the cross node of the underground utility tunnel.Comparing the presence or absence of partitions,the structural damage of the crossing nodes of the tunnel under the conditions of different heigh ts of the explosion shock wave propagation,summarizing the dynamic response law of the underground crossing points of the utility tunnel and the reasons for this phenomenon,giving the anti-explosion design of the crossing nodes Reasonable advice.In order to provide a theoretical reference for the construction design of the explosion-proof measures of the utility tunnel.