Study On Anti-explosion Performance Of Foam Concrete Composite Lining Structure

After decades of construction and development,China has gradually formed a relatively perfect traffic system.The number of subway tunnels is constantly increasing,and people travel in more diversified ways.However,the increasingly complex international situation and frequent traffic accidents make urban traffic safety face many new challenges.The tunnel is generally located in the traffic throat,and the internal space is relatively closed.Once the explosion accident occurs,it will bring incalculable loss.Therefore,the research on the anti-explosion performance of the tunnel lining layer has important practical significance and economic value for the development of China.Through theoretical analysis and numerical simulation verification,this paper analyzes the dynamic response and anti-explosion performance of tunnel single-layer lining structure and foamed concrete composite lining structure under the action of external explosion.Specific research contents and results mainly include the following points:1.The numerical model of single-layer lining structure was established by using the dynamic analysis software ANSYS/LS-DYNA to study the dynamic response of single-layer lining structure under the action of explosion.The simulation results show that the overall deformation characteristics of the single-layer lining structure under the action of explosion are vertical extrusion and horizontal expansion.The dynamic response of the tunnel lining superstructure under the action of external detonation is the largest and the dynamic response gradually decreases with the increase of detonation distance.2.Study the influence of overburden on the dynamic response of tunnel lining structure.The simulation results show that the overburden of explosives can effectively seal off the explosion energy and avoid energy dissipation too fast.The higher the overburden density of explosives,the more explosive energy will be sealed by overburden,and the higher the dynamic response degree of the lining structure of underground tunnels will be3.Study the anti-explosion performance of foamed concrete composite lining structure.The simulation results show that foamed concrete composite lining structure has better anti-explosion performance than monolayer lining structure,foamed concrete can effectively absorb explosion energy and reduce the damage of lining internal structure under explosion action,in which the effective stress of arch in composite lining structure decreases by 31.54%～43.81%.4.Analyze the influence of the position and combination form of foamed concrete on the anti-explosion performance of composite lining structure.The results show that the ratio of the thickness of the outer arch to the thickness of the inner arch is 1:2～1:3,and the anti-explosion performance is the best.Compared with the three-layer composite lining structure and single-layer lining structure,the five-layer composite lining structure has better anti-explosion performance.The maximum effective stress of the external arch and the internal arch of the five-layer composite lining structure can be reduced by 19.12%and 38.8%respectively.Figure[52]table[8]reference[53]...