Study On The Protective Properties Of Subway Column And Tunnel Lining Subjected To Blast Loading

A subway station includes two parts, the platform and the parking, it's supported by several concrete columns to form a closed underground space. A subway tunnel mainly depends on its surrounding concrete lining to support. Once the columns or the lining was damaged under an accidental explosion, the whole structure may collapse, or even buildings above the ground may be damaged, this will be a huge disaster.Based on the hydrodynamic theory and the explosion mechanics, and using ANSYS/LS-DYNA software, this paper simulates explosions inside the subway station and the tunnel with ALE and fluid-solid coupling methods, and investigates the response of the structural member under explosive impact and the effect of some explosion-proof methods. The primary work and achievement are summarized as follows.(1) Internal space models of the subway station are established to study the column's response in different positions explosions. The result shows that, when the explosion is very close to the column, the part of the column, which is near the explosive, will be broken. And when the explosion is far from the column, the response of the column is very complex. On the back of the column, the stress level may be higher than on the front because of the blast wave, the reflection wave, etc. There are some other parts, such as the corners of the column, easy to be damaged also.(2) To comparatively analyse effects of two explosion-proof methods, different models of the column which is covered by foam aluminum and pasted CFRP respectively are established, and responses of the column under different positions explosions are simulated. The result shows that, the foam aluminum protective layer can decay the blast wave very well, and provide good protection for subway columns. Pasting CFRP makes the maximal stress of the column down and stress distribution be evener. It also has some explosion-proof effects, but they are far fewer than those of the foam aluminum protective layer. So the foam aluminum protective layer should be preferred firstly in the explosion-proof design.(3) The coupling models of explosive-air-tunnel lining-soil system are established to simulate explosions in the tunnel where a foam aluminum protective layer is or is not set on the lining. By comparing the responses of the tunnel lining and analysing the effect of explosion-proof of the foam aluminum protective layer, it is shown that the foam aluminum protective layer can significantly reduce stress level of the tunnel lining and make the stress distributed evenly, the explosion-proof effect is obvious.