Dynamic Responses And Blast Resistance Of Two-way Subway Tunnels Subjected To Explosion Load Inside One-sided Tunnel

At the present time, the exploitation of underground space has been becoming the important component of the basic development of our country. Underground structures, such as subways and underground commercial spaces, should have the sufficient anti-explosion ability to prevent from blast triggered by accidents or terroristic attacks. Therefore, studying the dynamic responses of underground structures to various internal explosions has important theoretic meanings and engineering values in the design, construction and anti-explosion analyses for underground structures. In this paper, the dynamic responses and anti-detonation measure of two-way subway tunnel subjected to explosion loads inside one-sided tunnel are investigated, and the primary works are as follows.(1) A whole numerical model, consisting of two-way subway tunnels, its surrounding finite stratified soil and the far-field semi-infinite soil, is established in consideration of soil-structure interaction using the coupling method of the finite and infinite element. Through the numerical simulation for the experiment held by Baron, the validity of the model proposed in the dissertation is proved.(2) Based on the geological reconnaissance materials of an actual subway engineering, the finite element model of soil is built, and the rules and developing trends for some responses of tunnel linings and the soil around, such as displacements, velocities, accelerations, normal stresses and shear stresses, are analyzed in detail, and meanwhile the traveling-wave effects and the attenuation characteristics of the underground explosion waves propagating along the semi-infinite soil are also testified.(3) As to the interaction between the tunnel linings and the soil around, the Goodman element is introduced as a kind of contacting element to investigate the laws of the slipping and debonding of interfaces. In addition, the effects of the explosion overpressure, the embedded depth and the spacing interval of the two-way subway tunnels, and the properties of soil surrounding the tunnels on the stress fields of the tunnels and soil around are discussed at length.(4) In reference to the breakage of tunnel linings under the blast, the foam aluminum is applied as a type of blast protection material to study its anti-blast effects on tunnel linings as well as its feasibility of engineering application.