Numerical Simulation Of Tunnel Antiknock Effect On The Performance For Expanded Polystyrene Sphere Concrete

EPS concrete isthe concrete with light weight containingExpandedPolystyrene Sphereparticles. Due to the characteristicof the Expanded PolystyreneSphere particles such aslow density and elastic modulus, theEPS concrete canreduce the weight of the structure.The sound velocity, wave velocity and acousticimpedance or impedance of the EPS concrete is far less than the common concrete,thus it can reflect most of the blast wave loadeffectively, reduce the velocity of thestress wave and weaken the intensity of the stress wave. At the same time thevibration cycle of the structure itself is long so the EPS concrete can absorb thewave energy fast. The effect of anti-explosion is very significant. The Ls-dynadynamic analysis program was used for the numerical simulationof the tunnelstructure under explosion load in this paper. Theprotection of EPS concrete layerwhich can buffer and absorb energy to the inside tunnel lining structure wasresearched. The research results show that EPS concrete can reflect and absorbtheenergy of the explosion stress wave. The simulation results show that:1、the sameEPS particle size and differentEPS content:The pressure of the arch top and archwaist inside of the tunnel lining and the peak value of the maximum principal stressdecreases with the increasing EPS content in concrete while the index of thepressure peak attenuation increases with the content of EPS in concrete. The EPScontent is higher, the buffer layer properties is stronger;2、 the same EPScontentand differentEPS particle size: The pressure of the arch top and arch waistinside of the tunnel lining and the peak value of the maximum principal stressincreases with the increasing EPS content in concrete while the index of thepressure peak attenuation decreases with the content of EPS in concrete.The EPSparticle size is smaller, the buffer layer properties is stronger;3、the same EPScontentandEPS particle size, different location of explosive: EPS concrete cushionlayer also has protective effect ofthe tunnel lining. The pressure of the arch top andarch waist inside of the tunnel lining and the peak value of the maximum principalstressdecreases with the increasing displacement of theexplosive location. Andtheattenuation index decreases with the increasing displacement of theexplosive location.