Study On Vibration Isolation Of Built Structure Under The Subway Environment

The subway plays an important part in reducing the pressure of the urban traffic.However, with the increase of the subway route and the increasing speed of the subway,a series of negative impact appear.One of the most common of is the vibration effects onbuildings along the subway.In this paper, based on the vibration problem of a nearby residential buildingcaused by Shanghai subway for the project background, supported by ANSYS finiteelement analysis software, establish the finite element analysis model of subway tunnel,analyze the dynamic effects on the ballast of the subway tunnel, establish finite elementanalysis model of the brick-concrete structure, input the acceleration of the ballast as thewave to the residents upstairs, use the dish spring vibration isolation device, compare ofthe role before setting vibration isolation and after setting vibration isolation under theinfluence of the subway through the process analysis.This paper mainly accomplished the following work:1. Using the discrete finite model to simulate the infinite foundation. Researchuniform viscoelastic artificial boundary theory, equal the Poisson’s ratio, shear modulus,elastic modulus and damp to simulate an equivalent property boundary cells.2. Research the ballast load affected by the train. According to the already calculateload between the sleeper train schedule to dissipate to the ballast. Train load eventuallyis reduced to the form of harmonic to input.3. Establish the entity model of the tunnel based on the theory of the finite element.Analyze the dynamic effects of the ballast in the subway tunnel. Extract the verticalacceleration. In finite element analysis, input the subway vibration wave to thestructure.4. Study the structure of the disc spring vibration isolation device, and puts forwardthe design method of disc spring vibration isolation device. The calculation formula ofdisc spring stiffness, capacity and the limit deformation is given. In this paper the designof disc spring vibration isolation device based on actual.5. Based on the finite element theory, taking a6layer brick structure as theresearch object divided into the following several ways to discuss,1) under theinfluence of the subway in simulation, no isolation structure’s effects.2) under theinfluence of the subway in simulation, isolation structure’s effects.3) under the influence of the subway in actual measurement,no isolation structure’s effects.4) underthe influence of the subway in actual measurement,isolation structure’s effects. On thebasis of the subway vibration impact on the ballast,3D entity analysis model isestablished by ANSYS, comparing the upper structure vibration response under allkinds of cases through the process analysis. After setting up disc spring vibrationisolation device, the displacement and acceleration between layers of the brick structureare decreased accordingly.