(1.East China Jiaotong University, Nanchang, Jiangxi 330013, China; 2.Guangzhou Metro Design and Research Institute Co. Ltd, Guangzhou, Guangdong 510010, China)
Abstract:Abstract:Research purposes: In order to study the influence of the key influence parameters on the stress and deformation of track subgrade structure under the train load and get the optimal parameters combination of the track subgrade, the finite element analysis model of short sleeper embedded track subgrade of tram is established, five factors to the track subgrade mechanical properties are studied with orthogonal test method, which are fastener stiffness, track plate thickness, thickness of the support layer, the total thickness of subgrade and subgrade compaction index K30. In order to make up for the deficiency of quantitative analysis of orthogonal experiment, the weight coefficient of each evaluation index is determined by analytic hierarchy process (AHP). Finally, the optimal parameters combination of short sleeper embedded track subgrade structure is determined. Research conclusions: (1) The stiffness of the fastener has the greatest influence on the rail displacement, and the thickness of the track slab has the greatest influence on the longitudinal bending moment of the track slab and the dynamic stress at the top of the subgrade, and the subgrade compaction index K30 has the greatest influence on the deformation of the top of the subgrade. (2)The weight coefficients of rail displacement, track slab bending moment, subgrade top displacement and dynamic stress are 0.085, 0.583, 0.043 and 0.289, respectively. (3)The optimal design scheme of track subgrade is fastener stiffness 40 kN / mm, the thickness of track plate of 0.24 m, the support layer thickness of 0.27 m, the total thickness of subgrade of 1.1 m, subgrade compaction index(K30) of 110 MPa/m. (4)Comprehensive use of orthogonal experiment and analytic hierarchy process can transform qualitative problems into quantitative problems, so that the analysis results are more scientific and convincing. (5)The research results have reference value for the design of tram short sleeper embedded track and subgrade.