【摘要】 为研究高速有砟道床中存在的累积沉降变化规律,通过PFC离散元软件,建立一定级配的高速铁路散粒体有砟道床的三维离散元模型。选取循环荷载频率分别为5,10,20,30 Hz,荷载幅值为3,5 kN,共8种荷载工况进行数值模拟,分析了道床力学性能,探讨了循环荷载的频率和振幅对道床沉降的影响。研究结果表明:循环荷载频率不超过20 Hz时,荷载频率对道床的沉降量及沉降速率的影响较小;循环荷载频率30 Hz时,其对道床的沉降量及沉降速率的影响显著增大;循环荷载幅值越大,道床的沉降量、沉降速率越大;循环荷载频率越大,道床的垂向刚度越大。更多还原

【Abstract】 To explore the variation laws of cumulative settlement in high-speed ballasted, the discrete element software PFC^3D 5.0 was used to establish a three-dimensional discrete element model of ballast bed with loose grain in graded high-speed railway. The cyclic load frequencies were set at 5 Hz, 10 Hz, 20 Hz and 30 Hz, and the load amplitudes were set at 3 kN and 5 kN. A total of 8 load conditions were selected for numerical simulation test. By analyzing the mechanical properties of the ballast bed, the influence of frequency and amplitude of cyclic load on the ballast bed settlement was discussed. The results show that when the cyclic load frequency does not exceed 20 Hz, the load frequency has little influence on the settlement and settlement rate of ballast bed. When the cyclic load frequency is greater than 30 Hz, the settlement and settlement rate of the ballast bed will increase significantly. The greater the amplitude of the cyclic load, the greater the settlement amount and rate of the ballast bed. The greater the frequency of the cyclic load, the vertical stiffness of the ballast bed will increase.更多还原