活动断裂带下聚氨酯固化道床受力与变形传递规律及其影响

Stress and Deformation Transfer Laws of Polyurethane Solidified Ballast Beds Under Active Fault Zones and Their Impact

为研究活动断裂带下聚氨酯固化道床结构的受力和变形传递规律及其影响,针对活动断裂带地质特征和聚氨酯固化道床结构特点,基于有限元法和仿真分析软件建立相应的有限元模型。研究结果表明:断裂所致的基础错动将直接映射到轨面,形成明显轨道不平顺,轨面不平顺线形与断裂面线形相近,但不完全重合;断裂位移导致轨面高低、方向变化率增量大于断裂角影响,断裂位移由5 mm增至20 mm,轨面高低、方向变化率增量分别为2.18,0.77 mm/m,断裂角由30°增至90°,轨面高低、方向变化率增量分别为0.11,0.03 mm/m,断裂位移是影响轨道不平顺的主要因素;正断层和走滑断层形成的钢轨变形波长分别为6.1~7.0 m和17.0~19.6 m,后者约为前者的3倍;正断层作用下,固化道床底部离缝宽度随断裂竖向位移v的增加而增大,断裂位置离缝明显,断裂位移为20 mm时,最大离缝宽度达10 mm以上;固化道床纵向应力分布连续,变形曲率最大处应力最大,但应力水平整体较低。

To investigate the stress and deformation transfer laws of polyurethane solidified ballast beds under active fault zones and their impacts,a corresponding finite element model was established according to the geological characteristics of active fault zones and the structural characteristics of the polyurethane solidified ballast beds,utilizing finite element methods and simulation analysis software.The results showed that the foundation dislocation caused by faults directly mapped to the track surface,resulting in significant track irregularities.The shape of the track surface irregularities closely resembled the fault surface but did not completely coincide.Displacement due to faults led to a larger increase in the elevation and direction change rate of the track surface compared to the effect of the fault angle.Specifically,as the fault displacement increased from 5 mm to 20 mm,the elevation and direction change rates of the track surface were 2.18 mm/m and 0.77 mm/m,respectively.In contrast,when the fault angle increased from 30°to 90°,the elevation and direction change rates were 0.11 mm/m and 0.03 mm/m,respectively.The fault displacement emerged as the main factor affecting track irregularity.The wavelengths of rail deformation formed by normal and strike-slip faults were 6.1~7.0 m and 17.0~19.6 m,respectively,with the latter being about three times longer than the former.The gap width at the bottom of the solidified ballast bed increased with the vertical displacement v of the faults under normal fault conditions.The gap at the fault location was pronounced,reaching a maximum width of over 10 mm when the fault displacement was 20 mm.The longitudinal stress distribution of the solidified ballast bed was continuous,with the maximum stress at the point of maximum deformation curvature but the overall stress levels remained relatively low.