新型在线监测钢弹簧浮置板轨道结构力学特性分析及应用

Analysis and Application of Structural Mechanical Properties of a New Type of On-line Monitoring Steel Spring Floating Slab track

钢弹簧浮置板轨道是城市轨道交通中广泛应用的一种减振降噪轨道结构形式。随着轨道服役时间的增长,浮置板轨道可能出现结构损伤、钢弹簧失效甚至断裂的情况。目前采用天窗时间进行检测,步骤繁琐且不易操作。基于此,提出一种新型可实时掌握浮置板轨道弹簧变形数据的在线监测钢弹簧浮置板轨道结构,通过数值模拟方法对其进行静动力学特性分析,基于现场实测数据进行在线监测应用效果评价。结果表明,新型在线监测钢弹簧浮置板轨道结构力学强度能满足正常使用要求,轨道板最大弯矩为149.7 kN·m,最大剪力为279.5 N,剪力铰最大应力为186 MPa;上承力板最大应力出现在和顶升设备接触位置,为146.1 MPa,在外套筒筒壁上最大应力为102.2 MPa;基于新型钢弹簧浮置板轨道结构,在其与其他轨道过渡的地段进行过渡设置,可使轨道结构过渡更加平缓,减小钢轨最大垂向位移0.85~1.25 mm。在钢弹簧浮置板隔振器内置入测距传感器和接近传感器,可分别实现钢弹簧压缩量测量与弹簧是否断裂或疲劳故障判断。该新型在线监测钢弹簧浮置板轨道结构已在南京地铁S6号线铺设,现场实测数据表明,该新型结构可实时精确地监测轨道结构位移。

Steel spring floating slab track is a kind of vibration and noise reduction track structure widely used in urban rail transit.With the increase of track service time,the structure damage,steel spring failure and even fracture of floating slab track may occur.Currently,skylight time is used for detection,which is cumbersome and difficult to operate.Based on this,this paper proposes a new type of steel spring floating slab track structure for online monitoring,which can grasp the deformation data of floating slab track spring in real time.The static and dynamic characteristics of the new structure are analyzed by numerical simulation method,and the application effect of online monitoring is evaluated based on the field measured data.The results show that the mechanical strength of the new online monitoring steel spring floating slab track structure can meet the requirements of normal use,the maximum bending moment of the track plate is 149.7 kN·m,the maximum shear force is 279.5 N,and the maximum shear hinge stress is 186 MPa.The maximum stress of 146.1 MPa of the upper bearing plate appears in the contact position with the jacking equipment,and the maximum stress of the outer sleeve wall is 102.2 MPa.Adopting the new steel spring floating slab track and reasonably setting it in the transition area with other tracks can make the transition of track structure more gentle and reduce the maximum vertical displacement of rail by 0.85-1.25 mm.The switching sensor and measuring sensor are inserted into the steel spring floating plate vibration isolator,which can measure the compression amount of the steel spring and judge whether the spring is broken or fatigue fault respectively.The new on-line monitoring steel spring floating slab track structure has been laid in Jurong metro line of Nanjing,and the field measurement data shows that the new structure can accurately monitor the track structure displacement in real time.