不同时速下地铁多种轨道结构现场测试与分析

近年来地铁振动污染问题日益突出,地铁中亦采用多种减振轨道结构型式用于减振。为详细评价各种减振轨道结构的减振效果,以地铁动力测试为依托,在频域内分析4种轨道结构各测试断面在不同时速下的振动特征。结果表明:对于长枕埋入式整体道床轨道而言,行车速度的增加对钢轨、道床、隧道竖向加速度低频范围内的影响较大,而在中高频影响较小。对于GJ-Ⅲ型中等减振扣件轨道,随着行车速度的增加,GJ-Ⅲ型中等减振扣件轨道减振效果下降较明显。同时随着行车速度的提高,橡胶隔振垫浮置板轨道仅对浮置板和隧道减振效果较稳定,而钢弹簧浮置板轨道对钢轨、浮置板及隧道减振效果都很稳定。

Test and Analysis of Vibration Characteristics of Metro Track Structures Subject to Different Speed

In recent years,the problem of subway vibration pollution becomes more and more prominent,and a variety of vibration reduction track structures are adopted in the subway. In order to evaluate the damping effect of various vibration reduction track structures,the vibration characteristics of four kinds of track structures subject to different speeds are analyzed in the frequency domain based on the dynamic test of subway. The results show that the effect of the increase of train speed on the vertical acceleration of rail,ballastless track bed,tunnel of monolithic track bed with buried long sleeper is significant in the low frequency band,while the effect is small in the middle-high frequency band. For GJ-Ⅲ medium type vibration damping rail fasteners,the vibration damping effect decreases obviously as the speed increases.Meanwhile the effect of the rubber vibration isolation pad floating slab track on ballastless track bed and tunnel wall is stable as the speed increases,while the vibration damping effect on rail,ballastless track bed and tunnel wall of steel spring floating slab track is also stable.