秦沈线月牙河特大桥轨道周期性高低不平顺分析

Analysis on Periodic Track Profile Vertical Irregularities of the Yueyahe Extra-long Bridge on the Qin-Shen Railway

结合月牙河特大桥动力分析和轨道不平顺分析,以及量测所得到的数据,表明桥上线路周期性高低不平顺并非动荷载下桥梁挠度变形造成的,也不是由车桥共振引起的,从所得到的数据分析来看,不平顺值的增长速度随时间的增加而逐渐减小,符合徐变上拱的发展规律。目前桥上线路高低不平顺值尚未达Ⅰ级超限,对行车安全没有造成影响。建议在客运专线建设中,进一步控制长大连续等跨简支梁的徐变上拱,尤其应控制二期恒载轨道铺设后的徐变上拱,并加强桥上线路高低不平顺的检测。桥上线路在达到高低不平顺Ⅰ级超限前,就及时进行大型养路机械捣固或调整扣件作业。由于在桥梁上产生相同的多个波连续作用,应对有关车辆在该特殊高低不平顺作用下的动力学性能进行校核。

According to dynamic analysis and track irregularities analysis and site measurement of the Yueyahe Extra-long Bridge, periodical track profile irregularities on the Bridge are seen to be caused neither by deflection of the Bridge under dynamic loads nor by resonant vibration between vehicles and the Bridge; the increasing speed of track irregularities decreases with the increase of time, which conforms to the rule of creep develop- ment. At present, the values of track profile irregularities have not reached defect level ]~ , so they have no in- fluence on traffic safety. It is suggested that creep of long and continuous equal-span simply-supported beams should be further controlled in construction of dedicated passenger line, especially after the secondary-stage deadqoad track laying and inspection should be intensified in respect of on-bridge track profile irregularities. Machine tamping or rail fastening adjustment should be carried out in time before defect level I is reached. Beacause of emergence and continuous action of multiple identicle waves on the bridge, dynamic behavior of vehicles under the effect of the special track vertical profile irregularities should be checked.