某线震后轨道设计方案研究

Study on the Track Design Scheme of a Railway Line After Earthquake

2022年1月8日门源发生6.9级地震,造成某线隧道二衬坍塌、桥梁梁体移位、接触网脱落等基础、设备严重损坏,并伴随钢轨折断、扣件脱落、道床倾斜等轨道震害,是我国高速铁路首次遭遇的强震作用下严重受灾事件。结合震后预测余滑变形量水平150~300 mm,垂向100 mm条件下,在设防区段提出一种“三孔连体套管承轨台可调式WJ-8型扣件+长枕埋入式单层道床预留切割孔”新型大调整量无砟轨道结构方案。其中,三孔连体套管承轨台可调式WJ-8型扣件在既有WJ-8型扣件基础上通过增设铁承轨台、调距块和三联套管等部件可满足单股钢轨左右位置调整量达152 mm,长枕埋入式单层道床中预留切割孔,便于在基础变形超出扣件调整范围后切割纠偏;通过对余滑变形后线路拟合获得拨距包络图,确定了大调整量无砟轨道铺设范围。

On January 8,2022,a 6.9-magnitude earthquake occurred in Menyuan,causing serious damages to the foundation and equipment such as the collapse of the secondary lining,the displacement of the beam body,the fall off of the overhead contact system,and accompanied by rail fracture,fastener fall off,track bed overturn and other track seismic disasters.It is the first serious disaster event under the action of a strong earthquake that China's high-speed railway has encountered.Based on the geological prediction of the residual slip deformation level of 150~300 mm and vertical 100 mm,this paper puts forward a new large adjustment ballastless track structure scheme of“adjustable WJ-8 fastener+long sleeper embedded single-layer track bed reserved cutting hole of three hole conjoined casing rail bearing platform”in the fortified section.Among them,the improved WJ-8 fastener can meet the requirement of 152 mm left and right position adjustment of single rail by adding iron rail support platform,distance adjusting block and triple sleeve on the basis of the existing WJ-8 fastener.Cutting holes are reserved in the embedded single layer track bed of long sleepers to facilitate cutting and correction after the foundation deformation exceeds the adjustment range of fasteners.Through the line fitting after the residual slip deformation,the offset envelope table is obtained,and the laying range of ballastless track with large adjustment is determined.