桥上CRTSⅢ型板式无砟轨道无缝线路伸缩力影响因素分析

Analysis on influencing factors of expansion-contraction force of CRTSⅢ slab track CWR on bridge

基于有限元法建立桥上CRTSⅢ型板式无砟轨道无缝线路精细化空间耦合模型,计算温度荷载作用下桥梁及轨道结构的伸缩力与位移,分析不同梁体温差、扣件纵向阻力、温度跨度、支座布置形式及相邻简支梁配跨数的影响.结果表明:桥梁及轨道结构的伸缩力与位移都随着梁体温差和温度跨度的增加而增大,且增幅明显;采用小阻力扣件时需要避免轨板相对位移过大而导致轨下胶垫滑出;对桥上无缝线路进行轨道结构和桥梁墩台检算时,可将连续梁两端相邻简支梁配跨数进行适当简化,以提高计算效率.

Based on finite element method,a detailed spatial coupling model of CRTS! slab track Continuously Welded Rail(CWR) on bridge is established in this paper,expansion-constraction forces and displacements of track and bridge structure under the temperature load are calculated,and certain nfluences of various elements are explored,which tnclude temperature difference of concrete beam,longitudinal resistance of fasteners,expansion length,support layout,and span number of adjacent bridges as well.The results show that expansion-constriction force and displacement of track and bridge structure tncrease significantly as temperature difference of concrete beam grows and expansion length widens.Meanwhile,to avoid the slipping out of rubber mats under rail in the adoption of small resistance fasteners,relative displacement of track panel is not to be oversized,and when checking the structure of CWR on bridge and calculating its bridge pier and abutment,the span number of adjacent bridges can be simplified accordingly so as to raise the calculating efficiency.