CRTSⅡ型板式轨道底座板后浇带脱空对轨道结构与行车的影响

Effects of post-pouring belt void of base slab on track structure and train operation of CRTSⅡ slab track

在不间断行车情况下,采用超高压水射流法对桥上CRTSⅡ型板式轨道底座板后浇带进行修复;建立了CRTSⅡ型板式轨道结构静力计算模型,分析了底座板后浇带不同脱空长度对钢轨、轨道板垂向位移与轨道板拉应力的影响;建立了车辆-轨道耦合动力计算模型,分析了底座板后浇带完全脱空长度为1.0 m时,正常行车对轨道结构、行车安全与舒适性的影响。计算结果表明:在1.5倍静轮载作用下,随着后浇带脱空长度增大,钢轨与轨道板垂向位移随之增大,当底座板后浇带完全脱空长度为1.0 m时,钢轨和轨道板的垂向位移均增大了0.03 mm,说明完全脱空对其垂向位移影响较小;后浇带脱空长度分别为0.7、0.8、0.9、1.0 m时,轨道板的最大拉应力分别为0.96、1.12、1.18、1.22 MPa,后浇带完全脱空时轨道板的最大拉应力小于其抗拉强度设计值1.96 MPa,轨道板不会开裂;列车运行速度为300 km·h-1,后浇带完全脱空长度为1.0 m时,钢轨和轨道板的最大垂向位移分别为0.91、0.32 mm,均小于《高速铁路工程动态验收技术规范》(TB 10761—2013)中钢轨和轨道板垂向位移的基准值1.5、0.4 mm,说明后浇带脱空后正常行车对轨道结构不会造成较大的影响;后浇带完全脱空时,轨道板垂向加速度约为正常时的3倍,说明正常行车将会增大下部基础的振动强度。静、动力分析结果表明,采用超高压水射流法修复底座板后浇带可允许列车以正常速度通行。

Under the uninterrupted train running condition,the post-pouring belt of CRTSⅡslab track base slab on the bridge was repaired by using the ultra-high pressure water jet method.The statics calculation model of CRTSⅡslab track structure was established,and the effects of post-pouring belt with different void length on the vertical displacements of rail and track slab and the tensile stress of track slab were analyzed.The vehicle-track coupling dynamics calculation model was established,and the influences of normal running on track structure,running safety and comfort were analyzed when the complete void length of the post-pouring belt of base slab was 1.0 m.Calculation result shows that under the action of 1.5 times static wheel load,the vertical displacements of rail and track slab increase with the increase of the void length of post-pouring belt.When the complete void length of post-pouring belt is 1.0 m,the vertical displacements of rail and track slab both increase by 0.03 mm,so the complete void has less effect on vertical displacements.When the void length of post-pouring belt is 0.7,0.8,0.9 and 1.0 m,respectively,the maximum tensile stress of track slab is 0.96,1.12,1.18 and 1.22 MPa,respectively.When the post-pouring belt completely voids,the maximum tensile stress is less than the designed tensile strength of 1.96 MPa,and the track slab will not crack.When the train speed is 300 km·h-1 and the complete void length of post-pouring belt is 1.0 m,the maximum vertical displacements of rail and track slab are 0.91 and 0.32 mm,and less than the reference values of 1.5 and 0.4 mm in Technical Regulations for Dynamic Acceptance for High-Speed Railways Construction(TB 10761—2013),which shows that the normal running after post-pouring belt voids can not cause great influence on the track structure.When the complete void of post-pouring belt occures,the vertical acceleration of track slab is about 3 times of the value under the normal condition,which indicates that normal running will increase the vibration intensity of the lower foundation.The statics and dynamics analysis results show that using the ultra-high pressure water jet method to repair the post-pouring belt of base slab can allow the train travel at normal speeds.1 tab,11 figs,31 refs.