高速铁路桥上II型轨道板砂浆层间离缝机理及影响研究

Some cracks occur between the slab and the mortar layer of the CRTS Ⅱ-type ballastless slab track on the bridges of high-speed railway operations in China. These cracks not only affect the stability, the smoothness, and the durability of the track structure, but also affect the running performance of the train. The project studies the CRTS Ⅱ-type ballastless slab track on the bridge, focusing on the mechanism of cracks and the influences of the cracks on the running performance of a high-speed train. Through theoretical analysis, experimental research and numerical simulation, firstly, the spacial interaction model between the track layer, theⅡ-type ballastless slab track, and the high-speed railway bridge will be established, and the related interaction mechanism will be ascertained. Secondly, the constitutive relations of the interface between the slab and the mortar layer with different factors will be specified. Thirdly, the laws of different factors influencing on the adhesive limit force and the action force between the slab and the mortar layer will be obtained. Fourthly, the mechanism of the cracks will be explored. Fifthly, the laws of cracks affecting the running performance of a high-speed train will be determined. Finally, the numerical cracking limit allowed and the methods for preventing cracking will be proposed. The study aims to ensure the good performance of the CRTS Ⅱ-type ballastless slab track-bridge system, as well as the good running performance of the high-speed train. The results will provide the theoretical supports for improving the design codes and maintenance rules of the CRTS Ⅱ-type ballastless slab track on bridge. Therefore, the project is of important engineering significance and academic value.

我国运营中的高速铁路桥上CRTS Ⅱ型轨道板砂浆层间局部出现一些离缝现象。离缝不仅影响轨道结构的稳定性、平顺性、耐久性，还影响列车的走行性。项目以桥上Ⅱ型板式无砟轨道为研究对象，围绕离缝机理及离缝对高速列车走行性能的影响展开研究。采用理论分析、试验研究、数值仿真相结合的研究方法，建立高速铁路Ⅱ型板式无砟轨道-桥梁及轨道层间相互作用空间模型，探明Ⅱ型板式无砟轨道-桥梁及轨道层间相互作用机理；明确不同因素下Ⅱ型轨道板砂浆层间粘结界面的本构关系；获取不同因素对桥上Ⅱ型轨道板砂浆层间极限粘结力、作用力的影响规律；揭示离缝机理；掌握离缝对列车走行性能的影响规律；提出离缝允许限值及有效预防离缝的方法。项目研究旨在保证Ⅱ型无砟轨道-桥梁系统良好的工作性能及高速列车良好的走行性能，成果可为完善Ⅱ型板式无砟轨道-桥梁一体化设计、养护与维修方法提供理论支撑，具有重要的工程意义和学术价值。

我国运营中的高速铁路桥上CRTSⅡ型轨道板砂浆层间局部出现一些离缝现象。离缝不仅影响轨道结构的稳定性、平顺性、耐久性，还影响列车的走行性。项目采用理论分析、试验研究、数值仿真相结合的方法，主要开展了（1）CRTSⅡ型板式无砟轨道砂浆层界面工作性能试验研究，（2）高速铁路连续梁与CRTSⅡ型板式无砟轨道系统相互作用研究，（3）CRTSⅡ型板式无砟轨道竖向稳定性力学模型及影响规律分析，（4）CA砂浆材料统计损伤本构关系和列车-轨道-桥梁耦合振动模型研究，（5）砂浆层离缝对车辆、轨道动力学响应影响分析，（6）探讨了桥上CRTSⅡ型板式无砟轨道砂浆层间离缝的原因、特点及预防CA砂浆离缝方法。重要结果包括：获得了砂浆层界面相对位移-约束力关系曲线；探讨了道床板伸缩刚度、CA砂浆层纵向刚度、滑动层摩擦系数以及桥墩纵向刚度对多跨长联连续梁桥桥上CRTSⅡ型板式无砟轨道受力特性的影响规律；用解析方法分析了轨道板初始弯曲、窄接缝弹性模量、CA砂浆黏结强度、轨道板纵向阻力对CRTSⅡ型板式无砟轨道竖向稳定性的影响规律；采用统计损伤力学理论，考虑应变率效应，建立了CA砂浆的统计损伤本构模型；研究了CRTSⅡ型板式无砟轨道砂浆层离缝宽度及长度对车体加速度、轮轨力、钢轨位移及加速度、轨道板位移及加速度、底座板位移及加速度等动力响应的影响规律；明确了桥上CRTSⅡ型板式无砟轨道砂浆层间离缝的原因，提出了预防CA砂浆离缝的技术措施。研究成果可为完善CRTSⅡ型板式无砟轨道-桥梁一体化设计、养护与维修方法提供理论支撑，具有重要的工程意义和学术价值。