高速铁路无砟轨道混凝土结构设计寿命提升方法与关键技术

为提升高铁混凝土结构设计寿命，选择直接承受高速列车冲击荷载的无砟轨道为载体，聚焦服役环境下无砟轨道混凝土微细观损伤机制、考虑冲击荷载损伤累积的高铁混凝土结构寿命预测模型两大关键科学问题，突破无砟轨道混凝土结构服役环境的相似还原以及混凝土高抗冲击韧性与高抗侵蚀耐久性的协同提升两大关键技术瓶颈，实现无砟轨道结构与桥涵主体结构百年同寿命设计目标。拟采用理论分析、试验研究和数值模拟相结合的手段，构建列车周期性冲击荷载表征方法，创新引入近场动力学方法模拟服役无砟轨道混凝土损伤破坏过程，揭示服役无砟轨道混凝土损伤机制和介质传输规律，构建基于冲击荷载损伤累积效应和腐蚀介质传输的混凝土结构寿命预测模型，形成长寿命高铁混凝土结构设计方法，创新基于韧性和耐久性协同调控的混凝土性能提升技术，形成具有自主知识产权的长寿命混凝土结构设计方法和提升技术，为无砟轨道百年设计寿命实现与更长寿命高铁结构设计与建设提供支撑。

Aiming to increase the design life of high-speed Railway concrete, theballastless track subjected to impact loading from high speed trains directly is employed as typical structure. It is paid attention on two scientific questions: microscopic damage mechanism of ballastless track concrete in service environment and the prediction model of service life based on medium transmission law and the cumulative condition of impact damage. In order to realize the design life of ballastless track structure to be the same as the main structure of bridge and culvert,there are two key technical bottlenecks need to be broken through, whichare the similar reduction of the true service environment and the synergistic improvement of the high impact toughness and high erosion resistance.The project will use a combination of theory, experimentation and numerical simulation to conduct research.The characterization method will be built up to simulate the periodic impact loading of high speed strain. The peridynamics method is built to simulate the damage procedure of ballastless track concrete.The damage mechanism and transferring rule of concrete employed in ballastless track structure will be researched under different service environment.The structural life prediction models will be built up based on modified damage coefficient caused by impact loading. A long-life ballastless track concrete structure design method will be established.The innovative technology to improve the durability of concrete will be proposed based on simultaneous improvement of toughness and impermeability.The design method and promotion technology will be formed for long-life concrete durability of ballastless track structure owned by Chinese intellectual property rights. It could also provide the theoretical and technical support for 100-year design life and long-term service safety.