高速铁路路基沉降高聚物注浆修复后动力性能及长期耐久性的试验研究

高速铁路路基的过大沉降影响轨道结构耐久性和列车运行安全,有必要及时通过抬升路基水平恢复轨道线路的垂向平整性。尝试通过在路基表层和轨道混凝土底座之间进行非水反应高分子聚合物填充注浆的方法实现轨道结构的整体均匀抬升。通过大型物理模型试验测试分析了抬升后轨道-路基的整体动力学性能及长期耐久性。通过定点循环激振试验对比分析了路基抬升前后的轨道整体刚度的变化规律,发现抬升后整体刚度相比抬升前略有减小,但对轨道-路基体系自振频率的影响有限；模拟列车运行的大周次循环加载测试了抬升后路基的动力累积沉降和动刚度变化过程,结果表明抬升后路基在列车长期荷载作用下具有较好的动力稳定性。

Experimental study on dynamic performance and long-term durability of high-speed railway subgrade rehabilitated by polymer injection technology

The excessive settlement of high-speed railway subgrade will adversely affect the durability of railway structures and the safe operation of trains, therefore the uplift of track structures will be demanded to restore the vertical alignments of the railway. An engineering attempt with injection of polymer materials between the roadbed surface and the concrete base of the slab track is adopted to uplift the track structures uniformly. Large-scale physical model tests are performed to study the dynamic performance and long-term durability of the uplifted track-subgrade system. The change of stiffness of the track-subgrade system after the uplift process is investigated based on the fixed-point cyclic loading tests. The test results indicate that the stiffness of the track structures is slightly reduced after the uplift process, but the change of the natural vibration frequency of the track-subgrade system is very limited. The investigation on cumulative settlement and dynamic stiffness of the uplifted track structures under very large cycles of simulated train moving loads shows that the uplifted track has satisfactory dynamic stability.