高速铁路路基沉降限值及其对无砟轨道受力的影响

对国内外高速铁路无砟轨道路基沉降的限值问题进行了分析研究。在此基础上，通过建立有限元模型，对路基沉降下的轨道板弯矩进行了计算，并与简化算法结果进行了对比分析。研究表明：对于我国设计速度300km／h的客运专线，路基不均匀沉降按15mm／20m控制，均匀沉降按30mm控制较为合适；特殊情况下，对于超过扣件调高量的路基沉降应借鉴国外的方式补充相关规定；在计算不均匀沉降产生的轨道板弯矩时，建议沉降曲面借鉴日本的假设，按15mm／20m半波长正弦曲面考虑；简化算法得到的轨道板弯矩值有可能比有限元直接建模得到的结果小，在工程设计中是否直接采用此法值得探讨。

Limited Value of Subgrade Settlement and its Influence on Mechanical Characteristics of Ballastless Track in High-Speed Railway

In this paper,analysis is carried out on limited value of ballastless track subgrade settlement of high-speed railway in China and other countries.Through finite element model,calculation is done on bending moment under slab in the condition of subgrade settlement.Analysis results are compared with that from simplified calculation method.It can be obtained that in our country,when the design speed is 300km/h,the un-uniform subgrade settlement should be within 15mm/20m,and uniform subgrade settlement should be within 30mm.In special circumstances,for the subgrade settlement which is greater than the height adjustment range of rail fastenings, correlative specification should be supplied according to measures in foreign countries.In calculation of slab bending moment caused by un-uniform subgrade settlement,assumptive curved face of settlement in Japan is proposed to be used.The slab bending moment calculated in finite element method may be greater than that in simplified calculation method.In engineering design,whether the simplified calculation method should be used is to be discussed.