高速铁路基床现场循环加载试验研究

详细地掌握高速铁路路基的动态特性与累积变形特性是对其进行合理设计的基础。结合达成线的建设，修建了路基试验段，埋设测试元件，使用新型的ZSS50循环加载设备，对试验段路基进行了现场循环加载试验研究，模拟了不同轴重列车的动力作用，分析了路基的动态特性及沉降规律。测试结果表明：路基的动态指标及工后沉降均满足设计要求，列车轴重对路基的动态特性影响显著；路基面动态响应沿横向的分布是不均匀的，轨下位置最大，轨枕端部位置次之，线路中线处最小，总体上呈马鞍形分布；动态响应随路基深度的增加而逐渐减小，在基床表层范围内衰减较快；ZSS50循环加载设备 可准确模拟不同轴重、不同时速列车对线路的动力作用，且操作简单、坚固耐用，是研究铁路轨道及路基动态特性的理想设备。

Experimental study of cyclic loading for subgrade bed of high speed railway

It’s the basis for designing subgrade bed to master detailedly dynamic performance and settlement laws of subgrade. Combining with the construction of Dazhou-Chengdu railway, the studying team buried test elements in subgrade and studied the dynamic performance and settlement laws of subgrade by using a new facility called ZSS50 which could simulate the train dynamic loads. The results indicate that the dynamic indexes and settlements meet the designing requirements; and an evident influencing factor for them is the axle load of train; along the cross section of subgrade, the dynamic responses are unequal, and show the saddle-shaped distribution; the dynamic responses decrease with the depth of subgrade increasing, and decrease faster in surface layer than in bottom layer; the ZSS50 can model exactly dynamic loads of train, it can be handled easily; and it is an ideal facility for studying the dynamic performance of track and subgrade.