红层泥岩及其改良填料路基动力响应试验研究

基床作为路基结构的重要组成部分，其填料的质量对路基、轨道、列车的动力响应影响显著。在实际工程中，基床填料通常可根据设计规范取为A、B组填料，但考虑到经济因素、力学性能等，也可采用既有填料或改良的既有填料。为了研究红层泥岩，A、B组填料，石灰改良红层泥岩分别作为基床填料时对路基动力响应的影响，进行了不同基床填料的现场激振试验。通过对动应力、加速度及沉降等数据的对比分析，得到以下结论：红层泥岩作为基床填料时，动应力与路基沉降在加载激振次数内可满足设计要求；与红层泥岩相比，当基床填料为A、B组填料与石灰改良红层泥岩时，路基表面的动应力与加速度分布更加均匀，因而此时路基的整体承载性能更优越。除此之外，后两种填料时路基内部动应力与加速度的衰减相对前者更显著，并且路基的沉降变形更小，特别是为石灰改良红层泥岩时。

Experimental study of dynamic response of subgrade with red mudstone and improved red mudstone

As an important part of the subgrade, the filling material quality of subgrade bed has a significant influence on the dynamic response of the subgrade, track, and train. In practical engineering, although filling material of group A, B can be directly used according to the design code in China, improved soils and even unimproved soils also may be used if the economic factors and mechanical properties are considered to meet the requirements. In order to study the influence of different filling materials, such as red mudstone, filling material of group A, B, and improved red mudstone, on dynamic response of subgrade, field vibration tests are carried out. According to the comparative analysis of the tested data, the following conclusions about dynamic stress, acceleration, and settlement have been obtained. When the red mudstone is used, the dynamic stress and settlement can meet the design requirements during the loading period. Compared with the responses when using red mudstone, the distributions of dynamic stress and acceleration along the cross-section of the subgrade surface are more uniform when filling material is group A, B and lime-modified red mudstone, so the overall bearing capacities of these subgrades are better at this time. Besides, the attenuations of the dynamic stress and acceleration along the depth of the subgrade are more obvious than that in the red mudstone; the settlement of the subgrade is smaller, especially when the improved red mudstone is used.