红层泥岩半刚性基床结构动态变形试验研究

高速铁路要为列车的高速行驶提供一个高平顺性和稳定性的轨下基础,而路基作为轨道结构的基础,必须具有强度高、刚度大、稳定性和耐久性好的特性。由于红层泥岩属于软岩,工程稳定性差,以红层泥岩作为基床的填料,其刚度明显不足,所以为了弥补基床表层的不足,在其顶部添加一层水泥稳定级配碎石。为了验证这些措施的效果,以便指导工程设计和施工,通过足尺动态模型试验,模拟在实际荷载条件下基床的动态变形特性,结果表明,采用水泥稳定级配碎石作为基床表层填料,静态变形明显降低,能够大幅降低动荷载作用时的动变形,减少了基床结构的永久变形,增强了轨道结构的稳定性。

Experimental research on dynamic deformations of semi-rigid structures of subgrade bed-mudstone of red beds

In order to cater for the operation requirements of high speed train, it is necessary for subgrade of track to be high stability and comfort; as the subgrade of track, strength and stiffness of roadbed structure, is very high and at the same time its stability and durability is very good. However, as for red bed mudstone, its engineering properties is bad as follows: it is easy to collapse and its strength is very low, which belongs to weak rock. As the stuffing of surface layer of subgrade bed, its stiffness is apparently lack, so in order to make up for the shortage of surface layer of subgrade bed, it is necessary to add a layer of cement stabilized grading crushed stones; to verify the effects of these disposal measures and guide the design and construction works, through dynamic full-scale model test in simulating actual loading conditions; it is indicated that by the use of cement stabilized grading crushed stones as stuffing of subgrade bed surface layer, static and dynamic deformation significantly can be reduced; and what’s more, permanent deformation of subgrade bed can be also reduced; and the stability of the track structure can be enhanced.