Full-scale laboratory testing of a geosynthetically reinforced soil railway structure
Full-scale laboratory testing of a geosynthetically reinforced soil railway structure
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DOI：
10.1016/j.trgeo.2021.100526
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发表时间：
2021-03-11
影响因子：
5.3
通讯作者：
Connolly, D. P.
中科院分区：
文献类型：
--
作者：
Esen, A. F.;Woodward, P. K.;Connolly, D. P.
铁路线路通常使用传统的倾斜式轨枕作为轨道支撑的主要方式。然而，土工合成加筋土（GRS）系统的使用已经越来越受欢迎，作为传统加筋土的替代品，特别是在日本的高速线路上。由于其较小的基底面积，该系统需要比传统装备更少的地面稳定/改善和更少的土地占用。本研究调查的即时和长期的沉降行为的土工合成加筋土挡墙（GRS-RW）系统受到循环荷载的两种轨道形式：混凝土板轨道和有碴轨道。首先，在受控的实验室条件下以全尺寸建造三轨枕混凝土板段，然后建造有碴轨道。两者都支撑在1.2米深的路基和符合铁路设计标准的防冻层上。两个不同的轴载荷大小被静态地施加，然后循环/动态地施加，使用6个致动器来复制移动的列车轴载荷。据观察，板式轨道在静态和循环荷载下的弹性和塑性变形方面表现得更好。总体而言，在单个循环载荷下，板式轨道的钢轨位移幅度约低25%，而有碴轨道上的轨枕位移幅度约高6-7倍。
Railway lines typically use traditional sloping embankments as the principal means of track support. However, the use of Geosynthetically Reinforced Soil (GRS) systems have gained popularity as alternatives to conventional embankments, particularly for high-speed lines in Japan. This system requires less ground stabilization/ improvement and less land take than conventional embankments due to its smaller base area. This research investigates the immediate and long-term settlement behaviour of a Geosynthetically Reinforced Soil with Retaining Wall (GRS-RW) system subject to cyclic loading for two track forms: a concrete slab track and a ballasted track. First, a three-sleeper concrete slab section is constructed at full-scale under controlled laboratory conditions, followed by a ballasted track. Both are supported on a 1.2 m deep subgrade and a frost protection layer in accordance with railway design standards. Two different axle load magnitudes are applied statically, and then cyclically/dynamically, using 6 actuators to replicate moving train axle loads. It is observed that the slab track performs significantly better in terms of elastic and plastic deformation under both static and cyclic loading. Overall, the amplitude of the rail displacement under an individual cycle loading was approximately 25% lower for the slab track and the amplitude of the sleeper displacement on the ballasted track was approximately 6-7 times higher.