土工格栅加固路桥过渡段的动测试分析

在秦沈铁路客运专线乙试验工点现场试验的基础上,对土工格栅加固后的路桥过渡段基床动响应特性及其影响因素进行了分析和研究.研究结果表明:随着行车速度增大,过渡段基床动应力增量为正;但当行车速度超过临界速度(220～230 km/h)后,基床动应力不再增加,反而减小;基床动应力的变化特征与其在基床中的位置密切相关,沿线路纵向水平方向上,动应力随距桥台背距离的增大而呈减小趋势;沿深度方向上,动应力随深度的增加而呈衰减趋势;过渡段沉降差的存在导致基床动应力增大,严格控制过渡段沉降差是高速铁路设计和施工的关键.

Dynamic Test Analysis on Roadbed-bridge Transition Section Reinforced by Geogrid

Based on the in-situ test in Qin-Shen passenger transport special railway line, the roadbed dynamic stress characteristic and its influencing factors are studied in this paper. The results show that the roadbed dynamic stress responses are influenced greatly by the magnitude of the train velocity, the roadbed dynamic stress increment is positive; while the tested velocity exceeds critical speed(commonly it is 220230 km/h), the road dynamic responses do not increase but decrease. The change characteristic of the roadbed dynamic stress responses are closely related to their position in roadbed, the dynamic stress responses in the railway line on the level direction decline with the increase of the distance from the abutment, and also the dynamic stress responses in the depth direction decline with the increase of the depth. The presence of settlement difference in transition section results in the increase of the dynamic stress, so controlling the settlement difference strictly is the key in the design and construction of express railway.