Research purposes:The increase of heavy-haul train axle load enhances the dynamic stress at different depths of the subgrade,leading to more and more serious subgrade issues such as mud pumping.In this paper,a series of refined model tests were carried out to study the characteristics of mud pumping of saturated silty clay subgrade under the heavy-haul train load.The influence of cyclic loading amplitude and loading frequency on the axial strain,excess pore water pressure,and fine particles migration characteristics of the sample was analyzed.Research conclusions:(1)The cyclic loading amplitude has a significant impact on the characteristics of mud pumping from silty clay subgrade.As the cyclic loading amplitude increases,axial strain and excess pore water pressure rise,intensifying mud pumping.(2)The loading frequency has a certain influence on the characteristics of subgrade mud pumping.In general,higher loading frequencies decrease the final axial strain and excess pore water pressure,reducing mud pumping quality post-test.The increased frequency can't accelerate the mud pumping severity,but can shorten the duration of mud pumping.(3)Under cyclic loading,the excess pore water pressure gradient drives the migration of fine particles in the subgrade soil,resulting in mud pumping.(4)The research results can provide a reference for the treatment of the mud pumping issues in the heavy-haul train subgrade.
关键词
重载铁路/翻浆冒泥/轴向应变/超孔隙水压力/细颗粒迁移/超孔隙水压力梯度
Key words
heavy-haul railway/mud pumping/axial strain/excess pore water pressure/fine particles migration/excess pore water pressure gradient
维普
万方数据