CAJ | 학술논문

重载铁路路基核心层为粗粒土，其直接承受轨道结构传递的列车动载的往复作用，但目前对粗粒土填料在重载列车往复作用下累积动应变的研究较少。为探索粗粒土填料在暴雨等极端恶劣天气或路基浸水时的累积动应变变化规律，利用基于MTS精确控制的动三轴试验系统，进行不同围压、多组动应力幅值下饱和粗颗粒土（铁路路基A级填料）的振动试验。由此获得一系列粗颗粒土累积动应变与振动次数的关系曲线，揭示动应力比对累积动应变发展类型的影响，得出基于围压的临界动应力比表达式以及累积动应变与振动次数的拟合关系式，同时证明一定振动次数时试样动应力与累积动应变关系比较符合双曲线模型。试验结果可供重载铁路路基核心层的动力变形稳定性评价和基于动力变形控制的路基设计参考和利用。
중재철로로기핵심층위조립토，기직접승수궤도결구전체적열차동재적왕복작용，단목전대조립토전료재중재열차왕복작용하루적동응변적연구교소。위탐색조립토전료재폭우등겁단악렬천기혹로기침수시적루적동응변변화규률，이용기우MTS정학공제적동삼축시험계통，진행불동위압、다조동응력폭치하포화조과립토（철로로기A급전료）적진동시험。유차획득일계렬조과립토루적동응변여진동차수적관계곡선，게시동응력비대루적동응변발전류형적영향，득출기우위압적림계동응력비표체식이급루적동응변여진동차수적의합관계식，동시증명일정진동차수시시양동응력여루적동응변관계비교부합쌍곡선모형。시험결과가공중재철로로기핵심층적동력변형은정성평개화기우동력변형공제적로기설계삼고화이용。
The core layer of heavy haul railway subgrade ,which is directly subject to the cyclic loading from up‐per track structure ,consists of coarse grained soil(CGS) . However ,currently ,fewer studies have been per‐formed on accumulative dynamic strain(ADS) of CGS filler under the cyclic effect of heavy haul trains . In or‐der to study the law of development of ADS of CGS filler under extreme weather conditions , such as heavy rain or under the situation when the subgrade suffers water immersion ,an independently developed MTS‐controlled triaxial testing system is used to carry out some dynamic triaxial tests of saturated CGS(railway subgrade class A packing) with different confining pressures and dynamic stress amplitudes . From these tests , the curve of the relationship between ADS and the number of vibration is acquired .Moreover ,the effect of critical dynamic stress ratio(CDSR) on ADS developing type is discovered . The expression formula of CDSR based on confining pressure and the fitted formulas between ADS and the number of vibration are obtained . Finally , the results prove that the hyperbolic model could approximately fit the relationship between dynamic stress and ADS with certain number of vibration . The results of these tests could be utilized for reference for the evaluation of the dynamic stress deformation stability of the subgrade core layer of heavy haul railway and design of subgrade based on dynamic deformation control .