动荷载作用下高速铁路风积土地基动力特性试验研究

Experimental Study of Dynamic Characteristics of Aeolian Soil Subgrade Subjected to High-Speed Train Dynamic Loading

根据辽西地区的地震资料和波速测试资料,通过动三轴试验,进行了地震冲击荷载和列车振动荷载两种动荷载作用下辽西风积土地基的动力特性试验研究。研究结果表明,风积土的动强度、动变形和动模量等指标与荷载类型、持续时间、振动频率和动应力幅值等条件有关。在地震荷载作用下,动荷载频率和动应力幅值越大、震动持续时间越长,其产生的动应变越大;在高速列车振动荷载作用下,土的动强度和动抗剪强度随振动次数的增加而降低;固结比相同时,动弹性模量Ed和动剪切模量Gd随固结压力的增大而增大;随动应变εd的增大而减小,且初始时刻减小速度明显,之后逐渐变缓。

Based on seismic data around Liaoning Province west region and wave velocity test data, through dynamic triaxial test, experimental study of dynamic characteristics of aeolian soil subgrade in west Liaoning Province subjected to both earthquake loading and high-speed train vibration loading was carried out. Results show that the dynamic strength, dynamic deformation, dynamic modulus and other indexes of aeolian soil are related to the load type, duration, frequency, dynamic stress amplitude and other conditions. Under earthquake loading, when specimens are subjected the same dynamic stress, the higher frequency is corresponding with the larger dynamic stress amplitude, the longer duration and larger dynamic deformation. When specimens are subjected to the vibration load of high-speed train, the dynamic strength and dynamic shear strength reduce along with the increase of vibration frequency. Under the same consolidation ratio condition, dynamic elastic modulus （Eu） and dynamic shear modulus （Gd） increase with the increase of consolidation pressure, but decrease with the εd increase, and reduce significantly at the initial time, then gradually slow down.