提速条件下粉土铁路路基动态稳定性研究  

Study on dynamic stability of silt subgrade subjected to train moving loading

作　　者：刘建坤[1] 肖军华[1] 杨献永[1] 陈立宏[1] 

机构地区：[1]北京交通大学土建学院,北京100044

出　　处：《岩土力学》2009年第2期399-405,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.50678020);北京交通大学科技基金(No.2005SM034)

摘　　要：路基的动态响应及稳定直接决定了提速列车运行的舒适度和安全性。通过室内循环三轴试验,模拟了路基在湿度变化与提速列车动荷载作用下的动态特性。根据试验结果,结合既有线提速路基的动应力变化规律发现:在最优含水率附近,当压实系数为0.90,提速情况下路基可保持稳定状态;若压实系数为0.85,在动应力不超过70 kPa时,路基稳定性较好,但随着动应力水平增加和加载频率增大,路基的累积变形加剧并产生动强度破坏。列车提速使路基的弹性变形增大,但对路基的回弹模量影响较小。路基湿度增加导致临界动应力、回弹模量显著降低,而回弹应变、循环累积应变迅速增加,有可能导致路基产生动强度破坏,因此,雨季时应限速行车。Comfort and safety of moving train is directly determined by dynamic response and stability of railroad subgrade.In order to investigate behaviors of silt subgrade soils subjected to moving train loading,cyclic triaxial tests including conditions of soil compacting factor,water content,deviator stress,and loaded frequency were conducted in laboratory.Based on the test results and field measurements of subgrade stress during train loading,it is found that with train speed increasing,silt railroad subgrade sh...

关 键 词：列车提速 路基 粉土 动态稳定性 循环三轴试验 

分 类 号：U212.22[交通运输工程—道路与铁道工程]