| 提速条件下粉土铁路路基动态稳定性研究 |
| |
| 引用本文： | 刘建坤,肖军华,杨献永,陈立宏.提速条件下粉土铁路路基动态稳定性研究[J].岩土力学,2009,30(2):399-405. |
| |
| 作者姓名： | 刘建坤 肖军华 杨献永 陈立宏 |
| |
| 作者单位： | 北京交通大学,土建学院,北京,100044 |
| |
| 基金项目： | 国家自然科学基金，北京交通大学科技基金 |
| |
| 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。
|
| 关 键 词： | 列车提速 路基 粉土 动态稳定性 循环三轴试验 |
| 收稿时间： | 2007-04-09 |
Study on dynamic stability of silt subgrade subjected to train moving loading |
| |
| LIU Jian-kun,XIAO Jun-hua,YANG Xian-yong,CHEN Li-hong.Study on dynamic stability of silt subgrade subjected to train moving loading[J].Rock and Soil Mechanics,2009,30(2):399-405. |
| |
| Authors: | LIU Jian-kun XIAO Jun-hua YANG Xian-yong CHEN Li-hong |
| |
| Institution: | School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China |
| |
| Abstract: | 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 should be stable if its natural moistness is near to optimum water content and compacting factor is not less than 0.9; moreover, if subgrade compacting factor is only 0.85 and deviator stress of subgrade surface is less than 70 kPa, subgrade is also stable; but it would lose stability at higher deviator stress level. With train speed increasing, the elastic deformation of subgrade rises linearly, but resilient modulus changes negligibly. With increase in saturation, the threshold stress and resilient modulus of subgrade decrease significantly, while the elastic strain and cumulative strain increase sharply; and it may result in failure of subgrade, so train speed should be limited in wet season in order to reduce subgrade deviator stress. |
| |
| Keywords: | train speed-increasing subgrade silt dynamic stability cyclic triaxial test |
| 本文献已被 维普 万方数据 等数据库收录！ |
| 点击此处可从《岩土力学》浏览原始摘要信息 |
| 点击此处可从《岩土力学》下载免费的PDF全文 |
|
