重复列车荷载作用下多年冻土路基长期变形分析  

Analysis of Long-Term Deformation of Railway Embankment at Repeated Train Load in Permafrost Regions

作　　者：吴志坚[1,2,3] 陈拓[4] 马巍[5] 

机构地区：[1]中国地震局(甘肃省)黄土地震工程重点实验室,兰州730000 [2]中国地震局兰州地震研究所,兰州730000 [3]甘肃省岩土防灾工程技术研究中心,兰州730000 [4]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [5]中国科学院冻土工程国家重点实验室,兰州730000

出　　处：《上海交通大学学报》2015年第7期929-934,共6页Journal of Shanghai Jiaotong University

基　　金：国家重点基础研究发展规划(973)项目(2012CB026106);国家自然科学基金项目(41472297);国家科技支撑计划(2015BAK15B01)资助

摘　　要：在青藏铁路北麓河段选取素填土路基断面开展列车通过实时振动测试,得到车载作用下路基路肩处的加速度时程曲线,并将该动力荷载转化为作用在路基表面的等效均布荷载.基于冻土三轴流变实验结果,对典型的青藏铁路多年冻土路基进行了重复列车荷载作用下的蠕变分析,得到了机车荷载作用下冻土路基所产生的长期变形量,量化了该部分变形在路基总变形中所占比例.研究结果表明,机车荷载作用下路基两侧坡脚产生较大的剪应变,并且逐渐向上扩展,垂直方向变形占总变形量的10%左右.Based on strong motion tests on typical embankment at Beilu River segment along the Qinghai- Tibet Railroad, the acceleration history waveforms near railway tracks were collected when the train was passing, and the dynamic train load was converted into equivalent creep stress by using the equivalent stat- ic force method. Moreover, the creep equation of frozen soil was introduced according to the result of fro- zen soil theological triaxial tests. The long-term deformation of the embankment at the train load was ob- tained, and the ratio of permanent deformation at the train load to the whole embankment deformation was quantized as well. The research results show that the vibration effect of repeated train load on deformation accounted for approximately 10~//00 of the total accumulative settlement of the embankment. The creep strain values at the slope toes are significant and extended upwards gradually, which increases with the de- velopment of time and the strain rate decreases instead.

关 键 词：长期变形 机车荷载 多年冻土 蠕变效应 

分 类 号：TU43[建筑科学—岩土工程]