重载铁路循环动载下水泥改良膨胀土路基动力特性  

Dynamic Characteristics of Cement-Improved Expansive Soil Subgrade under Cyclic Dynamic Load of Heavy Haul Railway

作　　者：商拥辉[1,2] 徐林荣[2,3] 蔡雨 刘维正[2] SHANG Yonghui;XU Linrong;CAI Yu;LIU Weizheng(School of Architecture and Civil Engineering,Huanghuai University,Zhumadian Henan 463000,China;School of Civil Engineering,Central South University,Changsha Hunan 410075,China;National Engineering Laboratory for High Speed Railway Construction,Central South University,Changsha Hunan 410075,China)

机构地区：[1]黄淮学院建筑工程学院,河南驻马店463000 [2]中南大学土木工程学院,湖南长沙410075 [3]中南大学高速铁路建造技术国家工程实验室,湖南长沙410075

出　　处：《中国铁道科学》2019年第6期19-29,共11页China Railway Science

基　　金：国家自然科学基金资助项目(51078358);国家自然科学基金高铁联合基金重点项目(U1134207)

摘　　要：基于蒙华浩勒报吉-吉安段重载铁路工程,建立列车-有砟轨道-基床-地基动力系统耦合三维数值模型,进行重载铁路循环列车动载作用下水泥改良膨胀土路基动力特性研究。结果表明:轴重25~30 t列车以时速120 km运行时路基面动应力范围为106.3~127.2 kPa,大于轴重25 t列车以时速60~150 km运行时路基面动应力范围(88.81~114.59 kPa)以及轴重17 t的高速列车以时速250~350 km运行时路基面动应力范围(60~85 kPa);重载铁路列车运行时路基面动应力沿路基深度逐渐衰减,在基床表层和底层范围内的衰减分别可达40%和80%以上,动应力影响深度达3~4 m,超过基床设计厚度2.5 m。鉴于动力影响深度范围内路基的动应力水平远低于同位置填料的临界动应力,由临界动应力法评估可知,重载铁路水泥改良膨胀土路基的动力稳定性满足服役要求。Based on the heavy haul railway engineering of Haolebaoji-Ji’an section of Menghua Railway, the coupling three-dimensional numerical model of train-ballasted track-subgrade bed-foundation dynamic system was established to study the dynamic characteristics of cement-improved expansive soil subgrade under the cyclic dynamic load of heavy haul railway train. Results show that the dynamic stress range of subgrade surface is 106.3~127.2 kPa when the train speed is 120 km·h-1 with the axle load of 25~30 t, which is larger than that of the subgrade surface(88.81~114.59 kPa) when the train is running at the speed of 60~150 km·h-1 with the axle load of 25 t and that of the subgrade surface(60~85 kPa) when the speed of high speed train is 250~350 km·h-1 with the axle load of 17 t. During the operation of heavy haul railway train, the dynamic stress of subgrade surface gradually attenuates along the depth of subgrade. The attenuation in the surface and bottom layers of subgrade bed can reach over 40% and 80% respectively. The influence depth of dynamic stress is 3~4 m, which is 2.5 m more than the design thickness of subgrade bed. In view of the fact that the dynamic stress level of subgrade in the range of dynamic influence depth is far lower than the critical dynamic stress of filler at the same position, it can be known from the evaluation of critical dynamic stress method that the dynamic stability of cement-improved expansive soil subgrade for heavy haul railway meets service requirements.

关 键 词：重载铁路 路基 水泥改良膨胀土 循环列车动载 动力特性 临界动应力 

分 类 号：U213.1[交通运输工程—道路与铁道工程]