不同含水状态级配碎石临界动应力及变形规律研究  

Study of Critical Dynamic Stress and Deformation Law of Graded Gravel under Different Moisture Content

作　　者：刘宝[1] 苏谦[1] PHAM Duc Phong 白皓[3] LAM Thi Huyen Hanh LIU Bao;SU Qian;BAI Hao(School of Civil Engineerings Southwest Jiaotong University,Chengdu 610031,China;Institute of Techniques for Special Engineering, Le Quy Don. Technical University, Hanoi 100803,Vietnam;Sichuan. Expressway Construction. &- Development Corporation., Chengdu 610041, China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]Le Quy Don技术大学特种工程学院,越南河内100803 [3]四川高速公路建设开发总公司,四川成都610041

出　　处：《铁道学报》2016年第6期100-107,共8页Journal of the China Railway Society

基　　金：国家自然科学基金(51378441,51578467)

摘　　要：为评估含水率变化对高速铁路无砟轨道基床表层级配碎石动力性能的影响,本文针对最优含水率和饱和含水率两种状态下级配碎石循环动力性能开展室内大型动三轴试验研究,分析级配碎石的临界动应力和累积变形特性。研究表明:累积变形与荷载作用次数、含水率关系密切,荷载作用次数超过10 000次后,含水率的影响逐渐显现,荷载作用次数达到20 000次时,饱和含水率的累积变形相对最优含水率增大70%;不同含水率级配碎石的衰减型和破坏型累积变形曲线可分别用Stewart模型和Monismith模型预测;级配碎石临界动应力随含水率增大而减小,随围压的增大线性增大,饱和含水状态对应的临界动应力较最优含水状态平均小13%。To evaluate the effect of changes in moisture content on the dynamic performance of graded gravel in the surface of ballastless track subgrade bed of high-speed railway,large scale indoor dynamic triaxial experi-ments were carried out on the dynamic performance of graded gravel under the two conditions of optimum mois-ture content and moisture saturation,to study the critical dynamic stress and the cumulative deformation char-acteristics of graded gravel.The research results indicated that the cumulative deformation was closely related to the number of load cycles and the moisture content.The influence of moisture content on the cumulative de-formation gradually emerged when the load cycle number exceeded 10000.The cumulative deformation under the condition of saturated water content increased by 70% relative to that under the state of optimum moisture content,when the load cycle number exceeded 20000.The cumulative deformation curve of graded gravel with different moisture content under the attenuation state and the breakdown state can be simulated by Stew-art model and Monismith model respectively.The critical dynamic stress of graded gravel decreased with the increase of moisture content while increased with the increase of confining pressure.The critical dynamic stress at the state of saturated water content was reduced on average by 13% compared with that at the state of opti-mum moisture content.

关 键 词：高速铁路 级配碎石 大型三轴试验 不同含水率 累积变形 临界动应力 

分 类 号：TU411.8[建筑科学—岩土工程]