长期循环荷载下粗粒土应变累积与塑性安定准则研究  

Strain accumulation and plastic shakedown criterion of coarse-grained soil under long-term cyclic loading

作　　者：胡永利 邬智峰 张东杰 李琼林 王利平 田光明 王晓鹏 HU Yongli;WU Zhifeng;ZHANG Dongjie;LI Qionglin;WANG Liping;TIAN Guangming;WANG Xiaopeng(School of Mechanical Engineering,Southwest Jiaotong University,Chengdu 610031,China;Jinan Communications Development&Investment Co.,Ltd.,Jinan 250101,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;China Railway 22nd Bureau Group 4th Corporation Limited,Tianjin 301700,China)

机构地区：[1]西南交通大学机械工程学院,四川成都610031 [2]济南交通发展投资有限公司,山东济南250101 [3]西南交通大学土木工程学院,四川成都610031 [4]中铁二十二局集团第四工程有限公司,天津301700

出　　处：《地震工程与工程振动》2025年第1期103-112,共10页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(52178356)。

摘　　要：压实粗粒土作为铁路路基基床表层的填筑材料,其在长期列车循环荷载作用下的动力响应对于整个路基结构的服役性能至关重要。文中研究进行了一系列循环三轴试验,以探究细颗粒含量、围压和循环应力幅值对粗粒土累积行为的影响。研究结果表明,在相同的循环荷载作用下,细颗粒含量较高的试样产生更少的累积轴向应变。此外,粗粒土试样在较高的围压或较低的循环应力幅值作用下产生的累积轴向应变也较少。随后,根据一个通用的安定准则确定了不同细颗粒含量粗粒土的塑性安定极限。结果表明,随着细颗粒含量的增加,粗粒土试样的塑性安定极限逐渐增大。在较高的围压作用下,粗粒土对应的塑性安定极限也更高。此外,通过在p-q平面上绘制与粗粒土塑性安定极限相对应的应力状态,建立细颗粒含量系数(fine content,FC)与现有安定准则中模型参数之间的关系式,进而提出了适用于不同细颗粒含量的粗粒土的统一塑性安定准则。研究成果可为铁路路基的设计和稳定性评估提供理论基础。The dynamic response of compacted coarse-grained soil as a filling material for the surface layer of railway subgrade bedding is crucial for the overall performance of the subgrade structure under long-term cyclic train loads.This study conducted a series of cyclic triaxial tests to investigate the effects of fine content,confining pressure,and cyclic stress amplitude on the accumulated behavior of coarse-grained soils.The test results indicate that under the same cyclic loading conditions,specimens with higher fine content 0x0E䥺Symbol`@@0x0Fexhibit less accumulated axial strain.Furthermore,coarse-grained soil specimens exhibit less accumulated axial strain under higher confining pressure or lower cyclic stress amplitudes.Subsequently,the plastic shakedown limit of coarse-grained soils with different fine contents was determined based on a universal shakedown criterion.The results demonstrate that the plastic shakedown limit of coarse-grained soil specimens gradually increases with an increase in fine content.Under higher confining pressure,the corresponding plastic shakedown limit of coarse-grained soil is also higher.Additionally,by plotting the stress state corresponding to the plastic shakedown limit of coarse-grained soil on the plane of p-q,a relationship was established between the coefficient of fine content(FC)and the model parameters in the existing shakedown criterion.A united plastic shakedown criterion is then proposed for coarse-grained soils with different fine contents.The conclusions can provide a theoretical foundation for the design and stability assessment of railway subgrades.

关 键 词：粗粒土 细颗粒含量 累积应变 塑性安定极限 

分 类 号：TU435[建筑科学—岩土工程]