摘要
为确保周口至平顶山高速公路工程中粉质黏土路段的顺利施工和长期稳定运营,该文针对该路段的粉质黏土,开展了对不同压实度试样在不同应力水平下的一维蠕变试验,研究了压实度对其长期蠕变力学特性的影响规律。通过建立相应的蠕变本构模型,为工程中粉质黏土路基的蠕变破坏防治提供理论依据。研究结果表明:(1)在相同应力水平下,随着压实度的增大,试样的瞬时应变、蠕应变及总应变均显著减小。其中,压实度对试样蠕应变的抑制作用最为明显,其次是总应变,而对试样瞬时应变的抑制作用最小;(2)不同压实度试样孔隙比-时间对数(e-lg t)曲线变化规律基本一致,均可划分为3个阶段,且在相同应力水平下,压实度越大,试样孔隙比总降低量越小;(3)相同应力水平下,随着压实度的增加,Burgers模型中的E_(1)、E_(2)、η_(1)、η_(2)均呈增大趋势,表明试样的瞬时弹性变形、黏弹性变形及稳态蠕变速率均减小,而在稳定蠕变阶段的时间延长。
In order to ensure the smooth construction and long-term stable operation of silty clay sections in the Zhoukou–Pingdingshan highway project,this paper conducted one-dimensional creep tests on silty clay samples with different compaction degrees under different stress levels and studied the effect law of compaction degree on its long-term creep mechanical properties.By establishing the corresponding creep constitutive models,a theoretical basis was provided for the prevention and control of creep failure in silty clay subgrades in engineering practice.Research results show that:①Under the same stress level,with the increase of compaction degree,the instantaneous strain,creep strain,and total strain of the samples all decrease significantly.Among them,the compaction degree has the most obvious inhibitory effect on the creep strain of the samples,followed by the total strain,and the inhibitory effect on the instantaneous strain of the samples is minimal;②The variation laws of the void ratio‑logarithm of time(e-lg t)curves of samples with different compaction degrees are basically consistent,which can all be divided into three stages.At the same stress level,the total reduction in void ratio of the samples becomes smaller as the compaction degree increases;③Under the same stress level,with the increase of compaction degree,the parameters E_(1),E_(2),η_(1),and η_(2) in the Burgers model all show an increasing trend,indicating that the instantaneous elastic deformation,viscoelastic deformation,and the steady-state creep rate of the samples are all decreasing,while the duration of the samples in the stable-state creep stage is increasing.
作者
李明超
吴钢荣
LI Mingchao;WU Gangrong(CCCC Second Highway Engineering Co.,Ltd.,Xi’an,Shaanxi 710061,China)
出处
《中外公路》
2025年第6期36-44,共9页
Journal of China & Foreign Highway
基金
江西省水工安全工程技术研究中心开放基金资助项目(编号:2023SKSG07)
