长期循环荷载下人工结构性软土累积变形规律及预测模型

发布时间：2018-10-08 07:03

【摘要】：针对软土地区路基运营后显著的长期沉降效应问题,以及天然沉积软土均具有一定结构性的特点,制备了不同胶结强度的人工结构性土,开展了结构性土与相应重塑土的压缩试验和动三轴试验,分析了循环次数、动应力比和结构性强度对土体累积塑性变形的影响规律。试验结果表明:土体累积变形随着循环次数、动应力比的增大而增大,随着结构性强度的提高而减小;累积应变曲线可分为破坏型、稳定型和临界型3种形式。进而考虑土结构性影响,在已有累积变形模型基础上引入应力灵敏度Sσ参数,分别建立了结构性软土的破坏型和稳定型的累积变形模型,较好地预测了结构性软土不同变形状态的累积应变曲线,并分析了模型参数随应力水平和结构强度的变化规律。
[Abstract]:Aiming at the obvious long-term settlement effect of roadbed in soft soil area and the structural characteristics of natural sedimentary soft soil, artificial structural soil with different cementing strength was prepared. The compression test and dynamic triaxial test of structural soil and corresponding remolded soil were carried out. The influence of cyclic times, dynamic stress ratio and structural strength on the cumulative plastic deformation of soil was analyzed. The experimental results show that the cumulative deformation of soil increases with the increase of cyclic times and the dynamic stress ratio, and decreases with the increase of structural strength, and the cumulative strain curve can be divided into three types: failure type, stable type and critical type. Furthermore, considering the influence of soil structure, the stress sensitivity S 蟽 parameter is introduced on the basis of the existing cumulative deformation model, and the failure and stable cumulative deformation models of structural soft soil are established, respectively. The cumulative strain curves of different deformation states of structural soft soil are well predicted, and the variation of model parameters with stress level and structural strength is analyzed.
【作者单位】：中南大学土木工程学院;湖南省交通规划勘察设计院有限公司;
【基金】：国家自然科学基金项目(51208517) 中国博士后科学基金项目(2013M530360) 中南大学中央高校基本科研业务费专项资金项目(2016zzts390)资助
【分类号】：U416.1

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