中文摘要：

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。

英文摘要：

This paper addresses the long-term settlement of embankment induced by the traffic loading and soil structure of natural soft clay. The artificial structured soils with different bonding strength are prepared. A series of compression test and dynamic triaxial tests are carried out to investigate the effects of cycle number, dynamic stress ratio and structured strength on the accumulative deformation behavior. The results indicate that accumulative deformation increases with the increase of cycle number and dynamic stress ratio, and decreases with the increase of structured strength. Three curve categories can be distinguished to describe relationships between accumulative plastic strain and cycle number. They are destructive, stable and critical types. Considering the impact of soil structure, a structured parameter called stress sensitivity Sa is introduced into existing accumulated deformation prediction model. Then destructive and stable empirical formulas are established. They can better predict various accumulative strain curves of structured soft soils with different deformation conditions. The variation of modelparameters with the stress level and structure strength is also analyzed.