考虑主应力轴旋转效应的交通荷载下饱和软黏土变形特性试验研究

发布时间：2018-01-19 02:37

本文关键词： 土力学主应力轴旋转交通荷载循环弱化饱和软黏土非共轴　出处：《岩石力学与工程学报》2016年05期 　论文类型：期刊论文

【摘要】：采用空心圆柱扭剪仪对原状饱和软黏土开展交通荷载诱发主应力幅值与主应力轴旋转耦合加载路径下的不排水试验研究。通过与循环三轴压缩试验对比,探讨主应力轴旋转对孔压、变形和应力应变的影响。分析广义剪应力对循环刚度和非共轴性的影响。试验结果表明,相比较循环三轴试验,交通荷载应力路径下所诱发的主应力轴旋转使孔压和应变显著变大,应力应变滞回圈刚度显著弱化。循环耦合加载路径下,存在剪切应力应变和正偏应力应变2种响应,应力应变刚度呈现各向异性弱(强)化,应变增量矢量有显著的非共轴性,非共轴性有显著分段特征。较低剪应力水平下,应变路径轨迹趋于稳定,循环刚度表现为强化,非共轴性趋于增大;而较高剪应力水平下,应变路径轨迹趋于破坏,随循环弱化,非共轴性减小。
[Abstract]:By using hollow cylindrical torsional shear apparatus, the undrained experimental study of traffic load-induced principal stress amplitude and rotating coupling loading path of principal stress axis is carried out on the intact saturated soft clay. The results are compared with cyclic triaxial compression test. The effects of rotation of principal stress axis on pore pressure, deformation and stress and strain are discussed. The effect of generalized shear stress on cyclic stiffness and non-coaxiality is analyzed. The experimental results show that the cyclic triaxial tests are compared. The rotation of principal stress axis induced by traffic load stress path significantly increases the pore pressure and strain, and weakens the stiffness of stress and strain hysteresis loop. There are two kinds of responses: shear stress strain and normal strain strain. The stiffness of stress and strain is weak (strong) anisotropy and the strain increment vector has obvious non-coaxial property. At the low shear stress level, the strain path trajectory tends to be stable, the cyclic stiffness is strengthened, and the non-coaxiality tends to increase. However, at higher shear stress level, the track of strain path tends to destroy, and with the weakening of cycle, the non-coaxial property decreases.
【作者单位】：同济大学地下建筑与工程系;同济大学岩土及地下工程教育部重点实验室;
【基金】：国家自然科学基金资助项目(41272291,51238009,51578413)~~
【分类号】：TU447
【正文快照】： 1引言作用于地基上的交通荷载会引起土单元上主应力轴方向发生连续的循环旋转[1]。已有研究显示,主应力轴旋转对土的变形特性有复杂的影响,相比较常规动三轴和循环扭剪等应力路径,主应力轴旋转使土体累积变形显著增大[2],并且有明显的非共轴性[3]。非共轴性指在加载过程中主应

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