天然沉积结构性黏土原位压缩规律及预测模型研究

发布时间：2018-08-08 13:37

【摘要】：通过天然沉积黏土的原状样与重塑样的压缩对比试验,揭示了屈服后土结构性的渐进性破损过程以及由常规ve-lgsσ曲线确定的压缩指数cC随固结压力呈非线性变化性状给实际工程沉降计算参数选取带来不便。采用vlg(1+e)-lgsσ双对数坐标表示方法,通过不同初始结构大小的黏土试验数据证实了vlg(1+e)-lgsσ压缩曲线在屈服前后段具有良好的线性关系,实现了结构屈服应力、屈服前后压缩指标有效统一确定。在该坐标体系下给出了考虑取样扰动影响的原位压缩曲线恢复方法,建立了结构性黏土的双线性压缩模型,结合文中与文献中试验数据给出了结构屈服应力与不排水强度、屈服后压缩指标与稳定指数SI和液限wL的经验关系。研究结果可为天然沉积土地基固结沉降计算参数的合理选取提供依据。
[Abstract]:Through the compression contrast test of the undisturbed sample and the remolded sample of the natural sedimentary clay, It is revealed that the progressive damage process of soil structure after yield and the nonlinear variation of compression exponent c _ (C) determined by conventional ve-lgs 蟽 curve with consolidation pressure bring inconvenience to the selection of practical engineering settlement calculation parameters. By using vlg (1e) -lgs 蟽 double logarithmic coordinate representation method, the experimental data of clay with different initial structure sizes show that the vlg (1e) -lgs 蟽 compression curve has a good linear relationship in the front and rear segments of yield, and the yield stress of the structure is realized. The compression index before and after yield is determined effectively and uniformly. In this coordinate system, an in-situ compression curve restoration method considering the influence of sampling disturbance is given, and a bilinear compression model of structural clay is established. The yield stress and undrained strength of the structure are given in combination with the experimental data in the paper and in the literature. Empirical relationship between yield compression index and stability index SI and liquid limit WL. The results can provide a basis for the reasonable selection of calculation parameters of consolidation settlement of natural sedimentary soil foundation.
【作者单位】：中南大学土木工程学院;长沙理工大学公路养护技术国家工程实验室;
【基金】：国家自然科学基金(No.51208517,No.51478054,No.U1134207) 中国博士后科学基金(No.2013M530360)
【分类号】：TU442

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