珠三角地区典型软土卸荷力学特性研究

摘要

The conventional three axis test and unloading mechanical test of three true triaxial have been carried out for three kinds of typical soil in the Pearl River Delta,such as Silty clay,silty sand and red clay.the mechanical properties of the soil under different stress path has been discussed.some meaningful research Conclusions have been obtained.such as shear strength of soil will greatly reduced under the lateral unloading conditions,the effective stress index decrease is greater than the total stress index,the shear strength index of sand were significantly less than silt soil and red clay and so on.And then,some proposals have been put forward that the soil unloading mechanical effect should fully consid-ered on the design and construction of super soft soil deep foundation pit engineering in Pearl River Delta area.%通过珠三角地区3种典型土层，即：淤泥质土、粉细砂以及红粘土进行室内常规三轴试验与真三轴卸荷力学试验，分析探讨了不同应力路径条件下土体的力学特性，得出了侧向卸荷条件下土体的抗剪强度指标大幅度降低，且有效应力指标降低幅度大于总应力指标，粉细砂抗剪强度指标降低幅度明显大于淤泥质土与红粘土的研究结论，并以此提出珠三角地区超大软土深基坑工程设计与施工应充分考虑土体卸荷力学效应的建议。