应力路径对天然沉积土压缩特性影响的试验研究

工程中如何考虑复杂应力路径对地基土压缩性状的影响是岩土工程中一个关键的问题。然而目前土体压缩性状的研究通常采用一维压缩和三向等压压缩试验，没有考虑应力路径的影响。通过对天然沉积土进行不同应力路径下的GDS三轴压缩试验，研究不同应力比对天然沉积土压缩性状的影响规律。结果表明：不同应力路径下天然沉积结构性土的平均结构屈服应力和结构屈服后的压缩性参数均先随应力比的增大而增大，达到最大值后又随着应力比的进一步增大而减小。通过对比分析不同应力路径下的GDS三轴压缩屈服性状与一维压缩屈服性状，得出天然沉积土的静止土压力系数在屈服过程中并非常数，而是呈现由小到大的变化，在屈服后趋于恒定。

Experimental study on different compression behaviors of natural clays caused by various stress paths

How to assess the effect of stress path on compression behaviors of natural soils is an important issue in geotechnical engineering practice.A series of GDS triaxial compression tests under different stress paths are performed.The change in compression behaviors under different stress paths is investigated.It is found that the mean yield effective stress and the compression index increase with the increase in stress ratio to the maximum and then decrease with the increase in stress ratio.The comparison of yield behaviors between triaxial compression tests and one-dimensional compression tests indicates that the coefficient of earth pressure at rest increases with stress level during the yielding of compression,and becomes constant when the stress level is in the post-yield state.