刚性与柔性边界条件下压实黄土变形特性研究

Study on the Deformation Characteristics of Compacted Loess under Rigid and Flexible Boundary Conditions

刚性边界与柔性边界是目前在路基施工中所存在的两种主要边界条件,而不同的边界条件对于路基土体的变形、沉降等具有显著的影响.采用三向加载设备,开展了不同压实度的黄土在刚性与柔性边界条件下的室内压缩试验,探讨了不同边界条件对压实黄土变形的影响以及引起压实黄土变形存在差异的根本原因.研究结果表明:压实度分别为88%、93%、96%的黄土在刚性和柔性边界条件下的三向受力压缩过程中抗压强度与压实度呈正相关;且当压实度相同时,围压越大,压实度下降得越少.提出了竖向应变与体应变之间的关系式,并推导了竖向应变与侧向应变之间的关系式.

Rigid and flexible boundary conditions constitute the two predominant types of conditions encountered in roadbed construction,each having a substantial influence on the deformation and settlement characteristics of the foundational soil.Utilizing custom-designed triaxial loading apparatus,this research conducts a series of indoor compression tests on compacted loess with varying degrees of compaction,under both rigid and flexible boundary conditions.The investigation aims to unravel the effects of these conditions on the deformation behavior of compacted loess,as well as to identify the fundamental mechanisms contributing to variations in deformation.Our findings reveal that the compressive strength of loess-tested at compaction degrees of 88%,93%,and 96%-exhibits a positive correlation with the degree of compaction during triaxial compressive loading under both types of boundary conditions.Moreover,under constant compaction degree,an increase in confining pressure results in a reduced reduction in compaction.The study further delineates equations for the relationships between vertical and volumetric strains,as well as between vertical and lateral strains.