密度及应力水平对珊瑚砂强度变形特性影响

为研究密度与应力水平对珊瑚砂强度和变形特性的影响，利用三轴仪，对珊瑚砂试样开展了一系列不同密度、不同应力水平条件下的三轴固结排水剪试验。根据试验结果分析了珊瑚砂密度和应力水平对其应力应变、体积变形特性及强度特性等的影响。结果表明，不同相对密度的试样均表现出剪胀特性，同一初始密度的试样，围压越大其剪胀现象越不显著。珊瑚砂初始切线模量随着围压和相对密度的增大而增大，可近似用直线表示，并建立了初始切线模量与相对密度和围压的关系式。相变点应变随围压的增大而增大，随相对密度的增大而减小。珊瑚砂强度指标φ₀和Δφ随着相对密度的增大而呈线性增大趋势。

Analysis of strength-deformation behavior of coral sand with different densities and stress levels

In order to study the influences of density and stress level on the strength and deformation characteristics of the coral sand, a series of triaxial consolidation drained shear tests with different densities and stress levels are carried out using a triaxial apparatus. Based on the experimental study results, the effects of the density and stress level of the coral sand on its stress-strain, volume deformation characteristics and strength characteristics are analyzed. The analysis results show that the specimens with different relative densities all have the dilatancy characteristics, while for the specimens with same initial density, the larger the confining pressure, the less obvious the dilatancy. The initial tangential modulus of the coral sand increases with the increase of the confining pressure and relative density, which can be approximately expressed by a straight line. The relationships between the initial tangent modulus, relative density and confining pressure are established in this paper. The strain at the phase transition point increases with the increase of the confining pressure and decreases with the increase of the relative density. The strength indexes of the coral sand increase linearly with the increase of the relative density, and the relationships between them are established.