珊瑚砂蠕变特性的试验研究
Experimental study on creep properties of coral sand
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摘要: 对两种相对密实度的珊瑚砂开展不同围压条件下的固结排水剪切试验,掌握了珊瑚砂的峰值强度及变形特性,进而对每种密度试样开展4种应力水平条件下的蠕变试验,并对试验前后的试样分别进行颗粒分析,研究应力水平及围压影响下的珊瑚砂蠕变特性及蠕变机理。试验结果表明,珊瑚砂的蠕变变形是颗粒滑移、错动、颗粒破碎、颗粒调整重组所引起,其蠕变变形受围压和应力水平影响显著,随围压和应力水平的增加而增大,而密度对其影响不明显,并建立了其蠕变变形与围压及应力水平之间的变化规律。Abstract: The consolidated drainage shear tests on the coral sand with two kinds of relative densities under different confining pressures are performed, and its peak strength and deformation characteristics are obtained. Then, the creep tests on the samples under four stress levels as well as their particle analysis tests before and after the creep tests are carried out, and the creep properties and creep mechanism of coral sand are studied considering the influences of stress levels and confining pressures. The results show that the creep deformation of coral sand is caused by particle slip, dislocation, particle breakage, particle adjustment and reorganization. The creep deformation characteristics of coral sand are significantly affected by the confining pressures and stress levels, while the densities have no obvious influences. It is shown that the creep deformation of coral sand increases with the increase of confining pressures and stress levels. Finally, the variation law between the creep deformation of coral sand and the confining pressures and stress levels is established.