不同粒径砂岩三轴压缩力学特性试验研究

Experimental Study on Mechanical Characteristics of Triaxial Compression of Sandstone in Different Sizes

以细、中两种粒径的四川砂岩进行常规三轴压缩试验，分析两种粒径砂岩的强度和变形特性。结果表明：砂岩的轴向峰值应变受粒径大小影响；两种砂岩在围压0～6MPa范围内，峰值应变占．有显著提高，而在围压8～16MPa范围，峰值应变8，不再变大，存在一个极限值；中颗粒砂岩峰值应变对围压的敏感程度高于细颗粒砂岩；砂岩的峰值应变与围压呈线性关系；岩石的矿物粒径大小影响着岩石的抗压强度。

With small-and medium-sized sandstone in Sichuan, common triaxial compression test was carried out to analyze the strength and deformation characteristics of the two kinds of sandstone. The result shows that the axial peak of the sandstone changes with the size ; under the confining pressure within 0- 6 MPa, the peak strainel of these sandstone increased greatly, however, under the confining pressure within 8 - 16 MPa, the peak strainel does not increase any more, with a limit arising; the peak strain of medium-sized sandstone is more sensitive to confining pressure than that of small-sized sandstone, and the peak strain depends linearly on confining pressure; as well as the size affects the compressive strength of the sandstone.