Journal of Nantong University (Natural Science Edition)

不同配比的土石混合体在荷载作用下展现出不同的变形特征,会影响工程的稳定性,为此,针对不同含石量的土石混合体,对其力学特性进行研究。首先,制备含石量分别为20%、40%、60%、80%的4组土石混合体立方样;然后,采用一种改进的大型室内剪切流变试验机对这些样品分别施加100、200和300 kPa垂直应力,进行室内直剪试验。试验结果表明:土石混合体的抗剪强度随着含石量的增加而增加,当含石量超过40%后,抗剪强度增加的幅度更为显著;在同一垂直应力下,随着含石量的增加,土石混合体的剪胀特性愈发显著;随着垂直应力的提高,土石混合体在剪切初期出现先剪缩再剪胀的特征,并且含石量越小,这种剪缩特征越明显。

The soil-rock mixture with different gradation exhibits different deformation characteristics under load,which affects the project stability. Therefore, to study the mechanical properties of soil-rock mixtures with different rock contents. The samples of soil-rock mixture with the stone content of 20%, 40%, 60% and 80% are prepared. The laboratory shear test is carried out under the vertical stress of 100 kPa, 200 kPa and 300 kPa with an improved large indoor shear rheological testing machine. The test results show that the shear strength of soil-rock mixture increases with the increase of stone content. When the stone content exceeds 40%, the increase is more obvious; under the same vertical stress, the shear dilatancy of the soil-rock mixture become more obvious with the increase of the stone content; and with the increase of the vertical stress, the shear contraction and expansion is identified at the initial stage of shearing. When the stone content is smaller, the shear contraction is more obvious.