分级加卸载下节理软岩流变试验及模型

采用分级增量循环加卸载方式，对金川有色金属公司 Ⅲ 矿区软弱节理矿岩进行蠕变试验，按瞬时弹性应变、滞后黏弹性应变、瞬时塑性应变与黏塑性应变对流变试验数据进行分析，探讨了软弱节理矿岩的黏弹塑性变形特性；引入2种非线性元件--裂隙闭合体和非线性牛顿体，并将它们和描述衰减蠕变特性的开尔文体及描述瞬弹性的虎克体相结合，得到了一种新的复合元件流变模型，以研究复杂条件下节理软岩的黏弹塑性变形特性.试验结果表明,复合元件流变力学模型能很好地描述节理软岩在不同应力水平下的蠕变特性,特别是裂隙闭合阶段和加速蠕变阶段的特性，金川Ⅲ 矿区矿岩蠕变试验曲线与理论曲线较为吻合.

Creep properties experiment and model of jointed soft rocks under step load and unload

A set of creep experiments were performed to study the viscoelasto plastic characteristics of  jointed  soft ore rock in Jinchuan Mine Ⅲ by a circular increment step load and unload method. The experimental data were analyzed according to instantaneous elastic strain, viscoplastic strain,instantaneous plastic strain and viscoplastic strain.The viscoelasto plastic characteristics of jointed soft ore rock were discussed. Based on scientific analysis on experimental data, the rules of creep strain and instantaneous strain under step load and unload were obtained. Brought forward two nonlinear components:closed cranny body and nonlinear Newton body, and combined them with Kelvin body describing the deceleration creep and Hoke body describing the instantaneous elasticity to gain a new multiple components creep model. The model was used to study viscoelasto plastic characteristics of jointed soft rocks, the creep characteristic curves were obtained through curve fitting. The test results show that the new multiple components creep model can effectively describe the creep properties of jointed soft rocks under different stress level,especially the properties of the cranny closed phase and the creep accelerated phase.The creep testing curves of the ore rock of Jinchuan Mine Ⅲ are coincident well with the theoretic curves. 