| 循环荷载作用下片麻岩劣化损伤机理与规律试验 |
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| 引用本文： | 杨龙,史小勇,陈钱,魏云杰,张明,吕文韬.循环荷载作用下片麻岩劣化损伤机理与规律试验[J].地质科技通报,2020,39(5):55-60. |
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| 作者姓名： | 杨龙 史小勇 陈钱 魏云杰 张明 吕文韬 |
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| 基金项目： | 中国地质调查局地质调查项目DD20179609中国地质调查局地质调查项目DD20190647 |
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| 摘 要： | 新疆塔县地区广泛分布的大规模片麻岩崩塌、滑坡主要是由于长期地震力循环作用下岩体劣化所致。为揭示该地区片麻岩在地震力作用下的劣化损伤机理，采用在不同应力水平条件下对片麻岩岩样进行循环荷载试验和三轴压缩试验的方法，分析了片麻岩阻尼参数及循环加、卸载前后三轴抗压强度的变化规律。研究结果表明:片麻岩阻尼比和阻尼系数随着循环荷载次数的增加而逐渐降低，随着应力水平的升高而增大；循环荷载作用后，片麻岩的三轴抗压强度均明显降低，且应力水平越高，降低的幅度越大；此外，片麻岩内部矿物颗粒的相互摩擦，原生微裂隙、孔洞的张开、闭合以及次生裂隙的产生、发展是导致其劣化损伤的主要机制。总的来说，长期地震力作用下，研究区片麻岩由于内部劣化损伤导致的力学性质降低，是该区域广泛发育大规模崩塌、滑坡等地质灾害的主要原因之一。
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| 关 键 词： | 片麻岩 循环荷载 阻尼参数 滞回圈 劣化损伤 |
| 收稿时间： | 2019-12-20 |
Mechanism and laws of deterioration and damage of gneisses under cyclic loading |
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| Abstract: | The collapses and landslides of gneiss in Taxian area of Xinjiang are mainly caused by the deterioration of rock mass under the long-term circulation of seismic force. In order to reveal the mechanism of deterioration and damage of gneiss under earthquake in Taxian area, constant amplitude cyclic loading tests and triaxial compression tests were carried out on gneiss samples under different stress levels in this paper. And the variation rules of hysteretic cycle, damping parameters and triaxial compressive strength before and after constant amplitude cyclic loading were analyzed. The results show that:the damping ratio and damping coefficient of gneiss decrease with the increase of cyclic loading and increase with the increase of stress level; after cyclic loading, the triaxial compressive strength of gneiss decreases significantly, and the higher the stress level is, the greater the reduction range is; in addition, the friction of mineral particles in gneiss, the opening and closing of primary micro-fissures and pores, and the generation and development of secondary fissures are the main mechanisms leading to their deterioration and damage. In short, under the long-term earthquake force, the mechanical property of gneiss in the study area has been reduced due to internal deterioration and damage, which is one of the main reasons for the extensive development of large-scale collapses, landslides and other geological disasters in this area. |
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