不同含水状态花岗岩断裂力学行为及声发射特征

发布时间：2018-02-12 21:17

本文关键词： 三点弯曲北山花岗岩振铃计数率加卸载饱和　出处：《岩土工程学报》2017年08期 　论文类型：期刊论文

【摘要】：利用MTS815 Flex Test GT岩石力学试验系统及声发射(AE)三维定位实时监测系统,对两种不同含水状态的深部细粒英云闪长岩进行了三点弯曲试验,得到烘干状态及饱水状态下花岗岩的载荷 LPD曲线、声发射振铃计数率、AE撞击数曲线。试验结果表明,在水的影响下花岗岩的断裂力学特性和声发射特征都有较大变化。饱水状态岩样的平均断裂韧度为干燥状态下的87.5%,且在试验过程中整体的变形变大,其刚度变小,脆性减弱,强度变低。在岩样三点弯曲的各个阶段,饱水岩样的声发射振铃计数率远小于干燥状态岩样;在试验过程中出现了明显的Kaiser效应。岩样以V型截面拉断破坏为主;饱和岩样声发射事件数远大于干燥岩样。研究结果对于受含水层影响的深部花岗岩岩土工程设计及施工具有重要的理论及实际指导意义。
[Abstract]:Using MTS815 Flex Test GT rock mechanics test system and acoustic emission (AE) 3D positioning real time monitoring system, three point bending tests were carried out on two kinds of deep fine-grained quartz diorite with different water-bearing states. The load LPD curve and AE impact number curve of granite under drying and saturated state are obtained. The experimental results show that the acoustic emission ring counting rate is higher than AE impact number curve. Under the influence of water, the fracture mechanics characteristics and acoustic emission characteristics of granite have great changes. The average fracture toughness of saturated rock samples is 87.5% in dry state, and the whole deformation becomes larger, the stiffness becomes smaller and the brittleness weakens during the test. In each stage of three-point bending of rock sample, the counting rate of acoustic emission ring of saturated rock sample is much smaller than that of dry rock sample, and there is obvious Kaiser effect in the process of test. The number of acoustic emission events of saturated rock samples is much larger than that of dry rock samples. The results of the study have important theoretical and practical guiding significance for the design and construction of deep granite geotechnical engineering affected by aquifer.
【作者单位】：四川大学水利水电学院;核工业北京地质研究院环境工程研究所;
【基金】：国家自然科学基金项目(51374148,51641405) 四川省青年基金项目(2017JQ0003)
【分类号】：TU45

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