铁磁质岩石挤压破坏过程磁感应强度异常的实验研究

发布时间：2018-04-11 11:25

  本文选题：铁磁质岩石 + 加热　； 参考：《东北大学》2014年硕士论文

【摘要】：岩石圈是人类赖以生存的地方,随着经济的不断发展,人类开始发展地下空间,由于地下围岩失稳、隧道塌方及洞室岩爆等地下工程问题的发生,直接影响着人类的生命及财产安全,因此了解在应力作用下岩石内部微裂隙的变化过程及规律对保证工程安全具有重大意义。本论文主要是研究铁磁质岩石试件挤压破坏全过程中,应力、应变和磁感应强度之间的关系,通过分析应力-应变-磁感应强度曲线,获得铁磁质岩石试件挤压破坏的前兆。本试验岩石采自于辽宁省辽阳市弓长岭矿,岩石本身带有磁场,并且强度符合试验量程,对其加工制作成标准的圆柱体试件。此岩石源自于偌大岩石圈的一小部分,岩石内部缺失较小的微裂隙,本试验根据岩石内部热膨胀各向异性等,对铁磁质岩石试件加热以增加岩石内部的微小裂隙,通过加载系统和双通道数据采集系统,对加热处理后的试件进行单轴挤压试验和实时监测,获得应力、应变和磁感应强度三者之间的对应关系,将岩石力学物理参数与磁学物理参数联系起来,形成一种岩石挤压破坏过程微观变化的磁性测试方法。对铁磁质岩石试件挤压破坏试验,经过数据处理和分析,获得岩石试件挤压破坏过程中的应力、应变和磁感应强度三者之间的关系曲线,总结出铁磁质岩石试件挤压破坏全过程岩石磁感应强度的变化规律和试件临界破坏时磁感应强度变化异常特征。试验结果表明：在应力上升阶段,随着应变的增加,应力增加,磁强变小；在塑流段,应力几乎保持不变,磁强发生了三种突变,一是由下降转变为上升,二是磁感应强度变化趋于平缓,三是磁感应强度突然快速下降；试件破坏后,随着应变的增加应力变小,磁强发生上升或趋于平缓。选用加热温度为700℃-600℃-700℃三次重复加热和300℃-600℃-500℃三次重复加热后,经过挤压破坏实验后,铁磁质岩石试件可以实现充分破坏。
[Abstract]:The lithosphere is the place on which human beings depend for survival. With the development of economy, human beings begin to develop underground space. Due to the instability of underground surrounding rock, tunnel collapse and cave rockburst, etc, underground engineering problems occur.The safety of human life and property is directly affected, so it is of great significance to understand the changing process and law of microcracks in rock under stress to ensure the safety of engineering.In this paper, the relationship between stress, strain and magnetic induction strength in the whole process of extrusion failure of ferromagnetic rock specimen is studied. By analyzing the stress-strain-magnetic induction intensity curve, the precursor of extrusion failure of ferromagnetic rock specimen is obtained.The test rock was collected from Gongchangling Mine in Liaoyang City Liaoning Province. The rock itself has magnetic field and its strength accords with the test range.The rock is derived from a small part of the huge lithosphere, and there is a small microcrack missing in the rock. According to the anisotropy of thermal expansion inside the rock, the specimen of ferromagnetic rock is heated to increase the tiny fissure inside the rock.Through loading system and two-channel data acquisition system, uniaxial extrusion test and real-time monitoring of the heated specimen are carried out, and the corresponding relationship among stress, strain and magnetic induction intensity is obtained.The rock mechanics and physical parameters are connected with the magnetic physical parameters to form a magnetic measurement method for the microscopic change of rock extrusion failure process.Through data processing and analysis, the relationship curves between stress, strain and magnetic induction strength during the extrusion failure of ferromagnetic rock specimens are obtained.The variation law of magnetic induction intensity of ferromagnetic rock specimen during the whole process of extrusion failure and the abnormal characteristics of magnetic induction intensity variation during critical failure of the specimen are summarized.The test results show that in the stress rising stage, the stress increases with the increase of strain, and the magnetic intensity becomes smaller; in the plastic flow section, the stress almost remains the same, and the magnetic intensity has three kinds of abrupt changes, one is from decreasing to increasing.Second, the change of magnetic induction intensity tends to be gentle, and the third is the sudden and rapid decrease of magnetic induction intensity; after the specimen is destroyed, the magnetic intensity increases or tends to be gentle with the increase of strain and the stress becomes smaller.When the heating temperature is 700 鈩，

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