【作者】 蔡亮；

【导师】 陈耕野；

【作者基本信息】 东北大学 ， 结构工程， 2008， 硕士

【摘要】 在岩石应力检测中,由于岩石内部结构的复杂性,需要综合各学科的知识,目前存在很多有用的方法,但还存在着一定程度的局限性和不足,本文利用岩石的电学特性,选择大理岩作为研究对象,进行了大理岩应力的电学频域特性实验研究。为了达到实验目的,本文建立了合理的大理岩应力电学频域特性实验系统,包括加载系统和电路系统两部分,由加载系统提供实验所需的加载程序,同时获得大理岩试件的应力应变值；电路系统对岩石试件提供可变频的交流电信号并可获得大理岩试件的电阻值。首先在交流输入电信号频率不变的情况下做大理岩应力应变电阻实验,选择两种矿物成分不同的大理岩进行实验,通过比较研究大理岩应力电阻变化关系；在此基础上做大理岩应力的电学频域特性实验,对大理岩试件进行加载,在加载过程中压力每增加5kN保持压力不变的同时,通过改变交流输入电信号频率获得电学频谱曲线后继续加载；对大理岩试件加载卸载,压力每增加10kN进行卸载,完全卸载后通过改变交流输入电信号频率获得电学频谱曲线,在合适的频域范围内研究大理岩应力的电学记忆性。通过对实验结果的分析研究得到结论：交流输入电信号频率不变的情况下,大理岩试件的电阻随着压缩应力的增加而增加,保持大理岩试件的应力不变时,试件电阻随着交流输入电信号频率的改变而变化,形成大理岩应力的电学频谱曲线,随应力水平升高电学频谱曲线逐渐上移,每一条频谱曲线对应一个应力水平,从而获得不同应力作用下对应的多条电学频谱曲线组成的大理岩应力的电学谱纹,通过对电学谱纹的分析研究应力与电学频谱特征的变化关系,拟合出数学公式用于反映大理岩应力的电学频域特性；大理岩试件每次完全卸载后的电学频谱曲线与初始零应力对应的电学频谱曲线存在差别,并且随着所受应力的增加而逐渐上移,表明大理岩试件应力的电学记忆性存在,通过各频谱曲线之间的相关性研究分析大理岩试件应力的电学记忆性。研究结论可用于岩石应力的检测,岩石内部结构变化的研究。更多还原

【Abstract】 In the testing of the rock structure, the stress testing of rock is very difficult because of the complicate rock fracturing, the stress testing method of the rock structure have to use others field’s knowledge. In recent years, there are some useful methods of the stress testing of rock but some limitation and shortage still existed to some extent. This paper choose marble as research object, then use electrical knowledge of rock to study the stress and electrical frequency effect of marble.The author of this paper has built the suitable experimental system for complete the experiment of electrical frequency characteristic of marble stress. The experimental system includes loading system and circuit system. The loading system is used for loading and measuring stress and strain value of marble specimen. The circuit system is used for offering AC signal of different frequency and acquiring the electrical resistance of marble specimen. At first, the stress, strain and electrical resistance experiment of marble specimen have finished under condition of invariable frequency of input AC signal. By analysis on the experimental data of two kinds of marble specimens which have different mineral compositions, the author has researched the change relation of electrical resistance with marble stress. On the basis of the stress, strain and electrical resistance experiments of marble, the author has done the experiment of electrical frequency characteristic of marble stress. When the pressure increases 5kN, the author stops loading and sustain loading until acquire the electrical spectrum line by changing the frequency of input AC signal. Then the experiment of loading-on and loading-off of marble specimen were carried out. When the pressure increases 10kN, the author starts unloading. The author has acquired electrical spectrum lines by changing frequency of input AC signal in suitable range when marble specimen stress has unloaded completely. The experiment is used for researching on electrical frequency memory characteristic of marble stress. By results we can discover several conclusions. If the frequency of input AC signal is invariable, the electrical resistance of marble specimen is increasing with the increase of stress. If the stress of rock specimen is invariable, the electrical resistance is changing with the change of the frequency.The electrical resistance of marble specimen can become electrical spectrum line by changing the frequency of input AC signal. With the increase of the stress, the electrical spectrum line moves up gradually. A piece of the spectrum line corresponds to a stress level. The stress electrical spectrum lines are obtained composed by several pieces of spectrum lines of different stress levels. According on analysis on the electrical spectrum lines, the author has studied the change relation of characteristic of electrical spectrum line with stress, then fitted mathematical formula to reflect electrical frequency characteristic of marble stress. The electrical spectrum line of rock specimen loaded off completely is different from the electrical spectrum line of initial zero stress. With the increase of the stress which had loaded on marble specimen, the electrical spectrum line moves up gradually, this phenomenon can show that the electrical memory characteristic of marble stress exists. The author has studied the memory characteristic of marble stress by using correlation between the electrical spectrum lines. These conclusions will be used for detection of rock stress and researching on inner structure of rock.更多还原