单轴加卸载条件下岩盐变形过程能量和声发射特征研究

发布时间：2018-04-29 03:33

本文选题：岩盐 + 滞回环　；参考：《工程科学与技术》2017年S2期

【摘要】：利用MTS815 Flex Test GT岩石力学试验系统及声发射(AE)实时监测系统,对取自平顶山和淮安两处矿井的纯盐岩进行单抽加卸载试验,得到岩盐的应力-应变加卸载曲线、声发射振铃计数率和能量率曲线,并从能量与声发射的角度研究纯岩盐变形破坏过程的基本特征。研究表明:岩盐单轴加卸载条件下,弹性变形阶段很短,屈服过程产生很大的塑形变形,且峰后的变形过程没有应力的急剧下降,整个试验过程中加卸、载之间滞回环面积很微小。在整个试验过程中,弹性应变能所占比例非常小;盐岩单轴加卸载变形破坏过程中,其耗散能随应变一直增加,且增长率递增,而当应力接近峰值时,增长率趋于恒定,耗散能曲线开始呈线性增长;弹性应变能在峰前一直增加,且增长率递减,在峰值处达到最大值,峰后开始下降。岩盐在试验初始阶段振铃计数率与能量率大量产生,后在屈服阶段呈现下降进入稳定发展期,直到峰值处,出现一个累计振铃计数和累计能量曲线的拐点,峰后以一个更高的速率稳定且呈现阶梯状发展。本文对于盐岩储气库的水溶开挖和采气过程中逐渐卸载的应力环境施工过程有一定的实际指导意义。
[Abstract]:Using the MTS815 Flex Test GT rock mechanics test system and the acoustic emission (AE) real-time monitoring system, the single pumping and unloading tests were carried out on the pure salt rocks from two mines in Pingdingshan and Huaian, and the stress strain loading and unloading curves of the rock salt, the rate of acoustic emission ringing count and the energy rate curve were obtained, and the pure rock salt was studied from the angle of energy and acoustic emission. The basic characteristics of the deformation and failure process are as follows: under the condition of uniaxial loading and unloading of rock salt, the elastic deformation stage is very short, the yield process has great plastic deformation, and the deformation process after the peak has no sharp drop of stress. The whole test process is unloaded and the area of the hysteresis loop is very small. In the whole process of the test, the elastic strain energy can be found. In the process of uniaxial loading and unloading, the dissipation energy of the salt rock increases with the strain, and the growth rate increases, and when the stress approaches the peak, the growth rate tends to be constant, the dissipative energy curve begins to increase linearly, the elastic strain can increase before the peak, and the growth rate decreases, and the peak reaches the maximum, and the peak is open after the peak. In the initial stage of the test, the rock salt was produced in a large number of ringing count rate and energy rate, and then decreased into the stable development period at the yield stage, until the peak, a cumulative ring counting and cumulative energy curve appeared, and the peak was stable at a higher rate and showed a ladder like development after the peak. In this paper, the salt rock storage tank was developed in this paper. The construction process of the stress environment gradually unloading during the process of water-soluble excavation and gas recovery has certain practical guiding significance.

【作者单位】：四川大学水力学与山区河流开发保护国家重点实验室;四川省水利水电勘测设计研究院;
【基金】：国家自然科学基金资助项目(51374148;51641405) 四川省青年基金资助项目(2017JQ0003)
【分类号】：TU45

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