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为得到不同类型煤体在压缩破坏过程中应力和电荷的变化规律,利用自主研制的电荷感应测试系统进行室内试验。试验分别对冲击型原煤试样、突出型原煤试样及型煤试样压缩破坏过程进行实时电荷监测。结果表明,不同类型的煤样在压缩过程中产生的应力变化曲线有明显的区别,冲击型煤样在加载过程中的应力-应变曲线在达到峰值应力前表现为较好的线性关系,峰后区的应力-应变曲线一般主要表现为近似竖直的直线。突出型煤样在加载过程中峰前区的应力曲线出现了多个峰值,在峰后区应力-应变曲线一般表现为上凹形的曲线。型煤试样的应力曲线峰前区有更为明显的压密阶段、线弹性阶段及弹塑性阶段,峰后区的应力-应变曲线一般表现为上凸的曲线。3种不同类型煤体压缩破裂时电荷感应信号峰值出现的位置及电荷感应信号的集中或分散程度也不同。冲击型煤样的电荷感应信号出现的位置相对比较集中,主要出现在峰值应力前后和试样完全失稳破坏阶段。突出型煤试样的电荷感应信号则比较分散,一般出现在应力出现峰值前后或应力急剧增加阶段。型煤试样的电荷感应信号一般出现在应力软化阶段,在峰值应力前阶段并没有收集到电荷感应信号。利用不同类型煤体在压缩破坏时的电荷感应信号不同,可以为矿山灾害的发生提供预报信息。
In order to get the variation of stress and charge during compression and destruction of different types of coal, a self-developed charge induction test system was used for indoor test. Experiments were carried out on the impact of the original coal samples, coal samples and briquette prominent compression damage process real-time charge monitoring. The results show that there are obvious differences between different types of coal samples during the compression process. The stress-strain curve of the impact coal samples shows a good linear relationship before the peak stress. The stress-strain curve of the zone generally shows mainly as an approximately vertical straight line. There are several peaks in the stress curve of the pre-peaked area during the loading process of the protruding briquette samples, and the stress-strain curve in the post-peak area generally shows the upper concave curve. The stress curve of briquette sample has a more obvious compaction stage in the pre-peak area. In the linear elastic phase and the elastoplastic phase, the stress-strain curve in the post-peak area is generally convex. The location of the peak of charge sensing signal and the concentration or dispersion of charge sensing signal of the three different types of coal under compressive rupture are also different. The location of charge-induced signal of impinging coal samples is relatively concentrated, mainly occurring before and after the peak stress and the complete destabilization failure of the sample. Outstanding briquette samples charge-induced signal is more dispersed, generally appear before or after stress peaks or sharp increase in stress stage. The charge sensing signal of the briquette sample generally appears in the stress softening stage, and no charge sensing signal is collected in the pre-peak stress stage. Using different types of coal in charge of compressive destruction of the charge signal is different, for the occurrence of mine disasters to provide forecast information.