Abstract

In the coal mining process, the limestone stratum under coal seams would be affected by high-pressure water, which has a significant influence on its physical and mechanical properties. To study the variation in limestone strength, uniaxial compression tests of three kinds of specimens processed with different water treatment methods are carried out, and the acoustic emission signals are collected during testing to analyze the failure characteristics of the specimens. The results show that the uniaxial compressive strengths of the naturally saturated and forcedly saturated limestone specimens are reduced by 28.01% and 28.27%, respectively, compared to that of the natural limestone specimens. Increasing the water content enhances the plastic deformation properties of this rock. Besides, the failure modes of the limestone specimens change from simple to complex with increasing water content: with increasing water content, it became easier for the specimens to maintain their original shape after failure, which is beneficial to increasing post peak strength.

Article highlights

1. 1.

   Considering the forcedly saturation state of the limestone under pressure in engineering environment.

2. 2.

   The acoustic emission is used to analyze the failure process of the limestone specimen during test.

3. 3.

   Some of the limestone specimen failure modes are different from those predicted by the Mohr-Coulomb strength theory.

4. 4.

   The water saturation weakening effect of limestone specimen is analyzed from the mechanical properties of water filled cracks and the physical and chemical reactions between the water and minerals in the limestone specimen.

中文翻译：

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单轴加载下石灰石自然和强迫饱和状态下的力学行为：实验研究

摘要

在采煤过程中，煤层下的石灰岩地层会受到高压水的影响，对其物理力学性能有显着影响。为研究石灰石强度的变化规律，对三种不同水处理方法处理的试件进行单轴压缩试验，并在试验过程中采集声发射信号，分析试件的破坏特性。结果表明，与天然石灰岩试件相比，天然饱和和强制饱和石灰岩试件的单轴抗压强度分别降低了28.01%和28.27%。增加含水量会增强这种岩石的塑性变形特性。除了，

文章亮点

1. 1.

   考虑工程环境压力下石灰石的强制饱和状态。

2. 2.

   声发射用于分析石灰石试件在试验过程中的破坏过程。

3. 3.

   一些石灰石试样的破坏模式与莫尔-库仑强度理论预测的不同。

4. 4.

   从充水裂缝的力学性质和石灰岩试件中水与矿物质之间的物理化学反应分析石灰岩试件的水饱和弱化作用。