【摘要】：西部礦區(qū)逐漸成為我國煤炭資源開發(fā)的重點,但水資源的匱乏卻成為制約當(dāng)?shù)孛禾抠Y源開發(fā)的瓶頸。因此,煤水共采已刻不容緩,而目前煤水共采方法主要包括保水開采和地下水庫技術(shù),尤其是地下水庫技術(shù)已在神東礦區(qū)大規(guī)模推廣應(yīng)用。地下水庫的穩(wěn)定性與人工壩體和煤柱壩體的穩(wěn)定性密切相關(guān),其中煤柱壩體的失穩(wěn)破壞不僅與其所受的荷載相關(guān),亦受到水的侵蝕作用的影響。因此,研究不同含水率下煤樣的剪切破壞特征,對揭示地下水庫煤柱壩體在水作用下的變形特征有著重要意義。論文以含水煤樣剪切破壞損傷規(guī)律為主要研究對象,通過壓剪試驗對煤樣剪切破壞強(qiáng)度及特征參數(shù)進(jìn)行系統(tǒng)研究。利用聲發(fā)射及紅外輻射等研究手段對不同含水率下煤樣剪切過程進(jìn)行反演和分析,得到不同含水狀態(tài)下煤樣剪切破壞聲發(fā)射及紅外輻射特征,并以此為建立模型,對含水煤樣剪切破壞過程損傷規(guī)律進(jìn)行分析。論文從吸水性實驗入手,首先確定5個浸水時間點;通過剪切試驗表明隨著含水率的升高,煤樣的抗剪強(qiáng)度逐漸降低,二者之間呈指數(shù)降低的關(guān)系。并對剪切強(qiáng)度參數(shù)c、φ進(jìn)行分析得出,煤樣浸水后二者均呈下降趨勢,同時基于含水率對摩爾庫倫破壞準(zhǔn)則參數(shù)進(jìn)行修正;通過對試樣剪切過程聲發(fā)射參數(shù)研究,得到聲發(fā)射計數(shù)及能率特征與應(yīng)力應(yīng)變曲線變化趨勢具有相關(guān)性,即隨著含水率的升高,聲發(fā)射計數(shù)及能率特征越不明顯;通過對剪切過程紅外特征參數(shù)AIRT的分析,得到隨著含水率增加,AIRT溫變幅度不斷降低,最高及最低輻射溫度呈現(xiàn)相同的趨勢。并結(jié)合表面輻射溫度熵及方差等參數(shù),得到含水率越高,表面溫度方差越小的趨勢;通過建立以聲發(fā)射計數(shù)特征為基礎(chǔ)的整體損傷變量以及以紅外輻射溫變點為基礎(chǔ)的表面損傷變量。得到整體損傷變量在反映煤樣更具前兆性和階段性,而表面損傷變量則在峰值破壞階段與應(yīng)力-時間曲線擬合度更高。最后對煤樣剪切破壞損傷模型作出評價,為研究壩體煤柱穩(wěn)定性提供可靠的判定依據(jù)。
[Abstract]:The western mining area has gradually become the focus of coal resources development in China, but the shortage of water resources has become the bottleneck restricting the development of local coal resources. Therefore, comining of coal and water is urgent. At present, the methods of coal and water mining mainly include water conservation and underground reservoir technology, especially the underground reservoir technology has been widely used in Shendong mining area. The stability of underground reservoir is closely related to the stability of artificial dam and coal pillar dam. The instability of coal pillar dam is affected not only by the load but also by the erosion of water. Therefore, it is of great significance to study the shear failure characteristics of coal samples under different water content in order to reveal the deformation characteristics of coal pillar dams in underground reservoirs under the action of water. In this paper, the shear failure strength and characteristic parameters of water-bearing coal samples are systematically studied by compression shear test. By means of acoustic emission and infrared radiation, the shear process of coal samples with different moisture content is inversed and analyzed, and the characteristics of acoustic emission and infrared radiation of coal samples under different water-bearing conditions are obtained, and the model is established. The damage law of water-bearing coal during shear failure is analyzed. The paper starts with the experiment of water absorption and determines five soaking time points. The shear test shows that the shear strength of coal sample decreases gradually with the increase of water content, and the relationship between them is exponential. The shear strength parameters c and 蠁 were analyzed and the results showed that both of them showed a downward trend after soaking, and the Mohr Coulomb failure criterion parameters were modified based on water content. By studying the acoustic emission parameters in shear process, it is found that the characteristics of acoustic emission counting and energy rate are correlated with the change trend of stress-strain curve, that is, with the increase of water content, the characteristics of acoustic emission counting and energy rate are less obvious. Through the analysis of infrared characteristic parameter AIRT in shear process, it is found that with the increase of moisture content, the temperature variation amplitude of AIRT decreases continuously, and the highest and lowest radiation temperatures show the same trend. Combined with the surface radiation temperature entropy and variance, the higher the moisture content, the smaller the surface temperature variance. The global damage variables based on the characteristics of acoustic emission counting and the surface damage variables based on the infrared radiation temperature change point are established. It is found that the whole damage variable is more precursor and stage than the surface damage variable in reflecting the coal sample, while the surface damage variable is more suitable to the stress-time curve at the peak failure stage. Finally, the shear failure damage model of coal sample is evaluated, which provides a reliable basis for studying the stability of dam coal pillar.
【學(xué)位授予單位】：中國礦業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TD821

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 馬立強(qiáng);張W，

本文編號：2362553