【摘要】：本文通過分析國內(nèi)外煤層注水改良煤體力學(xué)性質(zhì)的研究現(xiàn)狀基礎(chǔ)之上,運(yùn)用強(qiáng)度理論和液橋力理論,從宏觀和微觀的角度,分析了合理注水增強(qiáng)粉煤固結(jié)力學(xué)性質(zhì)的機(jī)理。通過試驗(yàn)及理論分析,總結(jié)了型煤在不同含水率條件下力學(xué)性質(zhì)的變化規(guī)律。結(jié)合現(xiàn)場(chǎng)試驗(yàn)考察,驗(yàn)證了松軟煤壁合理注水后,煤壁板結(jié)效果增強(qiáng),有效的防止松軟煤壁的大范圍片幫。本文研究主要內(nèi)容及結(jié)論如下:1.結(jié)合現(xiàn)場(chǎng)考察和試驗(yàn),對(duì)制備型煤的原煤樣基礎(chǔ)參數(shù)進(jìn)行分析。得出采集的煤樣具有含水率低,強(qiáng)度低的,易破碎的特點(diǎn),符合本文的研究要求。根據(jù)理論分析與試驗(yàn),確定了型煤制備過程的成型壓力和粒徑配比,利用自行研制的型煤模具,加工制備了具有不同含水率的型煤。2.利用RMT-150B型巖石力學(xué)試驗(yàn)系統(tǒng)對(duì)已制備的不同含水率的型煤試樣進(jìn)行單、三軸壓縮試驗(yàn),通過試驗(yàn)結(jié)果分析型煤在不同含水率條件下力學(xué)性質(zhì)的變化規(guī)律。試驗(yàn)結(jié)果表明在單軸壓縮條件下,隨著型煤成型水分的增大,型煤試樣的單軸抗壓強(qiáng)度和彈性模量呈現(xiàn)先增大后減小的趨勢(shì),而泊松比隨著成型水分的增大呈現(xiàn)先減小后增大的趨勢(shì)。當(dāng)煤樣的成型水分含量在7%左右時(shí),單軸抗壓強(qiáng)度最大為0.821MPa,彈性模量最大值為1.332GPa,泊松比處于最小值,為0.267。在不同圍壓的三軸壓縮的條件下,隨著圍壓的增大,型煤的抗壓強(qiáng)度隨之增大。利用強(qiáng)度準(zhǔn)則,求出不同含水率型煤的內(nèi)聚力和內(nèi)摩擦角,結(jié)果顯示,隨著含水率的增大,型煤的內(nèi)聚力和內(nèi)摩擦角先增大后減小。3.通過濕煤顆粒作用力的微觀分析,在微觀作用力中濕顆粒間的液橋力對(duì)顆粒的影響最大。通過分析液橋力模型,分析不同含量水分影響濕煤顆粒固結(jié)的作用機(jī)理。并且對(duì)顆粒間影響的液橋力的因素進(jìn)行分析。豐富了煤體固結(jié)的理論,為煤層合理注水固結(jié)粉煤,為防止粉煤類工作面片幫提供了微觀理論依據(jù)。4.論文研究中,對(duì)朱仙莊煤礦的Ⅱ863綜采放頂煤工作面進(jìn)行了煤壁淺孔注水試驗(yàn)研究。通過對(duì)煤層注水濕潤效果的測(cè)定及考察,得出注水有效影響范圍測(cè)定為橫向6m,縱向1.0-1.2m。實(shí)施煤壁淺孔注水后,距底板1.0-3.6m范圍內(nèi)煤體的含水量大大提高,煤體被較好地潤濕,為形成一定厚度的粘結(jié)層創(chuàng)造了有利條件,對(duì)防止煤壁片幫起到關(guān)鍵性作用通過現(xiàn)場(chǎng)考察,注水后煤壁片幫得到有效控制。
[Abstract]:In this paper, based on the analysis of the present situation of improving the mechanical properties of coal body by coal seam water injection at home and abroad, using strength theory and liquid bridge force theory, the mechanism of reasonable water injection to enhance the consolidation mechanical properties of pulverized coal is analyzed from the macroscopic and microscopic angles. Through experiment and theoretical analysis, the change law of mechanical properties of briquette under different moisture content is summarized. Combined with the field test, it is proved that after reasonable injection of soft coal wall, the effect of coal wall panel junction is enhanced, and the large scale flake of soft coal wall is effectively prevented. The main contents and conclusions of this paper are as follows: 1. Based on field investigation and test, the basic parameters of raw coal sample prepared from briquette were analyzed. It is concluded that the collected coal samples have the characteristics of low moisture content, low strength and easy breakage, which accord with the research requirements of this paper. According to the theoretical analysis and experiment, the forming pressure and particle size ratio of briquette preparation process were determined, and the briquette coal with different moisture content was prepared by using the molded coal mould developed by ourselves. The uniaxial and triaxial compression tests of briquette samples with different moisture content were carried out by using RMT-150B rock mechanics test system. The variation of mechanical properties of briquette under different moisture content was analyzed by test results. The experimental results show that the uniaxial compressive strength and elastic modulus of briquette samples increase first and then decrease with the increase of briquette forming moisture under uniaxial compression condition. The Poisson's ratio decreases first and then increases with the increase of molding moisture. When the moisture content of the sample is about 7%, the uniaxial compressive strength is 0.821 MPA, the modulus of elasticity is 1.332 GPA, and the Poisson's ratio is at the minimum of 0.267. Under the condition of triaxial compression with different confining pressures, the compressive strength of briquette increases with the increase of confining pressure. The cohesion and friction angle of briquettes with different moisture content were calculated by using the strength criterion. The results showed that the cohesion and friction angle of briquette increased first and then decreased by 0.3 with the increase of moisture content. According to the microscopic analysis of the wet-coal particle force, the influence of the liquid bridge force between the wet particles on the particle is the greatest. By analyzing the liquid bridge force model, the mechanism of the effect of moisture content on the consolidation of wet coal particles is analyzed. The influence factors of liquid bridge force between particles are analyzed. It enriches the theory of coal body consolidation, provides microscopic theoretical basis for rational water injection of coal seam to consolidate pulverized coal, and provides micro theoretical basis for preventing coal face. In this paper, the water injection test of shallow hole in coal wall of 鈪，

本文編號(hào)：2162469