本文選題：巖石力學　切入點：巖爆　出處：《廣西大學》2017年碩士論文　論文類型：學位論文

【摘要】：巖爆是高地應力條件下的一種劇烈的巖石動力破壞現(xiàn)象。在深部高地應力條件下,工程開挖擾動常常誘發(fā)嚴重的巖爆破壞。巖爆的發(fā)生通常伴隨著巖石碎塊高速猛烈彈射、拋出以及大量的能量釋放,會給施工人員生命、施工設(shè)備安全以及工程進度帶來嚴重的威脅。因此,對脆性巖石的巖爆進行研究是十分有必要的。此外,在實際工程中,很大一部分巖爆是由開挖爆破、機械鉆鑿、地震波等動力擾動荷載誘發(fā)的。對于水工隧洞洞室群之間的邊墻、礦山的頂拱及底板等特殊結(jié)構(gòu)處的花崗巖巖體常處于雙向受壓的狀態(tài),在動力擾動荷載作用下很容易誘發(fā)巖爆破壞。因此,有必要開展雙軸受壓花崗巖在不同動力擾動荷載作用下誘發(fā)巖爆的試驗研究。本文利用自主研發(fā)的巖爆試驗系統(tǒng),采用長方體花崗巖為巖石試件,開展了二維動靜組合巖爆試驗,模擬了雙向受壓狀態(tài)下不同擾動荷載誘發(fā)巖爆的全過程,研究了不同動力擾動荷載對巖爆的影響。采用變形測試系統(tǒng)、聲發(fā)射系統(tǒng)、高速攝像系統(tǒng)等技術(shù)手段,對試驗過程進行全方位、多角度的監(jiān)測。對比分析了不同動力擾動荷載誘發(fā)巖爆及自發(fā)型巖爆的彈射過程和彈射動能、破壞形態(tài)、變形和損傷特性、聲發(fā)射特征。試驗結(jié)果表明:(1)動力擾動荷載對巖爆的強烈程度有重要影響。豎向靜應力為110MPa時,強擾動荷載作用下巖爆的彈射動能是中擾動荷載作用下的7.6倍,弱擾動荷載沒能觸發(fā)巖爆的發(fā)生,彈射動能接近于0。豎向靜應力為179MPa時,弱擾動巖爆的彈射動能高于自發(fā)型巖爆的彈射總動能,這說明靜應力水平和動力擾動荷載強度越高,巖爆越容易被動力擾動觸發(fā),被觸發(fā)巖爆的彈射動能越大。(2)巖石的破壞形態(tài)特征受動力擾動荷載的影響較大。自發(fā)型巖爆后母巖較為完整,裂紋細短;強擾動荷載下的母巖發(fā)生強烈的剪切破壞;弱擾動荷載下的母巖底部張拉、剪切裂紋完全貫通;中擾動荷載下的母巖發(fā)生嚴重膨脹,中部張拉、剪切裂紋完全貫通。這說明動力擾動荷載越強,巖爆后母巖的破壞程度越嚴重。此外,通過對比彈射碎塊的特征,可以知道擾動荷載能夠促進豎向裂紋的發(fā)育。(3)動力擾動荷載對試件發(fā)生巖爆破壞前豎向累積應變有明顯影響。豎向靜應力為11OMPa時,強擾動荷載作用下試件的豎向應變大于弱擾動荷載作用下的,小于中擾動荷載作用下的,這說明擾動荷載的強弱可以影響巖石發(fā)生破壞時的累積變形,且較強的擾動荷載更容易導致巖石產(chǎn)生更大的累積變形。豎向靜應力為179MPa時,弱擾動荷載作用下巖爆試件的豎向應變明顯高于豎向靜應力為11OMPa時弱擾動荷載作用下試件的豎向應變,即初始靜應力的提高有助于巖石累積變形的增大。對比自發(fā)型巖爆和弱擾動觸發(fā)巖爆可知,前者的豎向應變小于后者,這說明在高應力條件下,即使微弱的擾動荷載也能使巖石產(chǎn)生更大的累積變形。(4)動力擾動荷載可以影響巖石的聲發(fā)射特性。豎向靜應力為110MPa時,強擾動荷載作用下試件的聲發(fā)射絕對能量累積最大值低于中擾動荷載作用下試件的聲發(fā)射絕對能量累積最大值,這表明巖石內(nèi)部結(jié)構(gòu)的損傷程度前者較后者要低,而前者的巖爆強度最大,由此說明低的能量耗散是誘發(fā)強烈?guī)r爆的基本條件之一,而動力擾動荷載越強被觸發(fā)的巖爆強烈程度越大。豎向靜應力為179MPa時,弱擾動荷載作用下試件的聲發(fā)射絕對能量累積最大值明顯高于豎向靜應力為110MPa時弱擾動荷載作用下試件的聲發(fā)射絕對能量累積最大值和相近豎向靜應力的自發(fā)型巖爆試件聲發(fā)射絕對能量累積最大值,這說明靜應力水平越高,被觸發(fā)巖爆破壞的劇烈程度越大。
[Abstract]:Rock burst is a kind of high rock dynamic damage phenomenon under the condition of severe stress. In deep high stress conditions, the excavation disturbance often cause serious rockburst. The occurrence of rock burst is usually accompanied by a high speed heavy rock fragments ejection, thrown and a lot of energy release, will give the construction personnel life. The construction equipment safety and engineering progress bring serious threat. Therefore, the brittle rock rock burst research is very necessary. In addition, in the actual project, a large part of rock burst by excavation blasting, mechanical drilling, seismic wave dynamic disturbance induced by load. For hydraulic tunnel caverns the side wall, granite mine roof and floor of the special structure in biaxial compression state, the dynamic disturbance loads easily induce rockburst. Therefore, it is necessary to carry out the double embossing Experimental study on load induced rockburst granite under different dynamic disturbance. The test system based on independent research and development of rock burst, the rectangular granite rock specimen, carry out two-dimensional combined dynamic and static tests of rock burst, the simulation of biaxial compression under different disturbance process load induced rockburst, different dynamic disturbance effect of load on rock burst was studied. The deformation measurement system, acoustic emission system, high speed camera system technology, a full range of test process, monitoring point. Comparative analysis of different power load disturbance induced rockburst and the ejection process and ejection kinetic energy, hair rock burst failure and deformation the damage characteristics of acoustic emission characteristics. Experimental results show that: (1) the load has an important influence on the intensity of rock burst power disturbance. The vertical static stress is 110MPa, strong disturbance loads of rockburst dynamic ejection Can be 7.6 times the disturbance of load, the weak perturbation load failed to trigger the occurrence of rock burst, the ejection kinetic energy is close to 0. vertical static stress is 179MPa, weak disturbance of rock burst is higher than the total kinetic energy from the kinetic energy of the ejection ejection type of rock burst, this shows that the static stress level and dynamic disturbance load strength the higher, the more easily trigger rock burst triggered by dynamic disturbance, rock burst ejection greater kinetic energy (2). Effect of dynamic disturbance load damage characteristics of rock greatly. Spontaneous rock burst rock stepmother is complete, thin and short crack; strong disturbance loads rock strong shear failure weak disturbance; rock bottom loading tension, shear crack completely through disturbance loads; rocks serious expansion, the central tension, shear crack completely through. The dynamic load disturbance is strong, the extent of damage of rock burst after rock more serious. In addition, the The ejection ratio features pieces, can know the perturbation load can promote vertical crack development. (3) the dynamic disturbance load on specimens of rock burst occurred before the failure of the vertical strain accumulation has obvious effect. The vertical static stress is 11OMPa, strong disturbance load test is larger than the vertical strain a weak disturbance loads. Less than the disturbance of load, the load disturbance strength can influence the cumulative deformation of rock failure occurs when the load disturbance, and strong rock more easily lead to produce greater cumulative deformation. The vertical static stress of 179MPa, the weak disturbance test of vertical strain was significantly higher than that of vertical static stress is 11OMPa weak disturbance load test under the vertical strain explosion loading rock, initial static stress helps to improve the rock accumulated deformation increases. Since the contrast and weak disturbance triggered the rock burst type rock, the former The vertical strain is less than the latter, which shows that under high stress conditions, even if the perturbation load weak can also produce greater cumulative deformation of rocks. (4) the dynamic disturbance load can influence acoustic emission of rocks. The vertical static stress is 110MPa, strong disturbance load specimens AE absolute maximum energy disturbance loads of specimens of AE cumulative maximum value is lower than the cumulative, which indicates that the internal structure of rock damage degree of the former is lower, while the rock burst intensity, indicating that low energy dissipation is one of the basic conditions of induced strong rockburst, and dynamic disturbance load more strong rock burst triggered strong degree. The vertical static stress is 179MPa, weak disturbance loads of specimens of AE cumulative maximum value was significantly higher than that of the vertical static stress of 110MPa weak disturbance load. The maximum absolute value of the absolute energy accumulation of the acoustic emission and the similar vertical static stress of the specimen is the highest value of the absolute energy accumulation of the acoustic emission, which indicates that the higher the static stress level is, the more severe the triggered rock burst is.

【學位授予單位】：廣西大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TU45

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