本文選題：沖擊地壓　切入點：裂隙煤巖　出處：《中國礦業(yè)大學(xué)》2017年博士論文

【摘要】：沖擊地壓是一種復(fù)雜的煤巖動力災(zāi)害,嚴(yán)重威脅著礦井的安全高效開采。隨著礦井開采深度和強度的增加,沖擊地壓災(zāi)害愈發(fā)嚴(yán)重。煤巖體含有不同種類及大小的裂隙結(jié)構(gòu)面,煤巖沖擊失穩(wěn)是裂隙煤巖體裂紋擴展貫通的結(jié)果�；诖�,本文緊緊圍繞裂隙煤巖動態(tài)破裂行為和沖擊失穩(wěn)機制,采用實驗測試、理論分析和現(xiàn)場試驗等方法,研究裂隙煤巖體受載條件下的動態(tài)失穩(wěn)特征及準(zhǔn)則;建立考慮結(jié)構(gòu)面的沖擊地壓模型,揭示共振效應(yīng)及地震波擾動對煤巖體沖擊失穩(wěn)的影響,分析現(xiàn)場實測沖擊地壓演化過程能量場及微震波形的動態(tài)特征。論文得到了如下主要成果:實驗測試了裂隙煤巖加載破壞的力學(xué)特征,結(jié)果表明,隨預(yù)制裂紋傾角的增大,應(yīng)力峰值、彈性模量和應(yīng)變能均呈先減小后增大的趨勢;隨著孔洞直徑的增加,應(yīng)力峰值、彈性模量和應(yīng)變能均逐漸降低,但降低幅度減小。預(yù)制裂紋傾角較小時,裂紋在孔洞周邊起裂,傾角較大時在預(yù)制裂紋尖端起裂,宏觀破壞均發(fā)生在二次起裂的裂紋貫通處�；趶椝苄粤W(xué)和損傷力學(xué)等建立了考慮裂隙壓密閉合效應(yīng)的統(tǒng)計損傷本構(gòu)模型,建立了裂紋的起裂準(zhǔn)則,分析了正應(yīng)力和切應(yīng)力的時變演化特征。裂隙煤巖單軸加載過程中釋放的累計聲發(fā)射能量和應(yīng)變能符合by(28)ax形式的冪函數(shù)關(guān)系。臨近失穩(wěn)破壞時聲發(fā)射長程相關(guān)性增強,多重分形參數(shù)增大;聲發(fā)射波形頻率降低,幅值增高,低頻帶小波包能量增加,低頻IMF分量所占能量增加,Hilbert瞬時能量增大�；诹严睹簬r動態(tài)破裂行為和聲發(fā)射信號非線性特征研究結(jié)果,提出了裂隙煤巖堅固體斷裂自組織擾動失穩(wěn)機制,并通過裂隙煤巖的動態(tài)破裂特征及聲發(fā)射參數(shù)進行了驗證。建立了考慮結(jié)構(gòu)面效應(yīng)的裂隙煤巖彈塑脆性突變模型,引入體能勢函數(shù)的概念,研究了煤巖動態(tài)變形破裂過程中能量積聚與耗散的聯(lián)系,得到了沖擊地壓發(fā)生的能量條件,建立了“體元-區(qū)域-系統(tǒng)”沖擊地壓模型,揭示了沖擊地壓的動態(tài)演化過程。在外界擾動或高應(yīng)力狀態(tài)下,系統(tǒng)某區(qū)域內(nèi)體元失穩(wěn)后迅速向鄰近體元釋放能量,當(dāng)該能量和鄰近體元原始能量之和達到鄰近體元的承受閾值后,鄰近體元失穩(wěn)并釋放能量形成“連鎖”反應(yīng),造成局部區(qū)域失穩(wěn),最終導(dǎo)致系統(tǒng)失穩(wěn),發(fā)生沖擊地壓�；诮Y(jié)構(gòu)動力學(xué)理論,從共振角度分析了地震波對含結(jié)構(gòu)面煤巖體沖擊失穩(wěn)的影響,共振作用的放大倍數(shù)與頻率比呈對稱分布,隨阻尼比減小呈冪函數(shù)增加。研究了地震波對煤巖體沖擊擾動失穩(wěn)破壞的響應(yīng)機制,擾動能量大,參與沖擊地壓過程的煤巖體較多,破壞范圍較大;擾動能量小,參與沖擊的煤巖體較少,破壞范圍較小。研究了沖擊地壓演化過程中能量場及微震波形的動態(tài)演化特征。結(jié)果表明,能量場處于動態(tài)調(diào)整狀態(tài)并向震源區(qū)集聚;臨近沖擊失穩(wěn)時煤巖破裂從小尺寸串級過渡到大尺寸串級,統(tǒng)計漲落愈來愈大,釋放能量增多,微震波形幅值增大,低頻成分增多,主頻率降低,波形的相似度及關(guān)聯(lián)性也越來越大,波形能量向低頻集聚。本研究成果對于深入認(rèn)識沖擊地壓機理和前兆規(guī)律,開展更加有效的監(jiān)測預(yù)警,促進沖擊地壓等煤巖動力災(zāi)害更加科學(xué)合理的防治具有重要的理論意義和應(yīng)用價值。
[Abstract]:Rockburst is a kind of complex coal rock dynamic disasters, a serious threat to the mine safety and efficient mining. With the increase of mining depth and intensity of rockburst disaster is more serious. The fissure structural plane of coal and rock with different shapes and sizes, rockburst instability crack rock fracture propagation. Based on the results of coal this, the article focuses on the fracture of coal rock dynamic fracture behavior and impact failure mechanism, the experimental test, theoretical analysis and field test, the research of fractured coal rock under dynamic load conditions the instability characteristics and standards; establish the model of rockburst considering structure, reveal the resonance effect and seismic wave disturbance instability effect of coal and rock impact, dynamic characteristic analysis of the evolution process of the energy field and wave field microseismic rockburst. The main results are as follows: the test of the coal rock and fissure Mechanical characteristics, load the results show that with increasing angle crack, peak stress, elastic modulus and strain energy were first decreased and then increased; with the increase of the pore diameter, peak stress, elastic modulus and strain energy are gradually decreased, but the decrease is reduced. Crack is small angle, cracks in the holes surrounding the crack, crack in prefabricated crack tip angle large, macroscopic failure occurred in two times the initiation of crack coalescence. The elastic-plastic mechanics and damage mechanics, damage constitutive model is established based on statistical damage fracture pressure closed effect consideration, established the criterion of cracks analysis, normal stress and shear stress of time-varying evolution. Fracture of coal rock uniaxial loading process in the release of the cumulative AE energy and strain energy with by (28) ax in the form of power function relationship. Near the failure of long-range correlation by acoustic emission Strong increase of multifractal parameters; acoustic emission waveform frequency decreases, the amplitude increased, low frequency band of wavelet packet energy increases, the low frequency IMF component for energy increases, Hilbert instantaneous energy increases. The fractures of coal rock dynamic fracture behavior of the acoustic emission signal the nonlinear characteristics of coal rock fracture based on solid fracture self organization disturbance instability mechanism is put forward and, through the dynamic fracture of coal rock burst characteristics and acoustic emission parameters were verified. By considering the effect of the surface structure of coal rock elastoplastic brittle fracture catastrophe model, introducing the concept of physical potential function, the research of the coal and rock dynamic deformation accumulation and dissipation of energy in the process of rupture, the impact of energy conditions the rock burst occurrence, established the rockburst model element - regional - system ", reveals the dynamic evolution process of rockburst. The external disturbance or in high stress state, a regional system The inner body element failure quickly to the adjacent element when the release of energy, energy and energy of the original element near the body and reach the threshold under adjacent voxels, the adjacent element instability and energy release form a "chain" reaction caused by local instability, resulting in system instability, occurrence of rockburst. Based on the theory of structural dynamics, from the point of view of the resonance of seismic wave on the impact of coal and rock with structural plane instability, resonance magnification and frequency ratio is symmetrical, with the damping ratio decreases exponentially increase. On the seismic wave on the coal and rock impact failure disturbed response mechanism failure, disturbance high energy, more coal and rock in rockburst process, damage range is large; the disturbance energy is small, less involved in the coal and rock impact failure, a smaller range. The dynamic evolution field and seismic waveform of rockburst in the evolution process Feature. The results show that the energy field in the dynamic adjustment and agglomeration to source region; near the shock instability of coal rock burst from small size to large size transition cascade cascade, statistical fluctuation is more and more big, the release of energy increased, microseismic wave amplitude increases, the low-frequency components increased, frequency decreased, and correlation of waveform similarity more and more, to the low frequency wave energy concentration. The results of this study for understanding the mechanism of rockburst and the precursory characteristics, to carry out more effective monitoring and early warning, promotion has important theoretical significance and application value of rockburst, coal rock dynamic disasters more scientific and reasonable prevention.

【學(xué)位授予單位】：中國礦業(yè)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TD324
，

本文編號：1709427