【摘要】：隨著我國(guó)金礦床開(kāi)采工業(yè)品位的降低,采空區(qū)周邊殘留的低品位礦體具有了開(kāi)采經(jīng)濟(jì)價(jià)值。由于大量采空區(qū)的存在,導(dǎo)致礦山開(kāi)采條件惡化,回采殘礦體過(guò)程中容易出現(xiàn)巷道失穩(wěn)、礦柱變形破壞和采場(chǎng)坍塌等問(wèn)題,嚴(yán)重威脅礦區(qū)作業(yè)人員和設(shè)備的安全。如何實(shí)現(xiàn)采空區(qū)周邊殘礦體安全開(kāi)采是當(dāng)前礦山企業(yè)亟待解決的難題。論文以某金礦山整合礦區(qū)殘礦體為研究對(duì)象,在綜合分析國(guó)內(nèi)外資料的基礎(chǔ)上,通過(guò)現(xiàn)場(chǎng)調(diào)查、理論研究、數(shù)值分析、工程驗(yàn)證等方法,對(duì)復(fù)雜破碎圍巖及礦柱穩(wěn)定性等關(guān)鍵問(wèn)題開(kāi)展研究,為礦山復(fù)雜破碎殘礦體創(chuàng)建安全開(kāi)采環(huán)境,指導(dǎo)殘礦體安全回采。取得的主要研究成果如下:(1)通過(guò)對(duì)整合礦區(qū)巖體的現(xiàn)場(chǎng)踏勘,明確了節(jié)理裂隙的分布特征;采用巖體基本質(zhì)量分級(jí)法(BQ)、巖體質(zhì)量力學(xué)分級(jí)法(RMR)分別對(duì)礦區(qū)巖體進(jìn)行質(zhì)量分級(jí)和評(píng)價(jià)。(2)利用板裂結(jié)構(gòu)理論和數(shù)值模擬相結(jié)合的方法,分析圍巖應(yīng)力的變化規(guī)律和巷道的安全性。采動(dòng)應(yīng)力作用是上盤巷道失穩(wěn)的主要誘因,上盤巷道圍巖垂直應(yīng)力超過(guò)巷道圍巖潰屈破壞極限應(yīng)力。(3)在板裂結(jié)構(gòu)力學(xué)模型分析的基礎(chǔ)上,結(jié)合正交數(shù)值計(jì)算的方法,明確了影響巷道安全系數(shù)(F)的各要素的敏感性大小順序?yàn)?節(jié)理間距、巷道埋深、巷道與采空區(qū)距離;利用多元非線性回歸方法構(gòu)建了巷道安全系數(shù)預(yù)測(cè)模型,現(xiàn)場(chǎng)工程驗(yàn)證表明,計(jì)算值與實(shí)際值相對(duì)誤差為4.4%,模型具有較高可靠性;建議1200m中段重新布設(shè)的巷道距離采空區(qū)不少于64.1m(F1.2)。(4)基于動(dòng)態(tài)強(qiáng)度折減方法,研究礦柱漸進(jìn)失穩(wěn)演變規(guī)律。通過(guò)折減計(jì)算,破損區(qū)首先出現(xiàn)在礦柱4個(gè)邊角部位,逐漸向底部中心區(qū)域擴(kuò)展,直至貫通整個(gè)礦柱;依據(jù)破損單元數(shù)量增長(zhǎng)趨勢(shì)將破損區(qū)可分為穩(wěn)定、擴(kuò)展、突變等3個(gè)演變過(guò)程。現(xiàn)場(chǎng)位移監(jiān)測(cè)結(jié)果驗(yàn)證了分析結(jié)果的正確性。(5)考慮外部荷載對(duì)礦柱穩(wěn)定性的影響,構(gòu)建礦柱力學(xué)分析模型,根據(jù)礦柱極限強(qiáng)度與荷載的比值確定礦柱的安全系數(shù)(K)。現(xiàn)場(chǎng)工程分析表明,1420m中段57~59線殘礦采場(chǎng),當(dāng)預(yù)留礦柱寬度為8m,高度為12m時(shí),采場(chǎng)處于穩(wěn)定狀態(tài)(K=1.62);隨著礦柱高度的增加,礦柱相應(yīng)安全系數(shù)值會(huì)降低,當(dāng)?shù)V柱高度達(dá)到30m時(shí),K=1.27,仍滿足殘礦安全開(kāi)采的基本要求。
[Abstract]:With the decrease of industrial grade of gold deposits in China, the residual low-grade orebodies around goaf have economic value in mining. Due to the existence of a large number of goaf, the mining conditions deteriorate, and the roadway instability, pillar deformation and stope collapse are easy to occur in the process of mining residual orebody, which seriously threatens the safety of operators and equipment in mining area. How to realize the safe mining of residual orebodies around goaf is an urgent problem to be solved in mining enterprises. This paper takes the residual orebody of a gold mine mountain integrated mining area as the research object, on the basis of comprehensive analysis of domestic and foreign data, through field investigation, theoretical research, numerical analysis, engineering verification and other methods. The key problems such as complex broken surrounding rock and pillar stability are studied in order to create a safe mining environment for complex broken residual orebodies and guide the safe mining of residual orebodies. The main research results are as follows: (1) through the field exploration of rock mass in the integrated mining area, the distribution characteristics of joint fissures are clarified; The rock mass quality classification method (BQ), rock mass mechanics classification method (RMR) is used to classify and evaluate the rock mass quality in mining area respectively. (2) the method of combining plate crack structure theory with numerical simulation is used. The variation law of surrounding rock stress and the safety of roadway are analyzed. The action of mining dynamic stress is the main inducement of the instability of the upper roadway, and the vertical stress of the surrounding rock of the upper roadway exceeds the ultimate stress of collapse and flexion of the surrounding rock of the roadway. (3) on the basis of the analysis of the mechanical model of the plate crack structure, combined with the orthogonal numerical calculation method, It is clear that the order of sensitivity of each factor affecting roadway safety factor (F) is as follows: joint spacing, roadway buried depth, roadway and goaf distance; The prediction model of roadway safety factor is constructed by using multivariate nonlinear regression method. The field engineering verification shows that the relative error between the calculated value and the actual value is 4.4%, and the model has high reliability. It is suggested that the distance between the roadway rearranged in the middle of 1200 m and goaf is not less than 64.1 m (F1.2). (4). Based on the dynamic strength reduction method, the evolution law of progressive instability of pillar is studied. Through the calculation of reduction, the damaged area first appears in the four sides and corners of the pillar, and gradually expands to the center area of the bottom until it runs through the whole pillar. According to the increasing trend of the number of damaged units, the damaged area can be divided into three evolution processes: stability, expansion and mutation. The field displacement monitoring results verify the correctness of the analysis results. (5) considering the influence of external load on the stability of the pillar, the mechanical analysis model of the pillar is constructed, and the safety factor (K). Of the pillar is determined according to the ratio of ultimate strength to load of the pillar. The field engineering analysis shows that when the width of the reserved pillar is 8 m and the height is 12 m, the stope is in a stable state (K 鈮，

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