(中南大學(xué) 資源與安全工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 科學(xué)分析地下采空區(qū)穩(wěn)定性是實(shí)現(xiàn)銅綠山露天礦Ⅰ號(hào)礦體殘礦安全高效回采的關(guān)鍵，考慮將間柱寬度d、空區(qū)跨度D、境界頂柱厚度h、尾砂堆高H等4個(gè)影響因素進(jìn)行正交設(shè)計(jì)并運(yùn)用FLAC3D模擬試驗(yàn)，對(duì)49組試驗(yàn)結(jié)果進(jìn)行極差、方差及回歸擬合分析，并結(jié)合安全系數(shù)與可靠度指標(biāo)對(duì)殘礦回采安全與效益進(jìn)行評(píng)估。結(jié)果表明：4個(gè)因子與位移量W、安全系數(shù)F的擬合度較高，相關(guān)系數(shù)R2≥0.952，建立一個(gè)反映4因素下空區(qū)位移W的綜合數(shù)學(xué)預(yù)測(cè)模型，結(jié)合工程應(yīng)用證明預(yù)測(cè)模型的有效性；影響采空區(qū)穩(wěn)定性的顯著程度依次為H＞d＞h＞D；并對(duì)比f(wàn)0.05與F值，得到重要性排序?yàn)镠>d>D>h，且均為不可忽視的重要因素；4個(gè)因子可靠度指標(biāo)在F≥1.7時(shí)收斂開(kāi)始于某值，此時(shí)安全系數(shù)與可靠度之間可達(dá)最優(yōu)化，且收斂值大小滿足H＞d＞h＞D。
關(guān)鍵字: 正交試驗(yàn)；可靠度指標(biāo)；數(shù)值模擬；露天坑堆尾；境界頂柱；
（School of Resources and Safety Engineering, Central South University, Changsha 410083, China）
Abstract:The stability of underground mined-out area is the key technology for Tong-lü-shan underground mining shifted from open-pit of safely and efficiently stoping residual ore was analyzed. The orthogonal experiment and simulation software FLAC3D based on four influence factors including column thickness (d), gob area span (D), roof thickness (h) and height of tailing gangue (H) were estimated. The test results of 49 groups were analyzed by the means of range, variance and regression analysis, meanwhile using factor of safety and reliability index to assess the safety and efficiency of the recovery. The results indicate that the degree of fit between 4 factors and displacement (W) or safety factor (F) is good, and the correlation coefficient (R2) is more than 0.952. A mathematical forecasting model of displacement under 4 factors is obtained, which is proved effectively during the engineering practice. The significant degree of influence on the stability of mined out area during the 4 factors meets the relationship of H＞d＞h＞D. The importance degree ranking meets H＞d＞D＞h by the comparison of confidence interval f0.05 and F, all of these 4 factors can’t be ignored. The optimal degree of safety and reliability can be reached when safety factor is more than 1.7 and the reliability index begins to converge.
Key words: orthogonal experiment; reliability index; numerical simulation; tailings discharge into open-pit; boundary pillar
