(廣西大學(xué) 資源環(huán)境與材料學(xué)院，南寧 530004)
摘 要: 開展柔性隔離層下單漏斗散體礦巖力鏈演化特征模擬研究，對(duì)于進(jìn)一步揭示柔性隔離層下散體介質(zhì)流動(dòng)規(guī)律的內(nèi)部作用機(jī)理具有重要意義。基于大量放礦同步充填留礦法數(shù)值試驗(yàn)?zāi)Ｐ停肞FC強(qiáng)大的數(shù)據(jù)處理及圖片輸出功能，結(jié)合接觸力學(xué)及統(tǒng)計(jì)力學(xué)相關(guān)知識(shí)，對(duì)單漏斗放礦過程散體介質(zhì)體系內(nèi)力鏈長度、數(shù)量、強(qiáng)度、方向、準(zhǔn)直系數(shù)等的演化特征進(jìn)行量化研究。結(jié)果表明：在柔性隔離層下單漏斗放礦過程，隨著放礦次數(shù)的增加強(qiáng)接觸占比逐漸由37%減小到32%，并在放礦后期逐漸保持穩(wěn)定，力鏈接觸作為強(qiáng)接觸自組織而成的結(jié)構(gòu)，其接觸占比在放礦過程穩(wěn)定在17%左右。力鏈總數(shù)隨著放礦次數(shù)的增加逐漸減少，并在放礦后期穩(wěn)定在810條左右，且不同放礦次數(shù)下力鏈長度的概率分布幾乎一致，均隨著力鏈長度的增加呈指數(shù)式遞減；隨著放礦次數(shù)增大力鏈強(qiáng)度的概率分布先呈指數(shù)式上升，再呈指數(shù)式下降，在0.7 ( 為平均接觸力)處出現(xiàn)一峰值。放礦初始階段，力鏈主要沿垂直方向分布，力鏈方向分布形態(tài)近似花生狀，此后隨著礦石顆粒的持續(xù)放出，力鏈方向分布形態(tài)由花生狀逐漸變?yōu)闄E圓最終演變成花瓣?duì)钚螒B(tài)，力鏈分布主方向由一個(gè)演變?yōu)槿齻€(gè)(垂直及與水平方向呈±30o夾角的方向)。力鏈準(zhǔn)直系數(shù)在第9次放礦結(jié)束后達(dá)到頂峰，隨后逐漸下降并保持穩(wěn)定。
關(guān)鍵字: 柔性隔離層；散體介質(zhì)；力鏈；同步充填；離散元
（School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China）
Abstract:It is of great significance to carry out the simulation on the evolution characteristics of the force chain in granular ore rock with a single funnel under a flexible isolation layer so as to further reveal the internal mechanism of the flow law of the granular medium under the flexible isolation layer. Based on the numerical test model of the mass draw and synchronous filling with shrinkage stoping method, the evolution characteristics of the force chain length, quantity, intensity, direction and collinear coefficient in the granular medium system with a single funnel during ore drawing process are quantitatively studied by using the powerful data processing and image output functions of PFC and combining with the relevant knowledge of contact mechanics and statistical mechanics. The results show that in the ore drawing process with a single funnel under a flexible isolation layer, the ratio of strong contact gradually decreases from 37% to 32% with the increase of ore drawing times, and gradually remains stable in the later stage of ore drawing. As a structure of strong contact self-organization, the contact ratio of force chain contact is stable at about 17% in the ore drawing process. The total number of force chains gradually decreases with the increase of the number of ore drawing, and stabilizes at about 810 in the later period of ore drawing. The probability distribution of force chain length under different times of ore drawing is almost the same, which decreases exponentially with the increase of the length of the force chain. The probability distribution of force chain strength under different times of ore drawing firstly increases exponentially and then decreases exponentially, and a peak value appears at 0.7 ( is the average contact force). In the initial stage of ore drawing, the force chain is mainly distributed along the vertical direction, and its distribution pattern is similar to that of peanut, with the increase of ore particles sustained drawn, the direction of the force chain distribution from peanut shape gradually into elliptical form eventually evolved into a petal shape form, and the main direction of force chain distribution evolved from one to three (the vertical direction and the direction with ±30o angle to the horizontal direction). The collimation coefficient of the force chain reached its peak after the 9th ore drawing, and then gradually declined and remained stable.
Key words: flexible isolation layer; granular media; force chain; synchronous filling; discrete element
