充填體與圍巖接觸成拱作用機(jī)理及強(qiáng)度模型研究
發(fā)布時間:2018-04-19 14:49
本文選題:階段空場嗣后充填法 + 充填體力學(xué); 參考:《北京科技大學(xué)》2017年博士論文
【摘要】:地下金屬礦山中,階段空場嗣后充填法是充填法與空場法的有機(jī)結(jié)合,代表了大規(guī)模高效率綠色清潔采礦的發(fā)展方向。但是該法中一步驟采場膠結(jié)充填體的膠充成本(水泥等添加)占充填總成本70%以上,如何在確保充填體揭露穩(wěn)定性的同時優(yōu)化控制膠充成本是制約安全經(jīng)濟(jì)充填采礦的瓶頸問題。為此,本文采取理論分析、解析計(jì)算、數(shù)值計(jì)算、實(shí)驗(yàn)測試、物理模型驗(yàn)證和礦山應(yīng)用驗(yàn)證相結(jié)合的研究手段,旨在突破充填成拱作用機(jī)理及影響因素分析、充填體拱應(yīng)力計(jì)算和強(qiáng)度需求計(jì)算中的關(guān)鍵瓶頸,為兩步驟階段空場嗣后充填法中采場充填體強(qiáng)度需求的優(yōu)化設(shè)計(jì)提供理論依據(jù)和方法參考。(1)定義了一種鋸齒型接觸單元以定量描述實(shí)際采場圍巖的表面特征,探索了充填體與圍巖之間嵌入線性平滑、非線性粗糙接觸單元對充填體應(yīng)力成拱效應(yīng)的影響規(guī)律,研究了充填體拱應(yīng)力分布對接觸面性質(zhì)(粗糙度指標(biāo)、剪切強(qiáng)度參數(shù))和充填體尺寸及物理力學(xué)參數(shù)的響應(yīng)機(jī)制,得出了更具普適性的根據(jù)采場圍巖邊壁特征進(jìn)行采場充填體拱應(yīng)力計(jì)算的數(shù)值模型與方法。(2)分析了用于充填體強(qiáng)度需求和穩(wěn)定性計(jì)算的經(jīng)典Mitchell法的提出過程,利用FLAC3D數(shù)值還原模擬了校驗(yàn)Mitchell法的物理模型試驗(yàn),對比研究了不同尺寸條件下充填體強(qiáng)度與揭露穩(wěn)定性的關(guān)系,獲取了經(jīng)典Mitchell法的適用條件,得到了揭露后膠結(jié)充填體的潛在滑動破壞模式及其描述方法。(3)研究了固結(jié)排水長期強(qiáng)度狀態(tài)下,二步驟采場非膠結(jié)充填體、揭露前和揭露后的一步驟采場膠結(jié)充填體的三維拱應(yīng)力分布模式,并分別建立了各采場充填體拱應(yīng)力的三維解析計(jì)算模型,得出了三維成拱狀態(tài)下非膠結(jié)充填體-膠結(jié)充填體-采場圍巖間的應(yīng)力傳遞作用規(guī)律及接觸力學(xué)邊界表征方法。(4)探索了階段空場嗣后充填法采充時序過程中,不同工況條件下非膠結(jié)充填體對膠結(jié)充填體的側(cè)壓作用機(jī)制,建立了一步驟采場膠結(jié)充填體強(qiáng)度需求的三維解析計(jì)算模型,與FLAC3D模擬搜索的強(qiáng)度需求三維數(shù)值解綜合對比后,獲得了采場充填體強(qiáng)度需求理論解的最優(yōu)解析計(jì)算模型與方法。(5)以工程依托礦山原位采場充填體中鉆孔取芯試樣的強(qiáng)度實(shí)測數(shù)據(jù)為樣本,研究了采場充填體強(qiáng)度分布離散性的數(shù)理統(tǒng)計(jì)學(xué)概率表征,據(jù)此定義了一種安全系數(shù)的浮動選取方法,定量描述了礦山現(xiàn)階段的整體充填技術(shù)水平和充填質(zhì)量控制效果,建立了采場充填體"強(qiáng)度需求理論解→實(shí)際充填質(zhì)量反饋→安全系數(shù)浮動選取→實(shí)際強(qiáng)度需求指標(biāo)"的動態(tài)優(yōu)化設(shè)計(jì)模型。
[Abstract]:In underground metal mines, the backfilling method is an organic combination of filling method and open-pit method, which represents the development direction of large-scale and high-efficiency green and clean mining.However, the filling cost (cement addition) of the stope cemented filling body in one step of the method accounts for more than 70% of the total filling cost.How to optimize and control the filling cost while ensuring the stability of the backfill is the bottleneck of the safe and economical backfill mining.Therefore, this paper adopts a combination of theoretical analysis, analytical calculation, numerical calculation, experimental testing, physical model verification and mine application verification to break through the mechanism of filling arch formation and the analysis of influencing factors.The key bottlenecks in stress calculation and strength requirement calculation of filling arch,This paper provides a theoretical basis and method reference for the optimization design of the strength requirement of stope backfill in the two-step open-pit subsequent filling method. A zigzag contact unit is defined to quantitatively describe the surface characteristics of the surrounding rock in the actual stope.The effect of linear smooth and nonlinear rough contact element on the stress arch effect between backfill and surrounding rock is explored. The effect of arch stress distribution on contact surface properties (roughness index) is studied.The response mechanism of the shear strength parameter and the size of the filling body and the physical and mechanical parameters,A more general numerical model and method for calculating arch stress of stope filling body according to the characteristics of side wall of stope surrounding rock are obtained. The process of the classical Mitchell method for calculating the strength demand and stability of stope is analyzed.The physical model test of verifying Mitchell method is simulated by FLAC3D numerical reduction. The relationship between the strength of the filling body and the exposure stability under different size conditions is compared and the applicable conditions of the classical Mitchell method are obtained.In this paper, the potential sliding failure mode and its description method of post-cemented backfill are obtained. The non-cemented backfill in two-step stope under the condition of long-term strength of consolidated drainage is studied.The three dimensional arch stress distribution model of cemented filling body of stope before and after disclosure is established, and the three dimensional analytical calculation model of arch stress of each stope filling body is established respectively.The law of stress transfer between non-cemented backfill, cemented backfill and stope surrounding rock and the boundary representation method of contact mechanics under the condition of three-dimensional arch formation are obtained.Based on the lateral pressure mechanism of non-cemented filling under different working conditions, a three-dimensional analytical calculation model of strength requirement of one-step stope cemented backfill is established, which is compared with the three-dimensional numerical solution of strength requirement searched by FLAC3D simulation.The optimal analytical model and method for the theoretical solution of the strength requirement of stope backfill are obtained.This paper studies the mathematical statistical probability representation of the discrete strength distribution of stope filling body, defines a floating selection method of safety factor, and quantitatively describes the overall filling technology level and filling quality control effect at the present stage of the mine.A dynamic optimum design model for stope backfill is established, which is based on the theory of strength demand theory and the feedback of practical filling quality and the floating of safety factor to select the index of actual strength demand.
【學(xué)位授予單位】:北京科技大學(xué)
【學(xué)位級別】:博士
【學(xué)位授予年份】:2017
【分類號】:TD853.34
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 Liu Guangsheng;Li Li;Yang Xiaocong;Guo Lijie;;Stability analyses of vertically exposed cemented backfill:A revisit to Mitchell's physical model tests[J];International Journal of Mining Science and Technology;2016年06期
2 Nabassé J.F.Koupouli;Tikou Belem;Patrice Rivard;Hervé Effenguet;;Direct shear tests on cemented paste backfill-rock wall and cemented paste backfill-backfill interfaces[J];Journal of Rock Mechanics and Geotechnical Engineering;2016年04期
3 吳愛祥;沈慧明;姜立春;焦華U,
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