本文關(guān)鍵詞： 降雨 尾礦庫 潰壩 彈性波　出處：《北京科技大學(xué)》2017年博士論文　論文類型：學(xué)位論文

【摘要】：尾礦庫是礦山主要控制工程和重大危險源。生產(chǎn)實踐表明:由于尾礦庫壩體構(gòu)成介質(zhì)的松散特性,致使其在外界擾動下,如降雨、地震、液化等條件下易引發(fā)尾礦庫潰壩事故,尤其是在連續(xù)降雨情況下極易引發(fā)尾礦庫潰壩。因此,開展降雨因素對尾礦庫潰壩的影響及安全預(yù)警技術(shù)研究,對提高尾礦庫降雨條件下安全運行,實現(xiàn)對尾礦庫潰壩的預(yù)測、預(yù)報,保障下游居民的生命財產(chǎn)安全,具有重要意義。本文對江西省自1960年起的14起尾礦庫事故尤其6起潰壩事故發(fā)生時的降雨情況進行了詳細統(tǒng)計,得出降雨條件下尾礦庫潰壩的模式,結(jié)合尾礦庫實例,開展了物理模擬試驗與數(shù)值模擬試驗,分析了尾礦壩在漸進潰壩和瞬時潰壩兩種模式下的演化規(guī)律,以及瞬時潰壩時水流的流動特性。而后,開展基于波導(dǎo)桿采集聲學(xué)信號的尾礦庫潰壩的優(yōu)化試驗,研究了不同波導(dǎo)桿桿徑與碎石粒徑條件下,潰壩破壞過程中的聲學(xué)特征,提出了基于聲學(xué)監(jiān)測的尾礦庫潰壩的預(yù)測方法。在此基礎(chǔ)上,建立了彈性波在波導(dǎo)桿中頻散方程,計算了衰減頻散曲線,分析彈性波在波導(dǎo)桿中傳播的衰減規(guī)律,進而對波導(dǎo)桿桿徑與碎石粒徑進行優(yōu)化選擇。最后,通過對某尾礦庫壩體進行了水平、豎向位移與彈性波監(jiān)測,對壩體穩(wěn)定性進行了科學(xué)分析。本文主要的研究內(nèi)容包括:(1)通過分析江西省6起尾礦庫潰壩事故時的降雨特征,得出潰壩事故均發(fā)生在汛期內(nèi),在事故發(fā)生時,尾礦庫所在地均有3天以上連續(xù)性降水,且潰壩事故的當(dāng)日,當(dāng)?shù)鼐谐^50mm的大暴雨。(2)尾礦庫潰壩的潰口破壞程度取決于溢流對壩體的沖刷侵蝕作用。在漸進潰壩條件下,潰壩過程表現(xiàn)出明顯的陡坎式漸進破壞模式;在瞬時潰壩條件下,壩體溝底底坡與潰壩水流方向相逆,右側(cè)壩段潰口水流在淤砂和折轉(zhuǎn)水流共同作用下形成壩下游逆時針旋流;左側(cè)壩段潰口水流形成左右兩個旋流。(3)在壩體臨近潰壩時彈性波能量分形維數(shù)表現(xiàn)為增大而后快速減小的趨勢,彈性波主頻位于15kHz～77.8 kHz,該特征可作為尾礦庫壩體潰壩的前兆特征。(4)彈性波在波導(dǎo)桿中的衰減隨著波導(dǎo)桿桿徑的增大而減小;當(dāng)采用10-16mm粒徑的碎石對波導(dǎo)桿包裹時,此時彈性波的主頻在0～0.25MHz范圍內(nèi)出現(xiàn)次數(shù)最多。因此,在工程實踐中,宜選用大桿徑的波導(dǎo)桿與10-16mm粒徑碎石的組合。(5)通過收集潰壩事故發(fā)生前不同時段的降雨數(shù)據(jù),運用統(tǒng)計分析方法,建立了基于降雨數(shù)據(jù)的二元logistic回歸模型,得到當(dāng)日降雨量與累計降雨量的定量關(guān)系,針對某尾礦庫安全度無法判定,對其進行了水平、豎向位移與彈性波監(jiān)測,通過分析監(jiān)測結(jié)果,認為該尾礦壩總體處于穩(wěn)定狀態(tài)。
[Abstract]:The tailing reservoir is the main control project and the major hazard source in the mine. The production practice shows that because of the loose characteristic of the dam body, the tailing reservoir is disturbed by the outside environment, such as rainfall and earthquake. It is easy to cause tailing dam break accident under the condition of liquefaction, especially in the case of continuous rainfall. Therefore, the influence of rainfall factors on tailing dam break and safety early warning technology are studied. It can improve the safe operation of tailing reservoir under rainfall condition, realize the prediction and forecast of tailing dam break, and ensure the safety of life and property of downstream residents. This paper makes detailed statistics on the rainfall situation of 14 tailing dam accidents, especially 6 dam-break accidents in Jiangxi Province since 1960, and obtains the model of tailing dam break under rainfall conditions. Combined with an example of tailings reservoir, physical and numerical simulation tests are carried out, and the evolution of tailings dam under two modes of progressive dam break and instantaneous dam break is analyzed, as well as the flow characteristics of water flow during transient dam break. The optimal test of tailing dam break based on acoustic signal acquisition by waveguide rod is carried out. The acoustic characteristics of dam break under different diameter of waveguide rod and gravel diameter are studied. The prediction method of tailing dam failure based on acoustic monitoring is proposed. Based on this, the dispersion equation of elastic wave in waveguide rod is established, and the attenuation dispersion curve is calculated. The attenuation law of elastic wave propagation in waveguide rod is analyzed, and then the diameter of waveguide rod and gravel diameter are optimized. Finally, the horizontal, vertical displacement and elastic wave monitoring of a tailing dam body are carried out. The stability of dam body is analyzed scientifically. The main research contents in this paper include: 1) by analyzing the rainfall characteristics of 6 tailing dam break accidents in Jiangxi Province, it is concluded that dam break accidents all occur in flood season. At the time of the accident, there are more than 3 days of continuous precipitation in the tailing area, and the day of dam break accident. There are more than 50 mm heavy rain in the local area.) the failure degree of dam break of tailing reservoir depends on the scour erosion effect of overflow on the dam body, under the condition of progressive dam break. The dam-break process shows obvious steep-ridge-type progressive failure mode. Under the condition of instantaneous dam break, the bottom slope of the dam body is opposite to the direction of the dam break flow, and the flow at the right end of the dam section is counterclockwise swirling under the combined action of silt and converted flow. When the dam body is near the dam break, the fractal dimension of elastic wave energy increases and then decreases rapidly. The main frequency of elastic wave is located at 15kHz ~ 77.8 kHz, which can be used as a precursor feature of dam collapse in tailing dam.) the attenuation of elastic wave in the waveguide rod decreases with the increase of the diameter of the waveguide rod. When the waveguide rod is wrapped with gravel of 10-16mm diameter, the main frequency of elastic wave appears most frequently in the range of 0 ~ 0.25MHz. Therefore, it is in engineering practice. The combination of large-diameter waveguide rod and 10-16mm diameter gravel should be used to collect the rainfall data of different periods before the dam break accident, and the statistical analysis method is used. A binary logistic regression model based on rainfall data was established, and the quantitative relationship between the daily rainfall and the accumulated rainfall was obtained. The vertical displacement and elastic wave monitoring results show that the tailings dam is in a stable state.
【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】：TD926.4

【參考文獻】

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本文編號：1452728