【摘要】：露天礦邊坡失穩(wěn)是一個復雜的非線性變化過程,在運營及開挖過程中,安全穩(wěn)定問題至關重要,關系到人民生命財產(chǎn)安全和環(huán)境保護評價。從多方面多角度深入開展巖土工程穩(wěn)定性研究與風險評價,具有重要的理論價值和實際意義。本文以江西省九江市城門山露天礦開挖邊坡為工程背景,針對現(xiàn)有邊坡穩(wěn)定性研究方法,運用現(xiàn)場實測、理論分析、試驗研究、數(shù)值模擬與監(jiān)測調(diào)研的綜合手段,基于地球物理勘探、能量原理、有限元強度折減法、突變理論、熵理論等,對邊坡工程的破壞模式、力學機制、能量規(guī)律、動態(tài)穩(wěn)定等問題開展深入的研究,建立有效的多模型綜合穩(wěn)定評價方法,揭示其變形破壞的演化特征和失穩(wěn)機理。主要進行了以下方面的研究:(1)在深刻認識地質(zhì)環(huán)境與EH-4地質(zhì)環(huán)境勘探基礎上,通過有限元與有限差分程序,建立了含斷層帶、多地層的復雜三維地質(zhì)模型,采用多區(qū)域的特征測點、單元的布控、追蹤,進行位移、速度、塑性屈服的時間與空間演化特征分析,動態(tài)演示預測了礦區(qū)邊坡易失穩(wěn)風險區(qū)段的災變過程,并結(jié)合位移矢量角指標,共同闡釋了邊坡系統(tǒng)平衡穩(wěn)定與臨滑失穩(wěn)的變化特征。(2)基于能量原理推導邊坡系統(tǒng)各類能量判據(jù),進行有限差分用戶子程序的二次開發(fā),Fish語言編制能量程序源代碼,充分利用計算機的可視化功能,詳細展現(xiàn)了重力勢能、彈性應變能、動能,以及耗散能的時空演化特征及其之間的轉(zhuǎn)化規(guī)律。從能量的角度,分析了邊坡"無序"、"有序"的"自組織"演化特征與復雜的內(nèi)在變化反應,以及具有"耗散結(jié)構(gòu)"的能量耗散與轉(zhuǎn)化的效率、特點趨勢。并提出局部能量釋放率指標,直接反映了不同特征區(qū)域的能量吸收、釋放、轉(zhuǎn)移等復雜的動態(tài)能量變化規(guī)律。(3)基于突變理論,推導了位移與能量的尖點突變模型,建立起位移、能量的突變判據(jù)與判別實現(xiàn)流程,進行邊坡系統(tǒng)的穩(wěn)態(tài)與能量突變分析,并與常規(guī)失穩(wěn)判據(jù)對比,具有較好的統(tǒng)一性與一致性。(4)依據(jù)開挖方案,分析了三期邊坡工程開挖全過程的卸荷變形與應力釋放特點,塑性區(qū)與穩(wěn)定性的動態(tài)特征、變化趨勢,以及各類能量場的時、空動態(tài),并結(jié)合能量釋放率指標與巖石破裂過程,闡釋了能量間的內(nèi)在轉(zhuǎn)化規(guī)律與耗散作用機制。模擬預測了開挖災變的風險垮塌區(qū),并結(jié)合已有的智能監(jiān)控調(diào)度系統(tǒng),有利于全方位地進行三期開挖的安全監(jiān)測、監(jiān)控調(diào)度與維穩(wěn)避險指導。(5)基于熵理論,提出了幾種新的邊坡穩(wěn)態(tài)評價方法:模糊相對隸屬模型、熵權-模糊集對分析、態(tài)勢遷躍與聯(lián)系熵法、滑坡總熵判別法,并與基于能量演化突變的有限差分數(shù)值模型進行綜合對比、相互驗證,具有較好的一致性,邏輯性強,信息利用率高,結(jié)果直觀準確,為邊坡穩(wěn)定性評價提供了多種新途徑。
[Abstract]:Slope instability in open-pit mines is a complicated nonlinear process. In operation and excavation, safety and stability is of great importance, which is related to the safety of people's life and property and the evaluation of environmental protection. It is of great theoretical and practical significance to carry out the stability research and risk assessment of geotechnical engineering from many aspects and many angles. This paper takes the excavation slope of Chengmenshan opencast mine in Jiujiang City, Jiangxi Province as the engineering background. Aiming at the existing slope stability research methods, the comprehensive means of field measurement, theoretical analysis, experimental study, numerical simulation and monitoring investigation are used. Based on geophysical exploration, energy principle, finite element strength reduction method, catastrophe theory, entropy theory and so on, the failure mode, mechanics mechanism, energy law and dynamic stability of slope engineering are studied deeply. An effective multi-model comprehensive stability evaluation method is established to reveal the evolution characteristics and instability mechanism of the deformation and failure. The main works are as follows: (1) on the basis of deep understanding of geological environment and EH-4 geological environment exploration, a complex three-dimensional geological model containing fault zone and multi-strata is established by finite element and finite difference program. The time and space evolution characteristics of displacement, velocity and plastic yield are analyzed by means of multi-area characteristic measurement points, unit control, tracking, displacement, and plastic yield. The dynamic demonstration and prediction of the catastrophic process in the unstable risk section of the mining slope are presented. Combined with displacement vector angle index, the variation characteristics of equilibrium stability and impending sliding instability of slope system are explained. (2) based on the energy principle, all kinds of energy criteria of slope system are derived, and the secondary development of finite difference user subroutine is carried out. The source code of the energy program is compiled by Fish language, which makes full use of the visualization function of the computer to show in detail the characteristics of the space-time evolution of gravitational potential energy, elastic strain energy, kinetic energy and dissipative energy, as well as the law of transformation between them. From the point of view of energy, this paper analyzes the characteristics and trends of "disordered", "self-organizing" evolution of slope and complex internal change reaction, as well as the efficiency of energy dissipation and transformation with "dissipative structure". The index of local energy release rate is put forward, which directly reflects the complex dynamic energy changes of different characteristic regions, such as energy absorption, release and transfer. (3) based on the catastrophe theory, the cusp catastrophe model of displacement and energy is derived. The catastrophe criterion of displacement and energy is established and its realization flow is established, and the steady state and energy abrupt change analysis of slope system is carried out, and compared with the conventional instability criterion, it has good unity and consistency. (4) according to the excavation scheme, The characteristics of unloading deformation and stress release, the dynamic characteristics of plastic zone and stability, the variation trend, and the time-space dynamics of various energy fields are analyzed, and the energy release rate index is combined with the rock fracture process. The inner law of energy transformation and the mechanism of dissipation are explained. The risk collapse area of excavation disaster is predicted by simulation and combined with the existing intelligent monitoring and dispatching system, which is conducive to the safety monitoring, monitoring and maintenance of the third phase excavation. (5) based on entropy theory, Several new steady state evaluation methods of slope are put forward: fuzzy relative membership model, entropy weight-fuzzy set pair analysis, situation transition and relation entropy method, landslide total entropy discriminating method. Compared with the finite difference numerical model based on the energy evolution catastrophe, it has good consistency, strong logic, high information utilization rate, and the results are intuitionistic and accurate, which provides a variety of new ways for slope stability evaluation.
【學位授予單位】：北京科技大學
【學位級別】：博士
【學位授予年份】：2017
【分類號】：TD804

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相關期刊論文 前10條

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本文編號：2346601