动载影响下含弱层煤岩边坡致灾机理研究

发布时间：2018-05-03 23:33

本文选题：露天矿煤岩边坡 + 动力载荷　；参考：《辽宁工程技术大学》2015年博士论文

【摘要】：露天煤矿爆破振动是诱发含弱层煤岩边坡失稳的重要因素,爆破地震波和边坡自重应力耦合作用下的含弱层边坡变形破坏特征具有特殊性,因此,含弱层边坡在爆破振动影响下变形特征及破坏机理己成为当前岩土工程、爆破工程领域亟待解决的一项重要课题热点问题。论文以内蒙古锡林浩特胜利东二露天矿为依托,通过理论分析、实验室相似模拟及现场爆破监测等手段对动载荷作用下含弱层煤岩边坡致灾机理进行了深入研究。通过对弱层泥岩进行不同含水率的直剪试验及蠕变特性试验,得出弱层在不同含水率、不同轴向压力情况下粘聚力和内摩擦角及蠕变特性曲线,建立了含弱层煤岩边坡的蠕变力学模型,导出动力荷载影响下含软弱弱层边坡流变方程,提出了失稳判别准则；通过自制含弱层煤岩边坡振动试验系统,模拟了爆破震动影响下含弱层边坡的动力变形破坏过程,揭示了含弱层煤岩边坡在爆破振动惯性力和水平错动力作用下,拉裂隙与剪切带加速贯通瞬间失稳的破坏机理,提出一种基于共振效应的确定不规则煤岩边坡自振周期的反演方法；基于LS-DYNA和Geo-slope软件,分析了受爆破荷载影响下有无弱层边坡煤岩边坡的动态变形特征及安全系数；通过现场监测数据统计分析,建立了爆破主振频率、质点振速与爆源距离的关系,确定了含弱层边坡质点振速、爆破主振频率安全阈值,并验证了爆破振动诱发弱层煤岩边坡蠕动加速变形的破坏机理。
[Abstract]:Blasting vibration in opencast coal mine is an important factor to induce the instability of coal and rock slope with weak strata. The deformation and failure characteristics of slope with weak stratum under the coupling of blasting seismic wave and gravity stress of slope have particularity. The deformation characteristics and failure mechanism of slope with weak layers under the influence of blasting vibration have become an important hot issue in the field of blasting engineering. Based on Xilinhaote Shengli East No.2 Open-pit Mine in Inner Mongolia, the disaster mechanism of coal-bearing rock slope with weak strata under dynamic load is studied by means of theoretical analysis, laboratory simulation and field blasting monitoring. Through the direct shear test and creep characteristic test of weak mudstone with different moisture content, the cohesive force, internal friction angle and creep characteristic curve of weak layer under different water content and different axial pressure are obtained. The creep mechanics model of coal and rock slope with weak stratum is established, the rheological equation of slope with weak layer under dynamic load is derived, and the criterion for judging instability is put forward, and the vibration test system of coal rock slope with weak stratum is developed. The dynamic deformation and failure process of the slope with weak layer under the influence of blasting vibration is simulated, and the failure mechanism of the slope with weak strata under the action of blasting vibration inertia force and horizontal staggered force is revealed. An inverse method for determining the natural vibration period of irregular coal and rock slopes based on resonance effect is proposed, and the dynamic deformation characteristics and safety factors of coal and rock slopes with or without weak strata under blasting load are analyzed based on LS-DYNA and Geo-slope software. Based on the statistical analysis of field monitoring data, the relationship between blasting main vibration frequency, particle vibration velocity and explosion source distance is established, and the safety threshold of blasting main vibration frequency and particle vibration velocity of slope with weak layer is determined. The failure mechanism of accelerated creep deformation induced by blasting vibration is verified.
【学位授予单位】：辽宁工程技术大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TD824.7

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