露天矿边坡采动破坏过程中的应变局部化特征分析

发布时间：2018-01-13 23:30

本文关键词：露天矿边坡采动破坏过程中的应变局部化特征分析　出处：《青岛理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：我国深受矿山滑坡灾害的影响,目前矿山高边坡滑坡坍塌是造成我国矿山事故的主要原因之一。矿山滑坡事故具有突发性、瞬时性、巨大破坏性的特征,是国内外科研工作者把矿山边坡灾害防治工作作为研究对象。在改革开放之后,我国经济快速发展,对于能源的需求量迅速增加,而我国有着丰富的矿产资源,因此为了追求高更好的经济效益,对于矿山的开采也是日益增加。随着矿山不断开采,形成深凹形高陡边坡,这些边坡受到降水、爆破震动、施工开采扰动等不确定因素,形成了安全隐患,威胁着矿区现场施工人员的安全,同时也造成了巨大了经济损失。论文以金川露天露天石英石矿边坡监测项目为背景,通过分析监测到的位移累计值,结合现场边坡局部破坏现象,分析了其周围2-C台阶和与滑坡体处于剖面相邻的3-C、4-C、5-C台阶边坡位移变化曲线。通过对监测数据的分析,变形局部化发生部位发生应力释放、转移和重新调整,应力场重新构建,部分应力转移到邻近区域岩体,距离破坏区域越近的区域岩体应力转移的越多,产生的位移变化越明显,边坡破坏程度也就越大。应力主要向上部台阶边坡岩体转移,对上部岩体影响较大。同时发现在3-C监测点处位移出现了潜在的滑动面,另外由于现场开挖扰动及自然因素的耦合作用,4-C、5-C监测点7.2m深度测斜仪的水平位移累积值出现了不同程度的波动。基于RFPA强度折减法,建立与实地相结合的边坡数值模型,真实地重现了1768平台在施工过程中的典型剖面中的多台阶局部岩土体渐进性失稳过程,分析了边坡失稳破坏过程中应变局部化现象;并从应力场、声发射、弹性模量变化的角度,分析边坡破坏过程中的应力应变变化规律,即多级边坡在破坏的过程中,起始损伤、损伤积累主要由张拉应力破坏引起,损伤的扩展和贯通主要由压剪应力引起,边坡靠近悬空面的岩体主要产生拉张剪切破坏;靠近悬空面岩体在发生张拉剪切破坏的过程中逐步向上部并向远离悬空面岩体扩展;当上部岩体的损伤点扩展成损伤区域并与下部岩体的损伤区域连通形成更大的损伤区域时,会引起岩体内部应力进一步桥越,进而引起更大范围岩体内部应力变化。
[Abstract]:At present, the landslide collapse of high slope is one of the main causes of mine accidents in China. Mine landslide accidents have the characteristics of sudden, instantaneous and huge destructive. Since the reform and opening up, China's economy has developed rapidly, the demand for energy has increased rapidly, and China has rich mineral resources. Therefore, in order to pursue higher and better economic benefits, mining is also increasing. With the continuous mining, the formation of deep concave high steep slope, these slopes are subject to precipitation, blasting vibration. The uncertain factors such as the disturbance of construction mining have formed the hidden danger of safety and threatened the safety of the construction personnel in the mining area. At the same time, it also caused huge economic losses. Based on the monitoring project of open-pit quartzite mine slope in Jinchuan, this paper analyzed the accumulated displacement value and combined with the local failure phenomenon of the site slope. The displacement variation curves of 2-C step and 3-C4-C4-C5-C step slope adjacent to the landslide are analyzed. The monitoring data are analyzed. Stress release, transfer and readjustment, stress field reconstruction, partial stress transfer to adjacent regional rock mass, the closer to the damage area, the more the regional rock mass stress transfer. The more obvious the displacement changes, the greater the failure degree of the slope. The stress is mainly transferred to the upper step slope rock mass. At the same time, it is found that there is a potential sliding surface at the monitoring point 3-C, in addition, because of the excavation disturbance and the coupling of natural factors. The cumulative value of horizontal displacement of 7.2m depth inclinometer at 5-C monitoring point fluctuates in varying degrees. Based on the RFPA strength reduction method, a slope numerical model combined with the field is established. The gradual instability process of multi-step local rock and soil in typical section of 1768 platform during construction is reproduced, and the strain localization phenomenon in the process of slope failure is analyzed. And from the stress field, acoustic emission, elastic modulus change angle, analysis of the slope failure process of the stress-strain variation law, that is, the multi-stage slope in the process of failure, initial damage. The damage accumulation is mainly caused by tensile stress failure, the extension and penetration of damage is mainly caused by compressive shear stress, and the tensile shear failure occurs mainly in the rock mass near the suspension plane. In the process of tensile shear failure, the rock mass near the suspended plane extends gradually to the upper part and to the rock mass far from the suspended plane. When the damage point of the upper rock expands into a damage area and is connected with the damage area of the lower rock mass to form a larger damage area, it will cause the internal stress of the rock mass to bridge further. And then cause the change of internal stress in a larger range of rock mass.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD873.3

【参考文献】