爆破荷载对蠕动边坡的累积效应及稳定性影响研究

【作者】 杨溢；

【导师】 张宗华；

【作者基本信息】 昆明理工大学 ， 地质工程， 2010， 博士

【摘要】 随着我国矿山建设的发展,在大型的露天矿山开采中,开采深度进一步加深,露天边坡高度增大,坡度变陡,边坡的稳定和安全直接关系到露天矿山开采的安全。生产爆破是日常生产活动,具有反复性,其爆破动荷载对边坡的作用也是具有反复性,日积月累对边坡岩体损伤产生累积作用。本文通过阅读大量的国内外文献,研究了岩质边坡动力问题研究的进展,并结合课题《小龙潭爆破振动降震研究》、《小龙潭爆破振动对边坡稳定性的影响》和《爆破震动对露天边坡与山体边坡复合体稳定性的影响研究》系统的研究了爆破振动对边坡岩体的动荷载的累积破坏效应。论文选用小波包分析理论及希尔伯特-黄(HHT)理论对所采集到的现场爆破振动信号进行分析,同时对这两种算法的实现过程进行了设计。利用MATLAB7.0对小波包理论和希尔伯特-黄变换(HHT)编写相关程序,对原始爆破振动信号进行分解重构,利用小波包理论着重分析了爆破振动信号中不同频带上能量的分布规律以及个频带能量随着传播距离及高程变化时的演化规律,得到IMF分量、瞬时能量、边际谱和能量谱。分析可知小龙潭布沼坝坑爆破震动的能量主要分布在信号的低频段,一般在20Hz以下,当随着爆心距增加高频信号能量将会损失,低频信号能量尤其是10Hz以下的低频信号成为能量的主体部分,这与边坡自振频率接近,容易对边坡的稳定性产生较大影响。论文结合国内外蠕动边坡的研究现状、研究趋势、蠕动边坡的类型及其变形、失稳空间预测,以小龙潭露天矿布沼坝蠕动边坡为研究对象,就生产爆破振动及其对布沼坝蠕动边坡的影响进行了系统分析和研究。论文以岩石动力学、断裂力学和损伤力学为理论基础,以SHPB系统为试验手段,研究边坡岩石在冲击准动态作用下的塑性损伤累积效应。论文选用了功能强大的FLAC3D的动力分析方法来研究爆破荷载对小龙潭矿务局布沼坝露天矿边坡稳定性影响,在边坡稳定性的数值计算中,首次在动载荷的计算中输入了三维爆破振动波并分析了其对边坡稳定性的影响,与输入一个方向的振动波相比更能与工程实践相符。更多还原

【Abstract】 Along with the development of mine construction in China, the mining depth has increased and side slopes have become higher and steeper during the mining in large-sized surface mines. The stability and safety of the slopes are directly related to the mining safety of the surface mines. The production blasting is a kind of daily production activity, with the characteristic of repeatability, and the influence of its blasting dynamic loads on the slope is also repeatable, so it has a cumulative effect on the damage of slope rock mass from month to month. In this thesis the author summarized the progress of research on dynamic problems of rock slope after reading a large number of home and abroad documents. He found that most research focused on calculation methods of slope’s dynamic stability and safety evaluation on slope stability, and little research had been done on dynamic load accumulation of slope blasting vibration. Therefore the author conducted a further and deeper study on the dynamic load cumulative destructive effect of blasting vibration on slope rock mass on the basis of projects of A Study on Reducing Vibration from Blasting in Xiaolongtan Open Coal Mine, Effect of Blasting Vibration on Slope Stability in Xiaolongtan Open Coal Mine and Effect of Blasting Vibration on Stability of Combined Body of Open Pit Slopes and Hillside Slopes.In this paper the writer described the transmission, energy, bandwidth and danger of blasting seismic waves after thoroughly analyzing the features of blasting seismic waves and dynamic mechanical properties of rock mass. He analyzed the blasting vibration signal collected on the field by utilizing Wavelet Packet Analysis and Hilbert-Huang Transform (HHT) and designed the realization process of these two algorithms. In addition, he also analyzed the general transmission features of blasting seismic waves. The author utilized MATLAB7.0 to edit relative programs for Wavelet Packet Analysis and Hilbert-Huang Transform (HHT), and decomposed and recomposed the original blasting vibration signals. The author obtained IMF component, instantaneous energy, marginal spectrum and energy spectrum.Analysis shows Xiaolongtan Buzhaoba pit blasting vibration energy is mainly distributed in the low frequency signal, generally in the 20Hz the following, when the center distance as the explosion energy will increase the high frequency signal loss, low frequency signal energy, especially low-frequency signals below 10Hz to become energy the main part, which is close to the natural frequency of the slope, easy to have a greater impact slope stability.After studying the home and abroad status quo and trend of research on creeping slopes, types and deformation of creeping slopes and space instability prediction, the author described the blasting vibration and its influence on Bu Zhaoba creeping slope, combining with the actual situation of Bu Zhaoba creeping slope in Xiaolongtan Open Coal Mine. The author utilized theories of rock dynamics, fracture mechanics and damage mechanics and SHPB as a test method to conduct a study on plastic damage cumulative effects of slope rocks under the action of quasi-dynamic impact. The author selected The FLAC3D powerful method to study the dynamic analysis of blast load on the Buzhaoba Xiaolongtan open pit slope stability, slope stability in the numerical calculation, the first time in the calculation of dynamic load input three-dimensional analysis of blast vibration waves and their effects on slope stability, and input vibration wave in one direction more than in line with engineering practice.更多还原