层状岩体深部巷道变形破坏物理模拟及红外探测研究

发布时间：2018-03-18 21:46

本文选题：层状岩体　切入点：物理模型　出处：《中国矿业大学(北京)》2015年博士论文　论文类型：学位论文

【摘要】：针对深部工程环境复杂岩体力学行为精细探测的科学问题,以不同倾角的层状沉积岩体作为物理模拟的研究对象,主要开展了水平岩层、45度倾斜岩层工程地质岩体的物理模拟实验及红外探测研究。通过对红外图像的处理分析,表明平均红外辐射温度的演化曲线揭示了岩体在外荷载作用下的变化规律,红外图像表征了岩体的结构响应,傅里叶频谱刻画了应力波在岩体中的传播及岩体的损伤程度。深入揭示了层理化岩体在高应力条件下变形破坏的力学规律。在红外图像的处理与分析方面取得了创新性成果。为了处理物理模型实验过程中采集的具有低信噪比和低对比度等缺陷的红外图像,提出了新的红外图像处理算法,该算法主要包括下列运算:图像折减去除环境辐射噪声,中值滤波减少脉冲噪声,高斯高通滤波(GHPF)去除周期性添加噪声,最后是多尺度形态学增强滤波(MIF)来增强低对比度红外图像。MIF是一个图像增强滤波器,它是基于白顶帽变换并同时放大图像峰值的原则开发的。正方形的结构元素有多尺度边长?,?的取值范围从最小探测裂纹到最大探测目标之间变换。还有灰度峰值,它是用比例因子1/?与红外图像的峰值相乘,从而可以把小的探测目标放大到一个较大的幅值并且把大的探测目标保持中等水平。经过处理后的红外图像能够清晰的反映温度场的微小变化。水平岩层物理模型巷道破坏的主要原因是巷道两帮水平应力释放、垂直应力增高,在巷道两帮形成无侧向约束的压应力区,该区域岩石以软弱煤层为主。煤层在集中压应力作用下产生塑性变形或沿节理弱面错动,最终引起煤层破碎变形。由于层状岩体破碎,层间基本无粘聚力,巷道两帮压应力区的集中应力只需克服层间摩擦力,就能引起层间滑移。实验中表现为初始加载阶段巷道两帮岩体向临空区水平推出,但是巷道本身尚未发生破坏。对于巷道顶、底板岩层在与层理方向平行的集中压力作用下,向巷道临空方向产生挠曲变形,主要表现为顶板下沉和底鼓。水平岩层物理模型的底板岩性主要为煤层,强度相对较低,极易发生底鼓现象。而巷道顶板可看作两端承受巨大压力挤压的承载岩梁,因此岩梁不是在垂直压力下以梁的形式破坏而是在巨大的水平压力作用下破坏的。在较大的水平压力作用下,岩梁拉应力区几近消失,故实验中巷道顶板并没有在较小的应力水平下就受拉破坏。水平岩层物理模型巷道采用新红外图像对岩体响应进行了分析,同时使用模型照片、旧红外图像与新红外图像进行对比,说明经过降噪滤波和图像增强滤波后的红外图像质量有明显的提高。新红外图像对岩石破坏的前兆预警是非常准确的,并且对水平岩层物理模型巷道岩体的破坏机制有了更深刻的理解。从红外特征分析和应变分析两种方法可以看出在应力增加时会对巷道围岩有明显的影响。而对于应变变化来讲,两帮和底板的应变变化明显要大于顶板的变化,说明巷道两帮及底板的煤层部位受外荷载的影响较大。红外图像揭示了在外荷载作用下,岩层之间存在强烈的静摩擦与动摩擦现象,其中动摩擦滑移是变形破坏的根源。45度倾斜岩层的平均红外辐射温度(irt)曲线表征了受载岩体的整体能量释放率。根据irt曲线可知45度倾斜岩层的破坏特征:在初始加载阶段irt曲线上的线性段表示模型的处于弹性完整状态,在后续加载阶段irt曲线的无规则多周期波动表示急倾斜岩体在压力作用下出现粘滑行为。外荷载水平和加载速率对irt曲线也有明显的影响:在低荷载水平和低加载速率下irt曲线震荡周期长并且振幅小;反之,在高荷载水平及高加载速率下irt曲线震荡周期短并且振幅大。通过红外图像序列可以很好的解释45度倾斜岩层地层之间的各向异性行为。初始加载阶段红外图像的温度分布呈现出散射无规则的模式,揭示此时模型处于弹性完整状态;在初始加载阶段也可以通过条带状分布的红外温度观察岩石的各向异性行为。在随后的加载过程中,静态摩擦与irt曲线的粘性阶段对应,岩层内部岩块之间激烈的静态摩擦和地层界面之间的静态摩擦通过高低温大尺度红外温度分布表征。综上所述,45度倾斜岩层物理模型在低加载水平阶段,对应于高红外温度条带的煤层由于激烈的内在摩擦首先发生变形,而对应于低红外温度条带的泥岩变形较小;在高加载水平阶段对应于irt曲线的滑动阶段,此阶段的红外温度分布模式发生反转,即:低红外温度条带表征煤层而高红外温度条带表征泥岩,揭示了由于滑动和断裂引起煤层松动。红外图像序列中的红外温度分布可以很好的表征巷道左右帮收缩、直接顶分离以及底鼓等现象。通过对45度倾斜岩层的红外图像分析可知加载速率对物理模型的破坏也有一定的影响,即:在低荷载水平和低加载速率下,模型岩体以静摩擦为主;在高荷载水平及高加载速率下,模型岩体主要发生动态摩擦、断裂、层间滑移等现象。45度倾斜岩层红外图像的傅里叶频谱分析表明:在低加载速率阶段,低辐值、无主导频率的主要分量代表了围岩变形的弹性阶段,高频带上的主要分量代表了岩体的损伤出现,损伤的程度与频率成反比;在高加载速率阶段,主要分量的辐值明显高于前者,其辐值最高的主要分量代表了关键破坏。说明傅里叶频谱对外荷载及应力变化更加敏感:在粘性阶段提供高波段和高振幅的前兆预警;在诱发断裂破坏的瞬间提供低波段和超高振幅预兆。与irt曲线及红外图像相比,图像矩阵的傅里叶频谱对外荷载的变化更加敏感。主要分量(周期分量)的频率和幅度可以很好的表征荷载增加和应力变化。在实验中的大多数加载阶段的侧压力系数都大于一,即:水平应力大于垂直应力。相应地水平频谱比垂直频谱有更多具有较高振幅的主要分量,很好的表征了岩石的各向异性。粘性阶段可与IRT曲线的峰值对应,并通过水平傅里叶频谱中具有高振幅落在高频段的单一分量表征。滑移阶段主要与IRT曲线的谷值相对应,可以通过具有高振幅并落在低频段的主要分量表征,也叫做所谓的频移。这些异常分量都是即将发生岩石破坏事件的前兆预警信息。用傅里叶频谱F(u)和F(v)及空间频率来描述红外图像的频谱特征。在超高频段的高幅值主要分量可以作为即将发生的动态层间滑动或断裂的前兆预警信息,还可对正在发生的动态特征进行预测。低频段的主要分量有以下两个特点:(1)如果是高振幅的主要分量可以作为大尺度层间滑动的前兆,(2)如果是振幅中等或较小的主要分量则可以作为应力重分布延伸影响的一个指标。经过处理后的红外图像通过两种红外温度分布模式能够很好的表征岩体的力学行为。在低加载水平阶段,煤层受荷载作用较强所以表现出高红外温度分布而泥岩层受荷载作用较弱故表现出低红外温度分布。在高加载水平阶段红外温度分布发生逆转,即:泥岩层受到较强的荷载作用而表现出高红外温度分布,煤层受到较弱的荷载作用表现为低红外温度分布。高红外温度分布模式表征岩石的静态层理摩擦,低红外温度分布模式则表征岩石的动态滑动摩擦。对两种不同角度岩层物理模型的红外图像进行比较,可以获得更多描述层状岩体结构效应的知识:对水平岩层物理模型来说红外图像的温度以局部化塑性方式分布;对于45度倾斜岩层物理模型来说红外图像中呈现出条带状的局部化温度分布,红外图像中高对比度的条带反映了岩层倾角导致模型发生不稳定摩擦滑动损伤。说明红外图像能直观的反应模型摩擦滑动等结构效应,揭示了物理模型在外荷载作用下的变形破坏机制与地层角度有密切关系。本文将红外热成像技术成功应用于大尺度物理模型实验探测,解决了热弹性与热塑性的识别问题。得到了水平岩层和45度倾斜岩层巷道在外荷载作用变形破坏特征。对复杂岩体结构的力学行为与破坏机理认识具有重要意义,无论是现场工程地质体的探测还是实验室大尺度物理模型实验的探测红外热成像技术都有广泛的应用前景。
[Abstract]:In view of the deep complex engineering environment scientific problems of mechanical behavior of rock mass fine detection, with different angle layered sedimentary rock mass as the research object of physical simulation, mainly carried out the level of rock physics 45 degree tilt rock engineering geological rock simulation experiment and infrared detection research on infrared image processing. Through the analysis, show that the average curve evolution the infrared radiation temperature reveals the variation of rock mass under external loads, the infrared image to characterize the response of rock structure, the Fourier spectrum depicts the damage degree of rock mass and propagation of stress wave in rock mass in. To reveal the laws of mechanics of deformation and failure of rock mass bedding under high stress conditions. To make innovation results in the processing and analysis of infrared image acquisition and processing. In order to process the physical model experiment with low signal-to-noise ratio and low contrast of defects such as red The external image, put forward the new infrared image processing algorithm, the algorithm mainly includes the following operations: image reduction and remove the environmental noise, median filter to reduce impulse noise, Gauss high pass filter (GHPF) to remove the periodic add noise, finally the multi-scale morphological filter (MIF) to enhance the low contrast infrared image.MIF an image enhancement filter, which is based on the development of the white top hat transformation and enlarge the image peak principle. The multi-scale structure elements of the square length, ranging from?? the minimum crack detection to transform between the maximum detection target. And it is a gray peak, with the proportion of 1/ factor and peak of infrared image multiplication? Thus, the detection of small target amplification to a larger amplitude and the detection target to keep the middle level. After the processed infrared image can reflect the temperature field in the clear Small changes. The main reason for the failure of horizontal rock physical model is the release of stress roadway two horizontal, vertical Li Zenggao, in two sides of roadway forming no lateral restraint compressive stress area, the area of rock to soft coal seam. Coal seam in compressive stress under the action of plastic deformation along the joints or weak surface dislocation, resulting in coal seam fracture deformation. Due to layered rock crushing, basically no cohesion between the layers, two sides of roadway pressure should be concentrated stress force need to overcome the friction between layers, can cause slippage between layers. As the initial loading phase of roadway rock area to help the two level launch in the experiment, but the roadway itself has not been destroyed. The roof and floor rock in parallel with the direction of the pressure, to the airport direction deflection, mainly for roof and floor heave. The level of rock physics model The main type of coal seam floor lithology, strength is relatively low, prone to floor heave phenomenon. And the roadway roof can be regarded as both ends under tremendous pressure extrusion bearing rock beam, so the rock beam in the vertical is not under pressure to beam fracture but at the level of the great pressure of the damage at the level of pressure. Large, rock beam tensile stress area almost disappeared, so the roof did not in the smaller stress level under tensile failure. The level of rock physical model of roadway with a new infrared image of rock response are analyzed, at the same time using the model of old photos, the infrared image was compared with that of new infrared image. After noise filtering and image enhancement significantly improve the quality of infrared image after filtering. The new infrared image is very accurate for early warning of rock failure, and the level of rock physical model of tunnel rock body The failure mechanism of a more profound understanding. Two methods are analyzed from the infrared characteristic analysis and strain can be seen in the stress increases will have obvious effects on the surrounding rock. The strain changes, changes of strain variation in two sides and bottom is bigger than the roof, coal roadway of two parts that help and floor. Affected by external load. The infrared image reveals that under the external loads, the existence of a strong static friction and dynamic friction phenomenon between the strata, dynamic friction slip is the deformation and failure of the average infrared radiation temperature.45 degrees inclined rock roots (IRT) curve was characterized by the overall energy release rate. According to the load of rock mass the failure characteristics of the IRT curve of 45 degree inclined strata: linear segments in the initial loading stage on IRT curve model in elastic state of complete, in the subsequent loading stage IRT curve of irregular periodic wave Said rock under pressure appears stick slip steep. The load level and the loading rate also has a significant effect on the IRT curve at low load and low loading rate IRT curve oscillation cycle long and small amplitude; conversely, in high load and high loading rate and short cycle shock IRT curve large amplitude. Through the infrared image sequences can well explain the 45 degree tilt anisotropic behavior of rock strata. The temperature distribution between the initial loading stage of infrared image showing irregular scattering model, this model revealed complete in elastic state; in the initial loading stage can also be through a zonal distribution of infrared temperature observation of rock anisotropic behavior. In the process of loading, static friction and viscous phase IRT curve correspondence between the rock internal rock fierce static friction and interface between strata The static friction through the large scale low temperature infrared temperature distribution characterization. In summary, 45 degree tilt rock physical model at low loading level, corresponding to the high temperature coal seam infrared bands due to the internal friction, intense deformation, and corresponds to the low temperature infrared mudstone band deformation; sliding phase at high loading level the stage corresponds to the IRT curve, the infrared temperature distribution pattern of this stage is reversed, namely: the low temperature infrared band and high temperature infrared characterization of coal seam strip characterization of mudstone, reveals the sliding and fracture caused by loose seam. The infrared temperature distribution in infrared image sequences can be characterized well around roadway help shrink directly the top and bottom drum separation phenomenon. Through the analysis of the failure of loading rate on the physical model of the infrared image 45 degrees tilt rock has a certain impact, namely: in the low load Load level and low loading rate, the model of rock mass to static friction; at high load level and high loading rate, the main model of rock dynamic friction, fracture, interlayer slip phenomenon of.45 degree tilt rock Fu Liye spectrum of infrared image analysis show that: in the low loading rate, low amplitude, main component no dominant frequencies represent the elastic deformation of the surrounding rock, the main component of the higher frequency band represents the emergence of rock damage, the damage degree varies inversely with the frequency; in high loading rate, the main component of the amplitude was significantly higher than that of the former, the main component of the highest amplitude represents a key failure. The Fu Liye spectrum of foreign load and stress changes more sensitive: to provide high band and high amplitude of early warning in the viscous phase; provide low band and high amplitude in the omen moment. And the fracture induced by IRT curve and infrared image As compared to the Fu Liye spectrum is more sensitive to the variation of external load of image matrix. The main component (periodic component) frequency and amplitude can be characterized by good load increase and the stress changes. The lateral pressure coefficient most loading stages in the experiment are greater than one, namely: the level of stress is greater than the vertical stress accordingly. The level of spectrum main component has higher amplitude more than the vertical spectrum of well characterized anisotropic rock. Viscous phase and IRT curves of the corresponding peak, and the level of the Fu Liye spectrum with high amplitude on single component characterization of high frequencies. The main slip stage and the IRT curve of the valley should be relative, you can fall on the main component characterization of low frequency with high amplitude, also called frequency shift. These abnormal components are early warning information of rock failure event will occur with the Fu Liye frequency. Spectrum of F (U) and F (V) and to describe the spatial frequency spectrum characteristics of the infrared image. The main component in high amplitude ultra-high frequency can be used as information early warning of impending slide between dynamic layer or fracture, but also can predict the dynamic characteristics of taking place. The main component of low frequency the following two characteristics: (1) if it is the main component of high amplitude can be used as a precursor of large scale sliding between layers, (2) if it is an indicator of the main components of medium or small amplitude can be used as the stress redistribution effect of the extension. After treated by infrared image as two infrared temperature distribution model can characterize the mass of the mechanical behavior. At low loading level, coal loading so strong showing high infrared temperature distribution and loading of weak mudstone layer showed the low infrared temperature distribution in high loading level stage. Infrared temperature distribution is reversed, namely: the mudstone layer by load strong and show high infrared temperature distribution of coal has been weak for the low load performance of infrared temperature distribution. The high temperature infrared static friction distribution characterization of rock bedding pattern, low infrared temperature distribution model of rock dynamic characterization of infrared image of sliding friction. Two different angle formation physical model were compared, can obtain more description of layered rock mass structure effect on the level of knowledge: the rock physical model for infrared image temperature on the localization of plastic type distribution; for the 45 degree tilt rock physics model for infrared images show a zonal localization of temperature distribution in the infrared image with high contrast the bands reflect the dip angle leads to model unstable sliding friction damage. Indicating that the reaction model of infrared image can intuitive The friction sliding structure effect, there is a close relationship between the deformation mechanism and formation angle reveals the physical model under external load. In this paper, the infrared thermal imaging technology is successfully applied in the experimental model of large scale physical detection, solves the problem of identifying the thermal elastic and thermal plasticity. The horizontal strata and 45 degree inclined strata the roadway deformation characteristics under the action of the external load. Has important significance on the mechanical behavior and failure mechanism of complex rock mass structure, both the detection technology of infrared thermal imaging detection experiment and laboratory scale physical model of the site engineering geological body has a wide application prospect.

【学位授予单位】：中国矿业大学(北京)
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TD322

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