【作者】 李义；

【导师】 赵阳升；

【作者基本信息】 太原理工大学 ， 采矿工程， 2009， 博士

【摘要】 围岩稳定性分析与评价是地下工程永恒的主题。本文通过理论分析,实验研究,相似模拟和数值模拟,系统研究了锚杆锚固质量无损检测的理论基础,测试方法、波形识别及质量评价指标参数。建立了巷道围岩变形破坏过程中锚杆工作荷载与巷道周边收敛变形位移之间的对应关系,提出了一种基于锚杆工作荷载无损检测的巷道围岩稳定性实时检测与评价的新方法,并在煤矿井下进行了小规模的工业性试验,取得了如下几个方面的研究成果:1.基于一维弹性杆的波动理论,建立了锚杆锚固状态下纵向振动的力学模型,得到了不同支承条件下锚杆在端头激发荷载作用下动态响应的解析解,为锚杆锚固质量无损检测技术提供了必要的理论支持。2.在实验室进行了锚杆锚固质量无损检测的实验研究,提出了评价锚杆锚固质量的六个指标参数,即有效锚固长度、幅值比、衰减系数、基频、频率比和动刚度。通过对锚杆端头所测得的加速度响应的时频分析,可以准确测定锚杆的有效锚固长度,判断锚固端与围岩之间的支承固结状况,评估锚杆的锚固质量及极限承载力。3.提出了“固结波速”的科学概念。通过模拟试验,确定了锚杆在锚固状态下,固结波速的赋值区间,得出了“锚杆与锚固体的粘结强度与固结波速在其赋值区间内呈负指数变化规律”的结论。根据锚固结构中固结波速的大小,可以预测锚杆的极限承载力,评价锚杆的锚固质量。4.通过理论分析和实验研究,得出了“锚杆工作荷载与锚杆受激振动的主频呈幂函数关系变化”的结论。提出了“基于锚杆工作荷载无损检测的巷道围岩稳定性检测与评价”的新方法。通过对锚杆工作荷载的无损检测,可以现场实时评估锚杆支护结构及其巷道围岩的稳定性。现场工业试验研究结果证明了上述结论的正确性。5.通过相似模型加载破坏试验,研究了巷道及地下结构变形、失稳、破坏各阶段锚杆工作荷载和围岩变形失稳的对应关系,揭示了模型加载变形破坏过程中,锚杆工作荷载随巷道围岩变形位移的演化规律。为通过锚杆工作荷载无损检测,评价锚固结构和巷道围岩稳定性,提供了必要的理论与技术支持6.根据相似模型试验的地质条件和原型尺寸,采用ANSYS有限元通用分析软件,进行了相应的计算机数值模拟,得出了与相似模型试验相同的结果,进一步验证了上述规律的正确性。7.采用小波分析、多分辨率分析和自适应滤波等等现代信号处理与分析方法,对原始测试信号进行分析处理。误差对比分析结果表明,以上几种分析方法表现出很好的一致性,联合使用会提高测试信号分析的可靠度。8.以MATLAB为平台,开发了锚杆锚固质量无损检测信号分析系统软件,初步实现了锚杆锚固质量无损检测的智能评价,提高了分析精度。程序界面形象直观。9.现场工业试验研究结果表明:用锚杆锚固质量无损检测的方法,现场测定锚杆的锚固质量和工作荷载,实时评估和判断锚固结构和巷道围岩的稳定性,是一种方便、快捷的巷道围岩稳定性实时检测与评价方法,具有广阔的工业应用前景。更多还原

【Abstract】 The analysis and evaluation of surrounding rock stability is an eternal theme of underground engineering. Through theoretical analysis, laboratory researches, similar simulations and numerical simulations, this article has systematically done the following: studies the nondestructive detection in the theoretical basis, test methods, wave shape identification and quality evaluation index parameter of anchorage quality of rock bolt, homologous relationship has been established between working load of bolt and the convergence and deformation and displacement of laneway’s periphery, forward a new method for real-time detection and evaluation of surrounding rock stability on the basis of the nondestructive detection of working load of bolt, and conducts some small-scale industrial test in the mine. The study achievements which have been obtained are as follows:1. On the basis of the theory of one dimension elastic wave motion, mechanics model of grouted rock bolt vertical vibration is established, and the analytical solution under different supporting conditions is found. These results provide theoretical supports for nondestructive detection of anchorage quality of rock bolt.2. The test and study of the nondestructive detection in anchorage quality of rock bolts has been conducted in the laboratory, and six parameters of evaluating the anchorage quality of rock bolt have been found: valid bounding length, ratio of amplitude, attenuation coefficient, primary frequency, ratio of frequency and dynamic stiffness. The analysis of response signal in the end of the rock bolt is helpful to accurately measure valid grout length, to judge consolidation situation between the anchorage and the surrounding rocks, and to evaluate anchorage quality and ultimate bearing capacity of rock bolt.3. The scientific concept of "consolidation wave speed" has been put forward. By some simulation tests, the upper and lower limit value of consolidation wave speed has been decided, and the conclusion that "the relationship between the bond strength and consolidating wave speed is negative exponential function" has been concluded. According to the consolidating wave speed in the anchorage structure, the rock bolt’s ultimate bearing capacity can be predicted, and the anchorage quality can be evaluated.4. Through the theoretical analysis and tests studies, the conclusion that "the relationship between working load of rock bolts and the main frequency of the response signal of rock bolt end is power exponent function" has been reached. A new method that " evaluate surrounding rock stability based on the nondestructive detection of the working load of bolt" has been raised. Through the nondestructive detection of rock bolt’s working load, the real-time evaluation of the supporting structure and the surrounding rock stability has been made. The field industrial test results proved the above-mentioned conclusion.5. By the similar model loading test, the relationship between working load of rock bolt and the deformation of the surrounding rocks has been found. This achievement helps to get a good method to evaluate the stability of anchorage’s structure and the surrounding rock by detecting the working bearing of bolts.6. Based on lab model, finite element model is made under ANSYS. Numerical simulation results agree well with the lab test. This also verifies above mentioned law.7. Wavelet analysis, multi-differentiate analysis, shelf-adaptive filter method, and some other signal processing methods have been used to analyze the testing signal. The error analysis shows that the above-mentioned methods are consistent with each other.8. MATLAB program for analyzing test signal, which can evaluate the anchorage quality of rock bolts, has been developed. The program helps to increase the analysis precision.9. The field test results show that it is feasible to use the method to measure the anchorage quality of rock bolts and its working load and then to make real-time evaluation of the stability of the surrounding rocks.更多还原