隧道锚杆锚固质量无损检测技术研究与应用

发布时间：2018-06-23 17:23

本文选题：隧道锚杆 + 锚固质量　；参考：《西南交通大学》2014年硕士论文

【摘要】：锚杆支护作为隧道初期支护常用的手段之一,已广泛的运用于公路、铁路、水利等工程中。为了有效的检测锚杆在工程中的使用效果,避免造成重大的工程灾害,锚杆无损检测已成为现在炙热的课题之一。本文从无损检测的理论研究出发,并结合模型试验和现场检测数据的分析,对三者所得到的结论进行对比分析,得到以下结论： (1)根据理论分析,并结合模型试验和工程实际的运用,测试后的波形曲线形态、频谱曲线特征,相位的特征及能量的变化等都能够很好的反映锚固体系内的具体信息。锚固质量较好的锚杆,其测试信号的振幅衰减比较均匀,其频谱曲线也只有一个主频,而锚固质量差的锚固体系,在其频谱曲线中会出现多个主频,锚固质量越差,多个主频之间的相差值越小。当锚固体系中出现缺陷时,波形曲线形态和相位图在相应的位置都会发生突变,缺陷程度越发严重,相位变化就越频繁。 (2)根据模型试验测试和结合隧道实测的数据可知,由于无损检测信号受外围的干扰影响较大,因此在数据分析时,应选择包括主频在内的适当滤波频率范围,滤波后的波形因与原波形相似。 (3)根据模型试验测试和结合隧道实测的数据可知,锚杆锚固存在缺陷时,其波速是介于锚杆处于自由状态和完全锚固之间,因此,在长度一定的时候,可以根据锚固体的波速来判断锚固质量。 (4)根据模型试验测试和结合隧道实测的数据可知,无损检测有效的测试长度会随着围岩和密实度的变化而变化,围岩级别较好或锚固密实度较好时,确定锚杆有效长度的准确性越高；缺陷越多,则会对杆底的反射波造成严重的干扰,无法识别杆底的反射波。应力波法检测锚杆长度的精确度也会随着锚杆的长度的增加而降低,也就是说,当锚杆超过一定长度时,应力波法无法识别锚杆的长度,因此在检测用长锚杆支护的隧道时,应考虑应力波法的适用性。
[Abstract]:Bolt support, as one of the commonly used methods in early tunnel support, has been widely used in highway, railway, water conservancy and other projects. In order to effectively detect the effect of anchor in engineering and avoid serious engineering disasters, nondestructive testing of anchor has become one of the hot topics. Based on the theoretical research of nondestructive testing and the analysis of model test and field test data, this paper makes a comparative analysis of the three conclusions, and draws the following conclusions: (1) according to the theoretical analysis, Combined with the model test and the application of engineering practice, the measured waveform curve shape, spectrum curve characteristics, phase characteristics and energy changes can well reflect the specific information in the Anchorage system. For the anchor rod with good anchoring quality, the amplitude attenuation of the test signal is more uniform, and the frequency spectrum curve has only one main frequency. However, the anchoring system with poor anchoring quality will have multiple main frequencies in its spectrum curve, and the worse the anchoring quality is, the worse the anchoring quality is. The smaller the difference between multiple main frequencies. When there are defects in the anchoring system, the shape and phase of the waveform curve will change in the corresponding position, and the defect degree will become more serious. The more frequent the phase change is, the more frequent the phase changes are. (2) according to the model test and tunnel test data, because the nondestructive testing signal is affected by the external interference, so in the data analysis, The proper filter frequency range, including the main frequency, should be selected, and the filtered waveform is similar to the original waveform. (3) according to the model test and combined with the measured data of tunnel, it is known that the anchor bolt has defects in anchoring. The wave velocity is between the free state and the complete anchoring of the anchor rod, so, when the length is fixed, The anchoring quality can be judged by the wave velocity of the anchors. (4) according to the model test and the tunnel data, the effective test length of nondestructive testing will change with the change of surrounding rock and compactness. When the surrounding rock level is better or the anchoring density is better, the accuracy of determining the effective length of the anchor rod is higher, and the more defects, the more serious interference will be caused to the reflection wave at the bottom of the rod, and the reflection wave of the bottom of the rod can not be identified. The accuracy of the stress wave method in detecting the length of the bolt also decreases with the increase of the length of the bolt, that is, when the bolt exceeds a certain length, the stress wave method cannot identify the length of the anchor, so in the detection of the tunnel supported by the long bolt, The applicability of stress wave method should be considered.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.7;U456.3

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