Applicability of two stress wave signal enhancement modes in anchorage quality testing of pre-stressed anchor (cable)

被引：0
|
作者：
Deng D. [1 ]
Li L. [1 ]
Zhao L. [1 ]
机构：
[1] School of Civil Engineering, Central South University, Changsha
来源：
Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology) | 2016年 / 47卷 / 03期
关键词：
Anchorage body; Excitation mode; Feature line method; Pre-stressed anchor (cable); Pulse time; Stress wave;
D O I：
10.11817/j.issn.1672-7207.2016.03.029
中图分类号：
学科分类号：
摘要：
With the growth of anchor (cable) length, the received pulse signal used to judge the quality of anchorage body (length of anchor (cable) and position of changed cross-section of anchorage body) on its top is weaker, and so the received pulse signal on the top of anchorage body should be strengthened so that stress wave method is also applied to detect the anchorage quality of longer anchor (cable).Two kinds of stress wave signal enhancement modes are selected as follows: pulse signal was transmitted on the top of anchorage body and amplified on its bottom; and pulse signals were transmitted simultaneously on the top and bottom of anchorage body. Then propagation velocity of stress wave was calculated by adopting complex body consisting of anchor (cable) and grouting body and stress wave displayed logarithmic spiral attenuation with time in dissemination process. Meanwhile, feature line method was used to calculate stress wave signal time during which the anchor body quality could be judged easily, and to calculate the velocity of received stress wave on the top of anchorage body from the bottom and changed cross-section of anchorage body. Some examples including three special types of anchorage body (full-length grouting with uniform cross-section, non-full-length grouting type with free segment, and full-length grouting with defective segment) were studied. The results show that except that the position of changed cross-section is closer to the top of anchor body, there is pulse signal time to easily judge the quality of anchor body for the second kind of signal enhancement mode. However, there is pulse signal time to easily judge the quality of anchor body only in case that the position of changed cross-section is farther to the top of anchor body for the first kind of signal enhancement mode. When the second kind of signal enhancement mode is used, the received pulse signals that can reflect information of anchor (cable) length and position of changed cross-section on top of anchorage body are signals that last the shortest time to reach the top from the bottom and changed cross-section, and so strength of the collected pulse signal by the second kind is better than that by the first kind. As there is a pair of opposing spread stress wave signal in the second kind of signal enhancement mode and each signal can reflect information of quality of anchorage body, so the emitted stress wave signal on the top and bottom of anchorage body needs different frequencies to distinguish the above-mentioned information. © 2016, Central South University of Technology. All right reserved.
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页码：936 / 945
页数：9
相关论文
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