电磁法检测锚固质量初探

近年来，锚杆、锚固质量的无损检测技术得到了较快的发展，目前的研究主要集中在应力波反射法上，但该方法还需要进一步的研究，以解决应力波反射信号变弱甚至消失后的问题。本文讨论了一种新的锚固质量无损检测方法——“电磁法”。在最简化物理模型基础上推导出对锚杆加载交变电流时地面磁感应强度分布规律的公式，据此正演计算并作出了几组磁感应强度归一化曲线，提出磁感应强度曲线计算机拟合反演方法可望检测出空锚段比例和空锚段的位置，成为锚固质量检测的一种新的技术方法。

A PRELIMINARY STUDY OF NONDESTRUCTIVE TESTING OF ROCK BOLTS USING ELECTROMAGNETIC METHOD

There has been a rapid development in the nondestructive testing field of rock bolts in recent years. Now the majority of researchers in this field are concentrating on the study of stress wave reflection method. But the validity of this method should be further studied when the reflecting signal dies down. This paper presents a new nondestructive anchoring quality testing method, viz. electromagnetic method. Based on a simplest physical model, the authors deduce the formulas for calculating magnetic induction intensity on different anchoring conditions when we electrify AC current in the rock bolt. The authors also analyse several nomalized curves of magnetic induction intensity which are drawn on the basis of the formulas and draw a conclusion that we can evaluate the anchoring quality by curve fitting.