瞬变电磁法用于堤防渗漏隐患探测的技术问题

瞬变电磁法具有分辨率高、探测速度快、操作简便、没有插入地下的电极等优点。该项技术已在物探中广泛应用。然而，对于堤防渗漏隐患探测而言，由于线圈太大、分辨率低，现有的瞬变电磁仪不能直接应用。作者研制成功堤防和土坝渗漏隐患探测专用瞬变电磁仪，并成功应用于３段堤防和７座大坝渗漏隐患探测。本文介绍堤防渗漏和隐患的特点、探测方法的特点、专用瞬变电磁仪在设计研制、现场应用中应考虑的几个关键技术问题。

TECHNIQUES OF TRANSIENT ELECTRO-MAGNETIC SOUNDING IN DETECTION OF HIDDEN DEFECTS IN LEVEES

The advantages of Transient Electro-Magnetic Sounding (TEM) are high resolution, fast detection, easy operation, and no electrodes into earth. This technique is widely employed in geophysical survey. But, the current instrument based on TEM can not be directly used for detection and positioning of hidden defects in levees, because of its low resolution, and huge coils. The authors have developed special instruments based on TEM and the instruments have been successfully applied to three levees and seven earth-fill dams. In this paper, discussed are the features of levees, the characteristics of the detecting method, and some key techniques which should be considered in development, design, and field operation of the instrument.