空间梯度瞬变电磁法在某地铁站桩位探测中的应用研究

Research on Application of Spatial Gradient Transient Electromagnetic Method in Detection of Pile Positions in a Metro Station

摘要:

空间梯度瞬变电磁探头为一发双收结构，一对完全相同的接收回线对称布设在发射回线两侧，两接收回线内信号反向串联或并联输出，相减后的采集信号在模拟信号层面大幅度压制了一次场的干扰，该特定结构使得空间梯度瞬变电磁法具有很强的抗侧向干扰能力。通过解译其抗侧向干扰原理，并开展物理模拟实验对旁侧干扰物位置、距离的干扰影响进行研究，验证了空间梯度瞬变电磁探头的侧向干扰抑制能力；市域工程场地实测结果也进一步验证了其抗干扰效果。研究表明，空间梯度瞬变电磁测量方法在市区强干扰背景下具有良好的工程应用前景。

Abstract:

The spatial gradient transient electromagnetic (TEM) probe adopts a single-transmitter dual-receiver structure, in which a pair of identical receiving loops are symmetrically arranged on both sides of the transmitting loop. The signals within the two receiving loops are output in reverse series or parallel. The subtracted collected signal significantly suppresses the interference of the primary field at the analog signal level. This specific structure endows the spatial gradient TEM method with a strong ability to resist lateral interference. By interpreting its principle of resisting lateral interference and conducting physical simulation experiments to study the interference influence of the position and distance of the adjacent interfering objects, the lateral interference suppression ability of the spatial gradient TEM probe is verified. The measured results of the municipal engineering site also further verify its anti-interference effect. The study result demonstrates that the spatial gradient TEM measurement method has a good engineering application prospect under the background of strong interference in urban areas.