堤坝渗漏隐患高分辨率磁共振探测及其全BLOCH反演方法研究

我国拥有世界最多的水库堤坝。有效监测堤坝渗漏位置、圈定渗漏通道，是保障堤坝安全运行的关键要素。本项目基于对地下水直接探测的磁共振技术，全面改进现有系统的局限性：优化激发脉冲矩分布及探测线圈参数，攻克发射系统储能模块模糊控制理论及并联充电技术，突破“米级”分辨率技术瓶颈；提出直流预极化场和交变场协同探测模式，提高MRS信号质量，实现堤坝0-30米无盲区、高精度探测；建立基于全BLOCH方程的MRS正演模型，探索全BLOCH磁共振反演方法，直接获取横向弛豫时间T2分布，计算水文地质参数，为渗漏点合理加固处理奠定基础。最后，应用本项目研发的MRS探测仪器及成像软件，进行实际堤坝渗漏探测，通过与地质资料对比，验证系统的有效性。本项目将提供一套用于堤坝渗漏隐患探测的新仪器和方法，为我国水库堤坝安全运行提供关键技术支撑。

This project is to apply the Magnetic Resonance Sounding (MRS) method on the dam leakage monitoring. We will base on the existing MRS detecting system, improve the detection resolution and efficiency by optimizing the distribution of the exciting pulse moment and the parameters of detecting coil, study the quick charging technology for the energy storage of emission system based on fuzzy control method. We aim to obtain the high-quality MRS signal and detect the dams at the depth from surface to 30 meters without fade zone. The cooperative detecting model of pre-polarization field with alternating field is designed. In order to increasing the accuracy of interpretation results by MRS detecting, the forward computational model based on BLOCH equation is established and the method of MRS inversion based on BLOCH equation is put forward. The reliability of this research is verified by comparing the results of the MRS detection instrument and imaging software in this project with geologic data. The set of instrument and method for detecting the hidden defect in dams which the project will provide builds the foundations for widespread and effective application of Magnetic Resonance Sounding System for groundwater detection.