实海环境下钢壳混凝土结构局部电位监测与参比电极稳定性研究

目的 确定高纯锌、钛以及铂等3种参比电极在不同工况下的稳定性差异，以及不同参比电极针对沉管的最佳使用位置。方法 以银/氯化银参比电极的监测电位数据为钢壳的实际电位基准，通过在不同区域设计安装电位传感器，持续监测沉管不同区域的钢壳电位，以及9个多月的波动情况。结果 高纯锌参比电极所监测数据的变化趋势与钢壳实际电位数据接近，且环境介质的改变对其监测电位数值的影响不大，电位数据波动小。铂和钛参比电极在钢壳底面海泥/抛石耦合的服役环境下，其监测电位数据稳定，但是二者在海水中监测电位时，对环境介质中的溶解氧浓度、金属离子等氧化性介质较为敏感，极易受到氧化性介质的影响，导致测得的电位偏移剧烈。结论 高纯锌参比电极更适合应用于沉管侧面阴极保护电位的长期监测，铂和钛参比电极更适用于钢壳底部保护电位的长期测量。

Local Potential Monitoring and Reference Electrode Stability of Steel Shell Concrete Structures in Marine Environment

The work aims to compare the stability of three reference electrodes made of high-purity zinc, titanium and platinum under various working conditions, and further determine where these electrodes should be positioned in the sinking tube for better performance. With the potential data measured through the Ag/AgCl reference electrode as the actual potential reference, the potential of the steel shell at different locations of the sinking tube was continuously monitored by the potential sensors installed in different areas for more than 9 mouths. The potential measured by the high-purity zinc reference electrode was close to the actual potential of the steel shell, and the change of the environment had little affect to the monitored results. Therefore, the high-purity zinc reference electrode could be used for the accurate measurement of the cathodic protection potential of steel shell surface. On the other side, the potential monitored by the platinum and titanium reference electrodes were stable under the environment of the sea mud/throwing stone at the bottom of the steel shell. However, the accuracy of these two electrodes could be easily affected by the oxidizing medias such as the dissolve oxygen, the metal ions, etc., resulting in large deviations in the measurement results. Therefore, high-purity zinc reference electrode is more suitable for long-term monitoring of cathodic protection potential on the side of the sinking tube, while platinum and titanium reference electrodes are more suitable for long-term measurement of protection potential at the bottom of the steel shell.