Two Evaluation Methods for Soil Corrosivity along Riyi Pipeline

Two methods were used to evaluate the soil corrosivity along the Riyi pipeline. One was measuring polarization curves to get corrosion current density, then according to the relationship between corrosion current density and actual weight loss rate to get the actual weight loss rate of the specimen, and to evaluate the soil corrosivity. Another method was constructing the BP neural network based on soil physical and chemical properties. Selecting a certain capacity of the training samples, and then according to the trained network, the corrosirity evaluation was conducted. The results show that two methods have good coherence. Comparison of the two methods, indicated that when the number of the test points was large, two evaluation methods all could be used. However, when the number is less, the second method show large errors, the first method should be used in that case.