For studying the rapid and accurate classification method of pile foundation defects

a multi-layer classification method is adopted to improve one -to-one support vector machine(SVM)multiple classifiers structure

build one-to-one two-layer classification model and propose two-layer multiple classification method based on SVM theory.Compared with the BP neural network

the learning and training of two-layer SVM classification is faster and the real-time of the classification processing is better.In addition

it has stronger adaptability in test environment based on small sample and better classification accuracy.The method is fit for analyzing the multi-category classification problem of defects diagnose of pile foundation such as smaller training samples

higher precise and more input and output classification variables

and provides important support to the recognition of pile foundation which had several defects.