基于机器学习的3种岩爆烈度分级预测模型对比研究

Comparative Study on Three Rockburst Prediction Models of Intensity Classification Based on Machine Learning

岩爆是大型地下岩土和深部资源开采工程中必须要解决的关键科学问题之一。综合考虑岩爆的影响因素、特点以及内外因条件,选取洞壁围岩最大切向应力、岩石单轴抗压强度、岩石单轴抗拉强度和岩石弹性能量指数组成岩爆预测指标体系。运用文献调研法,建立了一个包含301组岩爆工程实例的数据库,并以此作为岩爆预测的样本数据。为准确可靠地预测岩爆灾害,基于机器学习技术,建立了RF-AHP-云模型、IGSO-SVM和DA-DNN 3种岩爆预测模型。通过对60组预测样本进行岩爆预测的工程实例分析,验证了3种模型的有效性和正确性。研究结果表明:DA-DNN、IGSO-SVM和RF-AHP-云模型的预测准确率分别为98.3%、90.0%和85.0%;DA-DNN模型理论通俗易懂,编码相对简单,容易实现;随着岩爆数据量的增加,DA-DNN模型应用前景更加广阔。

Rockburst is one of the key scientific problems that must be solved in large-scale underground geotechnical engineering and deep mineral resource mining.The safety of personnel and equipment on site was directly threatened by rockburst.Rockburst could be effectively avoided and controlled in time by scientific and accurate rockburst prediction of intensity classification.Through the analysis of six rockburst engineering examples,on the basis of the factors,characteristics and causes of rockburst,a rockburst prediction index system composed of four evaluation indices,i.e.,tunnel-wall surrounding rock’s maximum tangential stress,rock uniaxial compressive strength,rock uniaxial tensile strength,and rock elastic energy index was established.With reference to other rockburst intensity classification schemes,considering the intensity of rockburst occurrence and the main influencing factors,the rockburst intensity was divided into four levels:None rockburst(Ⅰ),slight rockburst(Ⅱ),intermediate rockburst(Ⅲ)and strong rockburst(Ⅳ).According to the selected rockburst evaluation index and rockburst intensity grade,a literature survey method was used to establish a database containing 301 groups of rockburst engineering examples,which would be used as the sample data for rockburst prediction.In order to accurately and reliably predicted rockburst disasters,machine learning technology was introduced.First,a random forest-based rockburst evaluation index importance analysis model was established,a new index weight calculation method of random forest-analytic hierarchy processs was proposed,and the rockburst prediction model based on the RF-AHP-cloud model was constructed.Then,the firefly algorithm based on good point set variable step strategy was introduced to optimize the penalty parameters and radial basis function parameters of the support vector machine,and the rockburst prediction model based onⅠGSO-SVM was constructed.Finally,the Dropout method was used to regularize the model,and the improved Adam algorithm was used to update weight,and the rockburst prediction model based on DADNN was constructed.The effectiveness and correctness of the three models were validated by the prediction results of 60 groups of rockburst engineering examples.The research results show that:The DA-DNN,ⅠGSOSVM,and RF-AHP-cloud model have prediction accuracy rates of 98.3%,90.0%and 85.0%.The core of rockburst intensity classification prediction based on cloud model is weight determination,and the RF-AHP weight calculation method proposed in this paper has a good effect.The data-drivenⅠGSO-SVM and DA-DNN models are based on rockburst engineering instance data.Through data mining,the rockburst intensity level can be effectively predicted,and higher prediction accuracy can be achieved by improvement.The theory of DADNN model is easy to understand,the coding is relatively simple and it is easy to implement.As various underground geotechnical engineering develops deeper,rockburst disasters occur frequently,the amount of rockburst data is increasing,and the DA-DNN model has a wider application prospect.