基于熵权-正态云模型的岩爆烈度分级预测研究

岩爆是深埋地下工程主要的工程地质灾害之一,其烈度分级预测是必须解决的岩石工程重大问题。针对岩爆烈度分级的不确定性,选取岩石单轴抗压强度与抗拉强度比σ_c/σ_t、切向应力与岩石单轴抗压强度比σ_θ/σ_c、弹性变形能指数Wet和岩石完整性系数K_v等定量化指标建立评价指标体系,应用熵权法确定各评价指标权重,结合云理论建立了岩爆烈度分级预测的熵权-正态云模型。以国内外12组典型岩爆工程实例对所建模型进行检验,并与逼近理想解法、高斯径向基函数法的判别结果及实际情况进行对比。为进一步考察该模型的有效性和实用性,利用该模型对终南山公路隧道工程竖井的岩爆实例进行分析。研究结果显示,基于熵权-正态云模型的岩爆判别预测结果与实际岩爆情况较吻合,表明熵权-正态云模型在研究岩爆烈度分级预测中具有良好的实用性和可靠性,可为深部地下工程岩爆烈度分级预测提供一种新思路。

Grading Prediction of rockburst intensity based on entropy and normal cloud model

Rockburst is one of the main engineering geological hazards occurring in the deep underground engineering construction. The classification of rockburst is an important issue which must be resolved in many underground engineering. Four quantitative indices including the ratio of rock′s compressive-tensile strength σc /σt，the stress coefficient of rock σθ /σc，the elastic energy index of rock Wet and integrality coefficient Kv are chosen as the predictor variables of rockburst，according to the unascertained factors of classification prediction of rockburst. The entropy method is adopted to determine the weighting coefficient for each evaluation index. Based on entropy method and the unascertained measurement theory，with 12 groups of typical engineering examples, rockbursts at home and abroad, an entropy and the normal cloud model to predict the possibility and classification of rockburst is established. Then the proposed model is validated with twelve typical rock projects and compared with the results of the technique for order preference by similarity to ideal solution method, the radial basis function-auto-regression method and the actual records. And then the model has applied to rockburst predicting calculation of Zhongnanshan tunnel ventilation shaft to study the effectiveness and feasibility of the model. The obtained results show a good agreement with practical rockburst classification. The results show the normal cloud model effective and available，and can be applied to the prediction for the possibility and classification of rockburst intensity in deep underground engineering.