动态修正偏移度阈值的灰色模型及其应用

摘要

The slope system is an open and multi-factor dynamic system.The establishing of grey forecasing model with high precision is of very important to analyze the evolution regularity of slope displacement and slope stability evaluation.Considering the water-softening influence of slope rock,the water-softening coefficient is introduced,water-softening total evolution equation related to the saturated water-water loss cycles is derived based on the relationship between water-softening parameters and stress-strain.The conventional threshold of the displacement increment deviation is modified based on the water-softening coefficient,so as to get the increment deviation threshold of the slope under the different deformation stage.Taken the modification value of displacement increment deviation as the identification index to identify the abnormal monitoring data and conduct data adjustment calculation,so as to establish the grey prediction model of dynamic correction of deviation threshold based on considering the influence of water-softening.The grey model established in this paper is applied to the slope engineering of Changshang open-pit tailings in Sanshandao Gold Mine,the analysis results show that the prediction results of the model is similar to the measured data,therefore,the prediction precise of the model is high,which further show that the displacement change trend in the dynamic cycle of water level fluctuation can be described effectively,and it has some important significance for studying the dynamic stability of slope.%边坡系统是一个开放的、多因素的动态系统,建立高精度的灰色预测模型,对分析边坡位移演变规律、评价边坡稳定性极为重要.考虑蓄水边坡岩石水致弱化的影响,引入水致弱化系数,通过岩石水致弱化参量及应力-应变关系,推导与饱水—失水循环次数有关的水致弱化总演化方程.结合水致弱化系数,对位移增量偏移度的常规阈值进行修正,得到在边坡不同变形阶段下的偏移度阈值.以位移增量偏移度修正阈值为识别指标,对监测数据异点进行识别平差,建立考虑水致弱化影响的动态修正偏移度阈值的灰色预测模型,并将该模型应用于三山岛仓上露天坑尾矿库边坡工程中.实例分析表明:该模型预测结果与实测数据较为接近,具有较高的精度,能够描述边坡在水位反复升降动态循环过程中的位移变化趋势,对研究边坡的动态稳定性具有重要意义.