为评估黄土高原地区地震滑坡致灾区域,提出一种基于模糊信息优化处理的地震滑坡滑距预测方法。在野外调查、室内试验和分析的基础上,对黄土高原的地震滑坡类型、性质和影响因素进行分析。以摩根斯坦-普莱斯法计算黄土边坡的稳定性,建立边坡最小安全系数与影响因素的关系,其影响因素主要包括地震烈度、比高、坡角、容重、内黏聚力、内摩擦角等,并在此基础上得到纯黄土地震滑坡滑距的影响关系。将黄土高原地区数次大震中采集到的93个样本数据进行归纳分析,建立模糊信息优化处理模型。所得的计算结果通过误差校验和与其他滑坡滑距预测方法进行对比,来证明本模型有较高的准确性。最后对天水市22个潜在滑坡的边坡进行滑距预测。
There have been many loess seismic landslides on the Loess Plateau of Northwest,China,which have seriously affected the normal agriculture,life,and local economy of the local residents due to their high frequency and the destruction that they cause.Disaster area analysis of loess seismic landslides and the sliding distance could ascertain the endanger scope and put forward suggestions for their prevention.To evaluate the influencing area of seismic landslides,a forecasting method was presented for the sliding distance of the seismic landslides on the Loess Plateau,by means of a fuzzy information model based on the data of 93 cases.Progress in the research is shown as follows:first,combining former research and components,the loess seismic landslides developed in the loess area are divided into four types:homogeneous loess landslides,loess-bedrock interface landslides,loess-gravel-bedrock landslides,and loess-bedrock landslides.Homogeneous loess landslides,which account for over 60% of the total seismic landslides,are a main focus of this paper.Second,the Morgenstern-Price method is used for calculating the stability of loess slopes.The relationship between different factors and the safe factor is discussed in the paper and the factors such as seismic intensity,relative altitude,slope angle,unit weight,internal cohesion,and internal friction angle can influence the safe factor.Third,the impact analysis of different factors on the sliding distance of loess seismic landslides is given.It can be seen that the earthquake magnitude determines the scale of landslide disaster area,and the seismic intensity affects the distribution of the landslides.Fourth,a fuzzy information model is used for the calculation of the sliding distance.By comparing with other methods,results show that the accuracy of this method is better for forecasting the disaster area.A fuzzy information matrix was established on the basis of 93 loess seismic landslides caused by South Tianshui 8.0earthquake in 1654,Tongwei 7.5earthquake in 1718,Haiy