Probability Analysis Of Loess Seismic Subsidence Based On Fuzzy Processing Of The Parameter Rank Division

China is the country which an earthquake occurs frequently, and many strong earthquakes occurred in history. Disasters caused by the earthquake occupies the quite prominent status in a variety of natural disasters. In the loess area of China's mid-west area, earthquakes have occurred many times, and all previous strong earthquakes had caused severe earthquake landslide, seismic subsidence, liquefaction and other loess earthquake disasters. Historically, there are such seismic subsidence examples which magnitudes are not large but seismic subsidence of loess extremely large. Thus, in order to prevent seismic subsidence hazard, we need to make risk prediction for seismic subsidence of loess area.Currently, predictions about seismic subsidence of loess area in Chica usually use the estimation method of amount of loess's seismic subsidence proposed by the idea of layerwise summation method and the forecast method of loess foundation's seismic subsidence based on the finite element numerical analysis method. However, the above two methods are deterministic, and can not reflect the randomness of the earthquake. Therefore, We may consider the method that introduce the probabilistic seismic hazard analysis method into the calculation of seismic subsidence. By analyzing the relation between the seismic subsidence and earthquake, and predicting seismic subsidence considered the impact of earthquake factor, we can derive the prediction method considering the randomness of earthquake about seismic subsidence of the loess area. Papers around this issue, mainly to do the following work:(1)Paper briefly discusses the seismic subsidence hazard of the loess area and the current research methods for seismic subsidence hazards, proposes the view that introduce the probability risk analysis method into seismic subsidence analysis;(2)Selects ground motion parameters used in this paper, and discusses the statistical relationship between the seismic subsidence of loess and ground motion parameters;(3)Based on the analysis in the randomness and fuzzy processing of grading of the peak ground acceleration and seismic subsidence index and the disposal classification of the impact factor of seismic subsidence, established the fuzzy probability model of seismic subsidence of loess. This model considered more uncertainty factors, make the prediction result of seismic subsidence hazards more accurately to reflect the reality. According to the model and combines with the related technology, loess region can be carried out seismic subsidence hazard zoning in general, and drawing the zoning map. This work has important practical significance for the seismic fortification.