地震液化侧向变形超过指定阈值的Probit模型初探

Probit model for exceedance of liquefaction-induced lateral deformation over a given threshold value due to earthquakes

基于地震液化侧向变形实测数据,通过数据统计分析了影响液化侧向变形的关键因素,并采用Probit建模方法,初步建立了地震液化侧向变形超过特定阈值的概率模型,并将模型预测结果与两个典型案例的实测数据进行了对比。该预测模型可以考虑震级、震距、场地坡度和液化土层厚度对液化侧向变形发生概率的影响。预测结果与实测数据的对比表明模型能够较好地预测发生大变形的概率,但对于小变形情况,模型预测结果偏保守。

The major factors influencing the liquefaction-induced lateral deformation are identified using statistical analysis based on post-earthquake reconnaissance data collected from historical earthquakes.A simple probability model is proposed within the framework of the Probit model for predicting the likelihood of liquefaction-induced deformation exceeding a given threshold value.The model prediction is compared with the historical data collected from two selected destructive earthquakes.The proposed model relates the probability to the earthquake moment,epicenter distance,slope of the ground surface and accumulated thickness of liquefiable soils.The comparison between the prediction and the field data indicates that the proposed model performs well particularly in cases of large displacements,while it provides a conservative estimate in cases of small displacements.