基岩条件对地震影响系数的影响

Influence of base rock condition on earthquake affecting coefficient

地震影响系数是城市小区规划和工程地震安全评价的一个重要参数,由于受地下岩体条件影响,难以准确确定地震影响系数,常规方法得到的地震影响场难以满足城市和重大工程抗震的精度要求。如何分析基岩条件对地震影响系数的影响是地震安全评价的关键工作之一。通过对地下岩体裂缝分布的数值模拟,求取基岩裂缝和地下能量等指标的分布,进而应用人工神经网络方法,得到基于基岩裂缝、能量、位移等指标分布的地震影响系数计算模型。以唐山市为例分析了计算结果,并对城市规划和工程建设提出了几点建议。

Earthquake affecting coefficient is one of the most important factors for city seismic microzonation and engineering earthquake security evaluation. Because of the influence of underground rock conditions, it is very difficulty to determine earthquake affecting field precisely, the result, which come from traditional method,couldn't meet the demand of earthquake resistant design in city and engineering construction.Therefore,the analysis of influence of base rock condition on earthquake affecting coefficient is necessary for earthquake security evaluation. By numerical simulation of underground rock fracture, the distribution of underground rock energy and fracture is calculated. Furthermore, neural network method is applied, and the calculating model of earthquake affecting coefficient is established based on the distribution of base rock fracture and energy. As an example, the calculated result of earthquake affecting field is analyzed and some suggestions for city planning and engineering construction are given.